19f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner//===- InstructionSimplify.cpp - Fold instruction operands ----------------===// 29f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner// 39f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner// The LLVM Compiler Infrastructure 49f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner// 59f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner// This file is distributed under the University of Illinois Open Source 69f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner// License. See LICENSE.TXT for details. 79f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner// 89f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner//===----------------------------------------------------------------------===// 99f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner// 109f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner// This file implements routines for folding instructions into simpler forms 114cd2ad15b43f21d641330b4b09961af08646445eDuncan Sands// that do not require creating new instructions. This does constant folding 124cd2ad15b43f21d641330b4b09961af08646445eDuncan Sands// ("add i32 1, 1" -> "2") but can also handle non-constant operands, either 134cd2ad15b43f21d641330b4b09961af08646445eDuncan Sands// returning a constant ("and i32 %x, 0" -> "0") or an already existing value 14ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands// ("and i32 %x, %x" -> "%x"). All operands are assumed to have already been 15ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands// simplified: This is usually true and assuming it simplifies the logic (if 16ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands// they have not been simplified then results are correct but maybe suboptimal). 179f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner// 189f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner//===----------------------------------------------------------------------===// 199f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 20a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands#define DEBUG_TYPE "instsimplify" 21fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth#include "llvm/GlobalAlias.h" 22562b84b3aea359d1f918184e355da82bf05eb290Jay Foad#include "llvm/Operator.h" 23a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands#include "llvm/ADT/Statistic.h" 246231d5be410e2d7967352b29ad01522fda15680dChandler Carruth#include "llvm/ADT/SetVector.h" 259f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner#include "llvm/Analysis/InstructionSimplify.h" 26f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky#include "llvm/Analysis/AliasAnalysis.h" 279f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner#include "llvm/Analysis/ConstantFolding.h" 281845009290e4d804ad377927bd8a08cca3036adcDuncan Sands#include "llvm/Analysis/Dominators.h" 29d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands#include "llvm/Analysis/ValueTracking.h" 303a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky#include "llvm/Support/ConstantRange.h" 31fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth#include "llvm/Support/GetElementPtrTypeIterator.h" 32d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner#include "llvm/Support/PatternMatch.h" 331845009290e4d804ad377927bd8a08cca3036adcDuncan Sands#include "llvm/Support/ValueHandle.h" 34e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands#include "llvm/Target/TargetData.h" 359f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattnerusing namespace llvm; 36d06094f0682f2ede03caff4892b1a57469896d48Chris Lattnerusing namespace llvm::PatternMatch; 379f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 3881a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattnerenum { RecursionLimit = 3 }; 39a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 40a3c44a5280042dbc0cde995675c225ede4528c6eDuncan SandsSTATISTIC(NumExpand, "Number of expansions"); 41a3c44a5280042dbc0cde995675c225ede4528c6eDuncan SandsSTATISTIC(NumFactor , "Number of factorizations"); 42a3c44a5280042dbc0cde995675c225ede4528c6eDuncan SandsSTATISTIC(NumReassoc, "Number of reassociations"); 43a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands 440aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstruct Query { 450aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const TargetData *TD; 460aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const TargetLibraryInfo *TLI; 470aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const DominatorTree *DT; 480aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands 490aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Query(const TargetData *td, const TargetLibraryInfo *tli, 509133783d5483e38b16af6c10df7a8bbe655d3446Bill Wendling const DominatorTree *dt) : TD(td), TLI(tli), DT(dt) {} 510aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands}; 520aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands 530aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyAndInst(Value *, Value *, const Query &, unsigned); 540aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyBinOp(unsigned, Value *, Value *, const Query &, 55618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier unsigned); 560aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyCmpInst(unsigned, Value *, Value *, const Query &, 57618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier unsigned); 580aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyOrInst(Value *, Value *, const Query &, unsigned); 590aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyXorInst(Value *, Value *, const Query &, unsigned); 60bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sandsstatic Value *SimplifyTruncInst(Value *, Type *, const Query &, unsigned); 611845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 62f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands/// getFalse - For a boolean type, or a vector of boolean type, return false, or 63f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands/// a vector with every element false, as appropriate for the type. 64f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sandsstatic Constant *getFalse(Type *Ty) { 6566d004ef708642bbdc38fd761507f2e9ee3970cdNick Lewycky assert(Ty->getScalarType()->isIntegerTy(1) && 66f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands "Expected i1 type or a vector of i1!"); 67f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return Constant::getNullValue(Ty); 68f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands} 69f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands 70f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands/// getTrue - For a boolean type, or a vector of boolean type, return true, or 71f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands/// a vector with every element true, as appropriate for the type. 72f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sandsstatic Constant *getTrue(Type *Ty) { 7366d004ef708642bbdc38fd761507f2e9ee3970cdNick Lewycky assert(Ty->getScalarType()->isIntegerTy(1) && 74f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands "Expected i1 type or a vector of i1!"); 75f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return Constant::getAllOnesValue(Ty); 76f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands} 77f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands 786dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands/// isSameCompare - Is V equivalent to the comparison "LHS Pred RHS"? 796dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sandsstatic bool isSameCompare(Value *V, CmpInst::Predicate Pred, Value *LHS, 806dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands Value *RHS) { 816dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands CmpInst *Cmp = dyn_cast<CmpInst>(V); 826dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands if (!Cmp) 836dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands return false; 846dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands CmpInst::Predicate CPred = Cmp->getPredicate(); 856dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands Value *CLHS = Cmp->getOperand(0), *CRHS = Cmp->getOperand(1); 866dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands if (CPred == Pred && CLHS == LHS && CRHS == RHS) 876dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands return true; 886dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands return CPred == CmpInst::getSwappedPredicate(Pred) && CLHS == RHS && 896dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands CRHS == LHS; 906dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands} 916dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands 921845009290e4d804ad377927bd8a08cca3036adcDuncan Sands/// ValueDominatesPHI - Does the given value dominate the specified phi node? 931845009290e4d804ad377927bd8a08cca3036adcDuncan Sandsstatic bool ValueDominatesPHI(Value *V, PHINode *P, const DominatorTree *DT) { 941845009290e4d804ad377927bd8a08cca3036adcDuncan Sands Instruction *I = dyn_cast<Instruction>(V); 951845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (!I) 961845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Arguments and constants dominate all instructions. 971845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return true; 981845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 99ff739c1575df58f3926c2f3b6e00a6c45f773523Chandler Carruth // If we are processing instructions (and/or basic blocks) that have not been 100ff739c1575df58f3926c2f3b6e00a6c45f773523Chandler Carruth // fully added to a function, the parent nodes may still be null. Simply 101ff739c1575df58f3926c2f3b6e00a6c45f773523Chandler Carruth // return the conservative answer in these cases. 102ff739c1575df58f3926c2f3b6e00a6c45f773523Chandler Carruth if (!I->getParent() || !P->getParent() || !I->getParent()->getParent()) 103ff739c1575df58f3926c2f3b6e00a6c45f773523Chandler Carruth return false; 104ff739c1575df58f3926c2f3b6e00a6c45f773523Chandler Carruth 1051845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // If we have a DominatorTree then do a precise test. 1065b8f0ddc7e5bc3c7ffe1b2226a8316796f18b90eEli Friedman if (DT) { 1075b8f0ddc7e5bc3c7ffe1b2226a8316796f18b90eEli Friedman if (!DT->isReachableFromEntry(P->getParent())) 1085b8f0ddc7e5bc3c7ffe1b2226a8316796f18b90eEli Friedman return true; 1095b8f0ddc7e5bc3c7ffe1b2226a8316796f18b90eEli Friedman if (!DT->isReachableFromEntry(I->getParent())) 1105b8f0ddc7e5bc3c7ffe1b2226a8316796f18b90eEli Friedman return false; 1115b8f0ddc7e5bc3c7ffe1b2226a8316796f18b90eEli Friedman return DT->dominates(I, P); 1125b8f0ddc7e5bc3c7ffe1b2226a8316796f18b90eEli Friedman } 1131845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 1141845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Otherwise, if the instruction is in the entry block, and is not an invoke, 1151845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // then it obviously dominates all phi nodes. 1161845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (I->getParent() == &I->getParent()->getParent()->getEntryBlock() && 1171845009290e4d804ad377927bd8a08cca3036adcDuncan Sands !isa<InvokeInst>(I)) 1181845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return true; 1191845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 1201845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return false; 1211845009290e4d804ad377927bd8a08cca3036adcDuncan Sands} 122a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1233421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// ExpandBinOp - Simplify "A op (B op' C)" by distributing op over op', turning 1243421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// it into "(A op B) op' (A op C)". Here "op" is given by Opcode and "op'" is 1253421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// given by OpcodeToExpand, while "A" corresponds to LHS and "B op' C" to RHS. 1263421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// Also performs the transform "(A op' B) op C" -> "(A op C) op' (B op C)". 1273421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// Returns the simplified value, or null if no simplification was performed. 1283421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sandsstatic Value *ExpandBinOp(unsigned Opcode, Value *LHS, Value *RHS, 1290aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands unsigned OpcToExpand, const Query &Q, 130618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier unsigned MaxRecurse) { 131e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer Instruction::BinaryOps OpcodeToExpand = (Instruction::BinaryOps)OpcToExpand; 1323421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 1333421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (!MaxRecurse--) 1343421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 1353421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1363421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Check whether the expression has the form "(A op' B) op C". 1373421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS)) 1383421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Op0->getOpcode() == OpcodeToExpand) { 1393421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // It does! Try turning it into "(A op C) op' (B op C)". 1403421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands Value *A = Op0->getOperand(0), *B = Op0->getOperand(1), *C = RHS; 1413421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Do "A op C" and "B op C" both simplify? 1420aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *L = SimplifyBinOp(Opcode, A, C, Q, MaxRecurse)) 1430aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *R = SimplifyBinOp(Opcode, B, C, Q, MaxRecurse)) { 1443421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // They do! Return "L op' R" if it simplifies or is already available. 1453421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // If "L op' R" equals "A op' B" then "L op' R" is just the LHS. 146124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if ((L == A && R == B) || (Instruction::isCommutative(OpcodeToExpand) 147124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands && L == B && R == A)) { 148a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumExpand; 1493421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return LHS; 150a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1513421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Otherwise return "L op' R" if it simplifies. 1520aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, Q, MaxRecurse)) { 153a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumExpand; 1543421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 155a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1563421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1573421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1583421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1593421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Check whether the expression has the form "A op (B op' C)". 1603421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS)) 1613421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Op1->getOpcode() == OpcodeToExpand) { 1623421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // It does! Try turning it into "(A op B) op' (A op C)". 1633421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands Value *A = LHS, *B = Op1->getOperand(0), *C = Op1->getOperand(1); 1643421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Do "A op B" and "A op C" both simplify? 1650aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *L = SimplifyBinOp(Opcode, A, B, Q, MaxRecurse)) 1660aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *R = SimplifyBinOp(Opcode, A, C, Q, MaxRecurse)) { 1673421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // They do! Return "L op' R" if it simplifies or is already available. 1683421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // If "L op' R" equals "B op' C" then "L op' R" is just the RHS. 169124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if ((L == B && R == C) || (Instruction::isCommutative(OpcodeToExpand) 170124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands && L == C && R == B)) { 171a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumExpand; 1723421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return RHS; 173a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1743421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Otherwise return "L op' R" if it simplifies. 1750aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, Q, MaxRecurse)) { 176a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumExpand; 1773421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 178a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1793421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1803421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1813421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1823421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 1833421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands} 1843421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1853421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// FactorizeBinOp - Simplify "LHS Opcode RHS" by factorizing out a common term 1863421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// using the operation OpCodeToExtract. For example, when Opcode is Add and 1873421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// OpCodeToExtract is Mul then this tries to turn "(A*B)+(A*C)" into "A*(B+C)". 1883421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// Returns the simplified value, or null if no simplification was performed. 1893421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sandsstatic Value *FactorizeBinOp(unsigned Opcode, Value *LHS, Value *RHS, 1900aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands unsigned OpcToExtract, const Query &Q, 191618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier unsigned MaxRecurse) { 192e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer Instruction::BinaryOps OpcodeToExtract = (Instruction::BinaryOps)OpcToExtract; 1933421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 1943421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (!MaxRecurse--) 1953421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 1963421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1973421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS); 1983421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS); 1993421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 2003421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (!Op0 || Op0->getOpcode() != OpcodeToExtract || 2013421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands !Op1 || Op1->getOpcode() != OpcodeToExtract) 2023421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 2033421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 2043421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // The expression has the form "(A op' B) op (C op' D)". 20582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Value *A = Op0->getOperand(0), *B = Op0->getOperand(1); 20682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Value *C = Op1->getOperand(0), *D = Op1->getOperand(1); 2073421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 2083421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Use left distributivity, i.e. "X op' (Y op Z) = (X op' Y) op (X op' Z)". 2093421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Does the instruction have the form "(A op' B) op (A op' D)" or, in the 2103421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // commutative case, "(A op' B) op (C op' A)"? 211124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (A == C || (Instruction::isCommutative(OpcodeToExtract) && A == D)) { 212124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Value *DD = A == C ? D : C; 2133421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Form "A op' (B op DD)" if it simplifies completely. 2143421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Does "B op DD" simplify? 2150aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(Opcode, B, DD, Q, MaxRecurse)) { 2163421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // It does! Return "A op' V" if it simplifies or is already available. 2171cd05bb605e3c3eee9197d3f10b628c60d0cc07aDuncan Sands // If V equals B then "A op' V" is just the LHS. If V equals DD then 2181cd05bb605e3c3eee9197d3f10b628c60d0cc07aDuncan Sands // "A op' V" is just the RHS. 219124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == B || V == DD) { 220a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumFactor; 221124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands return V == B ? LHS : RHS; 222a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 2233421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Otherwise return "A op' V" if it simplifies. 2240aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *W = SimplifyBinOp(OpcodeToExtract, A, V, Q, MaxRecurse)) { 225a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumFactor; 2263421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return W; 227a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 2283421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 2293421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 2303421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 2313421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Use right distributivity, i.e. "(X op Y) op' Z = (X op' Z) op (Y op' Z)". 2323421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Does the instruction have the form "(A op' B) op (C op' B)" or, in the 2333421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // commutative case, "(A op' B) op (B op' D)"? 234124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (B == D || (Instruction::isCommutative(OpcodeToExtract) && B == C)) { 235124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Value *CC = B == D ? C : D; 2363421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Form "(A op CC) op' B" if it simplifies completely.. 2373421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Does "A op CC" simplify? 2380aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(Opcode, A, CC, Q, MaxRecurse)) { 2393421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // It does! Return "V op' B" if it simplifies or is already available. 2401cd05bb605e3c3eee9197d3f10b628c60d0cc07aDuncan Sands // If V equals A then "V op' B" is just the LHS. If V equals CC then 2411cd05bb605e3c3eee9197d3f10b628c60d0cc07aDuncan Sands // "V op' B" is just the RHS. 242124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == A || V == CC) { 243a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumFactor; 244124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands return V == A ? LHS : RHS; 245a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 2463421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Otherwise return "V op' B" if it simplifies. 2470aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *W = SimplifyBinOp(OpcodeToExtract, V, B, Q, MaxRecurse)) { 248a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumFactor; 2493421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return W; 250a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 2513421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 2523421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 2533421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 2543421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 2553421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands} 2563421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 2573421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// SimplifyAssociativeBinOp - Generic simplifications for associative binary 2583421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// operations. Returns the simpler value, or null if none was found. 259e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramerstatic Value *SimplifyAssociativeBinOp(unsigned Opc, Value *LHS, Value *RHS, 2600aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 261e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer Instruction::BinaryOps Opcode = (Instruction::BinaryOps)Opc; 262566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands assert(Instruction::isAssociative(Opcode) && "Not an associative operation!"); 263566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 264566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 265566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (!MaxRecurse--) 266566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return 0; 267566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 268566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS); 269566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS); 270566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 271566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Transform: "(A op B) op C" ==> "A op (B op C)" if it simplifies completely. 272566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Op0 && Op0->getOpcode() == Opcode) { 273566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = Op0->getOperand(0); 274566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *B = Op0->getOperand(1); 275566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *C = RHS; 276566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 277566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Does "B op C" simplify? 2780aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(Opcode, B, C, Q, MaxRecurse)) { 279566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // It does! Return "A op V" if it simplifies or is already available. 280566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If V equals B then "A op V" is just the LHS. 281124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == B) return LHS; 282566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Otherwise return "A op V" if it simplifies. 2830aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *W = SimplifyBinOp(Opcode, A, V, Q, MaxRecurse)) { 284a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumReassoc; 285566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return W; 286a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 287566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 288566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 289566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 290566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Transform: "A op (B op C)" ==> "(A op B) op C" if it simplifies completely. 291566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Op1 && Op1->getOpcode() == Opcode) { 292566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = LHS; 293566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *B = Op1->getOperand(0); 294566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *C = Op1->getOperand(1); 295566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 296566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Does "A op B" simplify? 2970aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(Opcode, A, B, Q, MaxRecurse)) { 298566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // It does! Return "V op C" if it simplifies or is already available. 299566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If V equals B then "V op C" is just the RHS. 300124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == B) return RHS; 301566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Otherwise return "V op C" if it simplifies. 3020aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *W = SimplifyBinOp(Opcode, V, C, Q, MaxRecurse)) { 303a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumReassoc; 304566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return W; 305a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 306566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 307566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 308566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 309566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // The remaining transforms require commutativity as well as associativity. 310566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (!Instruction::isCommutative(Opcode)) 311566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return 0; 312566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 313566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Transform: "(A op B) op C" ==> "(C op A) op B" if it simplifies completely. 314566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Op0 && Op0->getOpcode() == Opcode) { 315566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = Op0->getOperand(0); 316566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *B = Op0->getOperand(1); 317566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *C = RHS; 318566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 319566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Does "C op A" simplify? 3200aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(Opcode, C, A, Q, MaxRecurse)) { 321566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // It does! Return "V op B" if it simplifies or is already available. 322566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If V equals A then "V op B" is just the LHS. 323124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == A) return LHS; 324566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Otherwise return "V op B" if it simplifies. 3250aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *W = SimplifyBinOp(Opcode, V, B, Q, MaxRecurse)) { 326a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumReassoc; 327566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return W; 328a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 329566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 330566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 331566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 332566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Transform: "A op (B op C)" ==> "B op (C op A)" if it simplifies completely. 333566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Op1 && Op1->getOpcode() == Opcode) { 334566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = LHS; 335566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *B = Op1->getOperand(0); 336566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *C = Op1->getOperand(1); 337566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 338566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Does "C op A" simplify? 3390aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(Opcode, C, A, Q, MaxRecurse)) { 340566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // It does! Return "B op V" if it simplifies or is already available. 341566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If V equals C then "B op V" is just the RHS. 342124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == C) return RHS; 343566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Otherwise return "B op V" if it simplifies. 3440aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *W = SimplifyBinOp(Opcode, B, V, Q, MaxRecurse)) { 345a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumReassoc; 346566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return W; 347a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 348566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 349566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 350566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 351566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return 0; 352566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands} 353566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 354b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// ThreadBinOpOverSelect - In the case of a binary operation with a select 355b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// instruction as an operand, try to simplify the binop by seeing whether 356b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// evaluating it on both branches of the select results in the same value. 