InstructionSimplify.cpp revision 1fca2c32cc99197215d3fd32a4ad05214c74edd1
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" 21a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands#include "llvm/ADT/Statistic.h" 229f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner#include "llvm/Analysis/InstructionSimplify.h" 239f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner#include "llvm/Analysis/ConstantFolding.h" 241845009290e4d804ad377927bd8a08cca3036adcDuncan Sands#include "llvm/Analysis/Dominators.h" 25d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands#include "llvm/Analysis/ValueTracking.h" 26d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner#include "llvm/Support/PatternMatch.h" 271845009290e4d804ad377927bd8a08cca3036adcDuncan Sands#include "llvm/Support/ValueHandle.h" 28e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands#include "llvm/Target/TargetData.h" 299f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattnerusing namespace llvm; 30d06094f0682f2ede03caff4892b1a57469896d48Chris Lattnerusing namespace llvm::PatternMatch; 319f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 32124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands#define RecursionLimit 3 33a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 34a3c44a5280042dbc0cde995675c225ede4528c6eDuncan SandsSTATISTIC(NumExpand, "Number of expansions"); 35a3c44a5280042dbc0cde995675c225ede4528c6eDuncan SandsSTATISTIC(NumFactor , "Number of factorizations"); 36a3c44a5280042dbc0cde995675c225ede4528c6eDuncan SandsSTATISTIC(NumReassoc, "Number of reassociations"); 37a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands 3882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sandsstatic Value *SimplifyAndInst(Value *, Value *, const TargetData *, 3982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands const DominatorTree *, unsigned); 40a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyBinOp(unsigned, Value *, Value *, const TargetData *, 411845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *, unsigned); 42a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyCmpInst(unsigned, Value *, Value *, const TargetData *, 431845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *, unsigned); 4482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sandsstatic Value *SimplifyOrInst(Value *, Value *, const TargetData *, 4582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands const DominatorTree *, unsigned); 4682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sandsstatic Value *SimplifyXorInst(Value *, Value *, const TargetData *, 4782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands const DominatorTree *, unsigned); 481845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 491845009290e4d804ad377927bd8a08cca3036adcDuncan Sands/// ValueDominatesPHI - Does the given value dominate the specified phi node? 501845009290e4d804ad377927bd8a08cca3036adcDuncan Sandsstatic bool ValueDominatesPHI(Value *V, PHINode *P, const DominatorTree *DT) { 511845009290e4d804ad377927bd8a08cca3036adcDuncan Sands Instruction *I = dyn_cast<Instruction>(V); 521845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (!I) 531845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Arguments and constants dominate all instructions. 541845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return true; 551845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 561845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // If we have a DominatorTree then do a precise test. 571845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (DT) 581845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return DT->dominates(I, P); 591845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 601845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Otherwise, if the instruction is in the entry block, and is not an invoke, 611845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // then it obviously dominates all phi nodes. 621845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (I->getParent() == &I->getParent()->getParent()->getEntryBlock() && 631845009290e4d804ad377927bd8a08cca3036adcDuncan Sands !isa<InvokeInst>(I)) 641845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return true; 651845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 661845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return false; 671845009290e4d804ad377927bd8a08cca3036adcDuncan Sands} 68a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 693421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// ExpandBinOp - Simplify "A op (B op' C)" by distributing op over op', turning 703421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// it into "(A op B) op' (A op C)". Here "op" is given by Opcode and "op'" is 713421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// given by OpcodeToExpand, while "A" corresponds to LHS and "B op' C" to RHS. 723421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// Also performs the transform "(A op' B) op C" -> "(A op C) op' (B op C)". 733421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// Returns the simplified value, or null if no simplification was performed. 743421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sandsstatic Value *ExpandBinOp(unsigned Opcode, Value *LHS, Value *RHS, 75e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer unsigned OpcToExpand, const TargetData *TD, 763421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 77e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer Instruction::BinaryOps OpcodeToExpand = (Instruction::BinaryOps)OpcToExpand; 783421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 793421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (!MaxRecurse--) 803421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 813421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 823421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Check whether the expression has the form "(A op' B) op C". 833421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS)) 843421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Op0->getOpcode() == OpcodeToExpand) { 853421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // It does! Try turning it into "(A op C) op' (B op C)". 863421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands Value *A = Op0->getOperand(0), *B = Op0->getOperand(1), *C = RHS; 873421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Do "A op C" and "B op C" both simplify? 883421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *L = SimplifyBinOp(Opcode, A, C, TD, DT, MaxRecurse)) 893421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *R = SimplifyBinOp(Opcode, B, C, TD, DT, MaxRecurse)) { 903421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // They do! Return "L op' R" if it simplifies or is already available. 913421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // If "L op' R" equals "A op' B" then "L op' R" is just the LHS. 92124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if ((L == A && R == B) || (Instruction::isCommutative(OpcodeToExpand) 93124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands && L == B && R == A)) { 94a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumExpand; 953421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return LHS; 96a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 973421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Otherwise return "L op' R" if it simplifies. 98a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, TD, DT, 99a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands MaxRecurse)) { 100a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumExpand; 1013421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 102a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1033421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1043421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1053421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1063421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Check whether the expression has the form "A op (B op' C)". 1073421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS)) 1083421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Op1->getOpcode() == OpcodeToExpand) { 1093421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // It does! Try turning it into "(A op B) op' (A op C)". 1103421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands Value *A = LHS, *B = Op1->getOperand(0), *C = Op1->getOperand(1); 1113421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Do "A op B" and "A op C" both simplify? 1123421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *L = SimplifyBinOp(Opcode, A, B, TD, DT, MaxRecurse)) 1133421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *R = SimplifyBinOp(Opcode, A, C, TD, DT, MaxRecurse)) { 1143421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // They do! Return "L op' R" if it simplifies or is already available. 1153421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // If "L op' R" equals "B op' C" then "L op' R" is just the RHS. 116124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if ((L == B && R == C) || (Instruction::isCommutative(OpcodeToExpand) 117124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands && L == C && R == B)) { 118a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumExpand; 1193421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return RHS; 120a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1213421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Otherwise return "L op' R" if it simplifies. 122a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, TD, DT, 123a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands MaxRecurse)) { 124a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumExpand; 1253421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 126a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1273421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1283421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1293421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1303421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 1313421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands} 1323421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1333421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// FactorizeBinOp - Simplify "LHS Opcode RHS" by factorizing out a common term 1343421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// using the operation OpCodeToExtract. For example, when Opcode is Add and 1353421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// OpCodeToExtract is Mul then this tries to turn "(A*B)+(A*C)" into "A*(B+C)". 1363421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// Returns the simplified value, or null if no simplification was performed. 1373421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sandsstatic Value *FactorizeBinOp(unsigned Opcode, Value *LHS, Value *RHS, 138e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer unsigned OpcToExtract, const TargetData *TD, 1393421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 140e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer Instruction::BinaryOps OpcodeToExtract = (Instruction::BinaryOps)OpcToExtract; 1413421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 1423421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (!MaxRecurse--) 1433421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 1443421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1453421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS); 1463421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS); 1473421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1483421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (!Op0 || Op0->getOpcode() != OpcodeToExtract || 1493421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands !Op1 || Op1->getOpcode() != OpcodeToExtract) 1503421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 1513421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1523421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // The expression has the form "(A op' B) op (C op' D)". 15382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Value *A = Op0->getOperand(0), *B = Op0->getOperand(1); 15482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Value *C = Op1->getOperand(0), *D = Op1->getOperand(1); 1553421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1563421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Use left distributivity, i.e. "X op' (Y op Z) = (X op' Y) op (X op' Z)". 1573421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Does the instruction have the form "(A op' B) op (A op' D)" or, in the 1583421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // commutative case, "(A op' B) op (C op' A)"? 159124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (A == C || (Instruction::isCommutative(OpcodeToExtract) && A == D)) { 160124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Value *DD = A == C ? D : C; 1613421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Form "A op' (B op DD)" if it simplifies completely. 1623421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Does "B op DD" simplify? 1633421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = SimplifyBinOp(Opcode, B, DD, TD, DT, MaxRecurse)) { 1643421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // It does! Return "A op' V" if it simplifies or is already available. 1651cd05bb605e3c3eee9197d3f10b628c60d0cc07aDuncan Sands // If V equals B then "A op' V" is just the LHS. If V equals DD then 1661cd05bb605e3c3eee9197d3f10b628c60d0cc07aDuncan Sands // "A op' V" is just the RHS. 167124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == B || V == DD) { 168a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumFactor; 169124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands return V == B ? LHS : RHS; 170a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1713421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Otherwise return "A op' V" if it simplifies. 172a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *W = SimplifyBinOp(OpcodeToExtract, A, V, TD, DT, MaxRecurse)) { 173a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumFactor; 1743421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return W; 175a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1763421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1773421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1783421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1793421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Use right distributivity, i.e. "(X op Y) op' Z = (X op' Z) op (Y op' Z)". 1803421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Does the instruction have the form "(A op' B) op (C op' B)" or, in the 1813421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // commutative case, "(A op' B) op (B op' D)"? 182124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (B == D || (Instruction::isCommutative(OpcodeToExtract) && B == C)) { 183124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Value *CC = B == D ? C : D; 1843421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Form "(A op CC) op' B" if it simplifies completely.. 1853421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Does "A op CC" simplify? 1863421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = SimplifyBinOp(Opcode, A, CC, TD, DT, MaxRecurse)) { 1873421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // It does! Return "V op' B" if it simplifies or is already available. 1881cd05bb605e3c3eee9197d3f10b628c60d0cc07aDuncan Sands // If V equals A then "V op' B" is just the LHS. If V equals CC then 1891cd05bb605e3c3eee9197d3f10b628c60d0cc07aDuncan Sands // "V op' B" is just the RHS. 190124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == A || V == CC) { 191a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumFactor; 192124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands return V == A ? LHS : RHS; 193a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1943421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Otherwise return "V op' B" if it simplifies. 195a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *W = SimplifyBinOp(OpcodeToExtract, V, B, TD, DT, MaxRecurse)) { 196a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumFactor; 1973421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return W; 198a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1993421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 2003421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 2013421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 2023421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 2033421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands} 2043421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 2053421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// SimplifyAssociativeBinOp - Generic simplifications for associative binary 2063421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// operations. Returns the simpler value, or null if none was found. 207e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramerstatic Value *SimplifyAssociativeBinOp(unsigned Opc, Value *LHS, Value *RHS, 208566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands const TargetData *TD, 209566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands const DominatorTree *DT, 210566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands unsigned MaxRecurse) { 211e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer Instruction::BinaryOps Opcode = (Instruction::BinaryOps)Opc; 212566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands assert(Instruction::isAssociative(Opcode) && "Not an associative operation!"); 213566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 214566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 215566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (!MaxRecurse--) 216566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return 0; 217566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 218566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS); 219566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS); 220566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 221566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Transform: "(A op B) op C" ==> "A op (B op C)" if it simplifies completely. 222566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Op0 && Op0->getOpcode() == Opcode) { 223566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = Op0->getOperand(0); 224566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *B = Op0->getOperand(1); 225566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *C = RHS; 226566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 227566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Does "B op C" simplify? 228566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyBinOp(Opcode, B, C, TD, DT, MaxRecurse)) { 229566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // It does! Return "A op V" if it simplifies or is already available. 230566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If V equals B then "A op V" is just the LHS. 231124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == B) return LHS; 232566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Otherwise return "A op V" if it simplifies. 233a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *W = SimplifyBinOp(Opcode, A, V, TD, DT, MaxRecurse)) { 234a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumReassoc; 235566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return W; 236a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 237566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 238566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 239566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 240566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Transform: "A op (B op C)" ==> "(A op B) op C" if it simplifies completely. 241566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Op1 && Op1->getOpcode() == Opcode) { 242566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = LHS; 243566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *B = Op1->getOperand(0); 244566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *C = Op1->getOperand(1); 245566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 246566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Does "A op B" simplify? 247566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyBinOp(Opcode, A, B, TD, DT, MaxRecurse)) { 248566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // It does! Return "V op C" if it simplifies or is already available. 249566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If V equals B then "V op C" is just the RHS. 250124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == B) return RHS; 251566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Otherwise return "V op C" if it simplifies. 