InstructionSimplify.cpp revision 68c0dbc14fb7599987fb3e27be4e12c1ac36535e
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" 21562b84b3aea359d1f918184e355da82bf05eb290Jay Foad#include "llvm/Operator.h" 22a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands#include "llvm/ADT/Statistic.h" 239f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner#include "llvm/Analysis/InstructionSimplify.h" 249f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner#include "llvm/Analysis/ConstantFolding.h" 251845009290e4d804ad377927bd8a08cca3036adcDuncan Sands#include "llvm/Analysis/Dominators.h" 26d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands#include "llvm/Analysis/ValueTracking.h" 273a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky#include "llvm/Support/ConstantRange.h" 28d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner#include "llvm/Support/PatternMatch.h" 291845009290e4d804ad377927bd8a08cca3036adcDuncan Sands#include "llvm/Support/ValueHandle.h" 30e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands#include "llvm/Target/TargetData.h" 319f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattnerusing namespace llvm; 32d06094f0682f2ede03caff4892b1a57469896d48Chris Lattnerusing namespace llvm::PatternMatch; 339f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 3481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattnerenum { RecursionLimit = 3 }; 35a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 36a3c44a5280042dbc0cde995675c225ede4528c6eDuncan SandsSTATISTIC(NumExpand, "Number of expansions"); 37a3c44a5280042dbc0cde995675c225ede4528c6eDuncan SandsSTATISTIC(NumFactor , "Number of factorizations"); 38a3c44a5280042dbc0cde995675c225ede4528c6eDuncan SandsSTATISTIC(NumReassoc, "Number of reassociations"); 39a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands 4082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sandsstatic Value *SimplifyAndInst(Value *, Value *, const TargetData *, 4182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands const DominatorTree *, unsigned); 42a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyBinOp(unsigned, Value *, Value *, const TargetData *, 431845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *, unsigned); 44a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyCmpInst(unsigned, Value *, Value *, const TargetData *, 451845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *, unsigned); 4682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sandsstatic Value *SimplifyOrInst(Value *, Value *, const TargetData *, 4782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands const DominatorTree *, unsigned); 4882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sandsstatic Value *SimplifyXorInst(Value *, Value *, const TargetData *, 4982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands const DominatorTree *, unsigned); 501845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 511845009290e4d804ad377927bd8a08cca3036adcDuncan Sands/// ValueDominatesPHI - Does the given value dominate the specified phi node? 521845009290e4d804ad377927bd8a08cca3036adcDuncan Sandsstatic bool ValueDominatesPHI(Value *V, PHINode *P, const DominatorTree *DT) { 531845009290e4d804ad377927bd8a08cca3036adcDuncan Sands Instruction *I = dyn_cast<Instruction>(V); 541845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (!I) 551845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Arguments and constants dominate all instructions. 561845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return true; 571845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 581845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // If we have a DominatorTree then do a precise test. 591845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (DT) 601845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return DT->dominates(I, P); 611845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 621845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Otherwise, if the instruction is in the entry block, and is not an invoke, 631845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // then it obviously dominates all phi nodes. 641845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (I->getParent() == &I->getParent()->getParent()->getEntryBlock() && 651845009290e4d804ad377927bd8a08cca3036adcDuncan Sands !isa<InvokeInst>(I)) 661845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return true; 671845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 681845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return false; 691845009290e4d804ad377927bd8a08cca3036adcDuncan Sands} 70a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 713421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// ExpandBinOp - Simplify "A op (B op' C)" by distributing op over op', turning 723421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// it into "(A op B) op' (A op C)". Here "op" is given by Opcode and "op'" is 733421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// given by OpcodeToExpand, while "A" corresponds to LHS and "B op' C" to RHS. 743421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// Also performs the transform "(A op' B) op C" -> "(A op C) op' (B op C)". 753421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// Returns the simplified value, or null if no simplification was performed. 763421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sandsstatic Value *ExpandBinOp(unsigned Opcode, Value *LHS, Value *RHS, 77e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer unsigned OpcToExpand, const TargetData *TD, 783421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 79e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer Instruction::BinaryOps OpcodeToExpand = (Instruction::BinaryOps)OpcToExpand; 803421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 813421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (!MaxRecurse--) 823421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 833421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 843421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Check whether the expression has the form "(A op' B) op C". 853421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS)) 863421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Op0->getOpcode() == OpcodeToExpand) { 873421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // It does! Try turning it into "(A op C) op' (B op C)". 883421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands Value *A = Op0->getOperand(0), *B = Op0->getOperand(1), *C = RHS; 893421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Do "A op C" and "B op C" both simplify? 903421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *L = SimplifyBinOp(Opcode, A, C, TD, DT, MaxRecurse)) 913421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *R = SimplifyBinOp(Opcode, B, C, TD, DT, MaxRecurse)) { 923421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // They do! Return "L op' R" if it simplifies or is already available. 933421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // If "L op' R" equals "A op' B" then "L op' R" is just the LHS. 94124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if ((L == A && R == B) || (Instruction::isCommutative(OpcodeToExpand) 95124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands && L == B && R == A)) { 96a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumExpand; 973421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return LHS; 98a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 993421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Otherwise return "L op' R" if it simplifies. 100a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, TD, DT, 101a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands MaxRecurse)) { 102a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumExpand; 1033421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 104a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1053421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1063421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1073421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1083421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Check whether the expression has the form "A op (B op' C)". 1093421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS)) 1103421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Op1->getOpcode() == OpcodeToExpand) { 1113421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // It does! Try turning it into "(A op B) op' (A op C)". 1123421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands Value *A = LHS, *B = Op1->getOperand(0), *C = Op1->getOperand(1); 1133421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Do "A op B" and "A op C" both simplify? 1143421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *L = SimplifyBinOp(Opcode, A, B, TD, DT, MaxRecurse)) 1153421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *R = SimplifyBinOp(Opcode, A, C, TD, DT, MaxRecurse)) { 1163421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // They do! Return "L op' R" if it simplifies or is already available. 1173421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // If "L op' R" equals "B op' C" then "L op' R" is just the RHS. 118124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if ((L == B && R == C) || (Instruction::isCommutative(OpcodeToExpand) 119124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands && L == C && R == B)) { 120a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumExpand; 1213421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return RHS; 122a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1233421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Otherwise return "L op' R" if it simplifies. 124a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *V = SimplifyBinOp(OpcodeToExpand, L, R, TD, DT, 125a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands MaxRecurse)) { 126a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumExpand; 1273421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 128a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1293421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1303421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1313421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1323421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 1333421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands} 1343421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1353421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// FactorizeBinOp - Simplify "LHS Opcode RHS" by factorizing out a common term 1363421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// using the operation OpCodeToExtract. For example, when Opcode is Add and 1373421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// OpCodeToExtract is Mul then this tries to turn "(A*B)+(A*C)" into "A*(B+C)". 1383421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// Returns the simplified value, or null if no simplification was performed. 1393421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sandsstatic Value *FactorizeBinOp(unsigned Opcode, Value *LHS, Value *RHS, 140e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer unsigned OpcToExtract, const TargetData *TD, 1413421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 142e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer Instruction::BinaryOps OpcodeToExtract = (Instruction::BinaryOps)OpcToExtract; 1433421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 1443421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (!MaxRecurse--) 1453421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 1463421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1473421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS); 1483421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS); 1493421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1503421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (!Op0 || Op0->getOpcode() != OpcodeToExtract || 1513421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands !Op1 || Op1->getOpcode() != OpcodeToExtract) 1523421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 1533421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1543421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // The expression has the form "(A op' B) op (C op' D)". 15582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Value *A = Op0->getOperand(0), *B = Op0->getOperand(1); 15682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Value *C = Op1->getOperand(0), *D = Op1->getOperand(1); 1573421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1583421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Use left distributivity, i.e. "X op' (Y op Z) = (X op' Y) op (X op' Z)". 1593421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Does the instruction have the form "(A op' B) op (A op' D)" or, in the 1603421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // commutative case, "(A op' B) op (C op' A)"? 161124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (A == C || (Instruction::isCommutative(OpcodeToExtract) && A == D)) { 162124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Value *DD = A == C ? D : C; 1633421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Form "A op' (B op DD)" if it simplifies completely. 1643421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Does "B op DD" simplify? 1653421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = SimplifyBinOp(Opcode, B, DD, TD, DT, MaxRecurse)) { 1663421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // It does! Return "A op' V" if it simplifies or is already available. 1671cd05bb605e3c3eee9197d3f10b628c60d0cc07aDuncan Sands // If V equals B then "A op' V" is just the LHS. If V equals DD then 1681cd05bb605e3c3eee9197d3f10b628c60d0cc07aDuncan Sands // "A op' V" is just the RHS. 169124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == B || V == DD) { 170a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumFactor; 171124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands return V == B ? LHS : RHS; 172a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1733421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Otherwise return "A op' V" if it simplifies. 174a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *W = SimplifyBinOp(OpcodeToExtract, A, V, TD, DT, MaxRecurse)) { 175a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumFactor; 1763421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return W; 177a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1783421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1793421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 1803421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1813421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Use right distributivity, i.e. "(X op Y) op' Z = (X op' Z) op (Y op' Z)". 1823421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Does the instruction have the form "(A op' B) op (C op' B)" or, in the 1833421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // commutative case, "(A op' B) op (B op' D)"? 184124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (B == D || (Instruction::isCommutative(OpcodeToExtract) && B == C)) { 185124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Value *CC = B == D ? C : D; 1863421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Form "(A op CC) op' B" if it simplifies completely.. 1873421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Does "A op CC" simplify? 1883421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = SimplifyBinOp(Opcode, A, CC, TD, DT, MaxRecurse)) { 1893421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // It does! Return "V op' B" if it simplifies or is already available. 1901cd05bb605e3c3eee9197d3f10b628c60d0cc07aDuncan Sands // If V equals A then "V op' B" is just the LHS. If V equals CC then 1911cd05bb605e3c3eee9197d3f10b628c60d0cc07aDuncan Sands // "V op' B" is just the RHS. 192124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == A || V == CC) { 193a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumFactor; 194124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands return V == A ? LHS : RHS; 195a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 1963421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Otherwise return "V op' B" if it simplifies. 197a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *W = SimplifyBinOp(OpcodeToExtract, V, B, TD, DT, MaxRecurse)) { 198a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumFactor; 1993421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return W; 200a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 2013421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 2023421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands } 2033421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 2043421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return 0; 2053421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands} 2063421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 2073421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// SimplifyAssociativeBinOp - Generic simplifications for associative binary 2083421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands/// operations. Returns the simpler value, or null if none was found. 209e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramerstatic Value *SimplifyAssociativeBinOp(unsigned Opc, Value *LHS, Value *RHS, 210566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands const TargetData *TD, 211566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands const DominatorTree *DT, 212566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands unsigned MaxRecurse) { 213e21083aa3a79506f896d95d7147c3c4627a77ef0Benjamin Kramer Instruction::BinaryOps Opcode = (Instruction::BinaryOps)Opc; 214566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands assert(Instruction::isAssociative(Opcode) && "Not an associative operation!"); 215566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 216566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 217566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (!MaxRecurse--) 218566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return 0; 219566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 220566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands BinaryOperator *Op0 = dyn_cast<BinaryOperator>(LHS); 221566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands BinaryOperator *Op1 = dyn_cast<BinaryOperator>(RHS); 222566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 223566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Transform: "(A op B) op C" ==> "A op (B op C)" if it simplifies completely. 224566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Op0 && Op0->getOpcode() == Opcode) { 225566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = Op0->getOperand(0); 226566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *B = Op0->getOperand(1); 227566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *C = RHS; 228566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 229566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Does "B op C" simplify? 230566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyBinOp(Opcode, B, C, TD, DT, MaxRecurse)) { 231566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // It does! Return "A op V" if it simplifies or is already available. 232566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If V equals B then "A op V" is just the LHS. 233124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == B) return LHS; 234566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Otherwise return "A op V" if it simplifies. 235a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *W = SimplifyBinOp(Opcode, A, V, TD, DT, MaxRecurse)) { 236a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumReassoc; 237566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return W; 238a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 239566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 240566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 241566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 242566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Transform: "A op (B op C)" ==> "(A op B) op C" if it simplifies completely. 243566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Op1 && Op1->getOpcode() == Opcode) { 244566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = LHS; 245566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *B = Op1->getOperand(0); 246566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *C = Op1->getOperand(1); 247566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 248566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Does "A op B" simplify? 249566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyBinOp(Opcode, A, B, TD, DT, MaxRecurse)) { 250566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // It does! Return "V op C" if it simplifies or is already available. 251566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If V equals B then "V op C" is just the RHS. 252124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == B) return RHS; 253566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Otherwise return "V op C" if it simplifies. 254a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *W = SimplifyBinOp(Opcode, V, C, TD, DT, MaxRecurse)) { 255a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumReassoc; 256566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return W; 257a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 258566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 259566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 260566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 261566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // The remaining transforms require commutativity as well as associativity. 262566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (!Instruction::isCommutative(Opcode)) 263566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return 0; 264566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 265566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Transform: "(A op B) op C" ==> "(C op A) op B" if it simplifies completely. 266566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Op0 && Op0->getOpcode() == Opcode) { 267566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = Op0->getOperand(0); 268566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *B = Op0->getOperand(1); 269566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *C = RHS; 270566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 271566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Does "C op A" simplify? 272566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyBinOp(Opcode, C, A, TD, DT, MaxRecurse)) { 273566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // It does! Return "V op B" if it simplifies or is already available. 