357b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// Returns the common value if so, otherwise returns null. 358b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sandsstatic Value *ThreadBinOpOverSelect(unsigned Opcode, Value *LHS, Value *RHS, 3590aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 3600312a93693abc2eb682b2b101c889959888fd883Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 3610312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (!MaxRecurse--) 3620312a93693abc2eb682b2b101c889959888fd883Duncan Sands return 0; 3630312a93693abc2eb682b2b101c889959888fd883Duncan Sands 364b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands SelectInst *SI; 365b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (isa<SelectInst>(LHS)) { 366b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands SI = cast<SelectInst>(LHS); 367b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } else { 368b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands assert(isa<SelectInst>(RHS) && "No select instruction operand!"); 369b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands SI = cast<SelectInst>(RHS); 370b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 371b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 372b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Evaluate the BinOp on the true and false branches of the select. 373b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *TV; 374b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *FV; 375b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (SI == LHS) { 3760aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands TV = SimplifyBinOp(Opcode, SI->getTrueValue(), RHS, Q, MaxRecurse); 3770aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands FV = SimplifyBinOp(Opcode, SI->getFalseValue(), RHS, Q, MaxRecurse); 378b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } else { 3790aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands TV = SimplifyBinOp(Opcode, LHS, SI->getTrueValue(), Q, MaxRecurse); 3800aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands FV = SimplifyBinOp(Opcode, LHS, SI->getFalseValue(), Q, MaxRecurse); 381b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 382b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 3837cf85e74e3885005ca8e5fdb155fa5351e255b85Duncan Sands // If they simplified to the same value, then return the common value. 384124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands // If they both failed to simplify then return null. 385124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (TV == FV) 386b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return TV; 387b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 388b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If one branch simplified to undef, return the other one. 389b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (TV && isa<UndefValue>(TV)) 390b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return FV; 391b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (FV && isa<UndefValue>(FV)) 392b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return TV; 393b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 394b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If applying the operation did not change the true and false select values, 395b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // then the result of the binop is the select itself. 396124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (TV == SI->getTrueValue() && FV == SI->getFalseValue()) 397b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return SI; 398b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 399b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If one branch simplified and the other did not, and the simplified 400b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // value is equal to the unsimplified one, return the simplified value. 401b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // For example, select (cond, X, X & Z) & Z -> X & Z. 402b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if ((FV && !TV) || (TV && !FV)) { 403b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Check that the simplified value has the form "X op Y" where "op" is the 404b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // same as the original operation. 405b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Instruction *Simplified = dyn_cast<Instruction>(FV ? FV : TV); 406b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (Simplified && Simplified->getOpcode() == Opcode) { 407b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // The value that didn't simplify is "UnsimplifiedLHS op UnsimplifiedRHS". 408b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // We already know that "op" is the same as for the simplified value. See 409b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // if the operands match too. If so, return the simplified value. 410b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *UnsimplifiedBranch = FV ? SI->getTrueValue() : SI->getFalseValue(); 411b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *UnsimplifiedLHS = SI == LHS ? UnsimplifiedBranch : LHS; 412b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *UnsimplifiedRHS = SI == LHS ? RHS : UnsimplifiedBranch; 413124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Simplified->getOperand(0) == UnsimplifiedLHS && 414124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Simplified->getOperand(1) == UnsimplifiedRHS) 415b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return Simplified; 416b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (Simplified->isCommutative() && 417124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Simplified->getOperand(1) == UnsimplifiedLHS && 418124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Simplified->getOperand(0) == UnsimplifiedRHS) 419b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return Simplified; 420b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 421b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 422b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 423b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return 0; 424b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands} 425b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 426b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// ThreadCmpOverSelect - In the case of a comparison with a select instruction, 427b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// try to simplify the comparison by seeing whether both branches of the select 428b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// result in the same value. Returns the common value if so, otherwise returns 429b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// null. 430b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sandsstatic Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS, 4310aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Value *RHS, const Query &Q, 432a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands unsigned MaxRecurse) { 4330312a93693abc2eb682b2b101c889959888fd883Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 4340312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (!MaxRecurse--) 4350312a93693abc2eb682b2b101c889959888fd883Duncan Sands return 0; 4360312a93693abc2eb682b2b101c889959888fd883Duncan Sands 437b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Make sure the select is on the LHS. 438b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (!isa<SelectInst>(LHS)) { 439b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands std::swap(LHS, RHS); 440b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Pred = CmpInst::getSwappedPredicate(Pred); 441b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 442b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands assert(isa<SelectInst>(LHS) && "Not comparing with a select instruction!"); 443b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands SelectInst *SI = cast<SelectInst>(LHS); 4446dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands Value *Cond = SI->getCondition(); 4456dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands Value *TV = SI->getTrueValue(); 4466dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands Value *FV = SI->getFalseValue(); 447b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 44850ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands // Now that we have "cmp select(Cond, TV, FV), RHS", analyse it. 449b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Does "cmp TV, RHS" simplify? 4500aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Value *TCmp = SimplifyCmpInst(Pred, TV, RHS, Q, MaxRecurse); 4516dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands if (TCmp == Cond) { 4526dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // It not only simplified, it simplified to the select condition. Replace 4536dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // it with 'true'. 4546dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands TCmp = getTrue(Cond->getType()); 4556dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands } else if (!TCmp) { 4566dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // It didn't simplify. However if "cmp TV, RHS" is equal to the select 4576dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // condition then we can replace it with 'true'. Otherwise give up. 4586dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands if (!isSameCompare(Cond, Pred, TV, RHS)) 4596dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands return 0; 4606dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands TCmp = getTrue(Cond->getType()); 46150ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands } 46250ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands 4636dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // Does "cmp FV, RHS" simplify? 4640aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Value *FCmp = SimplifyCmpInst(Pred, FV, RHS, Q, MaxRecurse); 4656dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands if (FCmp == Cond) { 4666dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // It not only simplified, it simplified to the select condition. Replace 4676dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // it with 'false'. 4686dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands FCmp = getFalse(Cond->getType()); 4696dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands } else if (!FCmp) { 4706dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // It didn't simplify. However if "cmp FV, RHS" is equal to the select 4716dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // condition then we can replace it with 'false'. Otherwise give up. 4726dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands if (!isSameCompare(Cond, Pred, FV, RHS)) 4736dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands return 0; 4746dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands FCmp = getFalse(Cond->getType()); 4756dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands } 4766dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands 4776dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // If both sides simplified to the same value, then use it as the result of 4786dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // the original comparison. 4796dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands if (TCmp == FCmp) 4806dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands return TCmp; 481aa97bb54f02784abefa0ae170af5937915bdb329Duncan Sands 482aa97bb54f02784abefa0ae170af5937915bdb329Duncan Sands // The remaining cases only make sense if the select condition has the same 483aa97bb54f02784abefa0ae170af5937915bdb329Duncan Sands // type as the result of the comparison, so bail out if this is not so. 484aa97bb54f02784abefa0ae170af5937915bdb329Duncan Sands if (Cond->getType()->isVectorTy() != RHS->getType()->isVectorTy()) 485aa97bb54f02784abefa0ae170af5937915bdb329Duncan Sands return 0; 4866dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // If the false value simplified to false, then the result of the compare 4876dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // is equal to "Cond && TCmp". This also catches the case when the false 4886dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // value simplified to false and the true value to true, returning "Cond". 4896dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands if (match(FCmp, m_Zero())) 4900aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyAndInst(Cond, TCmp, Q, MaxRecurse)) 4916dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands return V; 4926dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // If the true value simplified to true, then the result of the compare 4936dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // is equal to "Cond || FCmp". 4946dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands if (match(TCmp, m_One())) 4950aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyOrInst(Cond, FCmp, Q, MaxRecurse)) 4966dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands return V; 4976dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // Finally, if the false value simplified to true and the true value to 4986dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands // false, then the result of the compare is equal to "!Cond". 4996dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands if (match(FCmp, m_One()) && match(TCmp, m_Zero())) 5006dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands if (Value *V = 5016dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands SimplifyXorInst(Cond, Constant::getAllOnesValue(Cond->getType()), 5020aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse)) 5036dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands return V; 5046dc9e2bf7455fa1494078d5d52f1363b05183f20Duncan Sands 505b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return 0; 506b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands} 507b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 508a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// ThreadBinOpOverPHI - In the case of a binary operation with an operand that 509a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// is a PHI instruction, try to simplify the binop by seeing whether evaluating 510a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// it on the incoming phi values yields the same result for every value. If so 511a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// returns the common value, otherwise returns null. 512a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *ThreadBinOpOverPHI(unsigned Opcode, Value *LHS, Value *RHS, 5130aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 5140312a93693abc2eb682b2b101c889959888fd883Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 5150312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (!MaxRecurse--) 5160312a93693abc2eb682b2b101c889959888fd883Duncan Sands return 0; 5170312a93693abc2eb682b2b101c889959888fd883Duncan Sands 518a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands PHINode *PI; 519a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands if (isa<PHINode>(LHS)) { 520a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands PI = cast<PHINode>(LHS); 5211845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Bail out if RHS and the phi may be mutually interdependent due to a loop. 5220aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (!ValueDominatesPHI(RHS, PI, Q.DT)) 5231845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return 0; 524a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } else { 525a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands assert(isa<PHINode>(RHS) && "No PHI instruction operand!"); 526a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands PI = cast<PHINode>(RHS); 5271845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Bail out if LHS and the phi may be mutually interdependent due to a loop. 5280aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (!ValueDominatesPHI(LHS, PI, Q.DT)) 5291845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return 0; 530a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } 531a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 532a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // Evaluate the BinOp on the incoming phi values. 533a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Value *CommonValue = 0; 534a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) { 535552008946530e01efdad15044e1f621883d14a3aDuncan Sands Value *Incoming = PI->getIncomingValue(i); 536ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If the incoming value is the phi node itself, it can safely be skipped. 537552008946530e01efdad15044e1f621883d14a3aDuncan Sands if (Incoming == PI) continue; 538a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Value *V = PI == LHS ? 5390aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands SimplifyBinOp(Opcode, Incoming, RHS, Q, MaxRecurse) : 5400aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands SimplifyBinOp(Opcode, LHS, Incoming, Q, MaxRecurse); 541a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation failed to simplify, or simplified to a different value 542a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // to previously, then give up. 543a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands if (!V || (CommonValue && V != CommonValue)) 544a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return 0; 545a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands CommonValue = V; 546a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } 547a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 548a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return CommonValue; 549a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 550a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 551a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// ThreadCmpOverPHI - In the case of a comparison with a PHI instruction, try 552a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// try to simplify the comparison by seeing whether comparing with all of the 553a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// incoming phi values yields the same result every time. If so returns the 554a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// common result, otherwise returns null. 555a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *ThreadCmpOverPHI(CmpInst::Predicate Pred, Value *LHS, Value *RHS, 5560aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 5570312a93693abc2eb682b2b101c889959888fd883Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 5580312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (!MaxRecurse--) 5590312a93693abc2eb682b2b101c889959888fd883Duncan Sands return 0; 5600312a93693abc2eb682b2b101c889959888fd883Duncan Sands 561a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // Make sure the phi is on the LHS. 562a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands if (!isa<PHINode>(LHS)) { 563a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands std::swap(LHS, RHS); 564a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Pred = CmpInst::getSwappedPredicate(Pred); 565a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } 566a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands assert(isa<PHINode>(LHS) && "Not comparing with a phi instruction!"); 567a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands PHINode *PI = cast<PHINode>(LHS); 568a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 5691845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Bail out if RHS and the phi may be mutually interdependent due to a loop. 5700aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (!ValueDominatesPHI(RHS, PI, Q.DT)) 5711845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return 0; 5721845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 573a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // Evaluate the BinOp on the incoming phi values. 574a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Value *CommonValue = 0; 575a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) { 576552008946530e01efdad15044e1f621883d14a3aDuncan Sands Value *Incoming = PI->getIncomingValue(i); 577ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If the incoming value is the phi node itself, it can safely be skipped. 578552008946530e01efdad15044e1f621883d14a3aDuncan Sands if (Incoming == PI) continue; 5790aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Value *V = SimplifyCmpInst(Pred, Incoming, RHS, Q, MaxRecurse); 580a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation failed to simplify, or simplified to a different value 581a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // to previously, then give up. 582a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands if (!V || (CommonValue && V != CommonValue)) 583a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return 0; 584a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands CommonValue = V; 585a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } 586a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 587a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return CommonValue; 588a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 589a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 5908aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner/// SimplifyAddInst - Given operands for an Add, see if we can 591d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner/// fold the result. If not, this returns null. 592ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sandsstatic Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 5930aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 594d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 595d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 596d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Constant *Ops[] = { CLHS, CRHS }; 5970aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ConstantFoldInstOperands(Instruction::Add, CLHS->getType(), Ops, 5980aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q.TD, Q.TLI); 5998aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner } 60012a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 6018aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner // Canonicalize the constant to the RHS. 6028aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner std::swap(Op0, Op1); 6038aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner } 60412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 605fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X + undef -> undef 606f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 607fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Op1; 60812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 609fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X + 0 -> X 610fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (match(Op1, m_Zero())) 611fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Op0; 612fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 613fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X + (Y - X) -> Y 614fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // (Y - X) + X -> Y 615ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands // Eg: X + -X -> 0 616124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Value *Y = 0; 617124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (match(Op1, m_Sub(m_Value(Y), m_Specific(Op0))) || 618124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands match(Op0, m_Sub(m_Value(Y), m_Specific(Op1)))) 619fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Y; 620fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 621fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X + ~X -> -1 since ~X = -X-1 622124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (match(Op0, m_Not(m_Specific(Op1))) || 623124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands match(Op1, m_Not(m_Specific(Op0)))) 624fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Constant::getAllOnesValue(Op0->getType()); 62587689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands 62682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands /// i1 add -> xor. 62775d289ed6201e82718343d7a36d2a2fa082f6217Duncan Sands if (MaxRecurse && Op0->getType()->isIntegerTy(1)) 6280aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1)) 62907f30fbd734069b80b90c6aeea0ae645ce3880c0Duncan Sands return V; 63082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 631566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Try some generic simplifications for associative operations. 6320aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::Add, Op0, Op1, Q, 633566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands MaxRecurse)) 634566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 635566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 6363421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Mul distributes over Add. Try some generic simplifications based on this. 6373421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::Add, Op0, Op1, Instruction::Mul, 6380aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse)) 6393421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 6403421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 64187689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // Threading Add over selects and phi nodes is pointless, so don't bother. 64287689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // Threading over the select in "A + select(cond, B, C)" means evaluating 64387689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // "A+B" and "A+C" and seeing if they are equal; but they are equal if and 64487689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // only if B and C are equal. If B and C are equal then (since we assume 64587689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // that operands have already been simplified) "select(cond, B, C)" should 64687689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // have been simplified to the common value of B and C already. Analysing 64787689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // "A+B" and "A+C" thus gains nothing, but costs compile time. Similarly 64887689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // for threading over phi nodes. 64987689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands 6508aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner return 0; 6518aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner} 6528aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner 653ee9a2e322af96accc9e55ed6373c0057453714b1Duncan SandsValue *llvm::SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 654618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetData *TD, const TargetLibraryInfo *TLI, 655618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const DominatorTree *DT) { 6560aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT), 6570aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands RecursionLimit); 658ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands} 659ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands 66090c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth/// \brief Accumulate the constant integer offset a GEP represents. 661fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth/// 66290c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth/// Given a getelementptr instruction/constantexpr, accumulate the constant 66390c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth/// offset from the base pointer into the provided APInt 'Offset'. Returns true 66490c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth/// if the GEP has all-constant indices. Returns false if any non-constant 66590c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth/// index is encountered leaving the 'Offset' in an undefined state. The 66690c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth/// 'Offset' APInt must be the bitwidth of the target's pointer size. 66790c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruthstatic bool accumulateGEPOffset(const TargetData &TD, GEPOperator *GEP, 66890c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth APInt &Offset) { 669fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth unsigned IntPtrWidth = TD.getPointerSizeInBits(); 67090c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth assert(IntPtrWidth == Offset.getBitWidth()); 671fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth 672fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth gep_type_iterator GTI = gep_type_begin(GEP); 673fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth for (User::op_iterator I = GEP->op_begin() + 1, E = GEP->op_end(); I != E; 674fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth ++I, ++GTI) { 675fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth ConstantInt *OpC = dyn_cast<ConstantInt>(*I); 67690c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth if (!OpC) return false; 677fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth if (OpC->isZero()) continue; 678fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth 679fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth // Handle a struct index, which adds its field offset to the pointer. 680fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth if (StructType *STy = dyn_cast<StructType>(*GTI)) { 68190c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth unsigned ElementIdx = OpC->getZExtValue(); 68290c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth const StructLayout *SL = TD.getStructLayout(STy); 683f72e0ca71507ab3d8566148e124fe21f4a051cd1Duncan Sands Offset += APInt(IntPtrWidth, SL->getElementOffset(ElementIdx)); 684fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth continue; 685fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth } 686fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth 687f72e0ca71507ab3d8566148e124fe21f4a051cd1Duncan Sands APInt TypeSize(IntPtrWidth, TD.getTypeAllocSize(GTI.getIndexedType())); 68890c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth Offset += OpC->getValue().sextOrTrunc(IntPtrWidth) * TypeSize; 689fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth } 69090c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth return true; 691fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth} 692fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth 693fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth/// \brief Compute the base pointer and cumulative constant offsets for V. 694fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth/// 695fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth/// This strips all constant offsets off of V, leaving it the base pointer, and 696fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth/// accumulates the total constant offset applied in the returned constant. It 697fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth/// returns 0 if V is not a pointer, and returns the constant '0' if there are 698fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth/// no constant offsets applied. 699fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruthstatic Constant *stripAndComputeConstantOffsets(const TargetData &TD, 700fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth Value *&V) { 701fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth if (!V->getType()->isPointerTy()) 702fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth return 0; 703fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth 70490c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth unsigned IntPtrWidth = TD.getPointerSizeInBits(); 70590c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth APInt Offset = APInt::getNullValue(IntPtrWidth); 706fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth 707fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth // Even though we don't look through PHI nodes, we could be called on an 708fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth // instruction in an unreachable block, which may be on a cycle. 709fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth SmallPtrSet<Value *, 4> Visited; 710fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth Visited.insert(V); 711fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth do { 712fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) { 7139d9e29b4a83818b066c09c8f832cec7641aa2115Chandler Carruth if (!GEP->isInBounds() || !accumulateGEPOffset(TD, GEP, Offset)) 714fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth break; 715fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth V = GEP->getPointerOperand(); 716fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth } else if (Operator::getOpcode(V) == Instruction::BitCast) { 717fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth V = cast<Operator>(V)->getOperand(0); 718fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) { 719fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth if (GA->mayBeOverridden()) 720fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth break; 721fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth V = GA->getAliasee(); 722fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth } else { 723fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth break; 724fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth } 725fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth assert(V->getType()->isPointerTy() && "Unexpected operand type!"); 726fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth } while (Visited.insert(V)); 727fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth 72890c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth Type *IntPtrTy = TD.getIntPtrType(V->getContext()); 72990c14fcb7ea3436a8b3053f8a9aa529c03011d34Chandler Carruth return ConstantInt::get(IntPtrTy, Offset); 730fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth} 731fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth 732fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth/// \brief Compute the constant difference between two pointer values. 733fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth/// If the difference is not a constant, returns zero. 734fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruthstatic Constant *computePointerDifference(const TargetData &TD, 735fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth Value *LHS, Value *RHS) { 736fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth Constant *LHSOffset = stripAndComputeConstantOffsets(TD, LHS); 737fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth if (!LHSOffset) 738fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth return 0; 739fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth Constant *RHSOffset = stripAndComputeConstantOffsets(TD, RHS); 740fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth if (!RHSOffset) 741fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth return 0; 742fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth 743fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth // If LHS and RHS are not related via constant offsets to the same base 744fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth // value, there is nothing we can do here. 745fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth if (LHS != RHS) 746fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth return 0; 747fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth 748fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth // Otherwise, the difference of LHS - RHS can be computed as: 749fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth // LHS - RHS 750fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth // = (LHSOffset + Base) - (RHSOffset + Base) 751fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth // = LHSOffset - RHSOffset 752fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth return ConstantExpr::getSub(LHSOffset, RHSOffset); 753fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth} 754fc72ae613afd7ca2526bb66156bafe8b0054cb3bChandler Carruth 755fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands/// SimplifySubInst - Given operands for a Sub, see if we can 756fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands/// fold the result. If not, this returns null. 757ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sandsstatic Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 7580aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 759fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (Constant *CLHS = dyn_cast<Constant>(Op0)) 760fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 761fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands Constant *Ops[] = { CLHS, CRHS }; 762fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return ConstantFoldInstOperands(Instruction::Sub, CLHS->getType(), 7630aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Ops, Q.TD, Q.TLI); 764fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands } 765fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 766fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X - undef -> undef 767fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // undef - X -> undef 768f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op0, m_Undef()) || match(Op1, m_Undef())) 769fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return UndefValue::get(Op0->getType()); 770fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 771fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X - 0 -> X 772fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (match(Op1, m_Zero())) 773fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Op0; 774fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 775fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X - X -> 0 776124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Op0 == Op1) 777fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Constant::getNullValue(Op0->getType()); 778fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 779fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands // (X*2) - X -> X 780fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands // (X<<1) - X -> X 781b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands Value *X = 0; 782fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands if (match(Op0, m_Mul(m_Specific(Op1), m_ConstantInt<2>())) || 783fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands match(Op0, m_Shl(m_Specific(Op1), m_One()))) 784fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands return Op1; 785fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands 786b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies. 787b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // For example, (X + Y) - Y -> X; (Y + X) - Y -> X 788b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands Value *Y = 0, *Z = Op1; 789b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (MaxRecurse && match(Op0, m_Add(m_Value(X), m_Value(Y)))) { // (X + Y) - Z 790b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // See if "V === Y - Z" simplifies. 7910aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, Y, Z, Q, MaxRecurse-1)) 792b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "X + V" simplifies. 7930aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Add, X, V, Q, MaxRecurse-1)) { 794b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does, we successfully reassociated! 795b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands ++NumReassoc; 796b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return W; 797b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 798b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // See if "V === X - Z" simplifies. 7990aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1)) 800b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "Y + V" simplifies. 8010aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Add, Y, V, Q, MaxRecurse-1)) { 802b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does, we successfully reassociated! 803b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands ++NumReassoc; 804b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return W; 805b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 806b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 80782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 808b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // X - (Y + Z) -> (X - Y) - Z or (X - Z) - Y if everything simplifies. 809b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // For example, X - (X + 1) -> -1 810b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands X = Op0; 811b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (MaxRecurse && match(Op1, m_Add(m_Value(Y), m_Value(Z)))) { // X - (Y + Z) 812b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // See if "V === X - Y" simplifies. 8130aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1)) 814b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "V - Z" simplifies. 8150aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Sub, V, Z, Q, MaxRecurse-1)) { 816b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does, we successfully reassociated! 817b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands ++NumReassoc; 818b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return W; 819b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 820b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // See if "V === X - Z" simplifies. 8210aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, Q, MaxRecurse-1)) 822b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "V - Y" simplifies. 8230aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Sub, V, Y, Q, MaxRecurse-1)) { 824b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does, we successfully reassociated! 825b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands ++NumReassoc; 826b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return W; 827b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 828b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 829b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands 830b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // Z - (X - Y) -> (Z - X) + Y if everything simplifies. 831b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // For example, X - (X - Y) -> Y. 832b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands Z = Op0; 833c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands if (MaxRecurse && match(Op1, m_Sub(m_Value(X), m_Value(Y)))) // Z - (X - Y) 834c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands // See if "V === Z - X" simplifies. 8350aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, Z, X, Q, MaxRecurse-1)) 836b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "V + Y" simplifies. 8370aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Add, V, Y, Q, MaxRecurse-1)) { 838c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands // It does, we successfully reassociated! 839c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands ++NumReassoc; 840c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands return W; 841c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands } 842c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands 843bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands // trunc(X) - trunc(Y) -> trunc(X - Y) if everything simplifies. 844bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands if (MaxRecurse && match(Op0, m_Trunc(m_Value(X))) && 845bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands match(Op1, m_Trunc(m_Value(Y)))) 846bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands if (X->getType() == Y->getType()) 847bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands // See if "V === X - Y" simplifies. 848bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, Q, MaxRecurse-1)) 849bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands // It does! Now see if "trunc V" simplifies. 850bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands if (Value *W = SimplifyTruncInst(V, Op0->getType(), Q, MaxRecurse-1)) 851bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands // It does, return the simplified "trunc V". 852bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands return W; 853bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands 854bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands // Variations on GEP(base, I, ...) - GEP(base, i, ...) -> GEP(null, I-i, ...). 855bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands if (Q.TD && match(Op0, m_PtrToInt(m_Value(X))) && 856bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands match(Op1, m_PtrToInt(m_Value(Y)))) 857bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands if (Constant *Result = computePointerDifference(*Q.TD, X, Y)) 858bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands return ConstantExpr::getIntegerCast(Result, Op0->getType(), true); 859bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands 8603421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Mul distributes over Sub. Try some generic simplifications based on this. 8613421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::Sub, Op0, Op1, Instruction::Mul, 8620aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse)) 8633421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 8643421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 865b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // i1 sub -> xor. 866b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (MaxRecurse && Op0->getType()->isIntegerTy(1)) 8670aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyXorInst(Op0, Op1, Q, MaxRecurse-1)) 868b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return V; 869b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands 870fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // Threading Sub over selects and phi nodes is pointless, so don't bother. 871fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // Threading over the select in "A - select(cond, B, C)" means evaluating 872fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // "A-B" and "A-C" and seeing if they are equal; but they are equal if and 873fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // only if B and C are equal. If B and C are equal then (since we assume 874fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // that operands have already been simplified) "select(cond, B, C)" should 875fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // have been simplified to the common value of B and C already. Analysing 876fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly 877fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // for threading over phi nodes. 878fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 879fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return 0; 880fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands} 881fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 882ee9a2e322af96accc9e55ed6373c0057453714b1Duncan SandsValue *llvm::SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 8830aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const TargetData *TD, const TargetLibraryInfo *TLI, 884618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const DominatorTree *DT) { 8850aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT), 8860aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands RecursionLimit); 887ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands} 888ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands 88982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands/// SimplifyMulInst - Given operands for a Mul, see if we can 89082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands/// fold the result. If not, this returns null. 8910aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyMulInst(Value *Op0, Value *Op1, const Query &Q, 8920aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands unsigned MaxRecurse) { 89382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 89482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 89582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Constant *Ops[] = { CLHS, CRHS }; 89682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return ConstantFoldInstOperands(Instruction::Mul, CLHS->getType(), 8970aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Ops, Q.TD, Q.TLI); 89882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands } 89982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 90082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // Canonicalize the constant to the RHS. 90182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands std::swap(Op0, Op1); 90282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands } 90382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 90482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // X * undef -> 0 905f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 90682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return Constant::getNullValue(Op0->getType()); 90782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 90882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // X * 0 -> 0 90982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (match(Op1, m_Zero())) 91082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return Op1; 91182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 91282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // X * 1 -> X 91382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (match(Op1, m_One())) 91482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return Op0; 91582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 9161895e98ef38afbe011575cc25f4889d96e37421bDuncan Sands // (X / Y) * Y -> X if the division is exact. 91755c6d57734cd2f141dc2d6912fc22746d5eeae54Benjamin Kramer Value *X = 0; 91855c6d57734cd2f141dc2d6912fc22746d5eeae54Benjamin Kramer if (match(Op0, m_Exact(m_IDiv(m_Value(X), m_Specific(Op1)))) || // (X / Y) * Y 91955c6d57734cd2f141dc2d6912fc22746d5eeae54Benjamin Kramer match(Op1, m_Exact(m_IDiv(m_Value(X), m_Specific(Op0))))) // Y * (X / Y) 92055c6d57734cd2f141dc2d6912fc22746d5eeae54Benjamin Kramer return X; 9211895e98ef38afbe011575cc25f4889d96e37421bDuncan Sands 9225413880654585f01ea9880f24f07f27c8da56ba8Nick Lewycky // i1 mul -> and. 92375d289ed6201e82718343d7a36d2a2fa082f6217Duncan Sands if (MaxRecurse && Op0->getType()->isIntegerTy(1)) 9240aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyAndInst(Op0, Op1, Q, MaxRecurse-1)) 92507f30fbd734069b80b90c6aeea0ae645ce3880c0Duncan Sands return V; 92682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 92782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // Try some generic simplifications for associative operations. 9280aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::Mul, Op0, Op1, Q, 92982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands MaxRecurse)) 93082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return V; 93182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 93282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // Mul distributes over Add. Try some generic simplifications based on this. 93382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Value *V = ExpandBinOp(Instruction::Mul, Op0, Op1, Instruction::Add, 9340aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse)) 93582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return V; 93682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 93782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // If the operation is with the result of a select instruction, check whether 93882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // operating on either branch of the select always yields the same value. 93982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 9400aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverSelect(Instruction::Mul, Op0, Op1, Q, 94182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands MaxRecurse)) 94282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return V; 94382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 94482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // If the operation is with the result of a phi instruction, check whether 94582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // operating on all incoming values of the phi always yields the same value. 94682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 9470aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverPHI(Instruction::Mul, Op0, Op1, Q, 94882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands MaxRecurse)) 94982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return V; 95082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 95182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return 0; 95282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands} 95382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 95482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan SandsValue *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const TargetData *TD, 955618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 95682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands const DominatorTree *DT) { 9570aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyMulInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); 95882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands} 95982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 960593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// SimplifyDiv - Given operands for an SDiv or UDiv, see if we can 961593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// fold the result. If not, this returns null. 962479b4b9ef06dd84097202ffa6aea07913cdf651cAnders Carlssonstatic Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1, 9630aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 964593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Constant *C0 = dyn_cast<Constant>(Op0)) { 965593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Constant *C1 = dyn_cast<Constant>(Op1)) { 966593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands Constant *Ops[] = { C0, C1 }; 9670aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI); 968593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands } 969593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands } 970593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 971a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands bool isSigned = Opcode == Instruction::SDiv; 972a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands 973593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // X / undef -> undef 974f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 975593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op1; 976593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 977593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // undef / X -> 0 978f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op0, m_Undef())) 979593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Constant::getNullValue(Op0->getType()); 980593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 981593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // 0 / X -> 0, we don't need to preserve faults! 982593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (match(Op0, m_Zero())) 983593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op0; 984593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 985593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // X / 1 -> X 986593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (match(Op1, m_One())) 987593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op0; 988593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 989593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Op0->getType()->isIntegerTy(1)) 990593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // It can't be division by zero, hence it must be division by one. 991593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op0; 992593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 993593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // X / X -> 1 994593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Op0 == Op1) 995593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return ConstantInt::get(Op0->getType(), 1); 996593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 997593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // (X * Y) / Y -> X if the multiplication does not overflow. 998593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands Value *X = 0, *Y = 0; 999593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (match(Op0, m_Mul(m_Value(X), m_Value(Y))) && (X == Op1 || Y == Op1)) { 1000593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Y != Op1) std::swap(X, Y); // Ensure expression is (X * Y) / Y, Y = Op1 100132a43cc0fc3cd42702d7859eaa58dd42f561a54dDuncan Sands OverflowingBinaryOperator *Mul = cast<OverflowingBinaryOperator>(Op0); 10024b720718fbda1194f925e0a9d931bc220e8b0e3aDuncan Sands // If the Mul knows it does not overflow, then we are good to go. 10034b720718fbda1194f925e0a9d931bc220e8b0e3aDuncan Sands if ((isSigned && Mul->hasNoSignedWrap()) || 10044b720718fbda1194f925e0a9d931bc220e8b0e3aDuncan Sands (!isSigned && Mul->hasNoUnsignedWrap())) 10054b720718fbda1194f925e0a9d931bc220e8b0e3aDuncan Sands return X; 1006593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // If X has the form X = A / Y then X * Y cannot overflow. 1007593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (BinaryOperator *Div = dyn_cast<BinaryOperator>(X)) 1008593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Div->getOpcode() == Opcode && Div->getOperand(1) == Y) 1009593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return X; 1010593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands } 1011593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 1012a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // (X rem Y) / Y -> 0 1013a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if ((isSigned && match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) || 1014a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands (!isSigned && match(Op0, m_URem(m_Value(), m_Specific(Op1))))) 1015a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands return Constant::getNullValue(Op0->getType()); 1016a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands 1017a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // If the operation is with the result of a select instruction, check whether 1018a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // operating on either branch of the select always yields the same value. 1019a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 10200aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse)) 1021a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands return V; 1022a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands 1023a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // If the operation is with the result of a phi instruction, check whether 1024a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // operating on all incoming values of the phi always yields the same value. 1025a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 10260aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse)) 1027a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands return V; 1028a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands 1029593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return 0; 1030593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 1031593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 1032593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// SimplifySDivInst - Given operands for an SDiv, see if we can 1033593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// fold the result. If not, this returns null. 10340aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifySDivInst(Value *Op0, Value *Op1, const Query &Q, 10350aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands unsigned MaxRecurse) { 10360aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, Q, MaxRecurse)) 1037593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return V; 1038593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 1039593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return 0; 1040593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 1041593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 1042593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan SandsValue *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const TargetData *TD, 1043618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 10441fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel const DominatorTree *DT) { 10450aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifySDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); 1046593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 1047593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 1048593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// SimplifyUDivInst - Given operands for a UDiv, see if we can 1049593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// fold the result. If not, this returns null. 10500aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyUDivInst(Value *Op0, Value *Op1, const Query &Q, 10510aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands unsigned MaxRecurse) { 10520aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, Q, MaxRecurse)) 1053593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return V; 1054593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 1055593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return 0; 1056593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 1057593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 1058593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan SandsValue *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const TargetData *TD, 1059618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 10601fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel const DominatorTree *DT) { 10610aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyUDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); 1062593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 1063593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 10640aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyFDivInst(Value *Op0, Value *Op1, const Query &Q, 10650aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands unsigned) { 10661fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel // undef / X -> undef (the undef could be a snan). 