252a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *W = SimplifyBinOp(Opcode, V, C, TD, DT, MaxRecurse)) { 253a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumReassoc; 254566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return W; 255a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 256566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 257566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 258566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 259566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // The remaining transforms require commutativity as well as associativity. 260566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (!Instruction::isCommutative(Opcode)) 261566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return 0; 262566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 263566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Transform: "(A op B) op C" ==> "(C op A) op B" if it simplifies completely. 264566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Op0 && Op0->getOpcode() == Opcode) { 265566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = Op0->getOperand(0); 266566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *B = Op0->getOperand(1); 267566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *C = RHS; 268566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 269566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Does "C op A" simplify? 270566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyBinOp(Opcode, C, A, TD, DT, MaxRecurse)) { 271566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // It does! Return "V op B" if it simplifies or is already available. 272566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If V equals A then "V op B" is just the LHS. 273124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == A) return LHS; 274566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Otherwise return "V op B" if it simplifies. 275a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *W = SimplifyBinOp(Opcode, V, B, TD, DT, MaxRecurse)) { 276a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumReassoc; 277566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return W; 278a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 279566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 280566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 281566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 282566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Transform: "A op (B op C)" ==> "B op (C op A)" if it simplifies completely. 283566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Op1 && Op1->getOpcode() == Opcode) { 284566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = LHS; 285566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *B = Op1->getOperand(0); 286566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *C = Op1->getOperand(1); 287566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 288566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Does "C op A" simplify? 289566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyBinOp(Opcode, C, A, TD, DT, MaxRecurse)) { 290566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // It does! Return "B op V" if it simplifies or is already available. 291566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If V equals C then "B op V" is just the RHS. 292124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == C) return RHS; 293566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Otherwise return "B op V" if it simplifies. 294a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *W = SimplifyBinOp(Opcode, B, V, TD, DT, MaxRecurse)) { 295a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumReassoc; 296566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return W; 297a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 298566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 299566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 300566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 301566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return 0; 302566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands} 303566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 304b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// ThreadBinOpOverSelect - In the case of a binary operation with a select 305b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// instruction as an operand, try to simplify the binop by seeing whether 306b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// evaluating it on both branches of the select results in the same value. 307b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// Returns the common value if so, otherwise returns null. 308b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sandsstatic Value *ThreadBinOpOverSelect(unsigned Opcode, Value *LHS, Value *RHS, 3091845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, 3101845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT, 3111845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 3120312a93693abc2eb682b2b101c889959888fd883Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 3130312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (!MaxRecurse--) 3140312a93693abc2eb682b2b101c889959888fd883Duncan Sands return 0; 3150312a93693abc2eb682b2b101c889959888fd883Duncan Sands 316b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands SelectInst *SI; 317b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (isa<SelectInst>(LHS)) { 318b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands SI = cast<SelectInst>(LHS); 319b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } else { 320b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands assert(isa<SelectInst>(RHS) && "No select instruction operand!"); 321b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands SI = cast<SelectInst>(RHS); 322b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 323b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 324b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Evaluate the BinOp on the true and false branches of the select. 325b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *TV; 326b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *FV; 327b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (SI == LHS) { 3281845009290e4d804ad377927bd8a08cca3036adcDuncan Sands TV = SimplifyBinOp(Opcode, SI->getTrueValue(), RHS, TD, DT, MaxRecurse); 3291845009290e4d804ad377927bd8a08cca3036adcDuncan Sands FV = SimplifyBinOp(Opcode, SI->getFalseValue(), RHS, TD, DT, MaxRecurse); 330b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } else { 3311845009290e4d804ad377927bd8a08cca3036adcDuncan Sands TV = SimplifyBinOp(Opcode, LHS, SI->getTrueValue(), TD, DT, MaxRecurse); 3321845009290e4d804ad377927bd8a08cca3036adcDuncan Sands FV = SimplifyBinOp(Opcode, LHS, SI->getFalseValue(), TD, DT, MaxRecurse); 333b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 334b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 3357cf85e74e3885005ca8e5fdb155fa5351e255b85Duncan Sands // If they simplified to the same value, then return the common value. 336124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands // If they both failed to simplify then return null. 337124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (TV == FV) 338b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return TV; 339b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 340b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If one branch simplified to undef, return the other one. 341b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (TV && isa<UndefValue>(TV)) 342b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return FV; 343b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (FV && isa<UndefValue>(FV)) 344b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return TV; 345b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 346b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If applying the operation did not change the true and false select values, 347b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // then the result of the binop is the select itself. 348124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (TV == SI->getTrueValue() && FV == SI->getFalseValue()) 349b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return SI; 350b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 351b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If one branch simplified and the other did not, and the simplified 352b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // value is equal to the unsimplified one, return the simplified value. 353b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // For example, select (cond, X, X & Z) & Z -> X & Z. 354b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if ((FV && !TV) || (TV && !FV)) { 355b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Check that the simplified value has the form "X op Y" where "op" is the 356b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // same as the original operation. 357b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Instruction *Simplified = dyn_cast<Instruction>(FV ? FV : TV); 358b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (Simplified && Simplified->getOpcode() == Opcode) { 359b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // The value that didn't simplify is "UnsimplifiedLHS op UnsimplifiedRHS". 360b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // We already know that "op" is the same as for the simplified value. See 361b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // if the operands match too. If so, return the simplified value. 362b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *UnsimplifiedBranch = FV ? SI->getTrueValue() : SI->getFalseValue(); 363b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *UnsimplifiedLHS = SI == LHS ? UnsimplifiedBranch : LHS; 364b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *UnsimplifiedRHS = SI == LHS ? RHS : UnsimplifiedBranch; 365124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Simplified->getOperand(0) == UnsimplifiedLHS && 366124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Simplified->getOperand(1) == UnsimplifiedRHS) 367b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return Simplified; 368b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (Simplified->isCommutative() && 369124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Simplified->getOperand(1) == UnsimplifiedLHS && 370124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Simplified->getOperand(0) == UnsimplifiedRHS) 371b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return Simplified; 372b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 373b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 374b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 375b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return 0; 376b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands} 377b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 378b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// ThreadCmpOverSelect - In the case of a comparison with a select instruction, 379b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// try to simplify the comparison by seeing whether both branches of the select 380b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// result in the same value. Returns the common value if so, otherwise returns 381b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// null. 382b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sandsstatic Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS, 383a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Value *RHS, const TargetData *TD, 3841845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT, 385a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands unsigned MaxRecurse) { 3860312a93693abc2eb682b2b101c889959888fd883Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 3870312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (!MaxRecurse--) 3880312a93693abc2eb682b2b101c889959888fd883Duncan Sands return 0; 3890312a93693abc2eb682b2b101c889959888fd883Duncan Sands 390b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Make sure the select is on the LHS. 391b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (!isa<SelectInst>(LHS)) { 392b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands std::swap(LHS, RHS); 393b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Pred = CmpInst::getSwappedPredicate(Pred); 394b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 395b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands assert(isa<SelectInst>(LHS) && "Not comparing with a select instruction!"); 396b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands SelectInst *SI = cast<SelectInst>(LHS); 397b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 398b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Now that we have "cmp select(cond, TV, FV), RHS", analyse it. 399b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Does "cmp TV, RHS" simplify? 4001845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *TCmp = SimplifyCmpInst(Pred, SI->getTrueValue(), RHS, TD, DT, 401a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands MaxRecurse)) 402b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // It does! Does "cmp FV, RHS" simplify? 4031845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *FCmp = SimplifyCmpInst(Pred, SI->getFalseValue(), RHS, TD, DT, 404a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands MaxRecurse)) 405b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // It does! If they simplified to the same value, then use it as the 406b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // result of the original comparison. 407124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (TCmp == FCmp) 408b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return TCmp; 409b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return 0; 410b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands} 411b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 412a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// ThreadBinOpOverPHI - In the case of a binary operation with an operand that 413a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// is a PHI instruction, try to simplify the binop by seeing whether evaluating 414a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// it on the incoming phi values yields the same result for every value. If so 415a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// returns the common value, otherwise returns null. 416a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *ThreadBinOpOverPHI(unsigned Opcode, Value *LHS, Value *RHS, 4171845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT, 4181845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 4190312a93693abc2eb682b2b101c889959888fd883Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 4200312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (!MaxRecurse--) 4210312a93693abc2eb682b2b101c889959888fd883Duncan Sands return 0; 4220312a93693abc2eb682b2b101c889959888fd883Duncan Sands 423a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands PHINode *PI; 424a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands if (isa<PHINode>(LHS)) { 425a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands PI = cast<PHINode>(LHS); 4261845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Bail out if RHS and the phi may be mutually interdependent due to a loop. 4271845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (!ValueDominatesPHI(RHS, PI, DT)) 4281845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return 0; 429a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } else { 430a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands assert(isa<PHINode>(RHS) && "No PHI instruction operand!"); 431a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands PI = cast<PHINode>(RHS); 4321845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Bail out if LHS and the phi may be mutually interdependent due to a loop. 4331845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (!ValueDominatesPHI(LHS, PI, DT)) 4341845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return 0; 435a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } 436a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 437a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // Evaluate the BinOp on the incoming phi values. 438a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Value *CommonValue = 0; 439a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) { 440552008946530e01efdad15044e1f621883d14a3aDuncan Sands Value *Incoming = PI->getIncomingValue(i); 441ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If the incoming value is the phi node itself, it can safely be skipped. 442552008946530e01efdad15044e1f621883d14a3aDuncan Sands if (Incoming == PI) continue; 443a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Value *V = PI == LHS ? 4441845009290e4d804ad377927bd8a08cca3036adcDuncan Sands SimplifyBinOp(Opcode, Incoming, RHS, TD, DT, MaxRecurse) : 4451845009290e4d804ad377927bd8a08cca3036adcDuncan Sands SimplifyBinOp(Opcode, LHS, Incoming, TD, DT, MaxRecurse); 446a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation failed to simplify, or simplified to a different value 447a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // to previously, then give up. 448a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands if (!V || (CommonValue && V != CommonValue)) 449a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return 0; 450a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands CommonValue = V; 451a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } 452a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 453a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return CommonValue; 454a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 455a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 456a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// ThreadCmpOverPHI - In the case of a comparison with a PHI instruction, try 457a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// try to simplify the comparison by seeing whether comparing with all of the 458a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// incoming phi values yields the same result every time. If so returns the 459a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// common result, otherwise returns null. 460a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *ThreadCmpOverPHI(CmpInst::Predicate Pred, Value *LHS, Value *RHS, 4611845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT, 4621845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 4630312a93693abc2eb682b2b101c889959888fd883Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 4640312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (!MaxRecurse--) 4650312a93693abc2eb682b2b101c889959888fd883Duncan Sands return 0; 4660312a93693abc2eb682b2b101c889959888fd883Duncan Sands 467a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // Make sure the phi is on the LHS. 468a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands if (!isa<PHINode>(LHS)) { 469a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands std::swap(LHS, RHS); 470a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Pred = CmpInst::getSwappedPredicate(Pred); 471a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } 472a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands assert(isa<PHINode>(LHS) && "Not comparing with a phi instruction!"); 473a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands PHINode *PI = cast<PHINode>(LHS); 474a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 4751845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Bail out if RHS and the phi may be mutually interdependent due to a loop. 4761845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (!ValueDominatesPHI(RHS, PI, DT)) 4771845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return 0; 4781845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 479a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // Evaluate the BinOp on the incoming phi values. 480a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Value *CommonValue = 0; 481a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) { 482552008946530e01efdad15044e1f621883d14a3aDuncan Sands Value *Incoming = PI->getIncomingValue(i); 483ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If the incoming value is the phi node itself, it can safely be skipped. 