274566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If V equals A then "V op B" is just the LHS. 275124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == A) return LHS; 276566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Otherwise return "V op B" if it simplifies. 277a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *W = SimplifyBinOp(Opcode, V, B, TD, DT, MaxRecurse)) { 278a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumReassoc; 279566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return W; 280a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 281566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 282566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 283566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 284566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Transform: "A op (B op C)" ==> "B op (C op A)" if it simplifies completely. 285566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Op1 && Op1->getOpcode() == Opcode) { 286566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *A = LHS; 287566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *B = Op1->getOperand(0); 288566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands Value *C = Op1->getOperand(1); 289566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 290566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Does "C op A" simplify? 291566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyBinOp(Opcode, C, A, TD, DT, MaxRecurse)) { 292566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // It does! Return "B op V" if it simplifies or is already available. 293566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If V equals C then "B op V" is just the RHS. 294124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (V == C) return RHS; 295566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Otherwise return "B op V" if it simplifies. 296a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands if (Value *W = SimplifyBinOp(Opcode, B, V, TD, DT, MaxRecurse)) { 297a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands ++NumReassoc; 298566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return W; 299a3c44a5280042dbc0cde995675c225ede4528c6eDuncan Sands } 300566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 301566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands } 302566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 303566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return 0; 304566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands} 305566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 306b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// ThreadBinOpOverSelect - In the case of a binary operation with a select 307b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// instruction as an operand, try to simplify the binop by seeing whether 308b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// evaluating it on both branches of the select results in the same value. 309b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// Returns the common value if so, otherwise returns null. 310b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sandsstatic Value *ThreadBinOpOverSelect(unsigned Opcode, Value *LHS, Value *RHS, 3111845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, 3121845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT, 3131845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 3140312a93693abc2eb682b2b101c889959888fd883Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 3150312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (!MaxRecurse--) 3160312a93693abc2eb682b2b101c889959888fd883Duncan Sands return 0; 3170312a93693abc2eb682b2b101c889959888fd883Duncan Sands 318b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands SelectInst *SI; 319b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (isa<SelectInst>(LHS)) { 320b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands SI = cast<SelectInst>(LHS); 321b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } else { 322b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands assert(isa<SelectInst>(RHS) && "No select instruction operand!"); 323b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands SI = cast<SelectInst>(RHS); 324b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 325b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 326b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Evaluate the BinOp on the true and false branches of the select. 327b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *TV; 328b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *FV; 329b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (SI == LHS) { 3301845009290e4d804ad377927bd8a08cca3036adcDuncan Sands TV = SimplifyBinOp(Opcode, SI->getTrueValue(), RHS, TD, DT, MaxRecurse); 3311845009290e4d804ad377927bd8a08cca3036adcDuncan Sands FV = SimplifyBinOp(Opcode, SI->getFalseValue(), RHS, TD, DT, MaxRecurse); 332b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } else { 3331845009290e4d804ad377927bd8a08cca3036adcDuncan Sands TV = SimplifyBinOp(Opcode, LHS, SI->getTrueValue(), TD, DT, MaxRecurse); 3341845009290e4d804ad377927bd8a08cca3036adcDuncan Sands FV = SimplifyBinOp(Opcode, LHS, SI->getFalseValue(), TD, DT, MaxRecurse); 335b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 336b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 3377cf85e74e3885005ca8e5fdb155fa5351e255b85Duncan Sands // If they simplified to the same value, then return the common value. 338124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands // If they both failed to simplify then return null. 339124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (TV == FV) 340b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return TV; 341b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 342b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If one branch simplified to undef, return the other one. 343b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (TV && isa<UndefValue>(TV)) 344b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return FV; 345b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (FV && isa<UndefValue>(FV)) 346b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return TV; 347b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 348b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If applying the operation did not change the true and false select values, 349b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // then the result of the binop is the select itself. 350124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (TV == SI->getTrueValue() && FV == SI->getFalseValue()) 351b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return SI; 352b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 353b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If one branch simplified and the other did not, and the simplified 354b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // value is equal to the unsimplified one, return the simplified value. 355b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // For example, select (cond, X, X & Z) & Z -> X & Z. 356b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if ((FV && !TV) || (TV && !FV)) { 357b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Check that the simplified value has the form "X op Y" where "op" is the 358b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // same as the original operation. 359b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Instruction *Simplified = dyn_cast<Instruction>(FV ? FV : TV); 360b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (Simplified && Simplified->getOpcode() == Opcode) { 361b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // The value that didn't simplify is "UnsimplifiedLHS op UnsimplifiedRHS". 362b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // We already know that "op" is the same as for the simplified value. See 363b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // if the operands match too. If so, return the simplified value. 364b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *UnsimplifiedBranch = FV ? SI->getTrueValue() : SI->getFalseValue(); 365b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *UnsimplifiedLHS = SI == LHS ? UnsimplifiedBranch : LHS; 366b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Value *UnsimplifiedRHS = SI == LHS ? RHS : UnsimplifiedBranch; 367124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Simplified->getOperand(0) == UnsimplifiedLHS && 368124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Simplified->getOperand(1) == UnsimplifiedRHS) 369b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return Simplified; 370b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (Simplified->isCommutative() && 371124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Simplified->getOperand(1) == UnsimplifiedLHS && 372124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Simplified->getOperand(0) == UnsimplifiedRHS) 373b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return Simplified; 374b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 375b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 376b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 377b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return 0; 378b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands} 379b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 380b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// ThreadCmpOverSelect - In the case of a comparison with a select instruction, 381b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// try to simplify the comparison by seeing whether both branches of the select 382b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// result in the same value. Returns the common value if so, otherwise returns 383b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands/// null. 384b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sandsstatic Value *ThreadCmpOverSelect(CmpInst::Predicate Pred, Value *LHS, 385a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Value *RHS, const TargetData *TD, 3861845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT, 387a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands unsigned MaxRecurse) { 3880312a93693abc2eb682b2b101c889959888fd883Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 3890312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (!MaxRecurse--) 3900312a93693abc2eb682b2b101c889959888fd883Duncan Sands return 0; 3910312a93693abc2eb682b2b101c889959888fd883Duncan Sands 392b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Make sure the select is on the LHS. 393b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands if (!isa<SelectInst>(LHS)) { 394b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands std::swap(LHS, RHS); 395b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands Pred = CmpInst::getSwappedPredicate(Pred); 396b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands } 397b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands assert(isa<SelectInst>(LHS) && "Not comparing with a select instruction!"); 398b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands SelectInst *SI = cast<SelectInst>(LHS); 399b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 40050ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands // Now that we have "cmp select(Cond, TV, FV), RHS", analyse it. 401b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // Does "cmp TV, RHS" simplify? 4021845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *TCmp = SimplifyCmpInst(Pred, SI->getTrueValue(), RHS, TD, DT, 40350ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands MaxRecurse)) { 404b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // It does! Does "cmp FV, RHS" simplify? 4051845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *FCmp = SimplifyCmpInst(Pred, SI->getFalseValue(), RHS, TD, DT, 40650ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands MaxRecurse)) { 407b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // It does! If they simplified to the same value, then use it as the 408b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // result of the original comparison. 409124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (TCmp == FCmp) 410b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return TCmp; 41150ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands Value *Cond = SI->getCondition(); 41250ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands // If the false value simplified to false, then the result of the compare 41350ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands // is equal to "Cond && TCmp". This also catches the case when the false 41450ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands // value simplified to false and the true value to true, returning "Cond". 41550ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands if (match(FCmp, m_Zero())) 41650ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands if (Value *V = SimplifyAndInst(Cond, TCmp, TD, DT, MaxRecurse)) 41750ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands return V; 41850ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands // If the true value simplified to true, then the result of the compare 41950ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands // is equal to "Cond || FCmp". 42050ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands if (match(TCmp, m_One())) 42150ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands if (Value *V = SimplifyOrInst(Cond, FCmp, TD, DT, MaxRecurse)) 42250ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands return V; 42350ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands // Finally, if the false value simplified to true and the true value to 42450ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands // false, then the result of the compare is equal to "!Cond". 42550ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands if (match(FCmp, m_One()) && match(TCmp, m_Zero())) 42650ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands if (Value *V = 42750ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands SimplifyXorInst(Cond, Constant::getAllOnesValue(Cond->getType()), 42850ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands TD, DT, MaxRecurse)) 42950ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands return V; 43050ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands } 43150ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands } 43250ca4d37f7f3b460c6441eb5ad14625a7d86b5d9Duncan Sands 433b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return 0; 434b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands} 435b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 436a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// ThreadBinOpOverPHI - In the case of a binary operation with an operand that 437a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// is a PHI instruction, try to simplify the binop by seeing whether evaluating 438a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// it on the incoming phi values yields the same result for every value. If so 439a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// returns the common value, otherwise returns null. 440a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *ThreadBinOpOverPHI(unsigned Opcode, Value *LHS, Value *RHS, 4411845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT, 4421845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 4430312a93693abc2eb682b2b101c889959888fd883Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 4440312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (!MaxRecurse--) 4450312a93693abc2eb682b2b101c889959888fd883Duncan Sands return 0; 4460312a93693abc2eb682b2b101c889959888fd883Duncan Sands 447a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands PHINode *PI; 448a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands if (isa<PHINode>(LHS)) { 449a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands PI = cast<PHINode>(LHS); 4501845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Bail out if RHS and the phi may be mutually interdependent due to a loop. 4511845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (!ValueDominatesPHI(RHS, PI, DT)) 4521845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return 0; 453a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } else { 454a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands assert(isa<PHINode>(RHS) && "No PHI instruction operand!"); 455a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands PI = cast<PHINode>(RHS); 4561845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Bail out if LHS and the phi may be mutually interdependent due to a loop. 4571845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (!ValueDominatesPHI(LHS, PI, DT)) 4581845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return 0; 459a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } 460a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 461a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // Evaluate the BinOp on the incoming phi values. 462a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Value *CommonValue = 0; 463a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) { 464552008946530e01efdad15044e1f621883d14a3aDuncan Sands Value *Incoming = PI->getIncomingValue(i); 465ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If the incoming value is the phi node itself, it can safely be skipped. 466552008946530e01efdad15044e1f621883d14a3aDuncan Sands if (Incoming == PI) continue; 467a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Value *V = PI == LHS ? 4681845009290e4d804ad377927bd8a08cca3036adcDuncan Sands SimplifyBinOp(Opcode, Incoming, RHS, TD, DT, MaxRecurse) : 4691845009290e4d804ad377927bd8a08cca3036adcDuncan Sands SimplifyBinOp(Opcode, LHS, Incoming, TD, DT, MaxRecurse); 470a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation failed to simplify, or simplified to a different value 471a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // to previously, then give up. 472a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands if (!V || (CommonValue && V != CommonValue)) 473a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return 0; 474a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands CommonValue = V; 475a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } 476a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 477a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return CommonValue; 478a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 479a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 480a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// ThreadCmpOverPHI - In the case of a comparison with a PHI instruction, try 481a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// try to simplify the comparison by seeing whether comparing with all of the 482a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// incoming phi values yields the same result every time. If so returns the 483a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands/// common result, otherwise returns null. 484a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *ThreadCmpOverPHI(CmpInst::Predicate Pred, Value *LHS, Value *RHS, 4851845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT, 4861845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 4870312a93693abc2eb682b2b101c889959888fd883Duncan Sands // Recursion is always used, so bail out at once if we already hit the limit. 4880312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (!MaxRecurse--) 4890312a93693abc2eb682b2b101c889959888fd883Duncan Sands return 0; 4900312a93693abc2eb682b2b101c889959888fd883Duncan Sands 491a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // Make sure the phi is on the LHS. 492a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands if (!isa<PHINode>(LHS)) { 493a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands std::swap(LHS, RHS); 494a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Pred = CmpInst::getSwappedPredicate(Pred); 495a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } 496a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands assert(isa<PHINode>(LHS) && "Not comparing with a phi instruction!"); 497a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands PHINode *PI = cast<PHINode>(LHS); 498a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 4991845009290e4d804ad377927bd8a08cca3036adcDuncan Sands // Bail out if RHS and the phi may be mutually interdependent due to a loop. 5001845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (!ValueDominatesPHI(RHS, PI, DT)) 5011845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return 0; 5021845009290e4d804ad377927bd8a08cca3036adcDuncan Sands 503a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // Evaluate the BinOp on the incoming phi values. 504a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands Value *CommonValue = 0; 505a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) { 506552008946530e01efdad15044e1f621883d14a3aDuncan Sands Value *Incoming = PI->getIncomingValue(i); 507ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If the incoming value is the phi node itself, it can safely be skipped. 