1067f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op0, m_Undef())) 10681fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel return Op0; 10691fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel 10701fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel // X / undef -> undef 1071f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 10721fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel return Op1; 10731fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel 10741fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel return 0; 10751fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel} 10761fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel 10771fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van BommelValue *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, const TargetData *TD, 1078618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 10791fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel const DominatorTree *DT) { 10800aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyFDivInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); 10811fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel} 10821fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel 1083f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands/// SimplifyRem - Given operands for an SRem or URem, see if we can 1084f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands/// fold the result. If not, this returns null. 1085f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sandsstatic Value *SimplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1, 10860aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 1087f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (Constant *C0 = dyn_cast<Constant>(Op0)) { 1088f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (Constant *C1 = dyn_cast<Constant>(Op1)) { 1089f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands Constant *Ops[] = { C0, C1 }; 10900aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI); 1091f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands } 1092f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands } 1093f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1094f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // X % undef -> undef 1095f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op1, m_Undef())) 1096f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Op1; 1097f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1098f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // undef % X -> 0 1099f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op0, m_Undef())) 1100f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Constant::getNullValue(Op0->getType()); 1101f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1102f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // 0 % X -> 0, we don't need to preserve faults! 1103f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op0, m_Zero())) 1104f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Op0; 1105f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1106f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // X % 0 -> undef, we don't need to preserve faults! 1107f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op1, m_Zero())) 1108f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return UndefValue::get(Op0->getType()); 1109f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1110f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // X % 1 -> 0 1111f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op1, m_One())) 1112f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Constant::getNullValue(Op0->getType()); 1113f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1114f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (Op0->getType()->isIntegerTy(1)) 1115f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // It can't be remainder by zero, hence it must be remainder by one. 1116f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Constant::getNullValue(Op0->getType()); 1117f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1118f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // X % X -> 0 1119f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (Op0 == Op1) 1120f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Constant::getNullValue(Op0->getType()); 1121f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1122f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // If the operation is with the result of a select instruction, check whether 1123f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // operating on either branch of the select always yields the same value. 1124f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 11250aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse)) 1126f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return V; 1127f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1128f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // If the operation is with the result of a phi instruction, check whether 1129f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // operating on all incoming values of the phi always yields the same value. 1130f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 11310aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse)) 1132f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return V; 1133f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1134f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return 0; 1135f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 1136f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1137f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands/// SimplifySRemInst - Given operands for an SRem, see if we can 1138f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands/// fold the result. If not, this returns null. 11390aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifySRemInst(Value *Op0, Value *Op1, const Query &Q, 11400aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands unsigned MaxRecurse) { 11410aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyRem(Instruction::SRem, Op0, Op1, Q, MaxRecurse)) 1142f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return V; 1143f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1144f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return 0; 1145f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 1146f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1147f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan SandsValue *llvm::SimplifySRemInst(Value *Op0, Value *Op1, const TargetData *TD, 1148618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 1149f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands const DominatorTree *DT) { 11500aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifySRemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); 1151f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 1152f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1153f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands/// SimplifyURemInst - Given operands for a URem, see if we can 1154f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands/// fold the result. If not, this returns null. 11550aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyURemInst(Value *Op0, Value *Op1, const Query &Q, 1156618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier unsigned MaxRecurse) { 11570aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyRem(Instruction::URem, Op0, Op1, Q, MaxRecurse)) 1158f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return V; 1159f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1160f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return 0; 1161f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 1162f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1163f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan SandsValue *llvm::SimplifyURemInst(Value *Op0, Value *Op1, const TargetData *TD, 1164618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 1165f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands const DominatorTree *DT) { 11660aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyURemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); 1167f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 1168f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 11690aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyFRemInst(Value *Op0, Value *Op1, const Query &, 1170618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier unsigned) { 1171f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // undef % X -> undef (the undef could be a snan). 1172f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op0, m_Undef())) 1173f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Op0; 1174f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1175f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // X % undef -> undef 1176f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op1, m_Undef())) 1177f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Op1; 1178f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1179f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return 0; 1180f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 1181f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1182f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan SandsValue *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, const TargetData *TD, 1183618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 1184f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands const DominatorTree *DT) { 11850aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyFRemInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); 1186f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 1187f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1188cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands/// SimplifyShift - Given operands for an Shl, LShr or AShr, see if we can 1189c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// fold the result. If not, this returns null. 1190cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sandsstatic Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1, 11910aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 1192c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (Constant *C0 = dyn_cast<Constant>(Op0)) { 1193c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (Constant *C1 = dyn_cast<Constant>(Op1)) { 1194c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands Constant *Ops[] = { C0, C1 }; 11950aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, Q.TD, Q.TLI); 1196c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands } 1197c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands } 1198c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1199cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // 0 shift by X -> 0 1200c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (match(Op0, m_Zero())) 1201c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Op0; 1202c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1203cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // X shift by 0 -> X 1204c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (match(Op1, m_Zero())) 1205c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Op0; 1206c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1207cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // X shift by undef -> undef because it may shift by the bitwidth. 1208f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 1209c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Op1; 1210c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1211c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands // Shifting by the bitwidth or more is undefined. 1212c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) 1213c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (CI->getValue().getLimitedValue() >= 1214c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands Op0->getType()->getScalarSizeInBits()) 1215c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return UndefValue::get(Op0->getType()); 1216c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1217cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // If the operation is with the result of a select instruction, check whether 1218cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // operating on either branch of the select always yields the same value. 1219cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 12200aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, Q, MaxRecurse)) 1221cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 1222cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 1223cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // If the operation is with the result of a phi instruction, check whether 1224cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // operating on all incoming values of the phi always yields the same value. 1225cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 12260aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, Q, MaxRecurse)) 1227cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 1228cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 1229cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return 0; 1230cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands} 1231cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 1232cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands/// SimplifyShlInst - Given operands for an Shl, see if we can 1233cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands/// fold the result. If not, this returns null. 123481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattnerstatic Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 12350aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 12360aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyShift(Instruction::Shl, Op0, Op1, Q, MaxRecurse)) 1237cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 1238cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 1239cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // undef << X -> 0 1240f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op0, m_Undef())) 1241cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return Constant::getNullValue(Op0->getType()); 1242cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 124381a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner // (X >> A) << A -> X 124481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Value *X; 124555c6d57734cd2f141dc2d6912fc22746d5eeae54Benjamin Kramer if (match(Op0, m_Exact(m_Shr(m_Value(X), m_Specific(Op1))))) 124681a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner return X; 1247c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return 0; 1248c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 1249c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 125081a0dc911586c77421c2255aa417dc9b350b9e20Chris LattnerValue *llvm::SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 1251618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetData *TD, const TargetLibraryInfo *TLI, 1252618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const DominatorTree *DT) { 12530aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyShlInst(Op0, Op1, isNSW, isNUW, Query (TD, TLI, DT), 12540aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands RecursionLimit); 1255c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 1256c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1257c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// SimplifyLShrInst - Given operands for an LShr, see if we can 1258c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// fold the result. If not, this returns null. 125981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattnerstatic Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact, 12600aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 12610aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyShift(Instruction::LShr, Op0, Op1, Q, MaxRecurse)) 1262cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 1263c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1264c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands // undef >>l X -> 0 1265f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op0, m_Undef())) 1266c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Constant::getNullValue(Op0->getType()); 1267c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 126881a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner // (X << A) >> A -> X 126981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Value *X; 127081a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) && 127181a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<OverflowingBinaryOperator>(Op0)->hasNoUnsignedWrap()) 127281a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner return X; 127352fb846578714d14bbde9b28884a6a8729217677Duncan Sands 1274c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return 0; 1275c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 1276c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 127781a0dc911586c77421c2255aa417dc9b350b9e20Chris LattnerValue *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact, 1278618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetData *TD, 1279618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 1280618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const DominatorTree *DT) { 12810aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyLShrInst(Op0, Op1, isExact, Query (TD, TLI, DT), 12820aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands RecursionLimit); 1283c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 1284c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1285c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// SimplifyAShrInst - Given operands for an AShr, see if we can 1286c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// fold the result. If not, this returns null. 128781a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattnerstatic Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact, 12880aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 12890aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyShift(Instruction::AShr, Op0, Op1, Q, MaxRecurse)) 1290cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 1291c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1292c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands // all ones >>a X -> all ones 1293c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (match(Op0, m_AllOnes())) 1294c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Op0; 1295c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1296c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands // undef >>a X -> all ones 1297f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op0, m_Undef())) 1298c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Constant::getAllOnesValue(Op0->getType()); 1299c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 130081a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner // (X << A) >> A -> X 130181a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Value *X; 130281a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) && 130381a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<OverflowingBinaryOperator>(Op0)->hasNoSignedWrap()) 130481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner return X; 130552fb846578714d14bbde9b28884a6a8729217677Duncan Sands 1306c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return 0; 1307c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 1308c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 130981a0dc911586c77421c2255aa417dc9b350b9e20Chris LattnerValue *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact, 1310618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetData *TD, 1311618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 1312618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const DominatorTree *DT) { 13130aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyAShrInst(Op0, Op1, isExact, Query (TD, TLI, DT), 13140aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands RecursionLimit); 1315c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 1316c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 13178aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner/// SimplifyAndInst - Given operands for an And, see if we can 13188aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner/// fold the result. If not, this returns null. 13190aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyAndInst(Value *Op0, Value *Op1, const Query &Q, 1320618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier unsigned MaxRecurse) { 13218aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 13228aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 13238aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner Constant *Ops[] = { CLHS, CRHS }; 1324d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return ConstantFoldInstOperands(Instruction::And, CLHS->getType(), 13250aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Ops, Q.TD, Q.TLI); 1326d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 132712a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1328d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // Canonicalize the constant to the RHS. 1329d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner std::swap(Op0, Op1); 1330d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 133112a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1332d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // X & undef -> 0 1333f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 1334d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Constant::getNullValue(Op0->getType()); 133512a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1336d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // X & X = X 1337124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Op0 == Op1) 1338d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 133912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 13402b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // X & 0 = 0 13412b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_Zero())) 1342d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op1; 134312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 13442b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // X & -1 = X 13452b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_AllOnes())) 13462b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Op0; 134712a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1348d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // A & ~A = ~A & A = 0 134981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner if (match(Op0, m_Not(m_Specific(Op1))) || 135081a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner match(Op1, m_Not(m_Specific(Op0)))) 1351d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Constant::getNullValue(Op0->getType()); 135212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1353d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // (A | ?) & A = A 135481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Value *A = 0, *B = 0; 1355d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (match(Op0, m_Or(m_Value(A), m_Value(B))) && 1356124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (A == Op1 || B == Op1)) 1357d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op1; 135812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1359d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // A & (A | ?) = A 1360d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (match(Op1, m_Or(m_Value(A), m_Value(B))) && 1361124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (A == Op0 || B == Op0)) 1362d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 136312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1364dd3149d57977d0632cfaf24290dd93416fb2a0efDuncan Sands // A & (-A) = A if A is a power of two or zero. 1365dd3149d57977d0632cfaf24290dd93416fb2a0efDuncan Sands if (match(Op0, m_Neg(m_Specific(Op1))) || 1366dd3149d57977d0632cfaf24290dd93416fb2a0efDuncan Sands match(Op1, m_Neg(m_Specific(Op0)))) { 13670aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (isPowerOfTwo(Op0, Q.TD, /*OrZero*/true)) 1368dd3149d57977d0632cfaf24290dd93416fb2a0efDuncan Sands return Op0; 13690aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (isPowerOfTwo(Op1, Q.TD, /*OrZero*/true)) 1370dd3149d57977d0632cfaf24290dd93416fb2a0efDuncan Sands return Op1; 1371dd3149d57977d0632cfaf24290dd93416fb2a0efDuncan Sands } 1372dd3149d57977d0632cfaf24290dd93416fb2a0efDuncan Sands 1373566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Try some generic simplifications for associative operations. 13740aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::And, Op0, Op1, Q, 13750aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands MaxRecurse)) 1376566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 13776844c8ea5a67e551be7106d6b7b9e1a64eecbe51Benjamin Kramer 13783421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // And distributes over Or. Try some generic simplifications based on this. 13793421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Or, 13800aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse)) 13813421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 13823421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 13833421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // And distributes over Xor. Try some generic simplifications based on this. 13843421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Xor, 13850aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse)) 13863421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 13873421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 13883421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Or distributes over And. Try some generic simplifications based on this. 13893421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::And, Op0, Op1, Instruction::Or, 13900aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse)) 13913421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 13923421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1393b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If the operation is with the result of a select instruction, check whether 1394b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // operating on either branch of the select always yields the same value. 13950312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 13960aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverSelect(Instruction::And, Op0, Op1, Q, 13970aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands MaxRecurse)) 1398a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 1399a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1400a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation is with the result of a phi instruction, check whether 1401a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // operating on all incoming values of the phi always yields the same value. 14020312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 14030aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverPHI(Instruction::And, Op0, Op1, Q, 14040312a93693abc2eb682b2b101c889959888fd883Duncan Sands MaxRecurse)) 1405b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return V; 1406b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 1407d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return 0; 1408d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner} 14099f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 14101845009290e4d804ad377927bd8a08cca3036adcDuncan SandsValue *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const TargetData *TD, 1411618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 14121845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT) { 14130aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyAndInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); 1414a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 1415a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1416d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner/// SimplifyOrInst - Given operands for an Or, see if we can 14179f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner/// fold the result. If not, this returns null. 14180aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyOrInst(Value *Op0, Value *Op1, const Query &Q, 14190aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands unsigned MaxRecurse) { 1420d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 1421d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 1422d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Constant *Ops[] = { CLHS, CRHS }; 1423d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return ConstantFoldInstOperands(Instruction::Or, CLHS->getType(), 14240aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Ops, Q.TD, Q.TLI); 1425d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 142612a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1427d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // Canonicalize the constant to the RHS. 1428d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner std::swap(Op0, Op1); 1429d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 143012a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1431d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // X | undef -> -1 1432f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 1433d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Constant::getAllOnesValue(Op0->getType()); 143412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1435d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // X | X = X 1436124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Op0 == Op1) 1437d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 1438d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner 14392b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // X | 0 = X 14402b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_Zero())) 1441d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 144212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 14432b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // X | -1 = -1 14442b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_AllOnes())) 14452b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Op1; 144612a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1447d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // A | ~A = ~A | A = -1 144881a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner if (match(Op0, m_Not(m_Specific(Op1))) || 144981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner match(Op1, m_Not(m_Specific(Op0)))) 1450d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Constant::getAllOnesValue(Op0->getType()); 145112a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1452d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // (A & ?) | A = A 145381a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Value *A = 0, *B = 0; 1454d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (match(Op0, m_And(m_Value(A), m_Value(B))) && 1455124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (A == Op1 || B == Op1)) 1456d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op1; 145712a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1458d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // A | (A & ?) = A 1459d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (match(Op1, m_And(m_Value(A), m_Value(B))) && 1460124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (A == Op0 || B == Op0)) 1461d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 146212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 146338f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer // ~(A & ?) | A = -1 146438f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer if (match(Op0, m_Not(m_And(m_Value(A), m_Value(B)))) && 146538f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer (A == Op1 || B == Op1)) 146638f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer return Constant::getAllOnesValue(Op1->getType()); 146738f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer 146838f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer // A | ~(A & ?) = -1 146938f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer if (match(Op1, m_Not(m_And(m_Value(A), m_Value(B)))) && 147038f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer (A == Op0 || B == Op0)) 147138f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer return Constant::getAllOnesValue(Op0->getType()); 147238f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer 1473566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Try some generic simplifications for associative operations. 