484552008946530e01efdad15044e1f621883d14a3aDuncan Sands if (Incoming == PI) continue; 4851845009290e4d804ad377927bd8a08cca3036adcDuncan Sands Value *V = SimplifyCmpInst(Pred, Incoming, RHS, TD, DT, MaxRecurse); 486a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation failed to simplify, or simplified to a different value 487a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // to previously, then give up. 488a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands if (!V || (CommonValue && V != CommonValue)) 489a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return 0; 490a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands CommonValue = V; 491a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } 492a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 493a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return CommonValue; 494a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 495a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 4968aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner/// SimplifyAddInst - Given operands for an Add, see if we can 497d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner/// fold the result. If not, this returns null. 498ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sandsstatic Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 499ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands const TargetData *TD, const DominatorTree *DT, 500ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands unsigned MaxRecurse) { 501d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 502d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 503d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Constant *Ops[] = { CLHS, CRHS }; 5048aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner return ConstantFoldInstOperands(Instruction::Add, CLHS->getType(), 5058aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner Ops, 2, TD); 5068aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner } 50712a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 5088aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner // Canonicalize the constant to the RHS. 5098aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner std::swap(Op0, Op1); 5108aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner } 51112a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 512fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X + undef -> undef 513fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (isa<UndefValue>(Op1)) 514fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Op1; 51512a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 516fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X + 0 -> X 517fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (match(Op1, m_Zero())) 518fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Op0; 519fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 520fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X + (Y - X) -> Y 521fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // (Y - X) + X -> Y 522ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands // Eg: X + -X -> 0 523124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Value *Y = 0; 524124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (match(Op1, m_Sub(m_Value(Y), m_Specific(Op0))) || 525124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands match(Op0, m_Sub(m_Value(Y), m_Specific(Op1)))) 526fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Y; 527fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 528fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X + ~X -> -1 since ~X = -X-1 529124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (match(Op0, m_Not(m_Specific(Op1))) || 530124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands match(Op1, m_Not(m_Specific(Op0)))) 531fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Constant::getAllOnesValue(Op0->getType()); 53287689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands 53382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands /// i1 add -> xor. 53475d289ed6201e82718343d7a36d2a2fa082f6217Duncan Sands if (MaxRecurse && Op0->getType()->isIntegerTy(1)) 53507f30fbd734069b80b90c6aeea0ae645ce3880c0Duncan Sands if (Value *V = SimplifyXorInst(Op0, Op1, TD, DT, MaxRecurse-1)) 53607f30fbd734069b80b90c6aeea0ae645ce3880c0Duncan Sands return V; 53782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 538566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Try some generic simplifications for associative operations. 539566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::Add, Op0, Op1, TD, DT, 540566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands MaxRecurse)) 541566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 542566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 5433421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Mul distributes over Add. Try some generic simplifications based on this. 5443421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::Add, Op0, Op1, Instruction::Mul, 5453421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 5463421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 5473421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 54887689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // Threading Add over selects and phi nodes is pointless, so don't bother. 54987689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // Threading over the select in "A + select(cond, B, C)" means evaluating 55087689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // "A+B" and "A+C" and seeing if they are equal; but they are equal if and 55187689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // only if B and C are equal. If B and C are equal then (since we assume 55287689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // that operands have already been simplified) "select(cond, B, C)" should 55387689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // have been simplified to the common value of B and C already. Analysing 55487689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // "A+B" and "A+C" thus gains nothing, but costs compile time. Similarly 55587689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // for threading over phi nodes. 55687689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands 5578aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner return 0; 5588aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner} 5598aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner 560ee9a2e322af96accc9e55ed6373c0057453714b1Duncan SandsValue *llvm::SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 561ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands const TargetData *TD, const DominatorTree *DT) { 562ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, TD, DT, RecursionLimit); 563ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands} 564ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands 565fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands/// SimplifySubInst - Given operands for a Sub, see if we can 566fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands/// fold the result. If not, this returns null. 567ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sandsstatic Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 5683421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands const TargetData *TD, const DominatorTree *DT, 569ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands unsigned MaxRecurse) { 570fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (Constant *CLHS = dyn_cast<Constant>(Op0)) 571fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 572fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands Constant *Ops[] = { CLHS, CRHS }; 573fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return ConstantFoldInstOperands(Instruction::Sub, CLHS->getType(), 574fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands Ops, 2, TD); 575fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands } 576fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 577fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X - undef -> undef 578fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // undef - X -> undef 579fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (isa<UndefValue>(Op0) || isa<UndefValue>(Op1)) 580fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return UndefValue::get(Op0->getType()); 581fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 582fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X - 0 -> X 583fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (match(Op1, m_Zero())) 584fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Op0; 585fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 586fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X - X -> 0 587124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Op0 == Op1) 588fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Constant::getNullValue(Op0->getType()); 589fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 590fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands // (X*2) - X -> X 591fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands // (X<<1) - X -> X 592b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands Value *X = 0; 593fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands if (match(Op0, m_Mul(m_Specific(Op1), m_ConstantInt<2>())) || 594fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands match(Op0, m_Shl(m_Specific(Op1), m_One()))) 595fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands return Op1; 596fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands 597b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies. 598b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // For example, (X + Y) - Y -> X; (Y + X) - Y -> X 599b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands Value *Y = 0, *Z = Op1; 600b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (MaxRecurse && match(Op0, m_Add(m_Value(X), m_Value(Y)))) { // (X + Y) - Z 601b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // See if "V === Y - Z" simplifies. 602b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, Y, Z, TD, DT, MaxRecurse-1)) 603b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "X + V" simplifies. 604b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Add, X, V, TD, DT, 605b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands MaxRecurse-1)) { 606b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does, we successfully reassociated! 607b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands ++NumReassoc; 608b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return W; 609b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 610b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // See if "V === X - Z" simplifies. 611b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, TD, DT, MaxRecurse-1)) 612b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "Y + V" simplifies. 613b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Add, Y, V, TD, DT, 614b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands MaxRecurse-1)) { 615b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does, we successfully reassociated! 616b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands ++NumReassoc; 617b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return W; 618b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 619b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 62082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 621b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // X - (Y + Z) -> (X - Y) - Z or (X - Z) - Y if everything simplifies. 622b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // For example, X - (X + 1) -> -1 623b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands X = Op0; 624b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (MaxRecurse && match(Op1, m_Add(m_Value(Y), m_Value(Z)))) { // X - (Y + Z) 625b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // See if "V === X - Y" simplifies. 626b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, TD, DT, MaxRecurse-1)) 627b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "V - Z" simplifies. 628b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Sub, V, Z, TD, DT, 629b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands MaxRecurse-1)) { 630b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does, we successfully reassociated! 631b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands ++NumReassoc; 632b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return W; 633b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 634b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // See if "V === X - Z" simplifies. 635b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, TD, DT, MaxRecurse-1)) 636b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "V - Y" simplifies. 637b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Sub, V, Y, TD, DT, 638b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands MaxRecurse-1)) { 639b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does, we successfully reassociated! 640b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands ++NumReassoc; 641b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return W; 642b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 643b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 644b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands 645b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // Z - (X - Y) -> (Z - X) + Y if everything simplifies. 646b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // For example, X - (X - Y) -> Y. 647b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands Z = Op0; 648c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands if (MaxRecurse && match(Op1, m_Sub(m_Value(X), m_Value(Y)))) // Z - (X - Y) 649c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands // See if "V === Z - X" simplifies. 650c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, Z, X, TD, DT, MaxRecurse-1)) 651b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "V + Y" simplifies. 652c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands if (Value *W = SimplifyBinOp(Instruction::Add, V, Y, TD, DT, 653c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands MaxRecurse-1)) { 654c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands // It does, we successfully reassociated! 655c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands ++NumReassoc; 656c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands return W; 657c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands } 658c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands 6593421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Mul distributes over Sub. Try some generic simplifications based on this. 6603421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::Sub, Op0, Op1, Instruction::Mul, 6613421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 6623421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 6633421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 664b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // i1 sub -> xor. 665b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (MaxRecurse && Op0->getType()->isIntegerTy(1)) 666b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *V = SimplifyXorInst(Op0, Op1, TD, DT, MaxRecurse-1)) 667b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return V; 668b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands 669fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // Threading Sub over selects and phi nodes is pointless, so don't bother. 670fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // Threading over the select in "A - select(cond, B, C)" means evaluating 671fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // "A-B" and "A-C" and seeing if they are equal; but they are equal if and 672fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // only if B and C are equal. If B and C are equal then (since we assume 673fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // that operands have already been simplified) "select(cond, B, C)" should 674fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // have been simplified to the common value of B and C already. Analysing 675fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly 676fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // for threading over phi nodes. 677fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 678fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return 0; 679fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands} 680fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 681ee9a2e322af96accc9e55ed6373c0057453714b1Duncan SandsValue *llvm::SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 682ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands const TargetData *TD, const DominatorTree *DT) { 683ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, TD, DT, RecursionLimit); 684ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands} 685ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands 68682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands/// SimplifyMulInst - Given operands for a Mul, see if we can 68782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands/// fold the result. If not, this returns null. 68882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sandsstatic Value *SimplifyMulInst(Value *Op0, Value *Op1, const TargetData *TD, 68982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 69082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 69182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 69282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Constant *Ops[] = { CLHS, CRHS }; 69382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return ConstantFoldInstOperands(Instruction::Mul, CLHS->getType(), 69482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Ops, 2, TD); 69582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands } 69682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 69782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // Canonicalize the constant to the RHS. 69882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands std::swap(Op0, Op1); 69982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands } 70082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 70182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // X * undef -> 0 70282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (isa<UndefValue>(Op1)) 70382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return Constant::getNullValue(Op0->getType()); 70482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 70582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // X * 0 -> 0 70682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (match(Op1, m_Zero())) 70782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return Op1; 70882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 70982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // X * 1 -> X 71082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (match(Op1, m_One())) 71182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return Op0; 71282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 71382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands /// i1 mul -> and. 71475d289ed6201e82718343d7a36d2a2fa082f6217Duncan Sands if (MaxRecurse && Op0->getType()->isIntegerTy(1)) 71507f30fbd734069b80b90c6aeea0ae645ce3880c0Duncan Sands if (Value *V = SimplifyAndInst(Op0, Op1, TD, DT, MaxRecurse-1)) 71607f30fbd734069b80b90c6aeea0ae645ce3880c0Duncan Sands return V; 71782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 71882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // Try some generic simplifications for associative operations. 71982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::Mul, Op0, Op1, TD, DT, 72082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands MaxRecurse)) 72182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return V; 72282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 72382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // Mul distributes over Add. Try some generic simplifications based on this. 72482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Value *V = ExpandBinOp(Instruction::Mul, Op0, Op1, Instruction::Add, 72582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands TD, DT, MaxRecurse)) 72682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return V; 72782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 72882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // If the operation is with the result of a select instruction, check whether 72982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // operating on either branch of the select always yields the same value. 73082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 73182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Value *V = ThreadBinOpOverSelect(Instruction::Mul, Op0, Op1, TD, DT, 73282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands MaxRecurse)) 73382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return V; 73482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 73582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // If the operation is with the result of a phi instruction, check whether 73682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // operating on all incoming values of the phi always yields the same value. 