508552008946530e01efdad15044e1f621883d14a3aDuncan Sands if (Incoming == PI) continue; 5091845009290e4d804ad377927bd8a08cca3036adcDuncan Sands Value *V = SimplifyCmpInst(Pred, Incoming, RHS, TD, DT, MaxRecurse); 510a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation failed to simplify, or simplified to a different value 511a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // to previously, then give up. 512a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands if (!V || (CommonValue && V != CommonValue)) 513a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return 0; 514a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands CommonValue = V; 515a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands } 516a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 517a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return CommonValue; 518a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 519a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 5208aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner/// SimplifyAddInst - Given operands for an Add, see if we can 521d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner/// fold the result. If not, this returns null. 522ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sandsstatic Value *SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 523ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands const TargetData *TD, const DominatorTree *DT, 524ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands unsigned MaxRecurse) { 525d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 526d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 527d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Constant *Ops[] = { CLHS, CRHS }; 5288aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner return ConstantFoldInstOperands(Instruction::Add, CLHS->getType(), 5298aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner Ops, 2, TD); 5308aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner } 53112a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 5328aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner // Canonicalize the constant to the RHS. 5338aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner std::swap(Op0, Op1); 5348aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner } 53512a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 536fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X + undef -> undef 537f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 538fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Op1; 53912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 540fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X + 0 -> X 541fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (match(Op1, m_Zero())) 542fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Op0; 543fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 544fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X + (Y - X) -> Y 545fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // (Y - X) + X -> Y 546ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands // Eg: X + -X -> 0 547124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands Value *Y = 0; 548124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (match(Op1, m_Sub(m_Value(Y), m_Specific(Op0))) || 549124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands match(Op0, m_Sub(m_Value(Y), m_Specific(Op1)))) 550fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Y; 551fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 552fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X + ~X -> -1 since ~X = -X-1 553124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (match(Op0, m_Not(m_Specific(Op1))) || 554124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands match(Op1, m_Not(m_Specific(Op0)))) 555fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Constant::getAllOnesValue(Op0->getType()); 55687689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands 55782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands /// i1 add -> xor. 55875d289ed6201e82718343d7a36d2a2fa082f6217Duncan Sands if (MaxRecurse && Op0->getType()->isIntegerTy(1)) 55907f30fbd734069b80b90c6aeea0ae645ce3880c0Duncan Sands if (Value *V = SimplifyXorInst(Op0, Op1, TD, DT, MaxRecurse-1)) 56007f30fbd734069b80b90c6aeea0ae645ce3880c0Duncan Sands return V; 56182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 562566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Try some generic simplifications for associative operations. 563566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::Add, Op0, Op1, TD, DT, 564566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands MaxRecurse)) 565566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 566566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 5673421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Mul distributes over Add. Try some generic simplifications based on this. 5683421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::Add, Op0, Op1, Instruction::Mul, 5693421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 5703421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 5713421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 57287689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // Threading Add over selects and phi nodes is pointless, so don't bother. 57387689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // Threading over the select in "A + select(cond, B, C)" means evaluating 57487689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // "A+B" and "A+C" and seeing if they are equal; but they are equal if and 57587689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // only if B and C are equal. If B and C are equal then (since we assume 57687689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // that operands have already been simplified) "select(cond, B, C)" should 57787689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // have been simplified to the common value of B and C already. Analysing 57887689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // "A+B" and "A+C" thus gains nothing, but costs compile time. Similarly 57987689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // for threading over phi nodes. 58087689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands 5818aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner return 0; 5828aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner} 5838aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner 584ee9a2e322af96accc9e55ed6373c0057453714b1Duncan SandsValue *llvm::SimplifyAddInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 585ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands const TargetData *TD, const DominatorTree *DT) { 586ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands return ::SimplifyAddInst(Op0, Op1, isNSW, isNUW, TD, DT, RecursionLimit); 587ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands} 588ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands 589fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands/// SimplifySubInst - Given operands for a Sub, see if we can 590fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands/// fold the result. If not, this returns null. 591ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sandsstatic Value *SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 5923421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands const TargetData *TD, const DominatorTree *DT, 593ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands unsigned MaxRecurse) { 594fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (Constant *CLHS = dyn_cast<Constant>(Op0)) 595fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 596fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands Constant *Ops[] = { CLHS, CRHS }; 597fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return ConstantFoldInstOperands(Instruction::Sub, CLHS->getType(), 598fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands Ops, 2, TD); 599fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands } 600fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 601fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X - undef -> undef 602fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // undef - X -> undef 603f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op0, m_Undef()) || match(Op1, m_Undef())) 604fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return UndefValue::get(Op0->getType()); 605fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 606fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X - 0 -> X 607fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands if (match(Op1, m_Zero())) 608fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Op0; 609fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 610fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // X - X -> 0 611124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Op0 == Op1) 612fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return Constant::getNullValue(Op0->getType()); 613fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 614fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands // (X*2) - X -> X 615fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands // (X<<1) - X -> X 616b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands Value *X = 0; 617fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands if (match(Op0, m_Mul(m_Specific(Op1), m_ConstantInt<2>())) || 618fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands match(Op0, m_Shl(m_Specific(Op1), m_One()))) 619fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands return Op1; 620fe02c69f84ad52d42be934e4fe702f03e4991a6aDuncan Sands 621b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // (X + Y) - Z -> X + (Y - Z) or Y + (X - Z) if everything simplifies. 622b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // For example, (X + Y) - Y -> X; (Y + X) - Y -> X 623b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands Value *Y = 0, *Z = Op1; 624b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (MaxRecurse && match(Op0, m_Add(m_Value(X), m_Value(Y)))) { // (X + Y) - Z 625b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // See if "V === Y - Z" simplifies. 626b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, Y, Z, TD, DT, MaxRecurse-1)) 627b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "X + V" simplifies. 628b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Add, X, V, 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 "Y + V" simplifies. 637b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Add, Y, V, TD, DT, 638b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands MaxRecurse-1)) { 639b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does, we successfully reassociated! 640b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands ++NumReassoc; 641b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return W; 642b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 643b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 64482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 645b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // X - (Y + Z) -> (X - Y) - Z or (X - Z) - Y if everything simplifies. 646b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // For example, X - (X + 1) -> -1 647b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands X = Op0; 648b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (MaxRecurse && match(Op1, m_Add(m_Value(Y), m_Value(Z)))) { // X - (Y + Z) 649b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // See if "V === X - Y" simplifies. 650b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, X, Y, TD, DT, MaxRecurse-1)) 651b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "V - Z" simplifies. 652b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Sub, V, Z, TD, DT, 653b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands MaxRecurse-1)) { 654b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does, we successfully reassociated! 655b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands ++NumReassoc; 656b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return W; 657b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 658b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // See if "V === X - Z" simplifies. 659b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, X, Z, TD, DT, MaxRecurse-1)) 660b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "V - Y" simplifies. 661b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *W = SimplifyBinOp(Instruction::Sub, V, Y, TD, DT, 662b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands MaxRecurse-1)) { 663b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does, we successfully reassociated! 664b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands ++NumReassoc; 665b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return W; 666b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 667b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands } 668b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands 669b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // Z - (X - Y) -> (Z - X) + Y if everything simplifies. 670b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // For example, X - (X - Y) -> Y. 671b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands Z = Op0; 672c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands if (MaxRecurse && match(Op1, m_Sub(m_Value(X), m_Value(Y)))) // Z - (X - Y) 673c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands // See if "V === Z - X" simplifies. 674c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands if (Value *V = SimplifyBinOp(Instruction::Sub, Z, X, TD, DT, MaxRecurse-1)) 675b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // It does! Now see if "V + Y" simplifies. 676c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands if (Value *W = SimplifyBinOp(Instruction::Add, V, Y, TD, DT, 677c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands MaxRecurse-1)) { 678c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands // It does, we successfully reassociated! 679c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands ++NumReassoc; 680c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands return W; 681c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands } 682c087e20331c8a4c3b77d96a73588e80c06d89e3dDuncan Sands 6833421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Mul distributes over Sub. Try some generic simplifications based on this. 6843421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::Sub, Op0, Op1, Instruction::Mul, 6853421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 6863421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 6873421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 688b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands // i1 sub -> xor. 689b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (MaxRecurse && Op0->getType()->isIntegerTy(1)) 690b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands if (Value *V = SimplifyXorInst(Op0, Op1, TD, DT, MaxRecurse-1)) 691b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands return V; 692b2f3c383ec62b959ee27d0a5fb890894c4e49e86Duncan Sands 693fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // Threading Sub over selects and phi nodes is pointless, so don't bother. 694fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // Threading over the select in "A - select(cond, B, C)" means evaluating 695fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // "A-B" and "A-C" and seeing if they are equal; but they are equal if and 696fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // only if B and C are equal. If B and C are equal then (since we assume 697fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // that operands have already been simplified) "select(cond, B, C)" should 698fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // have been simplified to the common value of B and C already. Analysing 699fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // "A-B" and "A-C" thus gains nothing, but costs compile time. Similarly 700fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands // for threading over phi nodes. 701fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 702fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands return 0; 703fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands} 704fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands 705ee9a2e322af96accc9e55ed6373c0057453714b1Duncan SandsValue *llvm::SimplifySubInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 706ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands const TargetData *TD, const DominatorTree *DT) { 707ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands return ::SimplifySubInst(Op0, Op1, isNSW, isNUW, TD, DT, RecursionLimit); 708ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands} 709ee9a2e322af96accc9e55ed6373c0057453714b1Duncan Sands 71082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands/// SimplifyMulInst - Given operands for a Mul, see if we can 71182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands/// fold the result. If not, this returns null. 71282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sandsstatic Value *SimplifyMulInst(Value *Op0, Value *Op1, const TargetData *TD, 71382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 71482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 71582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 71682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Constant *Ops[] = { CLHS, CRHS }; 71782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return ConstantFoldInstOperands(Instruction::Mul, CLHS->getType(), 71882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Ops, 2, TD); 71982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands } 72082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 72182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // Canonicalize the constant to the RHS. 72282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands std::swap(Op0, Op1); 72382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands } 72482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 72582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // X * undef -> 0 726f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 72782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return Constant::getNullValue(Op0->getType()); 72882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 72982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // X * 0 -> 0 73082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (match(Op1, m_Zero())) 73182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return Op1; 73282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 73382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // X * 1 -> X 73482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (match(Op1, m_One())) 73582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return Op0; 73682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 7371895e98ef38afbe011575cc25f4889d96e37421bDuncan Sands // (X / Y) * Y -> X if the division is exact. 7381895e98ef38afbe011575cc25f4889d96e37421bDuncan Sands Value *X = 0, *Y = 0; 739aeaf3d484b4d4c35e8794378c4b6cfbbde718dd1Chris Lattner if ((match(Op0, m_IDiv(m_Value(X), m_Value(Y))) && Y == Op1) || // (X / Y) * Y 740aeaf3d484b4d4c35e8794378c4b6cfbbde718dd1Chris Lattner (match(Op1, m_IDiv(m_Value(X), m_Value(Y))) && Y == Op0)) { // Y * (X / Y) 741c6ee9181a51fdfa3c07e1e53695681c55aa98ce4Chris Lattner BinaryOperator *Div = cast<BinaryOperator>(Y == Op1 ? Op0 : Op1); 742c6ee9181a51fdfa3c07e1e53695681c55aa98ce4Chris Lattner if (Div->isExact()) 7431895e98ef38afbe011575cc25f4889d96e37421bDuncan Sands return X; 7441895e98ef38afbe011575cc25f4889d96e37421bDuncan Sands } 7451895e98ef38afbe011575cc25f4889d96e37421bDuncan Sands 7465413880654585f01ea9880f24f07f27c8da56ba8Nick Lewycky // i1 mul -> and. 74775d289ed6201e82718343d7a36d2a2fa082f6217Duncan Sands if (MaxRecurse && Op0->getType()->isIntegerTy(1)) 74807f30fbd734069b80b90c6aeea0ae645ce3880c0Duncan Sands if (Value *V = SimplifyAndInst(Op0, Op1, TD, DT, MaxRecurse-1)) 74907f30fbd734069b80b90c6aeea0ae645ce3880c0Duncan Sands return V; 75082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 75182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // Try some generic simplifications for associative operations. 75282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::Mul, Op0, Op1, TD, DT, 75382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands MaxRecurse)) 75482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return V; 75582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 75682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // Mul distributes over Add. Try some generic simplifications based on this. 75782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Value *V = ExpandBinOp(Instruction::Mul, Op0, Op1, Instruction::Add, 75882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands TD, DT, MaxRecurse)) 75982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return V; 76082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 76182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // If the operation is with the result of a select instruction, check whether 76282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // operating on either branch of the select always yields the same value. 76382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 76482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Value *V = ThreadBinOpOverSelect(Instruction::Mul, Op0, Op1, TD, DT, 76582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands MaxRecurse)) 76682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return V; 76782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 76882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // If the operation is with the result of a phi instruction, check whether 76982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands // operating on all incoming values of the phi always yields the same value. 77082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 77182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands if (Value *V = ThreadBinOpOverPHI(Instruction::Mul, Op0, Op1, TD, DT, 77282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands MaxRecurse)) 77382fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return V; 77482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 77582fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return 0; 77682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands} 77782fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 77882fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan SandsValue *llvm::SimplifyMulInst(Value *Op0, Value *Op1, const TargetData *TD, 77982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands const DominatorTree *DT) { 78082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands return ::SimplifyMulInst(Op0, Op1, TD, DT, RecursionLimit); 78182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands} 78282fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands 783593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// SimplifyDiv - Given operands for an SDiv or UDiv, see if we can 784593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// fold the result. If not, this returns null. 785479b4b9ef06dd84097202ffa6aea07913cdf651cAnders Carlssonstatic Value *SimplifyDiv(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1, 786593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands const TargetData *TD, const DominatorTree *DT, 787593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands unsigned MaxRecurse) { 788593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Constant *C0 = dyn_cast<Constant>(Op0)) { 789593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Constant *C1 = dyn_cast<Constant>(Op1)) { 790593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands Constant *Ops[] = { C0, C1 }; 791593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, 2, TD); 792593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands } 793593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands } 794593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 795a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands bool isSigned = Opcode == Instruction::SDiv; 796a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands 797593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // X / undef -> undef 798f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 799593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op1; 800593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 801593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // undef / X -> 0 802f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op0, m_Undef())) 803593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Constant::getNullValue(Op0->getType()); 804593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 805593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // 0 / X -> 0, we don't need to preserve faults! 