14740aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::Or, Op0, Op1, Q, 14750aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands MaxRecurse)) 1476566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 14776844c8ea5a67e551be7106d6b7b9e1a64eecbe51Benjamin Kramer 14783421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Or distributes over And. Try some generic simplifications based on this. 14790aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ExpandBinOp(Instruction::Or, Op0, Op1, Instruction::And, Q, 14800aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands MaxRecurse)) 14813421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 14823421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 14833421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // And distributes over Or. Try some generic simplifications based on this. 14843421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::Or, Op0, Op1, Instruction::And, 14850aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse)) 14863421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 14873421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1488b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If the operation is with the result of a select instruction, check whether 1489b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // operating on either branch of the select always yields the same value. 14900312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 14910aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverSelect(Instruction::Or, Op0, Op1, Q, 14920312a93693abc2eb682b2b101c889959888fd883Duncan Sands MaxRecurse)) 1493a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 1494a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1495a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation is with the result of a phi instruction, check whether 1496a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // operating on all incoming values of the phi always yields the same value. 14970312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 14980aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverPHI(Instruction::Or, Op0, Op1, Q, MaxRecurse)) 1499b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return V; 1500b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 15019f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner return 0; 15029f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner} 15039f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 15041845009290e4d804ad377927bd8a08cca3036adcDuncan SandsValue *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const TargetData *TD, 1505618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 15061845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT) { 15070aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyOrInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); 1508a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 1509d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner 15102b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands/// SimplifyXorInst - Given operands for a Xor, see if we can 15112b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands/// fold the result. If not, this returns null. 15120aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyXorInst(Value *Op0, Value *Op1, const Query &Q, 15130aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands unsigned MaxRecurse) { 15142b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 15152b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 15162b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands Constant *Ops[] = { CLHS, CRHS }; 15172b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return ConstantFoldInstOperands(Instruction::Xor, CLHS->getType(), 15180aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Ops, Q.TD, Q.TLI); 15192b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands } 15202b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 15212b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // Canonicalize the constant to the RHS. 15222b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands std::swap(Op0, Op1); 15232b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands } 15242b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 15252b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // A ^ undef -> undef 1526f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 1527f8b1a5ea9602bb65a5cf59d3d34f2851a08cdc3eDuncan Sands return Op1; 15282b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 15292b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // A ^ 0 = A 15302b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_Zero())) 15312b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Op0; 15322b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 1533f23d4adbfaf870d5fa67c6bff0da7891d3a98f9dEli Friedman // A ^ A = 0 1534f23d4adbfaf870d5fa67c6bff0da7891d3a98f9dEli Friedman if (Op0 == Op1) 1535f23d4adbfaf870d5fa67c6bff0da7891d3a98f9dEli Friedman return Constant::getNullValue(Op0->getType()); 1536f23d4adbfaf870d5fa67c6bff0da7891d3a98f9dEli Friedman 15372b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // A ^ ~A = ~A ^ A = -1 153881a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner if (match(Op0, m_Not(m_Specific(Op1))) || 153981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner match(Op1, m_Not(m_Specific(Op0)))) 15402b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Constant::getAllOnesValue(Op0->getType()); 15412b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 1542566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Try some generic simplifications for associative operations. 15430aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::Xor, Op0, Op1, Q, 15440aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands MaxRecurse)) 1545566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 15462b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 15473421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // And distributes over Xor. Try some generic simplifications based on this. 15483421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::Xor, Op0, Op1, Instruction::And, 15490aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse)) 15503421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 15513421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 155287689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // Threading Xor over selects and phi nodes is pointless, so don't bother. 155387689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // Threading over the select in "A ^ select(cond, B, C)" means evaluating 155487689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // "A^B" and "A^C" and seeing if they are equal; but they are equal if and 155587689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // only if B and C are equal. If B and C are equal then (since we assume 155687689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // that operands have already been simplified) "select(cond, B, C)" should 155787689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // have been simplified to the common value of B and C already. Analysing 155887689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // "A^B" and "A^C" thus gains nothing, but costs compile time. Similarly 155987689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // for threading over phi nodes. 15602b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 15612b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return 0; 15622b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands} 15632b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 15642b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan SandsValue *llvm::SimplifyXorInst(Value *Op0, Value *Op1, const TargetData *TD, 1565618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 15662b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands const DominatorTree *DT) { 15670aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyXorInst(Op0, Op1, Query (TD, TLI, DT), RecursionLimit); 15682b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands} 15692b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 1570db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattnerstatic Type *GetCompareTy(Value *Op) { 1571210c5d4880b525e064088b6fec713260128c16ebChris Lattner return CmpInst::makeCmpResultType(Op->getType()); 1572210c5d4880b525e064088b6fec713260128c16ebChris Lattner} 1573210c5d4880b525e064088b6fec713260128c16ebChris Lattner 1574e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands/// ExtractEquivalentCondition - Rummage around inside V looking for something 1575e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands/// equivalent to the comparison "LHS Pred RHS". Return such a value if found, 1576e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands/// otherwise return null. Helper function for analyzing max/min idioms. 1577e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sandsstatic Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred, 1578e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands Value *LHS, Value *RHS) { 1579e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands SelectInst *SI = dyn_cast<SelectInst>(V); 1580e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (!SI) 1581e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return 0; 1582e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands CmpInst *Cmp = dyn_cast<CmpInst>(SI->getCondition()); 1583e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (!Cmp) 1584e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return 0; 1585e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands Value *CmpLHS = Cmp->getOperand(0), *CmpRHS = Cmp->getOperand(1); 1586e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Pred == Cmp->getPredicate() && LHS == CmpLHS && RHS == CmpRHS) 1587e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return Cmp; 1588e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Pred == CmpInst::getSwappedPredicate(Cmp->getPredicate()) && 1589e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands LHS == CmpRHS && RHS == CmpLHS) 1590e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return Cmp; 1591e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return 0; 1592e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands} 1593e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands 159458725a66c02865686c70132e8b9bd231eb66da63Chandler Carruthstatic Constant *computePointerICmp(const TargetData &TD, 159558725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth CmpInst::Predicate Pred, 159658725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth Value *LHS, Value *RHS) { 159758725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth // We can only fold certain predicates on pointer comparisons. 159858725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth switch (Pred) { 159958725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth default: 160058725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth return 0; 160158725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth 160258725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth // Equality comaprisons are easy to fold. 160358725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth case CmpInst::ICMP_EQ: 160458725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth case CmpInst::ICMP_NE: 160558725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth break; 160658725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth 160758725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth // We can only handle unsigned relational comparisons because 'inbounds' on 160858725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth // a GEP only protects against unsigned wrapping. 160958725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth case CmpInst::ICMP_UGT: 161058725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth case CmpInst::ICMP_UGE: 161158725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth case CmpInst::ICMP_ULT: 161258725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth case CmpInst::ICMP_ULE: 161358725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth // However, we have to switch them to their signed variants to handle 161458725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth // negative indices from the base pointer. 161558725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth Pred = ICmpInst::getSignedPredicate(Pred); 161658725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth break; 161758725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth } 161858725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth 161958725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth Constant *LHSOffset = stripAndComputeConstantOffsets(TD, LHS); 162058725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth if (!LHSOffset) 162158725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth return 0; 162258725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth Constant *RHSOffset = stripAndComputeConstantOffsets(TD, RHS); 162358725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth if (!RHSOffset) 162458725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth return 0; 162558725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth 162658725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth // If LHS and RHS are not related via constant offsets to the same base 162758725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth // value, there is nothing we can do here. 162858725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth if (LHS != RHS) 162958725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth return 0; 163058725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth 163158725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth return ConstantExpr::getICmp(Pred, LHSOffset, RHSOffset); 163258725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth} 1633009e2650d69fe93bda1864340c5f000e56c52fb8Chris Lattner 16349dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// SimplifyICmpInst - Given operands for an ICmpInst, see if we can 16359dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// fold the result. If not, this returns null. 1636a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, 16370aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 16389f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate; 16399dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner assert(CmpInst::isIntPredicate(Pred) && "Not an integer compare!"); 164012a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1641d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(LHS)) { 16428f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(RHS)) 16430aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.TD, Q.TLI); 1644d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner 1645d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // If we have a constant, make sure it is on the RHS. 1646d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner std::swap(LHS, RHS); 1647d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Pred = CmpInst::getSwappedPredicate(Pred); 1648d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 164912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1650db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *ITy = GetCompareTy(LHS); // The return type. 1651db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *OpTy = LHS->getType(); // The operand type. 165212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1653210c5d4880b525e064088b6fec713260128c16ebChris Lattner // icmp X, X -> true/false 1654c8e14b3d37b80abb6adb4b831af0452d9ecbf2b2Chris Lattner // X icmp undef -> true/false. For example, icmp ugt %X, undef -> false 1655c8e14b3d37b80abb6adb4b831af0452d9ecbf2b2Chris Lattner // because X could be 0. 1656124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (LHS == RHS || isa<UndefValue>(RHS)) 1657210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred)); 165812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 16596dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // Special case logic when the operands have i1 type. 166066d004ef708642bbdc38fd761507f2e9ee3970cdNick Lewycky if (OpTy->getScalarType()->isIntegerTy(1)) { 16616dc91253ab1872e118b08511a09d5c934988354eDuncan Sands switch (Pred) { 16626dc91253ab1872e118b08511a09d5c934988354eDuncan Sands default: break; 16636dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_EQ: 16646dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X == 1 -> X 16656dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_One())) 16666dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 16676dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 16686dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_NE: 16696dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X != 0 -> X 16706dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_Zero())) 16716dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 16726dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 16736dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_UGT: 16746dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X >u 0 -> X 16756dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_Zero())) 16766dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 16776dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 16786dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_UGE: 16796dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X >=u 1 -> X 16806dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_One())) 16816dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 16826dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 16836dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_SLT: 16846dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X <s 0 -> X 16856dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_Zero())) 16866dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 16876dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 16886dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_SLE: 16896dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X <=s -1 -> X 16906dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_One())) 16916dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 16926dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 16936dc91253ab1872e118b08511a09d5c934988354eDuncan Sands } 16946dc91253ab1872e118b08511a09d5c934988354eDuncan Sands } 169512a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1696f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // icmp <object*>, <object*/null> - Different identified objects have 1697f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // different addresses (unless null), and what's more the address of an 1698f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // identified local is never equal to another argument (again, barring null). 1699f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // Note that generalizing to the case where LHS is a global variable address 1700f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // or null is pointless, since if both LHS and RHS are constants then we 1701f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // already constant folded the compare, and if only one of them is then we 1702f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // moved it to RHS already. 1703ea79b8e03ca7c7be72832c11e9d4d78f11b728b3Benjamin Kramer Value *LHSPtr = LHS->stripPointerCasts(); 1704ea79b8e03ca7c7be72832c11e9d4d78f11b728b3Benjamin Kramer Value *RHSPtr = RHS->stripPointerCasts(); 17052c3acb0e273a50a9b4eeaf9d5544f6168bda85a6Eli Friedman if (LHSPtr == RHSPtr) 17062c3acb0e273a50a9b4eeaf9d5544f6168bda85a6Eli Friedman return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred)); 1707f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky 1708b053fc1c92b6b81c47d5e2c092b0f3ea04fd5b87Chris Lattner // Be more aggressive about stripping pointer adjustments when checking a 1709b053fc1c92b6b81c47d5e2c092b0f3ea04fd5b87Chris Lattner // comparison of an alloca address to another object. We can rip off all 1710b053fc1c92b6b81c47d5e2c092b0f3ea04fd5b87Chris Lattner // inbounds GEP operations, even if they are variable. 171184dfc32ff906271c373819595e60a173624e1184Chandler Carruth LHSPtr = LHSPtr->stripInBoundsOffsets(); 1712f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky if (llvm::isIdentifiedObject(LHSPtr)) { 171384dfc32ff906271c373819595e60a173624e1184Chandler Carruth RHSPtr = RHSPtr->stripInBoundsOffsets(); 1714f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky if (llvm::isKnownNonNull(LHSPtr) || llvm::isKnownNonNull(RHSPtr)) { 1715f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // If both sides are different identified objects, they aren't equal 1716f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // unless they're null. 1717c17731d65d2c059a71256ee995cbb057ff28a109Bill Wendling if (LHSPtr != RHSPtr && llvm::isIdentifiedObject(RHSPtr) && 1718798d013bcba198af628d2dab8448f709b96e4a75Bill Wendling Pred == CmpInst::ICMP_EQ) 1719c17731d65d2c059a71256ee995cbb057ff28a109Bill Wendling return ConstantInt::get(ITy, false); 1720f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky 1721f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // A local identified object (alloca or noalias call) can't equal any 1722961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth // incoming argument, unless they're both null or they belong to 1723961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth // different functions. The latter happens during inlining. 1724961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth if (Instruction *LHSInst = dyn_cast<Instruction>(LHSPtr)) 1725961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth if (Argument *RHSArg = dyn_cast<Argument>(RHSPtr)) 1726961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth if (LHSInst->getParent()->getParent() == RHSArg->getParent() && 1727961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth Pred == CmpInst::ICMP_EQ) 1728961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth return ConstantInt::get(ITy, false); 1729f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky } 1730f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky 1731f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // Assume that the constant null is on the right. 1732c17731d65d2c059a71256ee995cbb057ff28a109Bill Wendling if (llvm::isKnownNonNull(LHSPtr) && isa<ConstantPointerNull>(RHSPtr)) { 1733798d013bcba198af628d2dab8448f709b96e4a75Bill Wendling if (Pred == CmpInst::ICMP_EQ) 1734c17731d65d2c059a71256ee995cbb057ff28a109Bill Wendling return ConstantInt::get(ITy, false); 1735798d013bcba198af628d2dab8448f709b96e4a75Bill Wendling else if (Pred == CmpInst::ICMP_NE) 1736c17731d65d2c059a71256ee995cbb057ff28a109Bill Wendling return ConstantInt::get(ITy, true); 1737c17731d65d2c059a71256ee995cbb057ff28a109Bill Wendling } 1738961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth } else if (Argument *LHSArg = dyn_cast<Argument>(LHSPtr)) { 173984dfc32ff906271c373819595e60a173624e1184Chandler Carruth RHSPtr = RHSPtr->stripInBoundsOffsets(); 1740961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth // An alloca can't be equal to an argument unless they come from separate 1741961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth // functions via inlining. 1742961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth if (AllocaInst *RHSInst = dyn_cast<AllocaInst>(RHSPtr)) { 1743961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth if (LHSArg->getParent() == RHSInst->getParent()->getParent()) { 1744961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth if (Pred == CmpInst::ICMP_EQ) 1745961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth return ConstantInt::get(ITy, false); 1746961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth else if (Pred == CmpInst::ICMP_NE) 1747961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth return ConstantInt::get(ITy, true); 1748961e1acfb275613679c0d00d4a0b4ed394b51a9dChandler Carruth } 1749c17731d65d2c059a71256ee995cbb057ff28a109Bill Wendling } 1750b053fc1c92b6b81c47d5e2c092b0f3ea04fd5b87Chris Lattner } 1751d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands 1752d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // If we are comparing with zero then try hard since this is a common case. 1753d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (match(RHS, m_Zero())) { 1754d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands bool LHSKnownNonNegative, LHSKnownNegative; 1755d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands switch (Pred) { 1756858143816d43e58b17bfd11cb1b57afbd7f0f893Craig Topper default: llvm_unreachable("Unknown ICmp predicate!"); 1757d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_ULT: 1758f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 1759d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_UGE: 1760f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 1761d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_EQ: 1762d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_ULE: 17630aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (isKnownNonZero(LHS, Q.TD)) 1764f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 1765d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1766d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_NE: 1767d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_UGT: 17680aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (isKnownNonZero(LHS, Q.TD)) 1769f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 1770d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1771d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_SLT: 17720aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD); 1773d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNegative) 1774f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 1775d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNonNegative) 1776f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 1777d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1778d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_SLE: 17790aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD); 1780d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNegative) 1781f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 17820aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.TD)) 1783f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 1784d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1785d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_SGE: 17860aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD); 1787d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNegative) 1788f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 1789d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNonNegative) 1790f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 1791d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1792d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_SGT: 17930aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, Q.TD); 1794d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNegative) 1795f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 17960aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (LHSKnownNonNegative && isKnownNonZero(LHS, Q.TD)) 1797f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 1798d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1799d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands } 1800d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands } 1801d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands 1802d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // See if we are doing a comparison with a constant integer. 1803210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) { 18043a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // Rule out tautological comparisons (eg., ult 0 or uge 0). 18053a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky ConstantRange RHS_CR = ICmpInst::makeConstantRange(Pred, CI->getValue()); 18063a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (RHS_CR.isEmptySet()) 18073a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky return ConstantInt::getFalse(CI->getContext()); 18083a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (RHS_CR.isFullSet()) 18093a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky return ConstantInt::getTrue(CI->getContext()); 18103a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky 18113a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // Many binary operators with constant RHS have easy to compute constant 18123a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // range. Use them to check whether the comparison is a tautology. 18133a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky uint32_t Width = CI->getBitWidth(); 18143a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt Lower = APInt(Width, 0); 18153a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt Upper = APInt(Width, 0); 18163a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky ConstantInt *CI2; 18173a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (match(LHS, m_URem(m_Value(), m_ConstantInt(CI2)))) { 18183a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'urem x, CI2' produces [0, CI2). 18193a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = CI2->getValue(); 18203a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_SRem(m_Value(), m_ConstantInt(CI2)))) { 18213a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'srem x, CI2' produces (-|CI2|, |CI2|). 18223a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = CI2->getValue().abs(); 18233a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Lower = (-Upper) + 1; 1824c65c747bc4ee7d3ca8463d33708bbb2aed38a809Duncan Sands } else if (match(LHS, m_UDiv(m_ConstantInt(CI2), m_Value()))) { 1825c65c747bc4ee7d3ca8463d33708bbb2aed38a809Duncan Sands // 'udiv CI2, x' produces [0, CI2]. 18267781ae5be570940178295f6f808215089a3fe411Eli Friedman Upper = CI2->getValue() + 1; 18273a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_UDiv(m_Value(), m_ConstantInt(CI2)))) { 18283a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'udiv x, CI2' produces [0, UINT_MAX / CI2]. 18293a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt NegOne = APInt::getAllOnesValue(Width); 18303a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (!CI2->isZero()) 18313a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = NegOne.udiv(CI2->getValue()) + 1; 18323a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_SDiv(m_Value(), m_ConstantInt(CI2)))) { 18333a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'sdiv x, CI2' produces [INT_MIN / CI2, INT_MAX / CI2]. 18343a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt IntMin = APInt::getSignedMinValue(Width); 18353a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt IntMax = APInt::getSignedMaxValue(Width); 18363a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt Val = CI2->getValue().abs(); 18373a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (!Val.isMinValue()) { 18383a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Lower = IntMin.sdiv(Val); 18393a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = IntMax.sdiv(Val) + 1; 18403a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } 18413a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_LShr(m_Value(), m_ConstantInt(CI2)))) { 18423a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'lshr x, CI2' produces [0, UINT_MAX >> CI2]. 18433a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt NegOne = APInt::getAllOnesValue(Width); 18443a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (CI2->getValue().ult(Width)) 18453a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = NegOne.lshr(CI2->getValue()) + 1; 18463a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_AShr(m_Value(), m_ConstantInt(CI2)))) { 18473a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'ashr x, CI2' produces [INT_MIN >> CI2, INT_MAX >> CI2]. 