73782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 73882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Value *V = ThreadBinOpOverPHI(Instruction::Mul, Op0, Op1, TD, DT, 73982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands MaxRecurse)) 74082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return V; 74182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 74282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return 0; 74382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands} 74482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 74582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan SandsValue *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const TargetData *TD, 74682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands const DominatorTree *DT) { 74782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return ::SimplifyMulInst(Op0, Op1, TD, DT, RecursionLimit); 74882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands} 74982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 750593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// SimplifyDiv - Given operands for an SDiv or UDiv, see if we can 751593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// fold the result. If not, this returns null. 752593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sandsstatic Value *SimplifyDiv(unsigned Opcode, Value *Op0, Value *Op1, 753593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands const TargetData *TD, const DominatorTree *DT, 754593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands unsigned MaxRecurse) { 755593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Constant *C0 = dyn_cast<Constant>(Op0)) { 756593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Constant *C1 = dyn_cast<Constant>(Op1)) { 757593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands Constant *Ops[] = { C0, C1 }; 758593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, 2, TD); 759593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands } 760593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands } 761593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 762a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands bool isSigned = Opcode == Instruction::SDiv; 763a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands 764593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // X / undef -> undef 765593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (isa<UndefValue>(Op1)) 766593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op1; 767593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 768593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // undef / X -> 0 769593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (isa<UndefValue>(Op0)) 770593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Constant::getNullValue(Op0->getType()); 771593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 772593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // 0 / X -> 0, we don't need to preserve faults! 773593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (match(Op0, m_Zero())) 774593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op0; 775593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 776593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // X / 1 -> X 777593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (match(Op1, m_One())) 778593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op0; 779593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // Vector case. TODO: Have m_One match vectors. 780593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (ConstantVector *Op1V = dyn_cast<ConstantVector>(Op1)) { 781593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (ConstantInt *X = cast_or_null<ConstantInt>(Op1V->getSplatValue())) 782593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (X->isOne()) 783593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op0; 784593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands } 785593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 786593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Op0->getType()->isIntegerTy(1)) 787593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // It can't be division by zero, hence it must be division by one. 788593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op0; 789593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 790593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // X / X -> 1 791593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Op0 == Op1) 792593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return ConstantInt::get(Op0->getType(), 1); 793593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 794593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // (X * Y) / Y -> X if the multiplication does not overflow. 795593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands Value *X = 0, *Y = 0; 796593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (match(Op0, m_Mul(m_Value(X), m_Value(Y))) && (X == Op1 || Y == Op1)) { 797593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Y != Op1) std::swap(X, Y); // Ensure expression is (X * Y) / Y, Y = Op1 79879f4eea7a3375aef93bf0d9fb1785ffee801eb84Duncan Sands BinaryOperator *Mul = cast<BinaryOperator>(Op0); 799593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // If the Mul knows it does not overflow, then we are good to go. 800593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if ((isSigned && Mul->hasNoSignedWrap()) || 801593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands (!isSigned && Mul->hasNoUnsignedWrap())) 802593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return X; 803593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // If X has the form X = A / Y then X * Y cannot overflow. 804593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (BinaryOperator *Div = dyn_cast<BinaryOperator>(X)) 805593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Div->getOpcode() == Opcode && Div->getOperand(1) == Y) 806593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return X; 807593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands } 808593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 809a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // (X rem Y) / Y -> 0 810a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if ((isSigned && match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) || 811a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands (!isSigned && match(Op0, m_URem(m_Value(), m_Specific(Op1))))) 812a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands return Constant::getNullValue(Op0->getType()); 813a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands 814a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // If the operation is with the result of a select instruction, check whether 815a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // operating on either branch of the select always yields the same value. 816a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 817a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, TD, DT, MaxRecurse)) 818a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands return V; 819a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands 820a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // If the operation is with the result of a phi instruction, check whether 821a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // operating on all incoming values of the phi always yields the same value. 822a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 823a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, TD, DT, MaxRecurse)) 824a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands return V; 825a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands 826593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return 0; 827593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 828593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 829593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// SimplifySDivInst - Given operands for an SDiv, see if we can 830593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// fold the result. If not, this returns null. 831593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sandsstatic Value *SimplifySDivInst(Value *Op0, Value *Op1, const TargetData *TD, 832593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 833593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, TD, DT, MaxRecurse)) 834593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return V; 835593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 836593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return 0; 837593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 838593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 839593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan SandsValue *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const TargetData *TD, 8401fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel const DominatorTree *DT) { 841593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return ::SimplifySDivInst(Op0, Op1, TD, DT, RecursionLimit); 842593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 843593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 844593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// SimplifyUDivInst - Given operands for a UDiv, see if we can 845593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// fold the result. If not, this returns null. 846593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sandsstatic Value *SimplifyUDivInst(Value *Op0, Value *Op1, const TargetData *TD, 847593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 848593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, TD, DT, MaxRecurse)) 849593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return V; 850593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 851593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return 0; 852593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 853593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 854593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan SandsValue *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const TargetData *TD, 8551fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel const DominatorTree *DT) { 856593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return ::SimplifyUDivInst(Op0, Op1, TD, DT, RecursionLimit); 857593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 858593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 8591fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommelstatic Value *SimplifyFDivInst(Value *Op0, Value *Op1, const TargetData *TD, 8601fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel const DominatorTree *DT, unsigned MaxRecurse) { 8611fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel // undef / X -> undef (the undef could be a snan). 8621fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel if (isa<UndefValue>(Op0)) 8631fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel return Op0; 8641fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel 8651fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel // X / undef -> undef 8661fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel if (isa<UndefValue>(Op1)) 8671fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel return Op1; 8681fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel 8691fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel return 0; 8701fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel} 8711fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel 8721fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van BommelValue *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, const TargetData *TD, 8731fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel const DominatorTree *DT) { 8741fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel return ::SimplifyFDivInst(Op0, Op1, TD, DT, RecursionLimit); 8751fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel} 8761fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel 877cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands/// SimplifyShift - Given operands for an Shl, LShr or AShr, see if we can 878c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// fold the result. If not, this returns null. 879cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sandsstatic Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1, 880cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands const TargetData *TD, const DominatorTree *DT, 881cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands unsigned MaxRecurse) { 882c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (Constant *C0 = dyn_cast<Constant>(Op0)) { 883c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (Constant *C1 = dyn_cast<Constant>(Op1)) { 884c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands Constant *Ops[] = { C0, C1 }; 885cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, 2, TD); 886c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands } 887c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands } 888c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 889cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // 0 shift by X -> 0 890c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (match(Op0, m_Zero())) 891c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Op0; 892c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 893cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // X shift by 0 -> X 894c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (match(Op1, m_Zero())) 895c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Op0; 896c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 897cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // X shift by undef -> undef because it may shift by the bitwidth. 898c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (isa<UndefValue>(Op1)) 899c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Op1; 900c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 901c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands // Shifting by the bitwidth or more is undefined. 902c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) 903c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (CI->getValue().getLimitedValue() >= 904c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands Op0->getType()->getScalarSizeInBits()) 905c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return UndefValue::get(Op0->getType()); 906c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 907cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // If the operation is with the result of a select instruction, check whether 908cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // operating on either branch of the select always yields the same value. 909cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 910cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, TD, DT, MaxRecurse)) 911cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 912cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 913cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // If the operation is with the result of a phi instruction, check whether 914cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // operating on all incoming values of the phi always yields the same value. 915cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 916cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, TD, DT, MaxRecurse)) 917cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 918cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 919cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return 0; 920cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands} 921cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 922cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands/// SimplifyShlInst - Given operands for an Shl, see if we can 923cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands/// fold the result. If not, this returns null. 924cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sandsstatic Value *SimplifyShlInst(Value *Op0, Value *Op1, const TargetData *TD, 925cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 926cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (Value *V = SimplifyShift(Instruction::Shl, Op0, Op1, TD, DT, MaxRecurse)) 927cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 928cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 929cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // undef << X -> 0 930cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (isa<UndefValue>(Op0)) 931cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return Constant::getNullValue(Op0->getType()); 932cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 933c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return 0; 934c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 935c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 936c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan SandsValue *llvm::SimplifyShlInst(Value *Op0, Value *Op1, const TargetData *TD, 937c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands const DominatorTree *DT) { 938c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return ::SimplifyShlInst(Op0, Op1, TD, DT, RecursionLimit); 939c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 940c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 941c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// SimplifyLShrInst - Given operands for an LShr, see if we can 942c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// fold the result. If not, this returns null. 943c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sandsstatic Value *SimplifyLShrInst(Value *Op0, Value *Op1, const TargetData *TD, 944c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 945cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (Value *V = SimplifyShift(Instruction::LShr, Op0, Op1, TD, DT, MaxRecurse)) 946cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 947c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 948c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands // undef >>l X -> 0 949c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (isa<UndefValue>(Op0)) 950c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Constant::getNullValue(Op0->getType()); 951c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 952c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return 0; 953c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 954c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 955c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan SandsValue *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, const TargetData *TD, 956c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands const DominatorTree *DT) { 957c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return ::SimplifyLShrInst(Op0, Op1, TD, DT, RecursionLimit); 958c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 959c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 960c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// SimplifyAShrInst - Given operands for an AShr, see if we can 961c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// fold the result. If not, this returns null. 962c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sandsstatic Value *SimplifyAShrInst(Value *Op0, Value *Op1, const TargetData *TD, 963c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 964cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (Value *V = SimplifyShift(Instruction::AShr, Op0, Op1, TD, DT, MaxRecurse)) 965cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 966c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 967c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands // all ones >>a X -> all ones 968c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (match(Op0, m_AllOnes())) 969c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Op0; 970c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 971c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands // undef >>a X -> all ones 972c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (isa<UndefValue>(Op0)) 973c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Constant::getAllOnesValue(Op0->getType()); 974c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 975c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return 0; 976c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 977c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 978c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan SandsValue *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, const TargetData *TD, 979c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands const DominatorTree *DT) { 980c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return ::SimplifyAShrInst(Op0, Op1, TD, DT, RecursionLimit); 981c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 982c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 9838aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner/// SimplifyAndInst - Given operands for an And, see if we can 9848aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner/// fold the result. If not, this returns null. 985a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyAndInst(Value *Op0, Value *Op1, const TargetData *TD, 9861845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 9878aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 9888aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 9898aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner Constant *Ops[] = { CLHS, CRHS }; 990d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return ConstantFoldInstOperands(Instruction::And, CLHS->getType(), 991d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Ops, 2, TD); 992d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 99312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 994d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // Canonicalize the constant to the RHS. 995d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner std::swap(Op0, Op1); 996d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 99712a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 998d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // X & undef -> 0 999d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (isa<UndefValue>(Op1)) 1000d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Constant::getNullValue(Op0->getType()); 100112a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1002d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // X & X = X 1003124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Op0 == Op1) 1004d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 100512a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 10062b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // X & 0 = 0 10072b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_Zero())) 1008d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op1; 100912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 10102b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // X & -1 = X 10112b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_AllOnes())) 10122b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Op0; 101312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1014d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // A & ~A = ~A & A = 0 1015e89ada98a6ed803ca865843678c4dd4cf77b14eeChandler Carruth Value *A = 0, *B = 0; 1016124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if ((match(Op0, m_Not(m_Value(A))) && A == Op1) || 1017124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (match(Op1, m_Not(m_Value(A))) && A == Op0)) 1018d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Constant::getNullValue(Op0->getType()); 101912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1020d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // (A | ?) & A = A 1021d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (match(Op0, m_Or(m_Value(A), m_Value(B))) && 1022124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (A == Op1 || B == Op1)) 1023d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op1; 102412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1025d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // A & (A | ?) = A 1026d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (match(Op1, m_Or(m_Value(A), m_Value(B))) && 1027124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (A == Op0 || B == Op0)) 1028d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 102912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1030566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Try some generic simplifications for associative operations. 1031566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::And, Op0, Op1, TD, DT, 1032566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands MaxRecurse)) 1033566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 10346844c8ea5a67e551be7106d6b7b9e1a64eecbe51Benjamin Kramer 10353421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // And distributes over Or. Try some generic simplifications based on this. 10363421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Or, 10373421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 10383421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 10393421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 10403421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // And distributes over Xor. Try some generic simplifications based on this. 10413421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Xor, 10423421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 10433421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 10443421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 10453421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Or distributes over And. Try some generic simplifications based on this. 10463421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::And, Op0, Op1, Instruction::Or, 10473421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 10483421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 10493421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1050b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If the operation is with the result of a select instruction, check whether 1051b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // operating on either branch of the select always yields the same value. 10520312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 10531845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *V = ThreadBinOpOverSelect(Instruction::And, Op0, Op1, TD, DT, 10540312a93693abc2eb682b2b101c889959888fd883Duncan Sands MaxRecurse)) 1055a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 1056a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1057a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation is with the result of a phi instruction, check whether 1058a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // operating on all incoming values of the phi always yields the same value. 10590312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 10601845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *V = ThreadBinOpOverPHI(Instruction::And, Op0, Op1, TD, DT, 10610312a93693abc2eb682b2b101c889959888fd883Duncan Sands MaxRecurse)) 1062b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return V; 1063b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 1064d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return 0; 1065d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner} 10669f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 10671845009290e4d804ad377927bd8a08cca3036adcDuncan SandsValue *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const TargetData *TD, 10681845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT) { 10691845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return ::SimplifyAndInst(Op0, Op1, TD, DT, RecursionLimit); 1070a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 1071a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1072d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner/// SimplifyOrInst - Given operands for an Or, see if we can 10739f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner/// fold the result. If not, this returns null. 1074a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyOrInst(Value *Op0, Value *Op1, const TargetData *TD, 10751845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 1076d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 1077d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 1078d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Constant *Ops[] = { CLHS, CRHS }; 1079d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return ConstantFoldInstOperands(Instruction::Or, CLHS->getType(), 1080d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Ops, 2, TD); 1081d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 108212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1083d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // Canonicalize the constant to the RHS. 1084d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner std::swap(Op0, Op1); 1085d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 108612a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1087d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // X | undef -> -1 1088d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (isa<UndefValue>(Op1)) 1089d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Constant::getAllOnesValue(Op0->getType()); 109012a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1091d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // X | X = X 1092124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Op0 == Op1) 1093d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 1094d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner 10952b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // X | 0 = X 10962b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_Zero())) 1097d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 109812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 10992b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // X | -1 = -1 11002b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_AllOnes())) 11012b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Op1; 110212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1103d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // A | ~A = ~A | A = -1 1104e89ada98a6ed803ca865843678c4dd4cf77b14eeChandler Carruth Value *A = 0, *B = 0; 1105124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if ((match(Op0, m_Not(m_Value(A))) && A == Op1) || 1106124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (match(Op1, m_Not(m_Value(A))) && A == Op0)) 1107d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Constant::getAllOnesValue(Op0->getType()); 110812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1109d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // (A & ?) | A = A 1110d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (match(Op0, m_And(m_Value(A), m_Value(B))) && 1111124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (A == Op1 || B == Op1)) 1112d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op1; 111312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1114d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // A | (A & ?) = A 1115d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (match(Op1, m_And(m_Value(A), m_Value(B))) && 1116124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (A == Op0 || B == Op0)) 1117d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 111812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1119566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Try some generic simplifications for associative operations. 1120566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::Or, Op0, Op1, TD, DT, 1121566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands MaxRecurse)) 1122566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 11236844c8ea5a67e551be7106d6b7b9e1a64eecbe51Benjamin Kramer 11243421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Or distributes over And. Try some generic simplifications based on this. 11253421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = ExpandBinOp(Instruction::Or, Op0, Op1, Instruction::And, 11263421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 11273421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 11283421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 11293421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // And distributes over Or. Try some generic simplifications based on this. 11303421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::Or, Op0, Op1, Instruction::And, 11313421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 11323421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 11333421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1134b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If the operation is with the result of a select instruction, check whether 1135b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // operating on either branch of the select always yields the same value. 11360312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 11371845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *V = ThreadBinOpOverSelect(Instruction::Or, Op0, Op1, TD, DT, 11380312a93693abc2eb682b2b101c889959888fd883Duncan Sands MaxRecurse)) 1139a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 1140a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1141a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation is with the result of a phi instruction, check whether 1142a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // operating on all incoming values of the phi always yields the same value. 11430312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 11441845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *V = ThreadBinOpOverPHI(Instruction::Or, Op0, Op1, TD, DT, 11450312a93693abc2eb682b2b101c889959888fd883Duncan Sands MaxRecurse)) 1146b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return V; 1147b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 11489f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner return 0; 11499f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner} 11509f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 11511845009290e4d804ad377927bd8a08cca3036adcDuncan SandsValue *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const TargetData *TD, 11521845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT) { 11531845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return ::SimplifyOrInst(Op0, Op1, TD, DT, RecursionLimit); 1154a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 1155d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner 11562b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands/// SimplifyXorInst - Given operands for a Xor, see if we can 11572b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands/// fold the result. If not, this returns null. 11582b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sandsstatic Value *SimplifyXorInst(Value *Op0, Value *Op1, const TargetData *TD, 11592b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 11602b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 11612b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 11622b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands Constant *Ops[] = { CLHS, CRHS }; 11632b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return ConstantFoldInstOperands(Instruction::Xor, CLHS->getType(), 11642b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands Ops, 2, TD); 11652b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands } 11662b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 11672b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // Canonicalize the constant to the RHS. 11682b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands std::swap(Op0, Op1); 11692b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands } 11702b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 11712b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // A ^ undef -> undef 11722b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (isa<UndefValue>(Op1)) 1173f8b1a5ea9602bb65a5cf59d3d34f2851a08cdc3eDuncan Sands return Op1; 11742b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 11752b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // A ^ 0 = A 11762b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_Zero())) 11772b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Op0; 11782b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 11792b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // A ^ A = 0 1180124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Op0 == Op1) 11812b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Constant::getNullValue(Op0->getType()); 11822b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 11832b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // A ^ ~A = ~A ^ A = -1 1184566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = 0; 1185124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if ((match(Op0, m_Not(m_Value(A))) && A == Op1) || 1186124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (match(Op1, m_Not(m_Value(A))) && A == Op0)) 11872b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Constant::getAllOnesValue(Op0->getType()); 11882b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 1189566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Try some generic simplifications for associative operations. 1190566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::Xor, Op0, Op1, TD, DT, 1191566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands MaxRecurse)) 1192566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 11932b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 11943421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // And distributes over Xor. Try some generic simplifications based on this. 11953421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::Xor, Op0, Op1, Instruction::And, 11963421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 11973421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 11983421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 119987689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // Threading Xor over selects and phi nodes is pointless, so don't bother. 120087689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // Threading over the select in "A ^ select(cond, B, C)" means evaluating 120187689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // "A^B" and "A^C" and seeing if they are equal; but they are equal if and 120287689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // only if B and C are equal. If B and C are equal then (since we assume 120387689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // that operands have already been simplified) "select(cond, B, C)" should 120487689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // have been simplified to the common value of B and C already. Analysing 120587689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // "A^B" and "A^C" thus gains nothing, but costs compile time. Similarly 120687689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // for threading over phi nodes. 12072b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 12082b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return 0; 12092b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands} 12102b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 12112b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan SandsValue *llvm::SimplifyXorInst(Value *Op0, Value *Op1, const TargetData *TD, 12122b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands const DominatorTree *DT) { 12132b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return ::SimplifyXorInst(Op0, Op1, TD, DT, RecursionLimit); 12142b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands} 12152b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 1216210c5d4880b525e064088b6fec713260128c16ebChris Lattnerstatic const Type *GetCompareTy(Value *Op) { 1217210c5d4880b525e064088b6fec713260128c16ebChris Lattner return CmpInst::makeCmpResultType(Op->getType()); 1218210c5d4880b525e064088b6fec713260128c16ebChris Lattner} 1219210c5d4880b525e064088b6fec713260128c16ebChris Lattner 12209dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// SimplifyICmpInst - Given operands for an ICmpInst, see if we can 12219dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// fold the result. If not, this returns null. 1222a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, 12231845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT, 12241845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 12259f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate; 12269dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner assert(CmpInst::isIntPredicate(Pred) && "Not an integer compare!"); 122712a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1228d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(LHS)) { 12298f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(RHS)) 12308f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, TD); 1231d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner 1232d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // If we have a constant, make sure it is on the RHS. 1233d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner std::swap(LHS, RHS); 1234d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Pred = CmpInst::getSwappedPredicate(Pred); 1235d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 123612a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 12376dc91253ab1872e118b08511a09d5c934988354eDuncan Sands const Type *ITy = GetCompareTy(LHS); // The return type. 12386dc91253ab1872e118b08511a09d5c934988354eDuncan Sands const Type *OpTy = LHS->getType(); // The operand type. 123912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1240210c5d4880b525e064088b6fec713260128c16ebChris Lattner // icmp X, X -> true/false 1241c8e14b3d37b80abb6adb4b831af0452d9ecbf2b2Chris Lattner // X icmp undef -> true/false. For example, icmp ugt %X, undef -> false 1242c8e14b3d37b80abb6adb4b831af0452d9ecbf2b2Chris Lattner // because X could be 0. 