806593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (match(Op0, m_Zero())) 807593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op0; 808593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 809593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // X / 1 -> X 810593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (match(Op1, m_One())) 811593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op0; 812593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 813593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Op0->getType()->isIntegerTy(1)) 814593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // It can't be division by zero, hence it must be division by one. 815593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return Op0; 816593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 817593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // X / X -> 1 818593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Op0 == Op1) 819593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return ConstantInt::get(Op0->getType(), 1); 820593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 821593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // (X * Y) / Y -> X if the multiplication does not overflow. 822593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands Value *X = 0, *Y = 0; 823593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (match(Op0, m_Mul(m_Value(X), m_Value(Y))) && (X == Op1 || Y == Op1)) { 824593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Y != Op1) std::swap(X, Y); // Ensure expression is (X * Y) / Y, Y = Op1 8254b720718fbda1194f925e0a9d931bc220e8b0e3aDuncan Sands BinaryOperator *Mul = cast<BinaryOperator>(Op0); 8264b720718fbda1194f925e0a9d931bc220e8b0e3aDuncan Sands // If the Mul knows it does not overflow, then we are good to go. 8274b720718fbda1194f925e0a9d931bc220e8b0e3aDuncan Sands if ((isSigned && Mul->hasNoSignedWrap()) || 8284b720718fbda1194f925e0a9d931bc220e8b0e3aDuncan Sands (!isSigned && Mul->hasNoUnsignedWrap())) 8294b720718fbda1194f925e0a9d931bc220e8b0e3aDuncan Sands return X; 830593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands // If X has the form X = A / Y then X * Y cannot overflow. 831593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (BinaryOperator *Div = dyn_cast<BinaryOperator>(X)) 832593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Div->getOpcode() == Opcode && Div->getOperand(1) == Y) 833593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return X; 834593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands } 835593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 836a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // (X rem Y) / Y -> 0 837a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if ((isSigned && match(Op0, m_SRem(m_Value(), m_Specific(Op1)))) || 838a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands (!isSigned && match(Op0, m_URem(m_Value(), m_Specific(Op1))))) 839a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands return Constant::getNullValue(Op0->getType()); 840a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands 841a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // If the operation is with the result of a select instruction, check whether 842a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // operating on either branch of the select always yields the same value. 843a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 844a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, TD, DT, MaxRecurse)) 845a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands return V; 846a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands 847a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // If the operation is with the result of a phi instruction, check whether 848a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands // operating on all incoming values of the phi always yields the same value. 849a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 850a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, TD, DT, MaxRecurse)) 851a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands return V; 852a3e292c7e85efb33899f08238f57a85996a05a0bDuncan Sands 853593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return 0; 854593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 855593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 856593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// SimplifySDivInst - Given operands for an SDiv, see if we can 857593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// fold the result. If not, this returns null. 858593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sandsstatic Value *SimplifySDivInst(Value *Op0, Value *Op1, const TargetData *TD, 859593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 860593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Value *V = SimplifyDiv(Instruction::SDiv, Op0, Op1, TD, DT, MaxRecurse)) 861593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return V; 862593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 863593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return 0; 864593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 865593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 866593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan SandsValue *llvm::SimplifySDivInst(Value *Op0, Value *Op1, const TargetData *TD, 8671fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel const DominatorTree *DT) { 868593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return ::SimplifySDivInst(Op0, Op1, TD, DT, RecursionLimit); 869593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 870593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 871593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// SimplifyUDivInst - Given operands for a UDiv, see if we can 872593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands/// fold the result. If not, this returns null. 873593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sandsstatic Value *SimplifyUDivInst(Value *Op0, Value *Op1, const TargetData *TD, 874593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 875593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands if (Value *V = SimplifyDiv(Instruction::UDiv, Op0, Op1, TD, DT, MaxRecurse)) 876593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return V; 877593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 878593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return 0; 879593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 880593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 881593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan SandsValue *llvm::SimplifyUDivInst(Value *Op0, Value *Op1, const TargetData *TD, 8821fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel const DominatorTree *DT) { 883593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands return ::SimplifyUDivInst(Op0, Op1, TD, DT, RecursionLimit); 884593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands} 885593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands 886f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sandsstatic Value *SimplifyFDivInst(Value *Op0, Value *Op1, const TargetData *, 887f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands const DominatorTree *, unsigned) { 8881fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel // undef / X -> undef (the undef could be a snan). 889f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op0, m_Undef())) 8901fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel return Op0; 8911fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel 8921fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel // X / undef -> undef 893f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 8941fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel return Op1; 8951fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel 8961fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel return 0; 8971fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel} 8981fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel 8991fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van BommelValue *llvm::SimplifyFDivInst(Value *Op0, Value *Op1, const TargetData *TD, 9001fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel const DominatorTree *DT) { 9011fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel return ::SimplifyFDivInst(Op0, Op1, TD, DT, RecursionLimit); 9021fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel} 9031fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel 904f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands/// SimplifyRem - Given operands for an SRem or URem, see if we can 905f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands/// fold the result. If not, this returns null. 906f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sandsstatic Value *SimplifyRem(Instruction::BinaryOps Opcode, Value *Op0, Value *Op1, 907f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands const TargetData *TD, const DominatorTree *DT, 908f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands unsigned MaxRecurse) { 909f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (Constant *C0 = dyn_cast<Constant>(Op0)) { 910f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (Constant *C1 = dyn_cast<Constant>(Op1)) { 911f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands Constant *Ops[] = { C0, C1 }; 912f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, 2, TD); 913f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands } 914f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands } 915f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 916f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // X % undef -> undef 917f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op1, m_Undef())) 918f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Op1; 919f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 920f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // undef % X -> 0 921f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op0, m_Undef())) 922f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Constant::getNullValue(Op0->getType()); 923f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 924f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // 0 % X -> 0, we don't need to preserve faults! 925f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op0, m_Zero())) 926f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Op0; 927f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 928f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // X % 0 -> undef, we don't need to preserve faults! 929f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op1, m_Zero())) 930f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return UndefValue::get(Op0->getType()); 931f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 932f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // X % 1 -> 0 933f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op1, m_One())) 934f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Constant::getNullValue(Op0->getType()); 935f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 936f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (Op0->getType()->isIntegerTy(1)) 937f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // It can't be remainder by zero, hence it must be remainder by one. 938f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Constant::getNullValue(Op0->getType()); 939f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 940f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // X % X -> 0 941f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (Op0 == Op1) 942f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Constant::getNullValue(Op0->getType()); 943f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 944f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // If the operation is with the result of a select instruction, check whether 945f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // operating on either branch of the select always yields the same value. 946f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 947f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, TD, DT, MaxRecurse)) 948f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return V; 949f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 950f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // If the operation is with the result of a phi instruction, check whether 951f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // operating on all incoming values of the phi always yields the same value. 952f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 953f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, TD, DT, MaxRecurse)) 954f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return V; 955f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 956f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return 0; 957f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 958f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 959f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands/// SimplifySRemInst - Given operands for an SRem, see if we can 960f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands/// fold the result. If not, this returns null. 961f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sandsstatic Value *SimplifySRemInst(Value *Op0, Value *Op1, const TargetData *TD, 962f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 963f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (Value *V = SimplifyRem(Instruction::SRem, Op0, Op1, TD, DT, MaxRecurse)) 964f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return V; 965f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 966f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return 0; 967f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 968f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 969f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan SandsValue *llvm::SimplifySRemInst(Value *Op0, Value *Op1, const TargetData *TD, 970f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands const DominatorTree *DT) { 971f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return ::SimplifySRemInst(Op0, Op1, TD, DT, RecursionLimit); 972f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 973f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 974f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands/// SimplifyURemInst - Given operands for a URem, see if we can 975f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands/// fold the result. If not, this returns null. 976f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sandsstatic Value *SimplifyURemInst(Value *Op0, Value *Op1, const TargetData *TD, 977f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 978f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (Value *V = SimplifyRem(Instruction::URem, Op0, Op1, TD, DT, MaxRecurse)) 979f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return V; 980f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 981f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return 0; 982f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 983f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 984f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan SandsValue *llvm::SimplifyURemInst(Value *Op0, Value *Op1, const TargetData *TD, 985f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands const DominatorTree *DT) { 986f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return ::SimplifyURemInst(Op0, Op1, TD, DT, RecursionLimit); 987f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 988f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 989f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sandsstatic Value *SimplifyFRemInst(Value *Op0, Value *Op1, const TargetData *, 990f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands const DominatorTree *, unsigned) { 991f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // undef % X -> undef (the undef could be a snan). 992f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op0, m_Undef())) 993f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Op0; 994f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 995f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands // X % undef -> undef 996f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands if (match(Op1, m_Undef())) 997f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return Op1; 998f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 999f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return 0; 1000f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 1001f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1002f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan SandsValue *llvm::SimplifyFRemInst(Value *Op0, Value *Op1, const TargetData *TD, 1003f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands const DominatorTree *DT) { 1004f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands return ::SimplifyFRemInst(Op0, Op1, TD, DT, RecursionLimit); 1005f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands} 1006f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands 1007cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands/// SimplifyShift - Given operands for an Shl, LShr or AShr, see if we can 1008c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// fold the result. If not, this returns null. 1009cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sandsstatic Value *SimplifyShift(unsigned Opcode, Value *Op0, Value *Op1, 1010cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands const TargetData *TD, const DominatorTree *DT, 1011cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands unsigned MaxRecurse) { 1012c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (Constant *C0 = dyn_cast<Constant>(Op0)) { 1013c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (Constant *C1 = dyn_cast<Constant>(Op1)) { 1014c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands Constant *Ops[] = { C0, C1 }; 1015cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return ConstantFoldInstOperands(Opcode, C0->getType(), Ops, 2, TD); 1016c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands } 1017c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands } 1018c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1019cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // 0 shift by X -> 0 1020c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (match(Op0, m_Zero())) 1021c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Op0; 1022c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1023cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // X shift by 0 -> X 1024c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (match(Op1, m_Zero())) 1025c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Op0; 1026c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1027cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // X shift by undef -> undef because it may shift by the bitwidth. 1028f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 1029c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Op1; 1030c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1031c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands // Shifting by the bitwidth or more is undefined. 1032c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) 1033c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (CI->getValue().getLimitedValue() >= 1034c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands Op0->getType()->getScalarSizeInBits()) 1035c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return UndefValue::get(Op0->getType()); 1036c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1037cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // If the operation is with the result of a select instruction, check whether 1038cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // operating on either branch of the select always yields the same value. 1039cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 1040cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (Value *V = ThreadBinOpOverSelect(Opcode, Op0, Op1, TD, DT, MaxRecurse)) 1041cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 1042cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 1043cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // If the operation is with the result of a phi instruction, check whether 1044cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // operating on all incoming values of the phi always yields the same value. 