18483a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt IntMin = APInt::getSignedMinValue(Width); 18493a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt IntMax = APInt::getSignedMaxValue(Width); 18503a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (CI2->getValue().ult(Width)) { 18513a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Lower = IntMin.ashr(CI2->getValue()); 18523a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = IntMax.ashr(CI2->getValue()) + 1; 18533a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } 18543a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_Or(m_Value(), m_ConstantInt(CI2)))) { 18553a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'or x, CI2' produces [CI2, UINT_MAX]. 18563a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Lower = CI2->getValue(); 18573a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_And(m_Value(), m_ConstantInt(CI2)))) { 18583a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'and x, CI2' produces [0, CI2]. 18593a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = CI2->getValue() + 1; 18603a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } 18613a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (Lower != Upper) { 18623a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky ConstantRange LHS_CR = ConstantRange(Lower, Upper); 18633a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (RHS_CR.contains(LHS_CR)) 18643a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky return ConstantInt::getTrue(RHS->getContext()); 18653a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (RHS_CR.inverse().contains(LHS_CR)) 18663a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky return ConstantInt::getFalse(RHS->getContext()); 1867210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 1868210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 18691ac7c9979a2d723ff4649ffad58df02732872a5fDuncan Sands 18709d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compare of cast, for example (zext X) != 0 -> X != 0 18719d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (isa<CastInst>(LHS) && (isa<Constant>(RHS) || isa<CastInst>(RHS))) { 18729d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Instruction *LI = cast<CastInst>(LHS); 18739d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Value *SrcOp = LI->getOperand(0); 1874db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *SrcTy = SrcOp->getType(); 1875db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *DstTy = LI->getType(); 18769d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 18779d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input 18789d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // if the integer type is the same size as the pointer type. 18790aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (MaxRecurse && Q.TD && isa<PtrToIntInst>(LI) && 18800aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q.TD->getPointerSizeInBits() == DstTy->getPrimitiveSizeInBits()) { 18819d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Constant *RHSC = dyn_cast<Constant>(RHS)) { 18829d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Transfer the cast to the constant. 18839d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(Pred, SrcOp, 18849d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantExpr::getIntToPtr(RHSC, SrcTy), 18850aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse-1)) 18869d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 18879d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } else if (PtrToIntInst *RI = dyn_cast<PtrToIntInst>(RHS)) { 18889d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RI->getOperand(0)->getType() == SrcTy) 18899d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compare without the cast. 18909d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0), 18910aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse-1)) 18929d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 18939d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 18949d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 18959d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 18969d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (isa<ZExtInst>(LHS)) { 18979d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (zext X), (zext Y) into a compare of X and Y if they have the 18989d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // same type. 18999d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (ZExtInst *RI = dyn_cast<ZExtInst>(RHS)) { 19009d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse && SrcTy == RI->getOperand(0)->getType()) 19019d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compare X and Y. Note that signed predicates become unsigned. 19029d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred), 19030aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands SrcOp, RI->getOperand(0), Q, 19049d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands MaxRecurse-1)) 19059d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 19069d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 19079d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (zext X), Cst into a compare of X and Cst if Cst is extended 19089d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // too. If not, then try to deduce the result of the comparison. 19099d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) { 19109d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compute the constant that would happen if we truncated to SrcTy then 19119d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // reextended to DstTy. 19129d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy); 19139d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant *RExt = ConstantExpr::getCast(CastInst::ZExt, Trunc, DstTy); 19149d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 19159d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // If the re-extended constant didn't change then this is effectively 19169d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // also a case of comparing two zero-extended values. 19179d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RExt == CI && MaxRecurse) 19189d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred), 19190aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands SrcOp, Trunc, Q, MaxRecurse-1)) 19209d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 19219d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 19229d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Otherwise the upper bits of LHS are zero while RHS has a non-zero bit 19239d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // there. Use this to work out the result of the comparison. 19249d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RExt != CI) { 19259d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands switch (Pred) { 1926858143816d43e58b17bfd11cb1b57afbd7f0f893Craig Topper default: llvm_unreachable("Unknown ICmp predicate!"); 19279d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // LHS <u RHS. 19289d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_EQ: 19299d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_UGT: 19309d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_UGE: 19319d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return ConstantInt::getFalse(CI->getContext()); 19329d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 19339d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_NE: 19349d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_ULT: 19359d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_ULE: 19369d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return ConstantInt::getTrue(CI->getContext()); 19379d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 19389d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // LHS is non-negative. If RHS is negative then LHS >s LHS. If RHS 19399d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // is non-negative then LHS <s RHS. 19409d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SGT: 19419d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SGE: 19429d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return CI->getValue().isNegative() ? 19439d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getTrue(CI->getContext()) : 19449d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getFalse(CI->getContext()); 19459d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 19469d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SLT: 19479d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SLE: 19489d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return CI->getValue().isNegative() ? 19499d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getFalse(CI->getContext()) : 19509d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getTrue(CI->getContext()); 19519d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 19529d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 19539d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 19549d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 19559d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 19569d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (isa<SExtInst>(LHS)) { 19579d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (sext X), (sext Y) into a compare of X and Y if they have the 19589d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // same type. 19599d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (SExtInst *RI = dyn_cast<SExtInst>(RHS)) { 19609d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse && SrcTy == RI->getOperand(0)->getType()) 19619d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compare X and Y. Note that the predicate does not change. 19629d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0), 19630aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse-1)) 19649d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 19659d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 19669d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (sext X), Cst into a compare of X and Cst if Cst is extended 19679d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // too. If not, then try to deduce the result of the comparison. 19689d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) { 19699d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compute the constant that would happen if we truncated to SrcTy then 19709d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // reextended to DstTy. 19719d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy); 19729d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant *RExt = ConstantExpr::getCast(CastInst::SExt, Trunc, DstTy); 19739d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 19749d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // If the re-extended constant didn't change then this is effectively 19759d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // also a case of comparing two sign-extended values. 19769d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RExt == CI && MaxRecurse) 19770aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyICmpInst(Pred, SrcOp, Trunc, Q, MaxRecurse-1)) 19789d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 19799d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 19809d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Otherwise the upper bits of LHS are all equal, while RHS has varying 19819d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // bits there. Use this to work out the result of the comparison. 19829d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RExt != CI) { 19839d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands switch (Pred) { 1984858143816d43e58b17bfd11cb1b57afbd7f0f893Craig Topper default: llvm_unreachable("Unknown ICmp predicate!"); 19859d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_EQ: 19869d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return ConstantInt::getFalse(CI->getContext()); 19879d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_NE: 19889d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return ConstantInt::getTrue(CI->getContext()); 19899d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 19909d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // If RHS is non-negative then LHS <s RHS. If RHS is negative then 19919d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // LHS >s RHS. 19929d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SGT: 19939d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SGE: 19949d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return CI->getValue().isNegative() ? 19959d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getTrue(CI->getContext()) : 19969d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getFalse(CI->getContext()); 19979d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SLT: 19989d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SLE: 19999d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return CI->getValue().isNegative() ? 20009d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getFalse(CI->getContext()) : 20019d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getTrue(CI->getContext()); 20029d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 20039d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // If LHS is non-negative then LHS <u RHS. If LHS is negative then 20049d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // LHS >u RHS. 20059d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_UGT: 20069d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_UGE: 20079d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Comparison is true iff the LHS <s 0. 20089d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse) 20099d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SLT, SrcOp, 20109d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant::getNullValue(SrcTy), 20110aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse-1)) 20129d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 20139d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands break; 20149d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_ULT: 20159d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_ULE: 20169d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Comparison is true iff the LHS >=s 0. 20179d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse) 20189d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SGE, SrcOp, 20199d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant::getNullValue(SrcTy), 20200aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse-1)) 20219d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 20229d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands break; 20239d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 20249d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 20259d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 20269d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 20279d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 20289d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 202952fb846578714d14bbde9b28884a6a8729217677Duncan Sands // Special logic for binary operators. 203052fb846578714d14bbde9b28884a6a8729217677Duncan Sands BinaryOperator *LBO = dyn_cast<BinaryOperator>(LHS); 203152fb846578714d14bbde9b28884a6a8729217677Duncan Sands BinaryOperator *RBO = dyn_cast<BinaryOperator>(RHS); 203252fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (MaxRecurse && (LBO || RBO)) { 203352fb846578714d14bbde9b28884a6a8729217677Duncan Sands // Analyze the case when either LHS or RHS is an add instruction. 203452fb846578714d14bbde9b28884a6a8729217677Duncan Sands Value *A = 0, *B = 0, *C = 0, *D = 0; 203552fb846578714d14bbde9b28884a6a8729217677Duncan Sands // LHS = A + B (or A and B are null); RHS = C + D (or C and D are null). 203652fb846578714d14bbde9b28884a6a8729217677Duncan Sands bool NoLHSWrapProblem = false, NoRHSWrapProblem = false; 203752fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (LBO && LBO->getOpcode() == Instruction::Add) { 203852fb846578714d14bbde9b28884a6a8729217677Duncan Sands A = LBO->getOperand(0); B = LBO->getOperand(1); 203952fb846578714d14bbde9b28884a6a8729217677Duncan Sands NoLHSWrapProblem = ICmpInst::isEquality(Pred) || 204052fb846578714d14bbde9b28884a6a8729217677Duncan Sands (CmpInst::isUnsigned(Pred) && LBO->hasNoUnsignedWrap()) || 204152fb846578714d14bbde9b28884a6a8729217677Duncan Sands (CmpInst::isSigned(Pred) && LBO->hasNoSignedWrap()); 204252fb846578714d14bbde9b28884a6a8729217677Duncan Sands } 204352fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (RBO && RBO->getOpcode() == Instruction::Add) { 204452fb846578714d14bbde9b28884a6a8729217677Duncan Sands C = RBO->getOperand(0); D = RBO->getOperand(1); 204552fb846578714d14bbde9b28884a6a8729217677Duncan Sands NoRHSWrapProblem = ICmpInst::isEquality(Pred) || 204652fb846578714d14bbde9b28884a6a8729217677Duncan Sands (CmpInst::isUnsigned(Pred) && RBO->hasNoUnsignedWrap()) || 204752fb846578714d14bbde9b28884a6a8729217677Duncan Sands (CmpInst::isSigned(Pred) && RBO->hasNoSignedWrap()); 204852fb846578714d14bbde9b28884a6a8729217677Duncan Sands } 204952fb846578714d14bbde9b28884a6a8729217677Duncan Sands 205052fb846578714d14bbde9b28884a6a8729217677Duncan Sands // icmp (X+Y), X -> icmp Y, 0 for equalities or if there is no overflow. 205152fb846578714d14bbde9b28884a6a8729217677Duncan Sands if ((A == RHS || B == RHS) && NoLHSWrapProblem) 205252fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (Value *V = SimplifyICmpInst(Pred, A == RHS ? B : A, 205352fb846578714d14bbde9b28884a6a8729217677Duncan Sands Constant::getNullValue(RHS->getType()), 20540aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse-1)) 205552fb846578714d14bbde9b28884a6a8729217677Duncan Sands return V; 205652fb846578714d14bbde9b28884a6a8729217677Duncan Sands 205752fb846578714d14bbde9b28884a6a8729217677Duncan Sands // icmp X, (X+Y) -> icmp 0, Y for equalities or if there is no overflow. 205852fb846578714d14bbde9b28884a6a8729217677Duncan Sands if ((C == LHS || D == LHS) && NoRHSWrapProblem) 205952fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (Value *V = SimplifyICmpInst(Pred, 206052fb846578714d14bbde9b28884a6a8729217677Duncan Sands Constant::getNullValue(LHS->getType()), 20610aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands C == LHS ? D : C, Q, MaxRecurse-1)) 206252fb846578714d14bbde9b28884a6a8729217677Duncan Sands return V; 206352fb846578714d14bbde9b28884a6a8729217677Duncan Sands 206452fb846578714d14bbde9b28884a6a8729217677Duncan Sands // icmp (X+Y), (X+Z) -> icmp Y,Z for equalities or if there is no overflow. 206552fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (A && C && (A == C || A == D || B == C || B == D) && 206652fb846578714d14bbde9b28884a6a8729217677Duncan Sands NoLHSWrapProblem && NoRHSWrapProblem) { 206752fb846578714d14bbde9b28884a6a8729217677Duncan Sands // Determine Y and Z in the form icmp (X+Y), (X+Z). 206852fb846578714d14bbde9b28884a6a8729217677Duncan Sands Value *Y = (A == C || A == D) ? B : A; 206952fb846578714d14bbde9b28884a6a8729217677Duncan Sands Value *Z = (C == A || C == B) ? D : C; 20700aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyICmpInst(Pred, Y, Z, Q, MaxRecurse-1)) 207152fb846578714d14bbde9b28884a6a8729217677Duncan Sands return V; 207252fb846578714d14bbde9b28884a6a8729217677Duncan Sands } 207352fb846578714d14bbde9b28884a6a8729217677Duncan Sands } 207452fb846578714d14bbde9b28884a6a8729217677Duncan Sands 207584dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky if (LBO && match(LBO, m_URem(m_Value(), m_Specific(RHS)))) { 2076786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky bool KnownNonNegative, KnownNegative; 207788cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky switch (Pred) { 207888cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky default: 207988cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky break; 2080786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky case ICmpInst::ICMP_SGT: 2081786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky case ICmpInst::ICMP_SGE: 20820aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD); 2083786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky if (!KnownNonNegative) 2084786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky break; 2085786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky // fall-through 208688cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky case ICmpInst::ICMP_EQ: 208788cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky case ICmpInst::ICMP_UGT: 208888cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky case ICmpInst::ICMP_UGE: 2089f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 2090786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky case ICmpInst::ICMP_SLT: 2091786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky case ICmpInst::ICMP_SLE: 20920aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands ComputeSignBit(LHS, KnownNonNegative, KnownNegative, Q.TD); 2093786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky if (!KnownNonNegative) 2094786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky break; 2095786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky // fall-through 209688cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky case ICmpInst::ICMP_NE: 209788cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky case ICmpInst::ICMP_ULT: 209888cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky case ICmpInst::ICMP_ULE: 2099f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 210088cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky } 210188cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky } 210284dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky if (RBO && match(RBO, m_URem(m_Value(), m_Specific(LHS)))) { 210384dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky bool KnownNonNegative, KnownNegative; 210484dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky switch (Pred) { 210584dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky default: 210684dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky break; 210784dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_SGT: 210884dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_SGE: 21090aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD); 211084dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky if (!KnownNonNegative) 211184dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky break; 211284dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky // fall-through 2113a0e2f38b25ce7c51c22ed40d8a315fe1dd98926dNick Lewycky case ICmpInst::ICMP_NE: 211484dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_UGT: 211584dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_UGE: 2116f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 211784dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_SLT: 211884dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_SLE: 21190aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands ComputeSignBit(RHS, KnownNonNegative, KnownNegative, Q.TD); 212084dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky if (!KnownNonNegative) 212184dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky break; 212284dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky // fall-through 2123a0e2f38b25ce7c51c22ed40d8a315fe1dd98926dNick Lewycky case ICmpInst::ICMP_EQ: 212484dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_ULT: 212584dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_ULE: 2126f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 212784dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky } 212884dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky } 212988cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky 2130c65c747bc4ee7d3ca8463d33708bbb2aed38a809Duncan Sands // x udiv y <=u x. 2131c65c747bc4ee7d3ca8463d33708bbb2aed38a809Duncan Sands if (LBO && match(LBO, m_UDiv(m_Specific(RHS), m_Value()))) { 2132c65c747bc4ee7d3ca8463d33708bbb2aed38a809Duncan Sands // icmp pred (X /u Y), X 2133c65c747bc4ee7d3ca8463d33708bbb2aed38a809Duncan Sands if (Pred == ICmpInst::ICMP_UGT) 2134c65c747bc4ee7d3ca8463d33708bbb2aed38a809Duncan Sands return getFalse(ITy); 2135c65c747bc4ee7d3ca8463d33708bbb2aed38a809Duncan Sands if (Pred == ICmpInst::ICMP_ULE) 2136c65c747bc4ee7d3ca8463d33708bbb2aed38a809Duncan Sands return getTrue(ITy); 2137c65c747bc4ee7d3ca8463d33708bbb2aed38a809Duncan Sands } 2138c65c747bc4ee7d3ca8463d33708bbb2aed38a809Duncan Sands 213958bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky if (MaxRecurse && LBO && RBO && LBO->getOpcode() == RBO->getOpcode() && 214058bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky LBO->getOperand(1) == RBO->getOperand(1)) { 214158bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky switch (LBO->getOpcode()) { 214258bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky default: break; 214358bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky case Instruction::UDiv: 214458bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky case Instruction::LShr: 214558bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky if (ICmpInst::isSigned(Pred)) 214658bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky break; 214758bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky // fall-through 214858bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky case Instruction::SDiv: 214958bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky case Instruction::AShr: 2150b6e7cd655c6ee119dbeacc321ee92387f983edb0Eli Friedman if (!LBO->isExact() || !RBO->isExact()) 215158bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky break; 215258bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0), 21530aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands RBO->getOperand(0), Q, MaxRecurse-1)) 215458bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky return V; 215558bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky break; 215658bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky case Instruction::Shl: { 2157c9d904ee2ca36ab6238ed93c7ad2ea67b5fd0a23Duncan Sands bool NUW = LBO->hasNoUnsignedWrap() && RBO->hasNoUnsignedWrap(); 215858bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky bool NSW = LBO->hasNoSignedWrap() && RBO->hasNoSignedWrap(); 215958bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky if (!NUW && !NSW) 216058bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky break; 216158bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky if (!NSW && ICmpInst::isSigned(Pred)) 216258bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky break; 216358bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0), 21640aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands RBO->getOperand(0), Q, MaxRecurse-1)) 216558bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky return V; 216658bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky break; 216758bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky } 216858bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky } 216958bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky } 217058bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky 2171ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Simplify comparisons involving max/min. 2172ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands Value *A, *B; 2173ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands CmpInst::Predicate P = CmpInst::BAD_ICMP_PREDICATE; 2174ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands CmpInst::Predicate EqP; // Chosen so that "A == max/min(A,B)" iff "A EqP B". 2175ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands 21768140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Signed variants on "max(a,b)>=a -> true". 2177ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (match(LHS, m_SMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) { 2178ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != RHS) std::swap(A, B); // smax(A, B) pred A. 2179ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B". 2180ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as smax(A, B) pred A. 2181ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = Pred; 2182ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } else if (match(RHS, m_SMax(m_Value(A), m_Value(B))) && 2183ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands (A == LHS || B == LHS)) { 2184ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != LHS) std::swap(A, B); // A pred smax(A, B). 2185ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B". 2186ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as smax(A, B) swapped-pred A. 2187ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = CmpInst::getSwappedPredicate(Pred); 2188ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) && 2189ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands (A == RHS || B == RHS)) { 2190ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != RHS) std::swap(A, B); // smin(A, B) pred A. 2191ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B". 2192ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as smax(-A, -B) swapped-pred -A. 2193ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Note that we do not need to actually form -A or -B thanks to EqP. 2194ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = CmpInst::getSwappedPredicate(Pred); 2195ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } else if (match(RHS, m_SMin(m_Value(A), m_Value(B))) && 2196ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands (A == LHS || B == LHS)) { 2197ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != LHS) std::swap(A, B); // A pred smin(A, B). 2198ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B". 2199ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as smax(-A, -B) pred -A. 2200ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Note that we do not need to actually form -A or -B thanks to EqP. 2201ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = Pred; 2202ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } 2203ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (P != CmpInst::BAD_ICMP_PREDICATE) { 2204ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Cases correspond to "max(A, B) p A". 2205ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands switch (P) { 2206ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands default: 2207ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands break; 2208ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_EQ: 2209ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_SLE: 2210e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Equivalent to "A EqP B". This may be the same as the condition tested 2211e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // in the max/min; if so, we can just return that. 2212e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B)) 2213e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 2214e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B)) 2215e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 2216e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Otherwise, see if "A EqP B" simplifies. 2217ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (MaxRecurse) 22180aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1)) 2219ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands return V; 2220ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands break; 2221ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_NE: 2222e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands case CmpInst::ICMP_SGT: { 2223e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP); 2224e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Equivalent to "A InvEqP B". This may be the same as the condition 2225e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // tested in the max/min; if so, we can just return that. 2226e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B)) 2227e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 2228e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B)) 2229e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 2230e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Otherwise, see if "A InvEqP B" simplifies. 