1243124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (LHS == RHS || isa<UndefValue>(RHS)) 1244210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred)); 124512a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 12466dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // Special case logic when the operands have i1 type. 12476dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (OpTy->isIntegerTy(1) || (OpTy->isVectorTy() && 12486dc91253ab1872e118b08511a09d5c934988354eDuncan Sands cast<VectorType>(OpTy)->getElementType()->isIntegerTy(1))) { 12496dc91253ab1872e118b08511a09d5c934988354eDuncan Sands switch (Pred) { 12506dc91253ab1872e118b08511a09d5c934988354eDuncan Sands default: break; 12516dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_EQ: 12526dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X == 1 -> X 12536dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_One())) 12546dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 12556dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 12566dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_NE: 12576dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X != 0 -> X 12586dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_Zero())) 12596dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 12606dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 12616dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_UGT: 12626dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X >u 0 -> X 12636dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_Zero())) 12646dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 12656dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 12666dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_UGE: 12676dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X >=u 1 -> X 12686dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_One())) 12696dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 12706dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 12716dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_SLT: 12726dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X <s 0 -> X 12736dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_Zero())) 12746dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 12756dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 12766dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_SLE: 12776dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X <=s -1 -> X 12786dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_One())) 12796dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 12806dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 12816dc91253ab1872e118b08511a09d5c934988354eDuncan Sands } 12826dc91253ab1872e118b08511a09d5c934988354eDuncan Sands } 128312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1284d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // icmp <alloca*>, <global/alloca*/null> - Different stack variables have 1285d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // different addresses, and what's more the address of a stack variable is 1286d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // never null or equal to the address of a global. Note that generalizing 1287d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // to the case where LHS is a global variable address or null is pointless, 1288d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // since if both LHS and RHS are constants then we already constant folded 1289d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // the compare, and if only one of them is then we moved it to RHS already. 1290d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (isa<AllocaInst>(LHS) && (isa<GlobalValue>(RHS) || isa<AllocaInst>(RHS) || 1291d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands isa<ConstantPointerNull>(RHS))) 1292d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // We already know that LHS != LHS. 1293d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::get(ITy, CmpInst::isFalseWhenEqual(Pred)); 1294d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands 1295d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // If we are comparing with zero then try hard since this is a common case. 1296d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (match(RHS, m_Zero())) { 1297d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands bool LHSKnownNonNegative, LHSKnownNegative; 1298d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands switch (Pred) { 1299d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands default: 1300d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands assert(false && "Unknown ICmp predicate!"); 1301d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_ULT: 1302d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::getFalse(LHS->getContext()); 1303d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_UGE: 1304d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::getTrue(LHS->getContext()); 1305d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_EQ: 1306d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_ULE: 1307d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (isKnownNonZero(LHS, TD)) 1308d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::getFalse(LHS->getContext()); 1309d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1310d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_NE: 1311d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_UGT: 1312d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (isKnownNonZero(LHS, TD)) 1313d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::getTrue(LHS->getContext()); 1314d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1315d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_SLT: 1316d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, TD); 1317d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNegative) 1318d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::getTrue(LHS->getContext()); 1319d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNonNegative) 1320d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::getFalse(LHS->getContext()); 1321d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1322d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_SLE: 1323d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, TD); 1324d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNegative) 1325d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::getTrue(LHS->getContext()); 1326d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNonNegative && isKnownNonZero(LHS, TD)) 1327d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::getFalse(LHS->getContext()); 1328d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1329d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_SGE: 1330d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, TD); 1331d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNegative) 1332d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::getFalse(LHS->getContext()); 1333d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNonNegative) 1334d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::getTrue(LHS->getContext()); 1335d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1336d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_SGT: 1337d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, TD); 1338d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNegative) 1339d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::getFalse(LHS->getContext()); 1340d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNonNegative && isKnownNonZero(LHS, TD)) 1341d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::getTrue(LHS->getContext()); 1342d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1343d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands } 1344d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands } 1345d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands 1346d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // See if we are doing a comparison with a constant integer. 1347210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) { 1348210c5d4880b525e064088b6fec713260128c16ebChris Lattner switch (Pred) { 1349210c5d4880b525e064088b6fec713260128c16ebChris Lattner default: break; 13506dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_UGT: 13516dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (CI->isMaxValue(false)) // A >u MAX -> FALSE 13526dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return ConstantInt::getFalse(CI->getContext()); 1353210c5d4880b525e064088b6fec713260128c16ebChris Lattner break; 1354210c5d4880b525e064088b6fec713260128c16ebChris Lattner case ICmpInst::ICMP_UGE: 1355210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (CI->isMinValue(false)) // A >=u MIN -> TRUE 1356210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::getTrue(CI->getContext()); 1357210c5d4880b525e064088b6fec713260128c16ebChris Lattner break; 13586dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_ULT: 13596dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (CI->isMinValue(false)) // A <u MIN -> FALSE 13606dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return ConstantInt::getFalse(CI->getContext()); 13616dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 13626dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_ULE: 13636dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (CI->isMaxValue(false)) // A <=u MAX -> TRUE 13646dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return ConstantInt::getTrue(CI->getContext()); 13656dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 13666dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_SGT: 13676dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (CI->isMaxValue(true)) // A >s MAX -> FALSE 13686dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return ConstantInt::getFalse(CI->getContext()); 13696dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 1370210c5d4880b525e064088b6fec713260128c16ebChris Lattner case ICmpInst::ICMP_SGE: 1371210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (CI->isMinValue(true)) // A >=s MIN -> TRUE 1372210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::getTrue(CI->getContext()); 1373210c5d4880b525e064088b6fec713260128c16ebChris Lattner break; 13746dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_SLT: 13756dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (CI->isMinValue(true)) // A <s MIN -> FALSE 13766dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return ConstantInt::getFalse(CI->getContext()); 13776dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 13786dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_SLE: 13796dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (CI->isMaxValue(true)) // A <=s MAX -> TRUE 13806dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return ConstantInt::getTrue(CI->getContext()); 13816dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 1382210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 1383210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 13841ac7c9979a2d723ff4649ffad58df02732872a5fDuncan Sands 13859d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compare of cast, for example (zext X) != 0 -> X != 0 13869d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (isa<CastInst>(LHS) && (isa<Constant>(RHS) || isa<CastInst>(RHS))) { 13879d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Instruction *LI = cast<CastInst>(LHS); 13889d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Value *SrcOp = LI->getOperand(0); 13899d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands const Type *SrcTy = SrcOp->getType(); 13909d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands const Type *DstTy = LI->getType(); 13919d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 13929d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input 13939d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // if the integer type is the same size as the pointer type. 13949d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse && TD && isa<PtrToIntInst>(LI) && 13959d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands TD->getPointerSizeInBits() == DstTy->getPrimitiveSizeInBits()) { 13969d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Constant *RHSC = dyn_cast<Constant>(RHS)) { 13979d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Transfer the cast to the constant. 13989d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(Pred, SrcOp, 13999d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantExpr::getIntToPtr(RHSC, SrcTy), 14009d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands TD, DT, MaxRecurse-1)) 14019d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 14029d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } else if (PtrToIntInst *RI = dyn_cast<PtrToIntInst>(RHS)) { 14039d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RI->getOperand(0)->getType() == SrcTy) 14049d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compare without the cast. 14059d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0), 14069d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands TD, DT, MaxRecurse-1)) 14079d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 14089d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 14099d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 14109d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 14119d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (isa<ZExtInst>(LHS)) { 14129d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (zext X), (zext Y) into a compare of X and Y if they have the 14139d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // same type. 14149d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (ZExtInst *RI = dyn_cast<ZExtInst>(RHS)) { 14159d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse && SrcTy == RI->getOperand(0)->getType()) 14169d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compare X and Y. Note that signed predicates become unsigned. 14179d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred), 14189d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands SrcOp, RI->getOperand(0), TD, DT, 14199d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands MaxRecurse-1)) 14209d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 14219d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 14229d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (zext X), Cst into a compare of X and Cst if Cst is extended 14239d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // too. If not, then try to deduce the result of the comparison. 14249d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) { 14259d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compute the constant that would happen if we truncated to SrcTy then 14269d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // reextended to DstTy. 14279d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy); 14289d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant *RExt = ConstantExpr::getCast(CastInst::ZExt, Trunc, DstTy); 14299d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 14309d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // If the re-extended constant didn't change then this is effectively 14319d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // also a case of comparing two zero-extended values. 14329d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RExt == CI && MaxRecurse) 14339d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred), 14349d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands SrcOp, Trunc, TD, DT, MaxRecurse-1)) 14359d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 14369d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 14379d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Otherwise the upper bits of LHS are zero while RHS has a non-zero bit 14389d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // there. Use this to work out the result of the comparison. 14399d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RExt != CI) { 14409d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands switch (Pred) { 14419d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands default: 14429d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands assert(false && "Unknown ICmp predicate!"); 14439d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // LHS <u RHS. 14449d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_EQ: 14459d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_UGT: 14469d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_UGE: 14479d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return ConstantInt::getFalse(CI->getContext()); 14489d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 14499d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_NE: 14509d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_ULT: 14519d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_ULE: 14529d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return ConstantInt::getTrue(CI->getContext()); 14539d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 14549d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // LHS is non-negative. If RHS is negative then LHS >s LHS. If RHS 14559d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // is non-negative then LHS <s RHS. 14569d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SGT: 14579d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SGE: 14589d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return CI->getValue().isNegative() ? 14599d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getTrue(CI->getContext()) : 14609d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getFalse(CI->getContext()); 14619d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 14629d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SLT: 14639d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SLE: 14649d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return CI->getValue().isNegative() ? 14659d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getFalse(CI->getContext()) : 14669d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getTrue(CI->getContext()); 14679d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 14689d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 14699d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 14709d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 14719d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 14729d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (isa<SExtInst>(LHS)) { 14739d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (sext X), (sext Y) into a compare of X and Y if they have the 14749d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // same type. 14759d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (SExtInst *RI = dyn_cast<SExtInst>(RHS)) { 14769d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse && SrcTy == RI->getOperand(0)->getType()) 14779d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compare X and Y. Note that the predicate does not change. 14789d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0), 14799d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands TD, DT, MaxRecurse-1)) 14809d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 14819d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 14829d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (sext X), Cst into a compare of X and Cst if Cst is extended 14839d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // too. If not, then try to deduce the result of the comparison. 14849d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) { 14859d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compute the constant that would happen if we truncated to SrcTy then 14869d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // reextended to DstTy. 14879d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy); 14889d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant *RExt = ConstantExpr::getCast(CastInst::SExt, Trunc, DstTy); 14899d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 14909d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // If the re-extended constant didn't change then this is effectively 14919d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // also a case of comparing two sign-extended values. 