1045cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 1046cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (Value *V = ThreadBinOpOverPHI(Opcode, Op0, Op1, TD, DT, MaxRecurse)) 1047cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 1048cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 1049cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return 0; 1050cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands} 1051cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 1052cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands/// SimplifyShlInst - Given operands for an Shl, see if we can 1053cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands/// fold the result. If not, this returns null. 105481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattnerstatic Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 105581a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner const TargetData *TD, const DominatorTree *DT, 105681a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner unsigned MaxRecurse) { 1057cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (Value *V = SimplifyShift(Instruction::Shl, Op0, Op1, TD, DT, MaxRecurse)) 1058cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 1059cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 1060cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands // undef << X -> 0 1061f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op0, m_Undef())) 1062cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return Constant::getNullValue(Op0->getType()); 1063cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands 106481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner // (X >> A) << A -> X 106581a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Value *X; 106681a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner if (match(Op0, m_Shr(m_Value(X), m_Specific(Op1))) && 106781a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<PossiblyExactOperator>(Op0)->isExact()) 106881a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner return X; 1069c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return 0; 1070c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 1071c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 107281a0dc911586c77421c2255aa417dc9b350b9e20Chris LattnerValue *llvm::SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW, 107381a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner const TargetData *TD, const DominatorTree *DT) { 107481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner return ::SimplifyShlInst(Op0, Op1, isNSW, isNUW, TD, DT, RecursionLimit); 1075c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 1076c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1077c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// SimplifyLShrInst - Given operands for an LShr, see if we can 1078c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// fold the result. If not, this returns null. 107981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattnerstatic Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact, 108081a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner const TargetData *TD, const DominatorTree *DT, 108181a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner unsigned MaxRecurse) { 1082cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (Value *V = SimplifyShift(Instruction::LShr, Op0, Op1, TD, DT, MaxRecurse)) 1083cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 1084c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1085c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands // undef >>l X -> 0 1086f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op0, m_Undef())) 1087c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Constant::getNullValue(Op0->getType()); 1088c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 108981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner // (X << A) >> A -> X 109081a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Value *X; 109181a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) && 109281a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<OverflowingBinaryOperator>(Op0)->hasNoUnsignedWrap()) 109381a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner return X; 109452fb846578714d14bbde9b28884a6a8729217677Duncan Sands 1095c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return 0; 1096c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 1097c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 109881a0dc911586c77421c2255aa417dc9b350b9e20Chris LattnerValue *llvm::SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact, 109981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner const TargetData *TD, const DominatorTree *DT) { 110081a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner return ::SimplifyLShrInst(Op0, Op1, isExact, TD, DT, RecursionLimit); 1101c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 1102c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1103c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// SimplifyAShrInst - Given operands for an AShr, see if we can 1104c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands/// fold the result. If not, this returns null. 110581a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattnerstatic Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact, 110681a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner const TargetData *TD, const DominatorTree *DT, 110781a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner unsigned MaxRecurse) { 1108cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands if (Value *V = SimplifyShift(Instruction::AShr, Op0, Op1, TD, DT, MaxRecurse)) 1109cf80bc1d4ac741620641c2bf48c25993bd478bd0Duncan Sands return V; 1110c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1111c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands // all ones >>a X -> all ones 1112c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands if (match(Op0, m_AllOnes())) 1113c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Op0; 1114c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 1115c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands // undef >>a X -> all ones 1116f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op0, m_Undef())) 1117c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return Constant::getAllOnesValue(Op0->getType()); 1118c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 111981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner // (X << A) >> A -> X 112081a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Value *X; 112181a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner if (match(Op0, m_Shl(m_Value(X), m_Specific(Op1))) && 112281a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<OverflowingBinaryOperator>(Op0)->hasNoSignedWrap()) 112381a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner return X; 112452fb846578714d14bbde9b28884a6a8729217677Duncan Sands 1125c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands return 0; 1126c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 1127c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 112881a0dc911586c77421c2255aa417dc9b350b9e20Chris LattnerValue *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact, 112981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner const TargetData *TD, const DominatorTree *DT) { 113081a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner return ::SimplifyAShrInst(Op0, Op1, isExact, TD, DT, RecursionLimit); 1131c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands} 1132c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands 11338aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner/// SimplifyAndInst - Given operands for an And, see if we can 11348aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner/// fold the result. If not, this returns null. 1135a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyAndInst(Value *Op0, Value *Op1, const TargetData *TD, 11361845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 11378aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 11388aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 11398aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner Constant *Ops[] = { CLHS, CRHS }; 1140d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return ConstantFoldInstOperands(Instruction::And, CLHS->getType(), 1141d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Ops, 2, TD); 1142d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 114312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1144d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // Canonicalize the constant to the RHS. 1145d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner std::swap(Op0, Op1); 1146d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 114712a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1148d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // X & undef -> 0 1149f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 1150d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Constant::getNullValue(Op0->getType()); 115112a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1152d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // X & X = X 1153124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Op0 == Op1) 1154d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 115512a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 11562b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // X & 0 = 0 11572b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_Zero())) 1158d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op1; 115912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 11602b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // X & -1 = X 11612b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_AllOnes())) 11622b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Op0; 116312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1164d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // A & ~A = ~A & A = 0 116581a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner if (match(Op0, m_Not(m_Specific(Op1))) || 116681a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner match(Op1, m_Not(m_Specific(Op0)))) 1167d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Constant::getNullValue(Op0->getType()); 116812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1169d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // (A | ?) & A = A 117081a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Value *A = 0, *B = 0; 1171d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (match(Op0, m_Or(m_Value(A), m_Value(B))) && 1172124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (A == Op1 || B == Op1)) 1173d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op1; 117412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1175d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // A & (A | ?) = A 1176d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (match(Op1, m_Or(m_Value(A), m_Value(B))) && 1177124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (A == Op0 || B == Op0)) 1178d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 117912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1180566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Try some generic simplifications for associative operations. 1181566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::And, Op0, Op1, TD, DT, 1182566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands MaxRecurse)) 1183566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 11846844c8ea5a67e551be7106d6b7b9e1a64eecbe51Benjamin Kramer 11853421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // And distributes over Or. Try some generic simplifications based on this. 11863421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Or, 11873421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 11883421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 11893421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 11903421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // And distributes over Xor. Try some generic simplifications based on this. 11913421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = ExpandBinOp(Instruction::And, Op0, Op1, Instruction::Xor, 11923421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 11933421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 11943421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 11953421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Or distributes over And. Try some generic simplifications based on this. 11963421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::And, Op0, Op1, Instruction::Or, 11973421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 11983421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 11993421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1200b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If the operation is with the result of a select instruction, check whether 1201b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // operating on either branch of the select always yields the same value. 12020312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 12031845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *V = ThreadBinOpOverSelect(Instruction::And, Op0, Op1, TD, DT, 12040312a93693abc2eb682b2b101c889959888fd883Duncan Sands MaxRecurse)) 1205a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 1206a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1207a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation is with the result of a phi instruction, check whether 1208a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // operating on all incoming values of the phi always yields the same value. 12090312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 12101845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *V = ThreadBinOpOverPHI(Instruction::And, Op0, Op1, TD, DT, 12110312a93693abc2eb682b2b101c889959888fd883Duncan Sands MaxRecurse)) 1212b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return V; 1213b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 1214d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return 0; 1215d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner} 12169f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 12171845009290e4d804ad377927bd8a08cca3036adcDuncan SandsValue *llvm::SimplifyAndInst(Value *Op0, Value *Op1, const TargetData *TD, 12181845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT) { 12191845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return ::SimplifyAndInst(Op0, Op1, TD, DT, RecursionLimit); 1220a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 1221a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1222d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner/// SimplifyOrInst - Given operands for an Or, see if we can 12239f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner/// fold the result. If not, this returns null. 1224a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyOrInst(Value *Op0, Value *Op1, const TargetData *TD, 12251845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 1226d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 1227d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 1228d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Constant *Ops[] = { CLHS, CRHS }; 1229d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return ConstantFoldInstOperands(Instruction::Or, CLHS->getType(), 1230d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Ops, 2, TD); 1231d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 123212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1233d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // Canonicalize the constant to the RHS. 1234d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner std::swap(Op0, Op1); 1235d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 123612a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1237d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // X | undef -> -1 1238f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 1239d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Constant::getAllOnesValue(Op0->getType()); 124012a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1241d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // X | X = X 1242124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Op0 == Op1) 1243d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 1244d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner 12452b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // X | 0 = X 12462b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_Zero())) 1247d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 124812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 12492b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // X | -1 = -1 12502b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_AllOnes())) 12512b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Op1; 125212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1253d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // A | ~A = ~A | A = -1 125481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner if (match(Op0, m_Not(m_Specific(Op1))) || 125581a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner match(Op1, m_Not(m_Specific(Op0)))) 1256d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Constant::getAllOnesValue(Op0->getType()); 125712a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1258d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // (A & ?) | A = A 125981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Value *A = 0, *B = 0; 1260d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (match(Op0, m_And(m_Value(A), m_Value(B))) && 1261124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (A == Op1 || B == Op1)) 1262d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op1; 126312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1264d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // A | (A & ?) = A 1265d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (match(Op1, m_And(m_Value(A), m_Value(B))) && 1266124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands (A == Op0 || B == Op0)) 1267d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return Op0; 126812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 126938f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer // ~(A & ?) | A = -1 127038f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer if (match(Op0, m_Not(m_And(m_Value(A), m_Value(B)))) && 127138f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer (A == Op1 || B == Op1)) 127238f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer return Constant::getAllOnesValue(Op1->getType()); 127338f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer 127438f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer // A | ~(A & ?) = -1 127538f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer if (match(Op1, m_Not(m_And(m_Value(A), m_Value(B)))) && 127638f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer (A == Op0 || B == Op0)) 127738f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer return Constant::getAllOnesValue(Op0->getType()); 127838f7f66fcc6ed5e43be4d9c96c782d4eabdb7342Benjamin Kramer 1279566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Try some generic simplifications for associative operations. 1280566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::Or, Op0, Op1, TD, DT, 1281566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands MaxRecurse)) 1282566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 12836844c8ea5a67e551be7106d6b7b9e1a64eecbe51Benjamin Kramer 12843421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // Or distributes over And. Try some generic simplifications based on this. 12853421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = ExpandBinOp(Instruction::Or, Op0, Op1, Instruction::And, 12863421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 12873421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 12883421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 12893421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // And distributes over Or. Try some generic simplifications based on this. 12903421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::Or, Op0, Op1, Instruction::And, 12913421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 12923421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 12933421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 1294b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If the operation is with the result of a select instruction, check whether 1295b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // operating on either branch of the select always yields the same value. 12960312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(Op0) || isa<SelectInst>(Op1)) 12971845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *V = ThreadBinOpOverSelect(Instruction::Or, Op0, Op1, TD, DT, 12980312a93693abc2eb682b2b101c889959888fd883Duncan Sands MaxRecurse)) 1299a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 1300a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 1301a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation is with the result of a phi instruction, check whether 1302a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // operating on all incoming values of the phi always yields the same value. 13030312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(Op0) || isa<PHINode>(Op1)) 13041845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *V = ThreadBinOpOverPHI(Instruction::Or, Op0, Op1, TD, DT, 13050312a93693abc2eb682b2b101c889959888fd883Duncan Sands MaxRecurse)) 1306b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return V; 1307b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 13089f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner return 0; 13099f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner} 13109f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 13111845009290e4d804ad377927bd8a08cca3036adcDuncan SandsValue *llvm::SimplifyOrInst(Value *Op0, Value *Op1, const TargetData *TD, 13121845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const DominatorTree *DT) { 13131845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return ::SimplifyOrInst(Op0, Op1, TD, DT, RecursionLimit); 1314a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 1315d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner 13162b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands/// SimplifyXorInst - Given operands for a Xor, see if we can 13172b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands/// fold the result. If not, this returns null. 13182b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sandsstatic Value *SimplifyXorInst(Value *Op0, Value *Op1, const TargetData *TD, 13192b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands const DominatorTree *DT, unsigned MaxRecurse) { 13202b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (Constant *CLHS = dyn_cast<Constant>(Op0)) { 13212b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (Constant *CRHS = dyn_cast<Constant>(Op1)) { 13222b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands Constant *Ops[] = { CLHS, CRHS }; 13232b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return ConstantFoldInstOperands(Instruction::Xor, CLHS->getType(), 13242b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands Ops, 2, TD); 13252b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands } 13262b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 13272b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // Canonicalize the constant to the RHS. 13282b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands std::swap(Op0, Op1); 13292b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands } 13302b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 13312b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // A ^ undef -> undef 1332f9e4a986c03fe3af7dbc9de0b0a9251280fbdf41Duncan Sands if (match(Op1, m_Undef())) 1333f8b1a5ea9602bb65a5cf59d3d34f2851a08cdc3eDuncan Sands return Op1; 13342b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 13352b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // A ^ 0 = A 13362b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands if (match(Op1, m_Zero())) 13372b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Op0; 13382b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 13392b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // A ^ A = 0 1340124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (Op0 == Op1) 13412b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Constant::getNullValue(Op0->getType()); 13422b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 13432b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands // A ^ ~A = ~A ^ A = -1 134481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner if (match(Op0, m_Not(m_Specific(Op1))) || 134581a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner match(Op1, m_Not(m_Specific(Op0)))) 13462b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return Constant::getAllOnesValue(Op0->getType()); 13472b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 1348566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // Try some generic simplifications for associative operations. 