2231ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (MaxRecurse) 22320aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1)) 2233ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands return V; 2234ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands break; 2235e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands } 2236ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_SGE: 2237ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Always true. 2238f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 2239ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_SLT: 2240ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Always false. 2241f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 2242ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } 2243ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } 2244ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands 22458140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Unsigned variants on "max(a,b)>=a -> true". 2246ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = CmpInst::BAD_ICMP_PREDICATE; 2247ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (match(LHS, m_UMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) { 2248ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != RHS) std::swap(A, B); // umax(A, B) pred A. 2249ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B". 2250ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as umax(A, B) pred A. 2251ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = Pred; 2252ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } else if (match(RHS, m_UMax(m_Value(A), m_Value(B))) && 2253ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands (A == LHS || B == LHS)) { 2254ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != LHS) std::swap(A, B); // A pred umax(A, B). 2255ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B". 2256ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as umax(A, B) swapped-pred A. 2257ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = CmpInst::getSwappedPredicate(Pred); 2258ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) && 2259ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands (A == RHS || B == RHS)) { 2260ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != RHS) std::swap(A, B); // umin(A, B) pred A. 2261ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B". 2262ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as umax(-A, -B) swapped-pred -A. 2263ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Note that we do not need to actually form -A or -B thanks to EqP. 2264ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = CmpInst::getSwappedPredicate(Pred); 2265ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } else if (match(RHS, m_UMin(m_Value(A), m_Value(B))) && 2266ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands (A == LHS || B == LHS)) { 2267ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != LHS) std::swap(A, B); // A pred umin(A, B). 2268ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B". 2269ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as umax(-A, -B) pred -A. 2270ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Note that we do not need to actually form -A or -B thanks to EqP. 2271ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = Pred; 2272ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } 2273ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (P != CmpInst::BAD_ICMP_PREDICATE) { 2274ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Cases correspond to "max(A, B) p A". 2275ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands switch (P) { 2276ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands default: 2277ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands break; 2278ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_EQ: 2279ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_ULE: 2280e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Equivalent to "A EqP B". This may be the same as the condition tested 2281e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // in the max/min; if so, we can just return that. 2282e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B)) 2283e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 2284e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B)) 2285e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 2286e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Otherwise, see if "A EqP B" simplifies. 2287ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (MaxRecurse) 22880aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyICmpInst(EqP, A, B, Q, MaxRecurse-1)) 2289ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands return V; 2290ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands break; 2291ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_NE: 2292e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands case CmpInst::ICMP_UGT: { 2293e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP); 2294e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Equivalent to "A InvEqP B". This may be the same as the condition 2295e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // tested in the max/min; if so, we can just return that. 2296e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B)) 2297e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 2298e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B)) 2299e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 2300e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Otherwise, see if "A InvEqP B" simplifies. 2301ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (MaxRecurse) 23020aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyICmpInst(InvEqP, A, B, Q, MaxRecurse-1)) 2303ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands return V; 2304ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands break; 2305e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands } 2306ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_UGE: 2307ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Always true. 2308f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 2309ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_ULT: 2310ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Always false. 2311f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 2312ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } 2313ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } 2314ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands 23158140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Variants on "max(x,y) >= min(x,z)". 23168140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands Value *C, *D; 23178140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (match(LHS, m_SMax(m_Value(A), m_Value(B))) && 23188140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands match(RHS, m_SMin(m_Value(C), m_Value(D))) && 23198140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands (A == C || A == D || B == C || B == D)) { 23208140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // max(x, ?) pred min(x, ?). 23218140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_SGE) 23228140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always true. 2323f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 23248140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_SLT) 23258140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always false. 2326f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 23278140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) && 23288140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands match(RHS, m_SMax(m_Value(C), m_Value(D))) && 23298140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands (A == C || A == D || B == C || B == D)) { 23308140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // min(x, ?) pred max(x, ?). 23318140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_SLE) 23328140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always true. 2333f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 23348140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_SGT) 23358140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always false. 2336f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 23378140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands } else if (match(LHS, m_UMax(m_Value(A), m_Value(B))) && 23388140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands match(RHS, m_UMin(m_Value(C), m_Value(D))) && 23398140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands (A == C || A == D || B == C || B == D)) { 23408140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // max(x, ?) pred min(x, ?). 23418140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_UGE) 23428140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always true. 2343f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 23448140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_ULT) 23458140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always false. 2346f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 23478140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) && 23488140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands match(RHS, m_UMax(m_Value(C), m_Value(D))) && 23498140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands (A == C || A == D || B == C || B == D)) { 23508140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // min(x, ?) pred max(x, ?). 23518140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_ULE) 23528140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always true. 2353f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getTrue(ITy); 23548140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_UGT) 23558140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always false. 2356f56138d4aeb6d271cb353d70a794fa1525d892c3Duncan Sands return getFalse(ITy); 23578140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands } 23588140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands 235958725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth // Simplify comparisons of related pointers using a powerful, recursive 236058725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth // GEP-walk when we have target data available.. 236158725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth if (Q.TD && LHS->getType()->isPointerTy() && RHS->getType()->isPointerTy()) 236258725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth if (Constant *C = computePointerICmp(*Q.TD, Pred, LHS, RHS)) 236358725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth return C; 236458725a66c02865686c70132e8b9bd231eb66da63Chandler Carruth 2365f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky if (GetElementPtrInst *GLHS = dyn_cast<GetElementPtrInst>(LHS)) { 2366f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky if (GEPOperator *GRHS = dyn_cast<GEPOperator>(RHS)) { 2367f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky if (GLHS->getPointerOperand() == GRHS->getPointerOperand() && 2368f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky GLHS->hasAllConstantIndices() && GRHS->hasAllConstantIndices() && 2369f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky (ICmpInst::isEquality(Pred) || 2370f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky (GLHS->isInBounds() && GRHS->isInBounds() && 2371f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky Pred == ICmpInst::getSignedPredicate(Pred)))) { 2372f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // The bases are equal and the indices are constant. Build a constant 2373f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // expression GEP with the same indices and a null base pointer to see 2374f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky // what constant folding can make out of it. 2375f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky Constant *Null = Constant::getNullValue(GLHS->getPointerOperandType()); 2376f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky SmallVector<Value *, 4> IndicesLHS(GLHS->idx_begin(), GLHS->idx_end()); 2377f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky Constant *NewLHS = ConstantExpr::getGetElementPtr(Null, IndicesLHS); 2378f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky 2379f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky SmallVector<Value *, 4> IndicesRHS(GRHS->idx_begin(), GRHS->idx_end()); 2380f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky Constant *NewRHS = ConstantExpr::getGetElementPtr(Null, IndicesRHS); 2381f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky return ConstantExpr::getICmp(Pred, NewLHS, NewRHS); 2382f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky } 2383f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky } 2384f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky } 2385f7087ea5088d58e81f08a3eeb39ba46fa18d0fd4Nick Lewycky 23861ac7c9979a2d723ff4649ffad58df02732872a5fDuncan Sands // If the comparison is with the result of a select instruction, check whether 23871ac7c9979a2d723ff4649ffad58df02732872a5fDuncan Sands // comparing with either branch of the select always yields the same value. 23880312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS)) 23890aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse)) 2390a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 2391a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 2392a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the comparison is with the result of a phi instruction, check whether 2393a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // doing the compare with each incoming phi value yields a common result. 23940312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(LHS) || isa<PHINode>(RHS)) 23950aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse)) 23963bbb0cc42b67b4bf2c488285666999963bab0f7eDuncan Sands return V; 23971ac7c9979a2d723ff4649ffad58df02732872a5fDuncan Sands 23989dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner return 0; 23999dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner} 24009dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 2401a74a58c83be492b7d5b7383656f049909394cff4Duncan SandsValue *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, 2402618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetData *TD, 2403618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 2404618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const DominatorTree *DT) { 24050aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyICmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT), 24060aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands RecursionLimit); 2407a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 2408a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 24099dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can 24109dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// fold the result. If not, this returns null. 2411a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS, 24120aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 24139dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate; 24149dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!"); 24159dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 2416d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(LHS)) { 24179dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner if (Constant *CRHS = dyn_cast<Constant>(RHS)) 24180aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, Q.TD, Q.TLI); 241912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2420d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // If we have a constant, make sure it is on the RHS. 2421d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner std::swap(LHS, RHS); 2422d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Pred = CmpInst::getSwappedPredicate(Pred); 2423d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 242412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2425210c5d4880b525e064088b6fec713260128c16ebChris Lattner // Fold trivial predicates. 2426210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (Pred == FCmpInst::FCMP_FALSE) 2427210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(GetCompareTy(LHS), 0); 2428210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (Pred == FCmpInst::FCMP_TRUE) 2429210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(GetCompareTy(LHS), 1); 2430210c5d4880b525e064088b6fec713260128c16ebChris Lattner 2431210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (isa<UndefValue>(RHS)) // fcmp pred X, undef -> undef 2432210c5d4880b525e064088b6fec713260128c16ebChris Lattner return UndefValue::get(GetCompareTy(LHS)); 2433210c5d4880b525e064088b6fec713260128c16ebChris Lattner 2434210c5d4880b525e064088b6fec713260128c16ebChris Lattner // fcmp x,x -> true/false. Not all compares are foldable. 2435124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (LHS == RHS) { 2436210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (CmpInst::isTrueWhenEqual(Pred)) 2437210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(GetCompareTy(LHS), 1); 2438210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (CmpInst::isFalseWhenEqual(Pred)) 2439210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(GetCompareTy(LHS), 0); 2440210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 244112a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2442210c5d4880b525e064088b6fec713260128c16ebChris Lattner // Handle fcmp with constant RHS 2443210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (Constant *RHSC = dyn_cast<Constant>(RHS)) { 2444210c5d4880b525e064088b6fec713260128c16ebChris Lattner // If the constant is a nan, see if we can fold the comparison based on it. 2445210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHSC)) { 2446210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (CFP->getValueAPF().isNaN()) { 2447210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (FCmpInst::isOrdered(Pred)) // True "if ordered and foo" 2448210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::getFalse(CFP->getContext()); 2449210c5d4880b525e064088b6fec713260128c16ebChris Lattner assert(FCmpInst::isUnordered(Pred) && 2450210c5d4880b525e064088b6fec713260128c16ebChris Lattner "Comparison must be either ordered or unordered!"); 2451210c5d4880b525e064088b6fec713260128c16ebChris Lattner // True if unordered. 2452210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::getTrue(CFP->getContext()); 2453210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 24546b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // Check whether the constant is an infinity. 24556b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman if (CFP->getValueAPF().isInfinity()) { 24566b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman if (CFP->getValueAPF().isNegative()) { 24576b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman switch (Pred) { 24586b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman case FCmpInst::FCMP_OLT: 24596b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // No value is ordered and less than negative infinity. 24606b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman return ConstantInt::getFalse(CFP->getContext()); 24616b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman case FCmpInst::FCMP_UGE: 24626b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // All values are unordered with or at least negative infinity. 24636b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman return ConstantInt::getTrue(CFP->getContext()); 24646b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman default: 24656b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman break; 24666b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } 24676b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } else { 24686b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman switch (Pred) { 24696b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman case FCmpInst::FCMP_OGT: 24706b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // No value is ordered and greater than infinity. 24716b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman return ConstantInt::getFalse(CFP->getContext()); 24726b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman case FCmpInst::FCMP_ULE: 24736b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // All values are unordered with and at most infinity. 24746b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman return ConstantInt::getTrue(CFP->getContext()); 24756b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman default: 24766b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman break; 24776b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } 24786b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } 24796b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } 2480210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 2481210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 248212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 248392826def593df7a422c7b07f09342febce81ddd3Duncan Sands // If the comparison is with the result of a select instruction, check whether 248492826def593df7a422c7b07f09342febce81ddd3Duncan Sands // comparing with either branch of the select always yields the same value. 24850312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS)) 24860aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, Q, MaxRecurse)) 2487a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 2488a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 2489a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the comparison is with the result of a phi instruction, check whether 2490a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // doing the compare with each incoming phi value yields a common result. 24910312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(LHS) || isa<PHINode>(RHS)) 24920aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, Q, MaxRecurse)) 24933bbb0cc42b67b4bf2c488285666999963bab0f7eDuncan Sands return V; 249492826def593df7a422c7b07f09342febce81ddd3Duncan Sands 24959f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner return 0; 24969f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner} 24979f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 2498a74a58c83be492b7d5b7383656f049909394cff4Duncan SandsValue *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS, 2499618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetData *TD, 2500618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 2501618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const DominatorTree *DT) { 25020aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyFCmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT), 25030aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands RecursionLimit); 2504a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 2505a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 2506047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner/// SimplifySelectInst - Given operands for a SelectInst, see if we can fold 2507047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner/// the result. If not, this returns null. 25080aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifySelectInst(Value *CondVal, Value *TrueVal, 25090aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Value *FalseVal, const Query &Q, 25100aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands unsigned MaxRecurse) { 2511047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner // select true, X, Y -> X 2512047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner // select false, X, Y -> Y 2513047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner if (ConstantInt *CB = dyn_cast<ConstantInt>(CondVal)) 2514047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return CB->getZExtValue() ? TrueVal : FalseVal; 251512a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2516047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner // select C, X, X -> X 2517124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (TrueVal == FalseVal) 2518047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return TrueVal; 251912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2520047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner if (isa<UndefValue>(CondVal)) { // select undef, X, Y -> X or Y 2521047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner if (isa<Constant>(TrueVal)) 2522047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return TrueVal; 2523047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return FalseVal; 2524047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner } 252568c0dbc14fb7599987fb3e27be4e12c1ac36535eDan Gohman if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X 252668c0dbc14fb7599987fb3e27be4e12c1ac36535eDan Gohman return FalseVal; 252768c0dbc14fb7599987fb3e27be4e12c1ac36535eDan Gohman if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X 252868c0dbc14fb7599987fb3e27be4e12c1ac36535eDan Gohman return TrueVal; 252912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2530047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return 0; 2531047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner} 2532047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner 25330aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan SandsValue *llvm::SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal, 25340aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const TargetData *TD, 25350aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const TargetLibraryInfo *TLI, 25360aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const DominatorTree *DT) { 25370aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifySelectInst(Cond, TrueVal, FalseVal, Query (TD, TLI, DT), 25380aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands RecursionLimit); 25390aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands} 25400aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands 2541c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner/// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can 2542c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner/// fold the result. If not, this returns null. 25430aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyGEPInst(ArrayRef<Value *> Ops, const Query &Q, unsigned) { 254485bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands // The type of the GEP pointer operand. 25451608769abeb1430dc34f31ffac0d9850f99ae36aNadav Rotem PointerType *PtrTy = dyn_cast<PointerType>(Ops[0]->getType()); 25461608769abeb1430dc34f31ffac0d9850f99ae36aNadav Rotem // The GEP pointer operand is not a pointer, it's a vector of pointers. 25471608769abeb1430dc34f31ffac0d9850f99ae36aNadav Rotem if (!PtrTy) 25481608769abeb1430dc34f31ffac0d9850f99ae36aNadav Rotem return 0; 254985bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands 2550c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner // getelementptr P -> P. 2551b9b54ebfed02f0654897d37e8a4448d3f8087558Jay Foad if (Ops.size() == 1) 2552c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner return Ops[0]; 2553c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner 255485bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands if (isa<UndefValue>(Ops[0])) { 255585bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands // Compute the (pointer) type returned by the GEP instruction. 2556a9203109f4ac95aa7e9624f2838e3d89623ec902Jay Foad Type *LastType = GetElementPtrInst::getIndexedType(PtrTy, Ops.slice(1)); 2557db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *GEPTy = PointerType::get(LastType, PtrTy->getAddressSpace()); 255885bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands return UndefValue::get(GEPTy); 255985bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands } 2560c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner 2561b9b54ebfed02f0654897d37e8a4448d3f8087558Jay Foad if (Ops.size() == 2) { 2562e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands // getelementptr P, 0 -> P. 2563c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner if (ConstantInt *C = dyn_cast<ConstantInt>(Ops[1])) 2564c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner if (C->isZero()) 2565c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner return Ops[0]; 2566e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands // getelementptr P, N -> P if P points to a type of zero size. 25670aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Q.TD) { 2568db125cfaf57cc83e7dd7453de2d509bc8efd0e5eChris Lattner Type *Ty = PtrTy->getElementType(); 25690aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Ty->isSized() && Q.TD->getTypeAllocSize(Ty) == 0) 2570e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands return Ops[0]; 2571e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands } 2572e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands } 257312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2574c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner // Check to see if this is constant foldable. 