14929d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RExt == CI && MaxRecurse) 14939d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(Pred, SrcOp, Trunc, TD, DT, 14949d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands MaxRecurse-1)) 14959d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 14969d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 14979d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Otherwise the upper bits of LHS are all equal, while RHS has varying 14989d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // bits there. Use this to work out the result of the comparison. 14999d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RExt != CI) { 15009d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands switch (Pred) { 15019d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands default: 15029d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands assert(false && "Unknown ICmp predicate!"); 15039d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_EQ: 15049d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return ConstantInt::getFalse(CI->getContext()); 15059d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_NE: 15069d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return ConstantInt::getTrue(CI->getContext()); 15079d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 15089d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // If RHS is non-negative then LHS <s RHS. If RHS is negative then 15099d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // LHS >s RHS. 15109d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SGT: 15119d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SGE: 15129d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return CI->getValue().isNegative() ? 15139d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getTrue(CI->getContext()) : 15149d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getFalse(CI->getContext()); 15159d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SLT: 15169d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SLE: 15179d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return CI->getValue().isNegative() ? 15189d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getFalse(CI->getContext()) : 15199d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getTrue(CI->getContext()); 15209d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 15219d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // If LHS is non-negative then LHS <u RHS. If LHS is negative then 15229d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // LHS >u RHS. 15239d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_UGT: 15249d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_UGE: 15259d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Comparison is true iff the LHS <s 0. 15269d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse) 15279d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SLT, SrcOp, 15289d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant::getNullValue(SrcTy), 15299d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands TD, DT, MaxRecurse-1)) 15309d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 15319d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands break; 15329d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_ULT: 15339d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_ULE: 15349d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Comparison is true iff the LHS >=s 0. 15359d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse) 15369d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SGE, SrcOp, 15379d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant::getNullValue(SrcTy), 15389d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands TD, DT, MaxRecurse-1)) 15399d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 15409d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands break; 15419d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 15429d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 15439d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 15449d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 15459d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 15469d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 15471ac7c9979a2d723ff4649ffad58df02732872a5fDuncan Sands // If the comparison is with the result of a select instruction, check whether 15481ac7c9979a2d723ff4649ffad58df02732872a5fDuncan Sands // comparing with either branch of the select always yields the same value. 15490312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS)) 15500312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, TD, DT, MaxRecurse)) 1551a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 1552a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1553a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the comparison is with the result of a phi instruction, check whether 1554a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // doing the compare with each incoming phi value yields a common result. 15550312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(LHS) || isa<PHINode>(RHS)) 15560312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, TD, DT, MaxRecurse)) 15573bbb0cc42b67b4bf2c488285666999963bab0f7eDuncan Sands return V; 15581ac7c9979a2d723ff4649ffad58df02732872a5fDuncan Sands 15599dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner return 0; 15609dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner} 15619dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 1562a74a58c83be492b7d5b7383656f049909394cff4Duncan SandsValue *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, 15631845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT) { 15641845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return ::SimplifyICmpInst(Predicate, LHS, RHS, TD, DT, RecursionLimit); 1565a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 1566a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 15679dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can 15689dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// fold the result. If not, this returns null. 1569a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS, 15701845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT, 15711845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 15729dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate; 15739dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!"); 15749dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 1575d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(LHS)) { 15769dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner if (Constant *CRHS = dyn_cast<Constant>(RHS)) 15779dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, TD); 157812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1579d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // If we have a constant, make sure it is on the RHS. 1580d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner std::swap(LHS, RHS); 1581d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Pred = CmpInst::getSwappedPredicate(Pred); 1582d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 158312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1584210c5d4880b525e064088b6fec713260128c16ebChris Lattner // Fold trivial predicates. 1585210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (Pred == FCmpInst::FCMP_FALSE) 1586210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(GetCompareTy(LHS), 0); 1587210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (Pred == FCmpInst::FCMP_TRUE) 1588210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(GetCompareTy(LHS), 1); 1589210c5d4880b525e064088b6fec713260128c16ebChris Lattner 1590210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (isa<UndefValue>(RHS)) // fcmp pred X, undef -> undef 1591210c5d4880b525e064088b6fec713260128c16ebChris Lattner return UndefValue::get(GetCompareTy(LHS)); 1592210c5d4880b525e064088b6fec713260128c16ebChris Lattner 1593210c5d4880b525e064088b6fec713260128c16ebChris Lattner // fcmp x,x -> true/false. Not all compares are foldable. 1594124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (LHS == RHS) { 1595210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (CmpInst::isTrueWhenEqual(Pred)) 1596210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(GetCompareTy(LHS), 1); 1597210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (CmpInst::isFalseWhenEqual(Pred)) 1598210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(GetCompareTy(LHS), 0); 1599210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 160012a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1601210c5d4880b525e064088b6fec713260128c16ebChris Lattner // Handle fcmp with constant RHS 1602210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (Constant *RHSC = dyn_cast<Constant>(RHS)) { 1603210c5d4880b525e064088b6fec713260128c16ebChris Lattner // If the constant is a nan, see if we can fold the comparison based on it. 1604210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHSC)) { 1605210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (CFP->getValueAPF().isNaN()) { 1606210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (FCmpInst::isOrdered(Pred)) // True "if ordered and foo" 1607210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::getFalse(CFP->getContext()); 1608210c5d4880b525e064088b6fec713260128c16ebChris Lattner assert(FCmpInst::isUnordered(Pred) && 1609210c5d4880b525e064088b6fec713260128c16ebChris Lattner "Comparison must be either ordered or unordered!"); 1610210c5d4880b525e064088b6fec713260128c16ebChris Lattner // True if unordered. 1611210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::getTrue(CFP->getContext()); 1612210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 16136b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // Check whether the constant is an infinity. 16146b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman if (CFP->getValueAPF().isInfinity()) { 16156b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman if (CFP->getValueAPF().isNegative()) { 16166b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman switch (Pred) { 16176b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman case FCmpInst::FCMP_OLT: 16186b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // No value is ordered and less than negative infinity. 16196b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman return ConstantInt::getFalse(CFP->getContext()); 16206b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman case FCmpInst::FCMP_UGE: 16216b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // All values are unordered with or at least negative infinity. 16226b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman return ConstantInt::getTrue(CFP->getContext()); 16236b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman default: 16246b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman break; 16256b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } 16266b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } else { 16276b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman switch (Pred) { 16286b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman case FCmpInst::FCMP_OGT: 16296b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // No value is ordered and greater than infinity. 16306b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman return ConstantInt::getFalse(CFP->getContext()); 16316b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman case FCmpInst::FCMP_ULE: 16326b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // All values are unordered with and at most infinity. 16336b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman return ConstantInt::getTrue(CFP->getContext()); 16346b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman default: 16356b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman break; 16366b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } 16376b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } 16386b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } 1639210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 1640210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 164112a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 164292826def593df7a422c7b07f09342febce81ddd3Duncan Sands // If the comparison is with the result of a select instruction, check whether 164392826def593df7a422c7b07f09342febce81ddd3Duncan Sands // comparing with either branch of the select always yields the same value. 16440312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS)) 16450312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, TD, DT, MaxRecurse)) 1646a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 1647a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1648a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the comparison is with the result of a phi instruction, check whether 1649a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // doing the compare with each incoming phi value yields a common result. 16500312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(LHS) || isa<PHINode>(RHS)) 16510312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, TD, DT, MaxRecurse)) 16523bbb0cc42b67b4bf2c488285666999963bab0f7eDuncan Sands return V; 165392826def593df7a422c7b07f09342febce81ddd3Duncan Sands 16549f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner return 0; 16559f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner} 16569f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 1657a74a58c83be492b7d5b7383656f049909394cff4Duncan SandsValue *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS, 16581845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT) { 16591845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return ::SimplifyFCmpInst(Predicate, LHS, RHS, TD, DT, RecursionLimit); 1660a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 1661a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1662047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner/// SimplifySelectInst - Given operands for a SelectInst, see if we can fold 1663047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner/// the result. If not, this returns null. 1664124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan SandsValue *llvm::SimplifySelectInst(Value *CondVal, Value *TrueVal, Value *FalseVal, 1665124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands const TargetData *TD, const DominatorTree *) { 1666047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner // select true, X, Y -> X 1667047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner // select false, X, Y -> Y 1668047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner if (ConstantInt *CB = dyn_cast<ConstantInt>(CondVal)) 1669047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return CB->getZExtValue() ? TrueVal : FalseVal; 167012a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1671047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner // select C, X, X -> X 1672124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (TrueVal == FalseVal) 1673047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return TrueVal; 167412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1675047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X 1676047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return FalseVal; 1677047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X 1678047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return TrueVal; 1679047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner if (isa<UndefValue>(CondVal)) { // select undef, X, Y -> X or Y 1680047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner if (isa<Constant>(TrueVal)) 1681047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return TrueVal; 1682047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return FalseVal; 1683047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner } 168412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1685047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return 0; 1686047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner} 1687047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner 1688c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner/// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can 1689c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner/// fold the result. If not, this returns null. 1690c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris LattnerValue *llvm::SimplifyGEPInst(Value *const *Ops, unsigned NumOps, 16911845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *) { 169285bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands // The type of the GEP pointer operand. 169385bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands const PointerType *PtrTy = cast<PointerType>(Ops[0]->getType()); 169485bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands 1695c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner // getelementptr P -> P. 1696c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner if (NumOps == 1) 1697c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner return Ops[0]; 1698c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner 169985bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands if (isa<UndefValue>(Ops[0])) { 170085bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands // Compute the (pointer) type returned by the GEP instruction. 170185bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands const Type *LastType = GetElementPtrInst::getIndexedType(PtrTy, &Ops[1], 170285bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands NumOps-1); 170385bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands const Type *GEPTy = PointerType::get(LastType, PtrTy->getAddressSpace()); 170485bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands return UndefValue::get(GEPTy); 170585bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands } 1706c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner 1707e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands if (NumOps == 2) { 1708e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands // getelementptr P, 0 -> P. 1709c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner if (ConstantInt *C = dyn_cast<ConstantInt>(Ops[1])) 1710c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner if (C->isZero()) 1711c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner return Ops[0]; 1712e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands // getelementptr P, N -> P if P points to a type of zero size. 1713e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands if (TD) { 171485bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands const Type *Ty = PtrTy->getElementType(); 1715a63395a30f9227bde826749d3480046301b47332Duncan Sands if (Ty->isSized() && TD->getTypeAllocSize(Ty) == 0) 1716e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands return Ops[0]; 1717e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands } 1718e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands } 171912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1720c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner // Check to see if this is constant foldable. 1721c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner for (unsigned i = 0; i != NumOps; ++i) 1722c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner if (!isa<Constant>(Ops[i])) 1723c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner return 0; 172412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1725c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner return ConstantExpr::getGetElementPtr(cast<Constant>(Ops[0]), 1726c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner (Constant *const*)Ops+1, NumOps-1); 1727c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner} 1728c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner 1729ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands/// SimplifyPHINode - See if we can fold the given phi. If not, returns null. 1730ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sandsstatic Value *SimplifyPHINode(PHINode *PN, const DominatorTree *DT) { 1731ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If all of the PHI's incoming values are the same then replace the PHI node 1732ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // with the common value. 1733ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands Value *CommonValue = 0; 1734ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands bool HasUndefInput = false; 1735ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { 1736ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands Value *Incoming = PN->getIncomingValue(i); 1737ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If the incoming value is the phi node itself, it can safely be skipped. 