1349566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Instruction::Xor, Op0, Op1, TD, DT, 1350566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands MaxRecurse)) 1351566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 13522b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 13533421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands // And distributes over Xor. Try some generic simplifications based on this. 13543421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands if (Value *V = FactorizeBinOp(Instruction::Xor, Op0, Op1, Instruction::And, 13553421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands TD, DT, MaxRecurse)) 13563421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands return V; 13573421d908539cc489d2b1dac67d8cbc07160b01dbDuncan Sands 135887689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // Threading Xor over selects and phi nodes is pointless, so don't bother. 135987689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // Threading over the select in "A ^ select(cond, B, C)" means evaluating 136087689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // "A^B" and "A^C" and seeing if they are equal; but they are equal if and 136187689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // only if B and C are equal. If B and C are equal then (since we assume 136287689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // that operands have already been simplified) "select(cond, B, C)" should 136387689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // have been simplified to the common value of B and C already. Analysing 136487689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // "A^B" and "A^C" thus gains nothing, but costs compile time. Similarly 136587689cfc54993959adb20b89a56bc58aad18ca56Duncan Sands // for threading over phi nodes. 13662b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 13672b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return 0; 13682b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands} 13692b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 13702b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan SandsValue *llvm::SimplifyXorInst(Value *Op0, Value *Op1, const TargetData *TD, 13712b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands const DominatorTree *DT) { 13722b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands return ::SimplifyXorInst(Op0, Op1, TD, DT, RecursionLimit); 13732b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands} 13742b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands 1375210c5d4880b525e064088b6fec713260128c16ebChris Lattnerstatic const Type *GetCompareTy(Value *Op) { 1376210c5d4880b525e064088b6fec713260128c16ebChris Lattner return CmpInst::makeCmpResultType(Op->getType()); 1377210c5d4880b525e064088b6fec713260128c16ebChris Lattner} 1378210c5d4880b525e064088b6fec713260128c16ebChris Lattner 1379e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands/// ExtractEquivalentCondition - Rummage around inside V looking for something 1380e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands/// equivalent to the comparison "LHS Pred RHS". Return such a value if found, 1381e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands/// otherwise return null. Helper function for analyzing max/min idioms. 1382e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sandsstatic Value *ExtractEquivalentCondition(Value *V, CmpInst::Predicate Pred, 1383e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands Value *LHS, Value *RHS) { 1384e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands SelectInst *SI = dyn_cast<SelectInst>(V); 1385e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (!SI) 1386e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return 0; 1387e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands CmpInst *Cmp = dyn_cast<CmpInst>(SI->getCondition()); 1388e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (!Cmp) 1389e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return 0; 1390e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands Value *CmpLHS = Cmp->getOperand(0), *CmpRHS = Cmp->getOperand(1); 1391e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Pred == Cmp->getPredicate() && LHS == CmpLHS && RHS == CmpRHS) 1392e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return Cmp; 1393e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Pred == CmpInst::getSwappedPredicate(Cmp->getPredicate()) && 1394e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands LHS == CmpRHS && RHS == CmpLHS) 1395e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return Cmp; 1396e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return 0; 1397e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands} 1398e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands 13999dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// SimplifyICmpInst - Given operands for an ICmpInst, see if we can 14009dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// fold the result. If not, this returns null. 1401a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, 14021845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT, 14031845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 14049f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate; 14059dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner assert(CmpInst::isIntPredicate(Pred) && "Not an integer compare!"); 140612a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1407d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(LHS)) { 14088f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(RHS)) 14098f73deaa8732a556046bf4ac6207be55972e3b74Chris Lattner return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, TD); 1410d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner 1411d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // If we have a constant, make sure it is on the RHS. 1412d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner std::swap(LHS, RHS); 1413d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Pred = CmpInst::getSwappedPredicate(Pred); 1414d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 141512a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 14166dc91253ab1872e118b08511a09d5c934988354eDuncan Sands const Type *ITy = GetCompareTy(LHS); // The return type. 14176dc91253ab1872e118b08511a09d5c934988354eDuncan Sands const Type *OpTy = LHS->getType(); // The operand type. 141812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1419210c5d4880b525e064088b6fec713260128c16ebChris Lattner // icmp X, X -> true/false 1420c8e14b3d37b80abb6adb4b831af0452d9ecbf2b2Chris Lattner // X icmp undef -> true/false. For example, icmp ugt %X, undef -> false 1421c8e14b3d37b80abb6adb4b831af0452d9ecbf2b2Chris Lattner // because X could be 0. 1422124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (LHS == RHS || isa<UndefValue>(RHS)) 1423210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(ITy, CmpInst::isTrueWhenEqual(Pred)); 142412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 14256dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // Special case logic when the operands have i1 type. 14266dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (OpTy->isIntegerTy(1) || (OpTy->isVectorTy() && 14276dc91253ab1872e118b08511a09d5c934988354eDuncan Sands cast<VectorType>(OpTy)->getElementType()->isIntegerTy(1))) { 14286dc91253ab1872e118b08511a09d5c934988354eDuncan Sands switch (Pred) { 14296dc91253ab1872e118b08511a09d5c934988354eDuncan Sands default: break; 14306dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_EQ: 14316dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X == 1 -> X 14326dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_One())) 14336dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 14346dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 14356dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_NE: 14366dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X != 0 -> X 14376dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_Zero())) 14386dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 14396dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 14406dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_UGT: 14416dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X >u 0 -> X 14426dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_Zero())) 14436dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 14446dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 14456dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_UGE: 14466dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X >=u 1 -> X 14476dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_One())) 14486dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 14496dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 14506dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_SLT: 14516dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X <s 0 -> X 14526dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_Zero())) 14536dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 14546dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 14556dc91253ab1872e118b08511a09d5c934988354eDuncan Sands case ICmpInst::ICMP_SLE: 14566dc91253ab1872e118b08511a09d5c934988354eDuncan Sands // X <=s -1 -> X 14576dc91253ab1872e118b08511a09d5c934988354eDuncan Sands if (match(RHS, m_One())) 14586dc91253ab1872e118b08511a09d5c934988354eDuncan Sands return LHS; 14596dc91253ab1872e118b08511a09d5c934988354eDuncan Sands break; 14606dc91253ab1872e118b08511a09d5c934988354eDuncan Sands } 14616dc91253ab1872e118b08511a09d5c934988354eDuncan Sands } 146212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 1463d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // icmp <alloca*>, <global/alloca*/null> - Different stack variables have 1464d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // different addresses, and what's more the address of a stack variable is 1465d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // never null or equal to the address of a global. Note that generalizing 1466d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // to the case where LHS is a global variable address or null is pointless, 1467d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // since if both LHS and RHS are constants then we already constant folded 1468d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // the compare, and if only one of them is then we moved it to RHS already. 1469d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (isa<AllocaInst>(LHS) && (isa<GlobalValue>(RHS) || isa<AllocaInst>(RHS) || 1470d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands isa<ConstantPointerNull>(RHS))) 147158bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky // We already know that LHS != RHS. 1472d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands return ConstantInt::get(ITy, CmpInst::isFalseWhenEqual(Pred)); 1473d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands 1474d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // If we are comparing with zero then try hard since this is a common case. 1475d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (match(RHS, m_Zero())) { 1476d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands bool LHSKnownNonNegative, LHSKnownNegative; 1477d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands switch (Pred) { 1478d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands default: 1479d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands assert(false && "Unknown ICmp predicate!"); 1480d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_ULT: 1481448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands // getNullValue also works for vectors, unlike getFalse. 1482448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return Constant::getNullValue(ITy); 1483d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_UGE: 1484448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands // getAllOnesValue also works for vectors, unlike getTrue. 1485448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return ConstantInt::getAllOnesValue(ITy); 1486d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_EQ: 1487d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_ULE: 1488d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (isKnownNonZero(LHS, TD)) 1489448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return Constant::getNullValue(ITy); 1490d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1491d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_NE: 1492d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_UGT: 1493d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (isKnownNonZero(LHS, TD)) 1494448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return ConstantInt::getAllOnesValue(ITy); 1495d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1496d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_SLT: 1497d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, TD); 1498d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNegative) 1499448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return ConstantInt::getAllOnesValue(ITy); 1500d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNonNegative) 1501448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return Constant::getNullValue(ITy); 1502d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1503d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_SLE: 1504d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, TD); 1505d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNegative) 1506448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return ConstantInt::getAllOnesValue(ITy); 1507d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNonNegative && isKnownNonZero(LHS, TD)) 1508448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return Constant::getNullValue(ITy); 1509d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1510d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_SGE: 1511d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, TD); 1512d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNegative) 1513448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return Constant::getNullValue(ITy); 1514d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNonNegative) 1515448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return ConstantInt::getAllOnesValue(ITy); 1516d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1517d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands case ICmpInst::ICMP_SGT: 1518d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands ComputeSignBit(LHS, LHSKnownNonNegative, LHSKnownNegative, TD); 1519d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNegative) 1520448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return Constant::getNullValue(ITy); 1521d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands if (LHSKnownNonNegative && isKnownNonZero(LHS, TD)) 1522448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return ConstantInt::getAllOnesValue(ITy); 1523d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands break; 1524d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands } 1525d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands } 1526d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands 1527d70d1a5c44609af091f6fc3e29193f9f4756a74fDuncan Sands // See if we are doing a comparison with a constant integer. 1528210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) { 15293a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // Rule out tautological comparisons (eg., ult 0 or uge 0). 15303a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky ConstantRange RHS_CR = ICmpInst::makeConstantRange(Pred, CI->getValue()); 15313a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (RHS_CR.isEmptySet()) 15323a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky return ConstantInt::getFalse(CI->getContext()); 15333a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (RHS_CR.isFullSet()) 15343a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky return ConstantInt::getTrue(CI->getContext()); 15353a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky 15363a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // Many binary operators with constant RHS have easy to compute constant 15373a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // range. Use them to check whether the comparison is a tautology. 15383a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky uint32_t Width = CI->getBitWidth(); 15393a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt Lower = APInt(Width, 0); 15403a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt Upper = APInt(Width, 0); 15413a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky ConstantInt *CI2; 15423a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (match(LHS, m_URem(m_Value(), m_ConstantInt(CI2)))) { 15433a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'urem x, CI2' produces [0, CI2). 15443a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = CI2->getValue(); 15453a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_SRem(m_Value(), m_ConstantInt(CI2)))) { 15463a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'srem x, CI2' produces (-|CI2|, |CI2|). 15473a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = CI2->getValue().abs(); 15483a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Lower = (-Upper) + 1; 15493a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_UDiv(m_Value(), m_ConstantInt(CI2)))) { 15503a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'udiv x, CI2' produces [0, UINT_MAX / CI2]. 15513a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt NegOne = APInt::getAllOnesValue(Width); 15523a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (!CI2->isZero()) 15533a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = NegOne.udiv(CI2->getValue()) + 1; 15543a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_SDiv(m_Value(), m_ConstantInt(CI2)))) { 15553a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'sdiv x, CI2' produces [INT_MIN / CI2, INT_MAX / CI2]. 15563a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt IntMin = APInt::getSignedMinValue(Width); 15573a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt IntMax = APInt::getSignedMaxValue(Width); 15583a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt Val = CI2->getValue().abs(); 15593a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (!Val.isMinValue()) { 15603a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Lower = IntMin.sdiv(Val); 15613a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = IntMax.sdiv(Val) + 1; 15623a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } 15633a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_LShr(m_Value(), m_ConstantInt(CI2)))) { 15643a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'lshr x, CI2' produces [0, UINT_MAX >> CI2]. 15653a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt NegOne = APInt::getAllOnesValue(Width); 15663a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (CI2->getValue().ult(Width)) 15673a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = NegOne.lshr(CI2->getValue()) + 1; 15683a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_AShr(m_Value(), m_ConstantInt(CI2)))) { 15693a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'ashr x, CI2' produces [INT_MIN >> CI2, INT_MAX >> CI2]. 15703a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt IntMin = APInt::getSignedMinValue(Width); 15713a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky APInt IntMax = APInt::getSignedMaxValue(Width); 15723a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (CI2->getValue().ult(Width)) { 15733a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Lower = IntMin.ashr(CI2->getValue()); 15743a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = IntMax.ashr(CI2->getValue()) + 1; 15753a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } 15763a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_Or(m_Value(), m_ConstantInt(CI2)))) { 15773a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'or x, CI2' produces [CI2, UINT_MAX]. 15783a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Lower = CI2->getValue(); 15793a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } else if (match(LHS, m_And(m_Value(), m_ConstantInt(CI2)))) { 15803a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky // 'and x, CI2' produces [0, CI2]. 15813a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky Upper = CI2->getValue() + 1; 15823a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky } 15833a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (Lower != Upper) { 15843a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky ConstantRange LHS_CR = ConstantRange(Lower, Upper); 15853a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (RHS_CR.contains(LHS_CR)) 15863a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky return ConstantInt::getTrue(RHS->getContext()); 15873a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky if (RHS_CR.inverse().contains(LHS_CR)) 15883a73e343d02ba3a00adf03311183cc0ccc960978Nick Lewycky return ConstantInt::getFalse(RHS->getContext()); 1589210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 1590210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 15911ac7c9979a2d723ff4649ffad58df02732872a5fDuncan Sands 15929d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compare of cast, for example (zext X) != 0 -> X != 0 15939d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (isa<CastInst>(LHS) && (isa<Constant>(RHS) || isa<CastInst>(RHS))) { 15949d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Instruction *LI = cast<CastInst>(LHS); 15959d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Value *SrcOp = LI->getOperand(0); 15969d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands const Type *SrcTy = SrcOp->getType(); 15979d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands const Type *DstTy = LI->getType(); 15989d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 15999d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (ptrtoint x), (ptrtoint/constant) into a compare of the input 16009d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // if the integer type is the same size as the pointer type. 16019d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse && TD && isa<PtrToIntInst>(LI) && 16029d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands TD->getPointerSizeInBits() == DstTy->getPrimitiveSizeInBits()) { 16039d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Constant *RHSC = dyn_cast<Constant>(RHS)) { 16049d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Transfer the cast to the constant. 