2575b9b54ebfed02f0654897d37e8a4448d3f8087558Jay Foad for (unsigned i = 0, e = Ops.size(); i != e; ++i) 2576c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner if (!isa<Constant>(Ops[i])) 2577c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner return 0; 257812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2579dab3d29605a5c83db41b28176273ef55961120c1Jay Foad return ConstantExpr::getGetElementPtr(cast<Constant>(Ops[0]), Ops.slice(1)); 2580c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner} 2581c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner 25820aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan SandsValue *llvm::SimplifyGEPInst(ArrayRef<Value *> Ops, const TargetData *TD, 25830aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const TargetLibraryInfo *TLI, 25840aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const DominatorTree *DT) { 25850aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyGEPInst(Ops, Query (TD, TLI, DT), RecursionLimit); 25860aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands} 25870aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands 2588dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands/// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we 2589dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands/// can fold the result. If not, this returns null. 25900aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyInsertValueInst(Value *Agg, Value *Val, 25910aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands ArrayRef<unsigned> Idxs, const Query &Q, 25920aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands unsigned) { 2593dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands if (Constant *CAgg = dyn_cast<Constant>(Agg)) 2594dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands if (Constant *CVal = dyn_cast<Constant>(Val)) 2595dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands return ConstantFoldInsertValueInstruction(CAgg, CVal, Idxs); 2596dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands 2597dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands // insertvalue x, undef, n -> x 2598dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands if (match(Val, m_Undef())) 2599dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands return Agg; 2600dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands 2601dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands // insertvalue x, (extractvalue y, n), n 2602dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands if (ExtractValueInst *EV = dyn_cast<ExtractValueInst>(Val)) 2603ae707bd5594e52a8b385760f99ff58aa8fede948Benjamin Kramer if (EV->getAggregateOperand()->getType() == Agg->getType() && 2604ae707bd5594e52a8b385760f99ff58aa8fede948Benjamin Kramer EV->getIndices() == Idxs) { 2605dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands // insertvalue undef, (extractvalue y, n), n -> y 2606dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands if (match(Agg, m_Undef())) 2607dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands return EV->getAggregateOperand(); 2608dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands 2609dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands // insertvalue y, (extractvalue y, n), n -> y 2610dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands if (Agg == EV->getAggregateOperand()) 2611dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands return Agg; 2612dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands } 2613dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands 2614dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands return 0; 2615dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands} 2616dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands 26170aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan SandsValue *llvm::SimplifyInsertValueInst(Value *Agg, Value *Val, 26180aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands ArrayRef<unsigned> Idxs, 26190aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const TargetData *TD, 26200aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const TargetLibraryInfo *TLI, 26210aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const DominatorTree *DT) { 26220aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyInsertValueInst(Agg, Val, Idxs, Query (TD, TLI, DT), 26230aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands RecursionLimit); 26240aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands} 26250aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands 2626ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands/// SimplifyPHINode - See if we can fold the given phi. If not, returns null. 26270aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyPHINode(PHINode *PN, const Query &Q) { 2628ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If all of the PHI's incoming values are the same then replace the PHI node 2629ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // with the common value. 2630ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands Value *CommonValue = 0; 2631ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands bool HasUndefInput = false; 2632ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { 2633ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands Value *Incoming = PN->getIncomingValue(i); 2634ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If the incoming value is the phi node itself, it can safely be skipped. 2635ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (Incoming == PN) continue; 2636ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (isa<UndefValue>(Incoming)) { 2637ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // Remember that we saw an undef value, but otherwise ignore them. 2638ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands HasUndefInput = true; 2639ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands continue; 2640ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands } 2641ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (CommonValue && Incoming != CommonValue) 2642ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands return 0; // Not the same, bail out. 2643ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands CommonValue = Incoming; 2644ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands } 2645ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands 2646ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If CommonValue is null then all of the incoming values were either undef or 2647ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // equal to the phi node itself. 2648ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (!CommonValue) 2649ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands return UndefValue::get(PN->getType()); 2650ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands 2651ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If we have a PHI node like phi(X, undef, X), where X is defined by some 2652ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // instruction, we cannot return X as the result of the PHI node unless it 2653ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // dominates the PHI block. 2654ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (HasUndefInput) 26550aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ValueDominatesPHI(CommonValue, PN, Q.DT) ? CommonValue : 0; 2656ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands 2657ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands return CommonValue; 2658ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands} 2659ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands 2660bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sandsstatic Value *SimplifyTruncInst(Value *Op, Type *Ty, const Query &Q, unsigned) { 2661bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands if (Constant *C = dyn_cast<Constant>(Op)) 2662bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands return ConstantFoldInstOperands(Instruction::Trunc, Ty, C, Q.TD, Q.TLI); 2663bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands 2664bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands return 0; 2665bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands} 2666bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands 2667bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan SandsValue *llvm::SimplifyTruncInst(Value *Op, Type *Ty, const TargetData *TD, 2668bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands const TargetLibraryInfo *TLI, 2669bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands const DominatorTree *DT) { 2670bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands return ::SimplifyTruncInst(Op, Ty, Query (TD, TLI, DT), RecursionLimit); 2671bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands} 2672bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands 2673d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner//=== Helper functions for higher up the class hierarchy. 26749dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 2675d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner/// SimplifyBinOp - Given operands for a BinaryOperator, see if we can 2676d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner/// fold the result. If not, this returns null. 2677a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, 26780aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 2679d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner switch (Opcode) { 268081a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner case Instruction::Add: 2681ffeb98ad3becfbb8e26270ef8751e37e4b6b0cd1Duncan Sands return SimplifyAddInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false, 26820aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse); 268381a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner case Instruction::Sub: 2684ffeb98ad3becfbb8e26270ef8751e37e4b6b0cd1Duncan Sands return SimplifySubInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false, 26850aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse); 26860aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands case Instruction::Mul: return SimplifyMulInst (LHS, RHS, Q, MaxRecurse); 26870aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands case Instruction::SDiv: return SimplifySDivInst(LHS, RHS, Q, MaxRecurse); 26880aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands case Instruction::UDiv: return SimplifyUDivInst(LHS, RHS, Q, MaxRecurse); 26890aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands case Instruction::FDiv: return SimplifyFDivInst(LHS, RHS, Q, MaxRecurse); 26900aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands case Instruction::SRem: return SimplifySRemInst(LHS, RHS, Q, MaxRecurse); 26910aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands case Instruction::URem: return SimplifyURemInst(LHS, RHS, Q, MaxRecurse); 26920aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands case Instruction::FRem: return SimplifyFRemInst(LHS, RHS, Q, MaxRecurse); 269381a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner case Instruction::Shl: 2694ffeb98ad3becfbb8e26270ef8751e37e4b6b0cd1Duncan Sands return SimplifyShlInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false, 26950aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q, MaxRecurse); 269681a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner case Instruction::LShr: 26970aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return SimplifyLShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse); 269881a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner case Instruction::AShr: 26990aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return SimplifyAShrInst(LHS, RHS, /*isExact*/false, Q, MaxRecurse); 27000aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands case Instruction::And: return SimplifyAndInst(LHS, RHS, Q, MaxRecurse); 27010aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands case Instruction::Or: return SimplifyOrInst (LHS, RHS, Q, MaxRecurse); 27020aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands case Instruction::Xor: return SimplifyXorInst(LHS, RHS, Q, MaxRecurse); 2703d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner default: 2704d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(LHS)) 2705d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(RHS)) { 2706d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Constant *COps[] = {CLHS, CRHS}; 27070aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, Q.TD, 27080aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Q.TLI); 2709d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 2710b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 2711566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If the operation is associative, try some generic simplifications. 2712566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Instruction::isAssociative(Opcode)) 27130aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Opcode, LHS, RHS, Q, MaxRecurse)) 2714566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 2715566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 27160aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands // If the operation is with the result of a select instruction check whether 2717b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // operating on either branch of the select always yields the same value. 27180312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS)) 27190aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverSelect(Opcode, LHS, RHS, Q, MaxRecurse)) 2720a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 2721a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 2722a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation is with the result of a phi instruction, check whether 2723a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // operating on all incoming values of the phi always yields the same value. 27240312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(LHS) || isa<PHINode>(RHS)) 27250aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, Q, MaxRecurse)) 2726b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return V; 2727b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 2728d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return 0; 2729d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 2730d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner} 27319dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 273212a86f5b3199e72e6d967781acc76340f5920e46Duncan SandsValue *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, 2733618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetData *TD, const TargetLibraryInfo *TLI, 2734618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const DominatorTree *DT) { 27350aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyBinOp(Opcode, LHS, RHS, Query (TD, TLI, DT), RecursionLimit); 2736a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 2737a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 27389dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// SimplifyCmpInst - Given operands for a CmpInst, see if we can 27399dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// fold the result. 2740a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS, 27410aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands const Query &Q, unsigned MaxRecurse) { 27429dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner if (CmpInst::isIntPredicate((CmpInst::Predicate)Predicate)) 27430aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return SimplifyICmpInst(Predicate, LHS, RHS, Q, MaxRecurse); 27440aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return SimplifyFCmpInst(Predicate, LHS, RHS, Q, MaxRecurse); 27459dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner} 27469dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 2747a74a58c83be492b7d5b7383656f049909394cff4Duncan SandsValue *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS, 2748618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetData *TD, const TargetLibraryInfo *TLI, 2749618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const DominatorTree *DT) { 27500aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands return ::SimplifyCmpInst(Predicate, LHS, RHS, Query (TD, TLI, DT), 27510aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands RecursionLimit); 2752a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 2753e34537856a544c83513e390ac9552a8bc3823346Chris Lattner 27540aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sandsstatic Value *SimplifyCallInst(CallInst *CI, const Query &) { 275571d050315704c23b235594d3fad5268c12d825e3Dan Gohman // call undef -> undef 275671d050315704c23b235594d3fad5268c12d825e3Dan Gohman if (isa<UndefValue>(CI->getCalledValue())) 275771d050315704c23b235594d3fad5268c12d825e3Dan Gohman return UndefValue::get(CI->getType()); 275871d050315704c23b235594d3fad5268c12d825e3Dan Gohman 275971d050315704c23b235594d3fad5268c12d825e3Dan Gohman return 0; 276071d050315704c23b235594d3fad5268c12d825e3Dan Gohman} 276171d050315704c23b235594d3fad5268c12d825e3Dan Gohman 2762e34537856a544c83513e390ac9552a8bc3823346Chris Lattner/// SimplifyInstruction - See if we can compute a simplified version of this 2763e34537856a544c83513e390ac9552a8bc3823346Chris Lattner/// instruction. If not, this returns null. 2764eff0581583ef10e2872e9baf537a04b67d992101Duncan SandsValue *llvm::SimplifyInstruction(Instruction *I, const TargetData *TD, 2765618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier const TargetLibraryInfo *TLI, 2766eff0581583ef10e2872e9baf537a04b67d992101Duncan Sands const DominatorTree *DT) { 2767d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Value *Result; 2768d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands 2769e34537856a544c83513e390ac9552a8bc3823346Chris Lattner switch (I->getOpcode()) { 2770e34537856a544c83513e390ac9552a8bc3823346Chris Lattner default: 2771618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier Result = ConstantFoldInstruction(I, TD, TLI); 2772d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 27738aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner case Instruction::Add: 2774d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1), 2775d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands cast<BinaryOperator>(I)->hasNoSignedWrap(), 2776d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands cast<BinaryOperator>(I)->hasNoUnsignedWrap(), 2777618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier TD, TLI, DT); 2778d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2779fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands case Instruction::Sub: 2780fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands Result = SimplifySubInst(I->getOperand(0), I->getOperand(1), 2781fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands cast<BinaryOperator>(I)->hasNoSignedWrap(), 2782fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands cast<BinaryOperator>(I)->hasNoUnsignedWrap(), 2783618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier TD, TLI, DT); 2784fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands break; 278582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands case Instruction::Mul: 2786618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier Result = SimplifyMulInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); 278782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands break; 2788593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands case Instruction::SDiv: 2789618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); 2790593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands break; 2791593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands case Instruction::UDiv: 2792618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); 2793593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands break; 27941fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel case Instruction::FDiv: 2795618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); 27961fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel break; 2797f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands case Instruction::SRem: 2798618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier Result = SimplifySRemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); 2799f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands break; 2800f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands case Instruction::URem: 2801618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier Result = SimplifyURemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); 2802f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands break; 2803f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands case Instruction::FRem: 2804618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); 2805f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands break; 2806c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands case Instruction::Shl: 280781a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Result = SimplifyShlInst(I->getOperand(0), I->getOperand(1), 280881a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<BinaryOperator>(I)->hasNoSignedWrap(), 280981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<BinaryOperator>(I)->hasNoUnsignedWrap(), 2810618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier TD, TLI, DT); 2811c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands break; 2812c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands case Instruction::LShr: 281381a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Result = SimplifyLShrInst(I->getOperand(0), I->getOperand(1), 281481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<BinaryOperator>(I)->isExact(), 2815618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier TD, TLI, DT); 2816c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands break; 2817c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands case Instruction::AShr: 281881a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Result = SimplifyAShrInst(I->getOperand(0), I->getOperand(1), 281981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<BinaryOperator>(I)->isExact(), 2820618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier TD, TLI, DT); 2821c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands break; 2822e34537856a544c83513e390ac9552a8bc3823346Chris Lattner case Instruction::And: 2823618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier Result = SimplifyAndInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); 2824d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2825e34537856a544c83513e390ac9552a8bc3823346Chris Lattner case Instruction::Or: 2826618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier Result = SimplifyOrInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); 2827d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 28282b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands case Instruction::Xor: 2829618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier Result = SimplifyXorInst(I->getOperand(0), I->getOperand(1), TD, TLI, DT); 28302b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands break; 2831e34537856a544c83513e390ac9552a8bc3823346Chris Lattner case Instruction::ICmp: 2832d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(), 2833618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier I->getOperand(0), I->getOperand(1), TD, TLI, DT); 2834d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2835e34537856a544c83513e390ac9552a8bc3823346Chris Lattner case Instruction::FCmp: 2836d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(), 2837618c1dbd293d15ee19f61b1156ab8086ad28311aChad Rosier I->getOperand(0), I->getOperand(1), TD, TLI, DT); 2838d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2839047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner case Instruction::Select: 2840d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifySelectInst(I->getOperand(0), I->getOperand(1), 28410aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands I->getOperand(2), TD, TLI, DT); 2842d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2843c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner case Instruction::GetElementPtr: { 2844c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner SmallVector<Value*, 8> Ops(I->op_begin(), I->op_end()); 28450aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Result = SimplifyGEPInst(Ops, TD, TLI, DT); 2846d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2847c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner } 2848dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands case Instruction::InsertValue: { 2849dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands InsertValueInst *IV = cast<InsertValueInst>(I); 2850dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands Result = SimplifyInsertValueInst(IV->getAggregateOperand(), 2851dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands IV->getInsertedValueOperand(), 28520aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands IV->getIndices(), TD, TLI, DT); 2853dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands break; 2854dabc2806726a286b00313419fac8461ebe0f774cDuncan Sands } 2855cd6636c737a82949ad13db2d0d918af6424fb78bDuncan Sands case Instruction::PHI: 28560aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Result = SimplifyPHINode(cast<PHINode>(I), Query (TD, TLI, DT)); 2857d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 285871d050315704c23b235594d3fad5268c12d825e3Dan Gohman case Instruction::Call: 28590aa85eb231dc76bcabcd35f6dc9a50536f607df3Duncan Sands Result = SimplifyCallInst(cast<CallInst>(I), Query (TD, TLI, DT)); 286071d050315704c23b235594d3fad5268c12d825e3Dan Gohman break; 2861bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands case Instruction::Trunc: 2862bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands Result = SimplifyTruncInst(I->getOperand(0), I->getType(), TD, TLI, DT); 2863bd0fe5642544d4ec3aee1ede7af60c006bae5cbfDuncan Sands break; 2864e34537856a544c83513e390ac9552a8bc3823346Chris Lattner } 2865d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands 2866d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands /// If called on unreachable code, the above logic may report that the 2867d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands /// instruction simplified to itself. Make life easier for users by 2868f8b1a5ea9602bb65a5cf59d3d34f2851a08cdc3eDuncan Sands /// detecting that case here, returning a safe value instead. 2869f8b1a5ea9602bb65a5cf59d3d34f2851a08cdc3eDuncan Sands return Result == I ? UndefValue::get(I->getType()) : Result; 2870e34537856a544c83513e390ac9552a8bc3823346Chris Lattner} 2871e34537856a544c83513e390ac9552a8bc3823346Chris Lattner 28726b980541df5846ad335c377c8803b517968daee2Chandler Carruth/// \brief Implementation of recursive simplification through an instructions 28736b980541df5846ad335c377c8803b517968daee2Chandler Carruth/// uses. 287440d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// 28756b980541df5846ad335c377c8803b517968daee2Chandler Carruth/// This is the common implementation of the recursive simplification routines. 28766b980541df5846ad335c377c8803b517968daee2Chandler Carruth/// If we have a pre-simplified value in 'SimpleV', that is forcibly used to 28776b980541df5846ad335c377c8803b517968daee2Chandler Carruth/// replace the instruction 'I'. Otherwise, we simply add 'I' to the list of 28786b980541df5846ad335c377c8803b517968daee2Chandler Carruth/// instructions to process and attempt to simplify it using 28796b980541df5846ad335c377c8803b517968daee2Chandler Carruth/// InstructionSimplify. 28806b980541df5846ad335c377c8803b517968daee2Chandler Carruth/// 28816b980541df5846ad335c377c8803b517968daee2Chandler Carruth/// This routine returns 'true' only when *it* simplifies something. The passed 28826b980541df5846ad335c377c8803b517968daee2Chandler Carruth/// in simplified value does not count toward this. 28836b980541df5846ad335c377c8803b517968daee2Chandler Carruthstatic bool replaceAndRecursivelySimplifyImpl(Instruction *I, Value *SimpleV, 28846b980541df5846ad335c377c8803b517968daee2Chandler Carruth const TargetData *TD, 28856b980541df5846ad335c377c8803b517968daee2Chandler Carruth const TargetLibraryInfo *TLI, 28866b980541df5846ad335c377c8803b517968daee2Chandler Carruth const DominatorTree *DT) { 28876b980541df5846ad335c377c8803b517968daee2Chandler Carruth bool Simplified = false; 28886231d5be410e2d7967352b29ad01522fda15680dChandler Carruth SmallSetVector<Instruction *, 8> Worklist; 28896b980541df5846ad335c377c8803b517968daee2Chandler Carruth 28906b980541df5846ad335c377c8803b517968daee2Chandler Carruth // If we have an explicit value to collapse to, do that round of the 28916b980541df5846ad335c377c8803b517968daee2Chandler Carruth // simplification loop by hand initially. 28926b980541df5846ad335c377c8803b517968daee2Chandler Carruth if (SimpleV) { 28936b980541df5846ad335c377c8803b517968daee2Chandler Carruth for (Value::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE; 28946b980541df5846ad335c377c8803b517968daee2Chandler Carruth ++UI) 2895c5b785b91c922bbb3d5adb4b042c976bebe00e4dChandler Carruth if (*UI != I) 28966231d5be410e2d7967352b29ad01522fda15680dChandler Carruth Worklist.insert(cast<Instruction>(*UI)); 28976b980541df5846ad335c377c8803b517968daee2Chandler Carruth 28986b980541df5846ad335c377c8803b517968daee2Chandler Carruth // Replace the instruction with its simplified value. 28996b980541df5846ad335c377c8803b517968daee2Chandler Carruth I->replaceAllUsesWith(SimpleV); 29006b980541df5846ad335c377c8803b517968daee2Chandler Carruth 29016b980541df5846ad335c377c8803b517968daee2Chandler Carruth // Gracefully handle edge cases where the instruction is not wired into any 29026b980541df5846ad335c377c8803b517968daee2Chandler Carruth // parent block. 29036b980541df5846ad335c377c8803b517968daee2Chandler Carruth if (I->getParent()) 29046b980541df5846ad335c377c8803b517968daee2Chandler Carruth I->eraseFromParent(); 29056b980541df5846ad335c377c8803b517968daee2Chandler Carruth } else { 29066231d5be410e2d7967352b29ad01522fda15680dChandler Carruth Worklist.insert(I); 29076b980541df5846ad335c377c8803b517968daee2Chandler Carruth } 290812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 29096231d5be410e2d7967352b29ad01522fda15680dChandler Carruth // Note that we must test the size on each iteration, the worklist can grow. 29106231d5be410e2d7967352b29ad01522fda15680dChandler Carruth for (unsigned Idx = 0; Idx != Worklist.size(); ++Idx) { 29116231d5be410e2d7967352b29ad01522fda15680dChandler Carruth I = Worklist[Idx]; 291212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 29136b980541df5846ad335c377c8803b517968daee2Chandler Carruth // See if this instruction simplifies. 29146b980541df5846ad335c377c8803b517968daee2Chandler Carruth SimpleV = SimplifyInstruction(I, TD, TLI, DT); 29156b980541df5846ad335c377c8803b517968daee2Chandler Carruth if (!SimpleV) 29166b980541df5846ad335c377c8803b517968daee2Chandler Carruth continue; 29176b980541df5846ad335c377c8803b517968daee2Chandler Carruth 29186b980541df5846ad335c377c8803b517968daee2Chandler Carruth Simplified = true; 29196b980541df5846ad335c377c8803b517968daee2Chandler Carruth 29206b980541df5846ad335c377c8803b517968daee2Chandler Carruth // Stash away all the uses of the old instruction so we can check them for 29216b980541df5846ad335c377c8803b517968daee2Chandler Carruth // recursive simplifications after a RAUW. This is cheaper than checking all 29226b980541df5846ad335c377c8803b517968daee2Chandler Carruth // uses of To on the recursive step in most cases. 29236b980541df5846ad335c377c8803b517968daee2Chandler Carruth for (Value::use_iterator UI = I->use_begin(), UE = I->use_end(); UI != UE; 29246b980541df5846ad335c377c8803b517968daee2Chandler Carruth ++UI) 29256231d5be410e2d7967352b29ad01522fda15680dChandler Carruth Worklist.insert(cast<Instruction>(*UI)); 292612a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 29276b980541df5846ad335c377c8803b517968daee2Chandler Carruth // Replace the instruction with its simplified value. 29286b980541df5846ad335c377c8803b517968daee2Chandler Carruth I->replaceAllUsesWith(SimpleV); 29296b980541df5846ad335c377c8803b517968daee2Chandler Carruth 29306b980541df5846ad335c377c8803b517968daee2Chandler Carruth // Gracefully handle edge cases where the instruction is not wired into any 29316b980541df5846ad335c377c8803b517968daee2Chandler Carruth // parent block. 29326b980541df5846ad335c377c8803b517968daee2Chandler Carruth if (I->getParent()) 29336b980541df5846ad335c377c8803b517968daee2Chandler Carruth I->eraseFromParent(); 293440d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner } 29356b980541df5846ad335c377c8803b517968daee2Chandler Carruth return Simplified; 29366b980541df5846ad335c377c8803b517968daee2Chandler Carruth} 293712a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 29386b980541df5846ad335c377c8803b517968daee2Chandler Carruthbool llvm::recursivelySimplifyInstruction(Instruction *I, 29396b980541df5846ad335c377c8803b517968daee2Chandler Carruth const TargetData *TD, 29406b980541df5846ad335c377c8803b517968daee2Chandler Carruth const TargetLibraryInfo *TLI, 29416b980541df5846ad335c377c8803b517968daee2Chandler Carruth const DominatorTree *DT) { 29426b980541df5846ad335c377c8803b517968daee2Chandler Carruth return replaceAndRecursivelySimplifyImpl(I, 0, TD, TLI, DT); 29436b980541df5846ad335c377c8803b517968daee2Chandler Carruth} 294412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 29456b980541df5846ad335c377c8803b517968daee2Chandler Carruthbool llvm::replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV, 29466b980541df5846ad335c377c8803b517968daee2Chandler Carruth const TargetData *TD, 29476b980541df5846ad335c377c8803b517968daee2Chandler Carruth const TargetLibraryInfo *TLI, 29486b980541df5846ad335c377c8803b517968daee2Chandler Carruth const DominatorTree *DT) { 29496b980541df5846ad335c377c8803b517968daee2Chandler Carruth assert(I != SimpleV && "replaceAndRecursivelySimplify(X,X) is not valid!"); 29506b980541df5846ad335c377c8803b517968daee2Chandler Carruth assert(SimpleV && "Must provide a simplified value."); 29516b980541df5846ad335c377c8803b517968daee2Chandler Carruth return replaceAndRecursivelySimplifyImpl(I, SimpleV, TD, TLI, DT); 295240d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner} 2953