1738ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (Incoming == PN) continue; 1739ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (isa<UndefValue>(Incoming)) { 1740ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // Remember that we saw an undef value, but otherwise ignore them. 1741ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands HasUndefInput = true; 1742ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands continue; 1743ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands } 1744ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (CommonValue && Incoming != CommonValue) 1745ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands return 0; // Not the same, bail out. 1746ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands CommonValue = Incoming; 1747ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands } 1748ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands 1749ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If CommonValue is null then all of the incoming values were either undef or 1750ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // equal to the phi node itself. 1751ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (!CommonValue) 1752ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands return UndefValue::get(PN->getType()); 1753ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands 1754ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If we have a PHI node like phi(X, undef, X), where X is defined by some 1755ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // instruction, we cannot return X as the result of the PHI node unless it 1756ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // dominates the PHI block. 1757ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (HasUndefInput) 1758ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands return ValueDominatesPHI(CommonValue, PN, DT) ? CommonValue : 0; 1759ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands 1760ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands return CommonValue; 1761ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands} 1762ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands 1763c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner 1764d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner//=== Helper functions for higher up the class hierarchy. 17659dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 1766d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner/// SimplifyBinOp - Given operands for a BinaryOperator, see if we can 1767d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner/// fold the result. If not, this returns null. 1768a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, 17691845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT, 17701845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 1771d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner switch (Opcode) { 1772ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands case Instruction::Add: return SimplifyAddInst(LHS, RHS, /* isNSW */ false, 1773ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands /* isNUW */ false, TD, DT, 1774ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands MaxRecurse); 1775ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands case Instruction::Sub: return SimplifySubInst(LHS, RHS, /* isNSW */ false, 1776ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands /* isNUW */ false, TD, DT, 1777ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands MaxRecurse); 177882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands case Instruction::Mul: return SimplifyMulInst(LHS, RHS, TD, DT, MaxRecurse); 1779593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands case Instruction::SDiv: return SimplifySDivInst(LHS, RHS, TD, DT, MaxRecurse); 1780593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands case Instruction::UDiv: return SimplifyUDivInst(LHS, RHS, TD, DT, MaxRecurse); 17811fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel case Instruction::FDiv: return SimplifyFDivInst(LHS, RHS, TD, DT, MaxRecurse); 1782c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands case Instruction::Shl: return SimplifyShlInst(LHS, RHS, TD, DT, MaxRecurse); 1783c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands case Instruction::LShr: return SimplifyLShrInst(LHS, RHS, TD, DT, MaxRecurse); 1784c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands case Instruction::AShr: return SimplifyAShrInst(LHS, RHS, TD, DT, MaxRecurse); 178582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands case Instruction::And: return SimplifyAndInst(LHS, RHS, TD, DT, MaxRecurse); 178682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands case Instruction::Or: return SimplifyOrInst(LHS, RHS, TD, DT, MaxRecurse); 178782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands case Instruction::Xor: return SimplifyXorInst(LHS, RHS, TD, DT, MaxRecurse); 1788d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner default: 1789d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(LHS)) 1790d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(RHS)) { 1791d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Constant *COps[] = {CLHS, CRHS}; 1792d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, 2, TD); 1793d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 1794b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 1795566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If the operation is associative, try some generic simplifications. 1796566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Instruction::isAssociative(Opcode)) 1797566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Opcode, LHS, RHS, TD, DT, 1798566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands MaxRecurse)) 1799566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 1800566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 1801b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If the operation is with the result of a select instruction, check whether 1802b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // operating on either branch of the select always yields the same value. 18030312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS)) 18041845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *V = ThreadBinOpOverSelect(Opcode, LHS, RHS, TD, DT, 18050312a93693abc2eb682b2b101c889959888fd883Duncan Sands MaxRecurse)) 1806a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 1807a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1808a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation is with the result of a phi instruction, check whether 1809a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // operating on all incoming values of the phi always yields the same value. 18100312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(LHS) || isa<PHINode>(RHS)) 18110312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, TD, DT, MaxRecurse)) 1812b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return V; 1813b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 1814d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return 0; 1815d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 1816d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner} 18179dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 181812a86f5b3199e72e6d967781acc76340f5920e46Duncan SandsValue *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, 18191845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT) { 18201845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return ::SimplifyBinOp(Opcode, LHS, RHS, TD, DT, RecursionLimit); 1821a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 1822a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 18239dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// SimplifyCmpInst - Given operands for a CmpInst, see if we can 18249dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// fold the result. 1825a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS, 18261845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT, 18271845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 18289dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner if (CmpInst::isIntPredicate((CmpInst::Predicate)Predicate)) 18291845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return SimplifyICmpInst(Predicate, LHS, RHS, TD, DT, MaxRecurse); 18301845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return SimplifyFCmpInst(Predicate, LHS, RHS, TD, DT, MaxRecurse); 18319dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner} 18329dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 1833a74a58c83be492b7d5b7383656f049909394cff4Duncan SandsValue *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS, 18341845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT) { 18351845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return ::SimplifyCmpInst(Predicate, LHS, RHS, TD, DT, RecursionLimit); 1836a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 1837e34537856a544c83513e390ac9552a8bc3823346Chris Lattner 1838e34537856a544c83513e390ac9552a8bc3823346Chris Lattner/// SimplifyInstruction - See if we can compute a simplified version of this 1839e34537856a544c83513e390ac9552a8bc3823346Chris Lattner/// instruction. If not, this returns null. 1840eff0581583ef10e2872e9baf537a04b67d992101Duncan SandsValue *llvm::SimplifyInstruction(Instruction *I, const TargetData *TD, 1841eff0581583ef10e2872e9baf537a04b67d992101Duncan Sands const DominatorTree *DT) { 1842d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Value *Result; 1843d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands 1844e34537856a544c83513e390ac9552a8bc3823346Chris Lattner switch (I->getOpcode()) { 1845e34537856a544c83513e390ac9552a8bc3823346Chris Lattner default: 1846d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = ConstantFoldInstruction(I, TD); 1847d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 18488aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner case Instruction::Add: 1849d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1), 1850d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands cast<BinaryOperator>(I)->hasNoSignedWrap(), 1851d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands cast<BinaryOperator>(I)->hasNoUnsignedWrap(), 1852d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands TD, DT); 1853d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 1854fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands case Instruction::Sub: 1855fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands Result = SimplifySubInst(I->getOperand(0), I->getOperand(1), 1856fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands cast<BinaryOperator>(I)->hasNoSignedWrap(), 1857fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands cast<BinaryOperator>(I)->hasNoUnsignedWrap(), 1858fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands TD, DT); 1859fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands break; 186082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands case Instruction::Mul: 186182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Result = SimplifyMulInst(I->getOperand(0), I->getOperand(1), TD, DT); 186282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands break; 1863593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands case Instruction::SDiv: 1864593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), TD, DT); 1865593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands break; 1866593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands case Instruction::UDiv: 1867593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), TD, DT); 1868593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands break; 18691fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel case Instruction::FDiv: 18701fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1), TD, DT); 18711fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel break; 1872c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands case Instruction::Shl: 1873c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands Result = SimplifyShlInst(I->getOperand(0), I->getOperand(1), TD, DT); 1874c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands break; 1875c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands case Instruction::LShr: 1876c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands Result = SimplifyLShrInst(I->getOperand(0), I->getOperand(1), TD, DT); 1877c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands break; 1878c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands case Instruction::AShr: 1879c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands Result = SimplifyAShrInst(I->getOperand(0), I->getOperand(1), TD, DT); 1880c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands break; 1881e34537856a544c83513e390ac9552a8bc3823346Chris Lattner case Instruction::And: 1882d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyAndInst(I->getOperand(0), I->getOperand(1), TD, DT); 1883d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 1884e34537856a544c83513e390ac9552a8bc3823346Chris Lattner case Instruction::Or: 1885d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyOrInst(I->getOperand(0), I->getOperand(1), TD, DT); 1886d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 18872b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands case Instruction::Xor: 18882b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands Result = SimplifyXorInst(I->getOperand(0), I->getOperand(1), TD, DT); 18892b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands break; 1890e34537856a544c83513e390ac9552a8bc3823346Chris Lattner case Instruction::ICmp: 1891d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(), 1892d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands I->getOperand(0), I->getOperand(1), TD, DT); 1893d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 1894e34537856a544c83513e390ac9552a8bc3823346Chris Lattner case Instruction::FCmp: 1895d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(), 1896d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands I->getOperand(0), I->getOperand(1), TD, DT); 1897d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 1898047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner case Instruction::Select: 1899d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifySelectInst(I->getOperand(0), I->getOperand(1), 1900d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands I->getOperand(2), TD, DT); 1901d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 1902c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner case Instruction::GetElementPtr: { 1903c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner SmallVector<Value*, 8> Ops(I->op_begin(), I->op_end()); 1904d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyGEPInst(&Ops[0], Ops.size(), TD, DT); 1905d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 1906c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner } 1907cd6636c737a82949ad13db2d0d918af6424fb78bDuncan Sands case Instruction::PHI: 1908d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyPHINode(cast<PHINode>(I), DT); 1909d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 1910e34537856a544c83513e390ac9552a8bc3823346Chris Lattner } 1911d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands 1912d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands /// If called on unreachable code, the above logic may report that the 1913d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands /// instruction simplified to itself. Make life easier for users by 1914f8b1a5ea9602bb65a5cf59d3d34f2851a08cdc3eDuncan Sands /// detecting that case here, returning a safe value instead. 1915f8b1a5ea9602bb65a5cf59d3d34f2851a08cdc3eDuncan Sands return Result == I ? UndefValue::get(I->getType()) : Result; 1916e34537856a544c83513e390ac9552a8bc3823346Chris Lattner} 1917e34537856a544c83513e390ac9552a8bc3823346Chris Lattner 191840d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// ReplaceAndSimplifyAllUses - Perform From->replaceAllUsesWith(To) and then 191940d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// delete the From instruction. In addition to a basic RAUW, this does a 192040d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// recursive simplification of the newly formed instructions. This catches 192140d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// things where one simplification exposes other opportunities. This only 192240d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// simplifies and deletes scalar operations, it does not change the CFG. 192340d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// 192440d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattnervoid llvm::ReplaceAndSimplifyAllUses(Instruction *From, Value *To, 1925eff0581583ef10e2872e9baf537a04b67d992101Duncan Sands const TargetData *TD, 1926eff0581583ef10e2872e9baf537a04b67d992101Duncan Sands const DominatorTree *DT) { 192740d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner assert(From != To && "ReplaceAndSimplifyAllUses(X,X) is not valid!"); 192812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1929d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // FromHandle/ToHandle - This keeps a WeakVH on the from/to values so that 1930d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // we can know if it gets deleted out from under us or replaced in a 1931d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // recursive simplification. 193240d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner WeakVH FromHandle(From); 1933d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner WeakVH ToHandle(To); 193412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 193540d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner while (!From->use_empty()) { 193640d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner // Update the instruction to use the new value. 1937d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner Use &TheUse = From->use_begin().getUse(); 1938d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner Instruction *User = cast<Instruction>(TheUse.getUser()); 1939d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner TheUse = To; 1940d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner 1941d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // Check to see if the instruction can be folded due to the operand 1942d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // replacement. For example changing (or X, Y) into (or X, -1) can replace 1943d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // the 'or' with -1. 1944d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner Value *SimplifiedVal; 1945d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner { 1946d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // Sanity check to make sure 'User' doesn't dangle across 1947d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // SimplifyInstruction. 1948d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner AssertingVH<> UserHandle(User); 194912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1950eff0581583ef10e2872e9baf537a04b67d992101Duncan Sands SimplifiedVal = SimplifyInstruction(User, TD, DT); 1951d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner if (SimplifiedVal == 0) continue; 195240d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner } 195312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1954d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // Recursively simplify this user to the new value. 1955eff0581583ef10e2872e9baf537a04b67d992101Duncan Sands ReplaceAndSimplifyAllUses(User, SimplifiedVal, TD, DT); 1956d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner From = dyn_cast_or_null<Instruction>((Value*)FromHandle); 1957d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner To = ToHandle; 195812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1959d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner assert(ToHandle && "To value deleted by recursive simplification?"); 196012a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1961d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // If the recursive simplification ended up revisiting and deleting 1962d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // 'From' then we're done. 1963d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner if (From == 0) 1964d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner return; 196540d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner } 196612a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1967d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // If 'From' has value handles referring to it, do a real RAUW to update them. 1968d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner From->replaceAllUsesWith(To); 196912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 197040d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner From->eraseFromParent(); 197140d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner} 1972