16059d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(Pred, SrcOp, 16069d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantExpr::getIntToPtr(RHSC, SrcTy), 16079d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands TD, DT, MaxRecurse-1)) 16089d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 16099d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } else if (PtrToIntInst *RI = dyn_cast<PtrToIntInst>(RHS)) { 16109d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RI->getOperand(0)->getType() == SrcTy) 16119d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compare without the cast. 16129d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0), 16139d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands TD, DT, MaxRecurse-1)) 16149d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 16159d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 16169d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 16179d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 16189d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (isa<ZExtInst>(LHS)) { 16199d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (zext X), (zext Y) into a compare of X and Y if they have the 16209d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // same type. 16219d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (ZExtInst *RI = dyn_cast<ZExtInst>(RHS)) { 16229d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse && SrcTy == RI->getOperand(0)->getType()) 16239d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compare X and Y. Note that signed predicates become unsigned. 16249d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred), 16259d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands SrcOp, RI->getOperand(0), TD, DT, 16269d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands MaxRecurse-1)) 16279d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 16289d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 16299d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (zext X), Cst into a compare of X and Cst if Cst is extended 16309d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // too. If not, then try to deduce the result of the comparison. 16319d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) { 16329d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compute the constant that would happen if we truncated to SrcTy then 16339d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // reextended to DstTy. 16349d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy); 16359d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant *RExt = ConstantExpr::getCast(CastInst::ZExt, Trunc, DstTy); 16369d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 16379d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // If the re-extended constant didn't change then this is effectively 16389d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // also a case of comparing two zero-extended values. 16399d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RExt == CI && MaxRecurse) 16409d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(ICmpInst::getUnsignedPredicate(Pred), 16419d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands SrcOp, Trunc, TD, DT, MaxRecurse-1)) 16429d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 16439d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 16449d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Otherwise the upper bits of LHS are zero while RHS has a non-zero bit 16459d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // there. Use this to work out the result of the comparison. 16469d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RExt != CI) { 16479d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands switch (Pred) { 16489d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands default: 16499d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands assert(false && "Unknown ICmp predicate!"); 16509d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // LHS <u RHS. 16519d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_EQ: 16529d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_UGT: 16539d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_UGE: 16549d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return ConstantInt::getFalse(CI->getContext()); 16559d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 16569d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_NE: 16579d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_ULT: 16589d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_ULE: 16599d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return ConstantInt::getTrue(CI->getContext()); 16609d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 16619d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // LHS is non-negative. If RHS is negative then LHS >s LHS. If RHS 16629d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // is non-negative then LHS <s RHS. 16639d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SGT: 16649d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SGE: 16659d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return CI->getValue().isNegative() ? 16669d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getTrue(CI->getContext()) : 16679d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getFalse(CI->getContext()); 16689d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 16699d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SLT: 16709d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SLE: 16719d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return CI->getValue().isNegative() ? 16729d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getFalse(CI->getContext()) : 16739d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getTrue(CI->getContext()); 16749d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 16759d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 16769d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 16779d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 16789d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 16799d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (isa<SExtInst>(LHS)) { 16809d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (sext X), (sext Y) into a compare of X and Y if they have the 16819d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // same type. 16829d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (SExtInst *RI = dyn_cast<SExtInst>(RHS)) { 16839d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse && SrcTy == RI->getOperand(0)->getType()) 16849d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compare X and Y. Note that the predicate does not change. 16859d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(Pred, SrcOp, RI->getOperand(0), 16869d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands TD, DT, MaxRecurse-1)) 16879d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 16889d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 16899d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Turn icmp (sext X), Cst into a compare of X and Cst if Cst is extended 16909d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // too. If not, then try to deduce the result of the comparison. 16919d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands else if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) { 16929d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Compute the constant that would happen if we truncated to SrcTy then 16939d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // reextended to DstTy. 16949d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant *Trunc = ConstantExpr::getTrunc(CI, SrcTy); 16959d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant *RExt = ConstantExpr::getCast(CastInst::SExt, Trunc, DstTy); 16969d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 16979d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // If the re-extended constant didn't change then this is effectively 16989d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // also a case of comparing two sign-extended values. 16999d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RExt == CI && MaxRecurse) 17009d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(Pred, SrcOp, Trunc, TD, DT, 17019d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands MaxRecurse-1)) 17029d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 17039d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 17049d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Otherwise the upper bits of LHS are all equal, while RHS has varying 17059d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // bits there. Use this to work out the result of the comparison. 17069d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (RExt != CI) { 17079d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands switch (Pred) { 17089d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands default: 17099d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands assert(false && "Unknown ICmp predicate!"); 17109d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_EQ: 17119d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return ConstantInt::getFalse(CI->getContext()); 17129d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_NE: 17139d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return ConstantInt::getTrue(CI->getContext()); 17149d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 17159d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // If RHS is non-negative then LHS <s RHS. If RHS is negative then 17169d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // LHS >s RHS. 17179d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SGT: 17189d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SGE: 17199d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return CI->getValue().isNegative() ? 17209d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getTrue(CI->getContext()) : 17219d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getFalse(CI->getContext()); 17229d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SLT: 17239d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_SLE: 17249d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return CI->getValue().isNegative() ? 17259d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getFalse(CI->getContext()) : 17269d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands ConstantInt::getTrue(CI->getContext()); 17279d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 17289d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // If LHS is non-negative then LHS <u RHS. If LHS is negative then 17299d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // LHS >u RHS. 17309d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_UGT: 17319d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_UGE: 17329d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Comparison is true iff the LHS <s 0. 17339d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse) 17349d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SLT, SrcOp, 17359d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant::getNullValue(SrcTy), 17369d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands TD, DT, MaxRecurse-1)) 17379d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 17389d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands break; 17399d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_ULT: 17409d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands case ICmpInst::ICMP_ULE: 17419d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands // Comparison is true iff the LHS >=s 0. 17429d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (MaxRecurse) 17439d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands if (Value *V = SimplifyICmpInst(ICmpInst::ICMP_SGE, SrcOp, 17449d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands Constant::getNullValue(SrcTy), 17459d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands TD, DT, MaxRecurse-1)) 17469d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands return V; 17479d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands break; 17489d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 17499d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 17509d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 17519d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 17529d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands } 17539d32f60a6f7dbd8e83187481cd2ae0a2f3e726ceDuncan Sands 175452fb846578714d14bbde9b28884a6a8729217677Duncan Sands // Special logic for binary operators. 175552fb846578714d14bbde9b28884a6a8729217677Duncan Sands BinaryOperator *LBO = dyn_cast<BinaryOperator>(LHS); 175652fb846578714d14bbde9b28884a6a8729217677Duncan Sands BinaryOperator *RBO = dyn_cast<BinaryOperator>(RHS); 175752fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (MaxRecurse && (LBO || RBO)) { 175852fb846578714d14bbde9b28884a6a8729217677Duncan Sands // Analyze the case when either LHS or RHS is an add instruction. 175952fb846578714d14bbde9b28884a6a8729217677Duncan Sands Value *A = 0, *B = 0, *C = 0, *D = 0; 176052fb846578714d14bbde9b28884a6a8729217677Duncan Sands // LHS = A + B (or A and B are null); RHS = C + D (or C and D are null). 176152fb846578714d14bbde9b28884a6a8729217677Duncan Sands bool NoLHSWrapProblem = false, NoRHSWrapProblem = false; 176252fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (LBO && LBO->getOpcode() == Instruction::Add) { 176352fb846578714d14bbde9b28884a6a8729217677Duncan Sands A = LBO->getOperand(0); B = LBO->getOperand(1); 176452fb846578714d14bbde9b28884a6a8729217677Duncan Sands NoLHSWrapProblem = ICmpInst::isEquality(Pred) || 176552fb846578714d14bbde9b28884a6a8729217677Duncan Sands (CmpInst::isUnsigned(Pred) && LBO->hasNoUnsignedWrap()) || 176652fb846578714d14bbde9b28884a6a8729217677Duncan Sands (CmpInst::isSigned(Pred) && LBO->hasNoSignedWrap()); 176752fb846578714d14bbde9b28884a6a8729217677Duncan Sands } 176852fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (RBO && RBO->getOpcode() == Instruction::Add) { 176952fb846578714d14bbde9b28884a6a8729217677Duncan Sands C = RBO->getOperand(0); D = RBO->getOperand(1); 177052fb846578714d14bbde9b28884a6a8729217677Duncan Sands NoRHSWrapProblem = ICmpInst::isEquality(Pred) || 177152fb846578714d14bbde9b28884a6a8729217677Duncan Sands (CmpInst::isUnsigned(Pred) && RBO->hasNoUnsignedWrap()) || 177252fb846578714d14bbde9b28884a6a8729217677Duncan Sands (CmpInst::isSigned(Pred) && RBO->hasNoSignedWrap()); 177352fb846578714d14bbde9b28884a6a8729217677Duncan Sands } 177452fb846578714d14bbde9b28884a6a8729217677Duncan Sands 177552fb846578714d14bbde9b28884a6a8729217677Duncan Sands // icmp (X+Y), X -> icmp Y, 0 for equalities or if there is no overflow. 177652fb846578714d14bbde9b28884a6a8729217677Duncan Sands if ((A == RHS || B == RHS) && NoLHSWrapProblem) 177752fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (Value *V = SimplifyICmpInst(Pred, A == RHS ? B : A, 177852fb846578714d14bbde9b28884a6a8729217677Duncan Sands Constant::getNullValue(RHS->getType()), 177952fb846578714d14bbde9b28884a6a8729217677Duncan Sands TD, DT, MaxRecurse-1)) 178052fb846578714d14bbde9b28884a6a8729217677Duncan Sands return V; 178152fb846578714d14bbde9b28884a6a8729217677Duncan Sands 178252fb846578714d14bbde9b28884a6a8729217677Duncan Sands // icmp X, (X+Y) -> icmp 0, Y for equalities or if there is no overflow. 178352fb846578714d14bbde9b28884a6a8729217677Duncan Sands if ((C == LHS || D == LHS) && NoRHSWrapProblem) 178452fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (Value *V = SimplifyICmpInst(Pred, 178552fb846578714d14bbde9b28884a6a8729217677Duncan Sands Constant::getNullValue(LHS->getType()), 178652fb846578714d14bbde9b28884a6a8729217677Duncan Sands C == LHS ? D : C, TD, DT, MaxRecurse-1)) 178752fb846578714d14bbde9b28884a6a8729217677Duncan Sands return V; 178852fb846578714d14bbde9b28884a6a8729217677Duncan Sands 178952fb846578714d14bbde9b28884a6a8729217677Duncan Sands // icmp (X+Y), (X+Z) -> icmp Y,Z for equalities or if there is no overflow. 179052fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (A && C && (A == C || A == D || B == C || B == D) && 179152fb846578714d14bbde9b28884a6a8729217677Duncan Sands NoLHSWrapProblem && NoRHSWrapProblem) { 179252fb846578714d14bbde9b28884a6a8729217677Duncan Sands // Determine Y and Z in the form icmp (X+Y), (X+Z). 179352fb846578714d14bbde9b28884a6a8729217677Duncan Sands Value *Y = (A == C || A == D) ? B : A; 179452fb846578714d14bbde9b28884a6a8729217677Duncan Sands Value *Z = (C == A || C == B) ? D : C; 179552fb846578714d14bbde9b28884a6a8729217677Duncan Sands if (Value *V = SimplifyICmpInst(Pred, Y, Z, TD, DT, MaxRecurse-1)) 179652fb846578714d14bbde9b28884a6a8729217677Duncan Sands return V; 179752fb846578714d14bbde9b28884a6a8729217677Duncan Sands } 179852fb846578714d14bbde9b28884a6a8729217677Duncan Sands } 179952fb846578714d14bbde9b28884a6a8729217677Duncan Sands 180084dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky if (LBO && match(LBO, m_URem(m_Value(), m_Specific(RHS)))) { 1801786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky bool KnownNonNegative, KnownNegative; 180288cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky switch (Pred) { 180388cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky default: 180488cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky break; 1805786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky case ICmpInst::ICMP_SGT: 1806786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky case ICmpInst::ICMP_SGE: 1807786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky ComputeSignBit(LHS, KnownNonNegative, KnownNegative, TD); 1808786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky if (!KnownNonNegative) 1809786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky break; 1810786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky // fall-through 181188cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky case ICmpInst::ICMP_EQ: 181288cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky case ICmpInst::ICMP_UGT: 181388cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky case ICmpInst::ICMP_UGE: 1814448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands // getNullValue also works for vectors, unlike getFalse. 1815448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return Constant::getNullValue(ITy); 1816786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky case ICmpInst::ICMP_SLT: 1817786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky case ICmpInst::ICMP_SLE: 1818786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky ComputeSignBit(LHS, KnownNonNegative, KnownNegative, TD); 1819786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky if (!KnownNonNegative) 1820786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky break; 1821786792784e898f29febb3e7270d54b0e21e3c904Nick Lewycky // fall-through 182288cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky case ICmpInst::ICMP_NE: 182388cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky case ICmpInst::ICMP_ULT: 182488cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky case ICmpInst::ICMP_ULE: 1825448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands // getAllOnesValue also works for vectors, unlike getTrue. 1826448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return Constant::getAllOnesValue(ITy); 182788cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky } 182888cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky } 182984dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky if (RBO && match(RBO, m_URem(m_Value(), m_Specific(LHS)))) { 183084dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky bool KnownNonNegative, KnownNegative; 183184dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky switch (Pred) { 183284dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky default: 183384dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky break; 183484dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_SGT: 183584dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_SGE: 183684dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky ComputeSignBit(RHS, KnownNonNegative, KnownNegative, TD); 183784dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky if (!KnownNonNegative) 183884dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky break; 183984dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky // fall-through 1840a0e2f38b25ce7c51c22ed40d8a315fe1dd98926dNick Lewycky case ICmpInst::ICMP_NE: 184184dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_UGT: 184284dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_UGE: 1843448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands // getAllOnesValue also works for vectors, unlike getTrue. 1844448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return Constant::getAllOnesValue(ITy); 184584dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_SLT: 184684dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_SLE: 184784dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky ComputeSignBit(RHS, KnownNonNegative, KnownNegative, TD); 184884dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky if (!KnownNonNegative) 184984dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky break; 185084dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky // fall-through 1851a0e2f38b25ce7c51c22ed40d8a315fe1dd98926dNick Lewycky case ICmpInst::ICMP_EQ: 185284dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_ULT: 185384dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky case ICmpInst::ICMP_ULE: 1854448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands // getNullValue also works for vectors, unlike getFalse. 1855448a6d3cc23f2a249778bb341ae26589568efdf8Duncan Sands return Constant::getNullValue(ITy); 185684dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky } 185784dd4fa2e36f72050f5c46577359f5df0467e3e4Nick Lewycky } 185888cd0aadb2849a259e8656b0ff8439ef660db7c5Nick Lewycky 185958bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky if (MaxRecurse && LBO && RBO && LBO->getOpcode() == RBO->getOpcode() && 186058bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky LBO->getOperand(1) == RBO->getOperand(1)) { 186158bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky switch (LBO->getOpcode()) { 186258bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky default: break; 186358bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky case Instruction::UDiv: 186458bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky case Instruction::LShr: 186558bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky if (ICmpInst::isSigned(Pred)) 186658bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky break; 186758bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky // fall-through 186858bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky case Instruction::SDiv: 186958bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky case Instruction::AShr: 1870b6e7cd655c6ee119dbeacc321ee92387f983edb0Eli Friedman if (!LBO->isExact() || !RBO->isExact()) 187158bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky break; 187258bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0), 187358bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky RBO->getOperand(0), TD, DT, MaxRecurse-1)) 187458bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky return V; 187558bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky break; 187658bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky case Instruction::Shl: { 187758bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky bool NUW = LBO->hasNoUnsignedWrap() && LBO->hasNoUnsignedWrap(); 187858bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky bool NSW = LBO->hasNoSignedWrap() && RBO->hasNoSignedWrap(); 187958bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky if (!NUW && !NSW) 188058bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky break; 188158bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky if (!NSW && ICmpInst::isSigned(Pred)) 188258bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky break; 188358bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky if (Value *V = SimplifyICmpInst(Pred, LBO->getOperand(0), 188458bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky RBO->getOperand(0), TD, DT, MaxRecurse-1)) 188558bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky return V; 188658bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky break; 188758bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky } 188858bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky } 188958bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky } 189058bfcdbcf6a7c1cac0187f7c6beb3afe9d8f5411Nick Lewycky 1891ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Simplify comparisons involving max/min. 1892ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands Value *A, *B; 1893ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands CmpInst::Predicate P = CmpInst::BAD_ICMP_PREDICATE; 1894ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands CmpInst::Predicate EqP; // Chosen so that "A == max/min(A,B)" iff "A EqP B". 1895ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands 18968140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Signed variants on "max(a,b)>=a -> true". 1897ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (match(LHS, m_SMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) { 1898ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != RHS) std::swap(A, B); // smax(A, B) pred A. 1899ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B". 1900ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as smax(A, B) pred A. 1901ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = Pred; 1902ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } else if (match(RHS, m_SMax(m_Value(A), m_Value(B))) && 1903ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands (A == LHS || B == LHS)) { 1904ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != LHS) std::swap(A, B); // A pred smax(A, B). 1905ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_SGE; // "A == smax(A, B)" iff "A sge B". 1906ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as smax(A, B) swapped-pred A. 1907ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = CmpInst::getSwappedPredicate(Pred); 1908ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) && 1909ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands (A == RHS || B == RHS)) { 1910ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != RHS) std::swap(A, B); // smin(A, B) pred A. 1911ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B". 1912ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as smax(-A, -B) swapped-pred -A. 1913ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Note that we do not need to actually form -A or -B thanks to EqP. 1914ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = CmpInst::getSwappedPredicate(Pred); 1915ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } else if (match(RHS, m_SMin(m_Value(A), m_Value(B))) && 1916ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands (A == LHS || B == LHS)) { 1917ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != LHS) std::swap(A, B); // A pred smin(A, B). 1918ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_SLE; // "A == smin(A, B)" iff "A sle B". 1919ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as smax(-A, -B) pred -A. 1920ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Note that we do not need to actually form -A or -B thanks to EqP. 1921ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = Pred; 1922ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } 1923ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (P != CmpInst::BAD_ICMP_PREDICATE) { 1924ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Cases correspond to "max(A, B) p A". 1925ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands switch (P) { 1926ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands default: 1927ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands break; 1928ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_EQ: 1929ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_SLE: 1930e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Equivalent to "A EqP B". This may be the same as the condition tested 1931e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // in the max/min; if so, we can just return that. 1932e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B)) 1933e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 1934e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B)) 1935e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 1936e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Otherwise, see if "A EqP B" simplifies. 1937ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (MaxRecurse) 1938ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (Value *V = SimplifyICmpInst(EqP, A, B, TD, DT, MaxRecurse-1)) 1939ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands return V; 1940ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands break; 1941ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_NE: 1942e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands case CmpInst::ICMP_SGT: { 1943e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP); 1944e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Equivalent to "A InvEqP B". This may be the same as the condition 1945e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // tested in the max/min; if so, we can just return that. 1946e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B)) 1947e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 1948e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B)) 1949e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 1950e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Otherwise, see if "A InvEqP B" simplifies. 1951ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (MaxRecurse) 1952e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = SimplifyICmpInst(InvEqP, A, B, TD, DT, MaxRecurse-1)) 1953ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands return V; 1954ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands break; 1955e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands } 1956ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_SGE: 1957ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Always true. 1958ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands return Constant::getAllOnesValue(ITy); 1959ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_SLT: 1960ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Always false. 1961ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands return Constant::getNullValue(ITy); 1962ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } 1963ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } 1964ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands 19658140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Unsigned variants on "max(a,b)>=a -> true". 1966ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = CmpInst::BAD_ICMP_PREDICATE; 1967ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (match(LHS, m_UMax(m_Value(A), m_Value(B))) && (A == RHS || B == RHS)) { 1968ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != RHS) std::swap(A, B); // umax(A, B) pred A. 1969ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B". 1970ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as umax(A, B) pred A. 1971ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = Pred; 1972ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } else if (match(RHS, m_UMax(m_Value(A), m_Value(B))) && 1973ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands (A == LHS || B == LHS)) { 1974ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != LHS) std::swap(A, B); // A pred umax(A, B). 1975ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_UGE; // "A == umax(A, B)" iff "A uge B". 1976ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as umax(A, B) swapped-pred A. 1977ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = CmpInst::getSwappedPredicate(Pred); 1978ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) && 1979ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands (A == RHS || B == RHS)) { 1980ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != RHS) std::swap(A, B); // umin(A, B) pred A. 1981ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B". 1982ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as umax(-A, -B) swapped-pred -A. 1983ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Note that we do not need to actually form -A or -B thanks to EqP. 1984ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = CmpInst::getSwappedPredicate(Pred); 1985ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } else if (match(RHS, m_UMin(m_Value(A), m_Value(B))) && 1986ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands (A == LHS || B == LHS)) { 1987ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (A != LHS) std::swap(A, B); // A pred umin(A, B). 1988ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands EqP = CmpInst::ICMP_ULE; // "A == umin(A, B)" iff "A ule B". 1989ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // We analyze this as umax(-A, -B) pred -A. 1990ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Note that we do not need to actually form -A or -B thanks to EqP. 1991ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands P = Pred; 1992ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } 1993ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (P != CmpInst::BAD_ICMP_PREDICATE) { 1994ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Cases correspond to "max(A, B) p A". 1995ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands switch (P) { 1996ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands default: 1997ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands break; 1998ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_EQ: 1999ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_ULE: 2000e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Equivalent to "A EqP B". This may be the same as the condition tested 2001e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // in the max/min; if so, we can just return that. 2002e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(LHS, EqP, A, B)) 2003e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 2004e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(RHS, EqP, A, B)) 2005e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 2006e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Otherwise, see if "A EqP B" simplifies. 2007ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (MaxRecurse) 2008ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (Value *V = SimplifyICmpInst(EqP, A, B, TD, DT, MaxRecurse-1)) 2009ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands return V; 2010ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands break; 2011ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_NE: 2012e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands case CmpInst::ICMP_UGT: { 2013e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands CmpInst::Predicate InvEqP = CmpInst::getInversePredicate(EqP); 2014e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Equivalent to "A InvEqP B". This may be the same as the condition 2015e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // tested in the max/min; if so, we can just return that. 2016e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(LHS, InvEqP, A, B)) 2017e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 2018e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = ExtractEquivalentCondition(RHS, InvEqP, A, B)) 2019e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands return V; 2020e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands // Otherwise, see if "A InvEqP B" simplifies. 2021ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands if (MaxRecurse) 2022e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands if (Value *V = SimplifyICmpInst(InvEqP, A, B, TD, DT, MaxRecurse-1)) 2023ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands return V; 2024ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands break; 2025e864b5b840c58d0b04324082ec94a7156743ed60Duncan Sands } 2026ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_UGE: 2027ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Always true. 2028ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands return Constant::getAllOnesValue(ITy); 2029ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands case CmpInst::ICMP_ULT: 2030ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands // Always false. 2031ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands return Constant::getNullValue(ITy); 2032ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } 2033ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands } 2034ad20681cdeaf72383891b153b925624aa585be4dDuncan Sands 20358140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Variants on "max(x,y) >= min(x,z)". 20368140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands Value *C, *D; 20378140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (match(LHS, m_SMax(m_Value(A), m_Value(B))) && 20388140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands match(RHS, m_SMin(m_Value(C), m_Value(D))) && 20398140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands (A == C || A == D || B == C || B == D)) { 20408140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // max(x, ?) pred min(x, ?). 20418140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_SGE) 20428140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always true. 20438140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands return Constant::getAllOnesValue(ITy); 20448140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_SLT) 20458140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always false. 20468140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands return Constant::getNullValue(ITy); 20478140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands } else if (match(LHS, m_SMin(m_Value(A), m_Value(B))) && 20488140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands match(RHS, m_SMax(m_Value(C), m_Value(D))) && 20498140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands (A == C || A == D || B == C || B == D)) { 20508140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // min(x, ?) pred max(x, ?). 20518140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_SLE) 20528140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always true. 20538140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands return Constant::getAllOnesValue(ITy); 20548140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_SGT) 20558140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always false. 20568140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands return Constant::getNullValue(ITy); 20578140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands } else if (match(LHS, m_UMax(m_Value(A), m_Value(B))) && 20588140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands match(RHS, m_UMin(m_Value(C), m_Value(D))) && 20598140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands (A == C || A == D || B == C || B == D)) { 20608140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // max(x, ?) pred min(x, ?). 20618140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_UGE) 20628140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always true. 20638140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands return Constant::getAllOnesValue(ITy); 20648140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_ULT) 20658140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always false. 20668140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands return Constant::getNullValue(ITy); 20678140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands } else if (match(LHS, m_UMin(m_Value(A), m_Value(B))) && 20688140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands match(RHS, m_UMax(m_Value(C), m_Value(D))) && 20698140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands (A == C || A == D || B == C || B == D)) { 20708140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // min(x, ?) pred max(x, ?). 20718140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_ULE) 20728140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always true. 20738140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands return Constant::getAllOnesValue(ITy); 20748140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands if (Pred == CmpInst::ICMP_UGT) 20758140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands // Always false. 20768140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands return Constant::getNullValue(ITy); 20778140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands } 20788140ad32ce45281ed2bc4f6ca388a6ed9f806550Duncan Sands 20791ac7c9979a2d723ff4649ffad58df02732872a5fDuncan Sands // If the comparison is with the result of a select instruction, check whether 20801ac7c9979a2d723ff4649ffad58df02732872a5fDuncan Sands // comparing with either branch of the select always yields the same value. 20810312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS)) 20820312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, TD, DT, MaxRecurse)) 2083a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 2084a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 2085a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the comparison is with the result of a phi instruction, check whether 2086a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // doing the compare with each incoming phi value yields a common result. 20870312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(LHS) || isa<PHINode>(RHS)) 20880312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, TD, DT, MaxRecurse)) 20893bbb0cc42b67b4bf2c488285666999963bab0f7eDuncan Sands return V; 20901ac7c9979a2d723ff4649ffad58df02732872a5fDuncan Sands 20919dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner return 0; 20929dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner} 20939dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 2094a74a58c83be492b7d5b7383656f049909394cff4Duncan SandsValue *llvm::SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, 20951845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT) { 20961845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return ::SimplifyICmpInst(Predicate, LHS, RHS, TD, DT, RecursionLimit); 2097a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 2098a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 20999dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can 21009dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// fold the result. If not, this returns null. 2101a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS, 21021845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT, 21031845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 21049dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner CmpInst::Predicate Pred = (CmpInst::Predicate)Predicate; 21059dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner assert(CmpInst::isFPPredicate(Pred) && "Not an FP compare!"); 21069dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 2107d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(LHS)) { 21089dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner if (Constant *CRHS = dyn_cast<Constant>(RHS)) 21099dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner return ConstantFoldCompareInstOperands(Pred, CLHS, CRHS, TD); 211012a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2111d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner // If we have a constant, make sure it is on the RHS. 2112d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner std::swap(LHS, RHS); 2113d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Pred = CmpInst::getSwappedPredicate(Pred); 2114d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 211512a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2116210c5d4880b525e064088b6fec713260128c16ebChris Lattner // Fold trivial predicates. 2117210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (Pred == FCmpInst::FCMP_FALSE) 2118210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(GetCompareTy(LHS), 0); 2119210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (Pred == FCmpInst::FCMP_TRUE) 2120210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(GetCompareTy(LHS), 1); 2121210c5d4880b525e064088b6fec713260128c16ebChris Lattner 2122210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (isa<UndefValue>(RHS)) // fcmp pred X, undef -> undef 2123210c5d4880b525e064088b6fec713260128c16ebChris Lattner return UndefValue::get(GetCompareTy(LHS)); 2124210c5d4880b525e064088b6fec713260128c16ebChris Lattner 2125210c5d4880b525e064088b6fec713260128c16ebChris Lattner // fcmp x,x -> true/false. Not all compares are foldable. 2126124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (LHS == RHS) { 2127210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (CmpInst::isTrueWhenEqual(Pred)) 2128210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(GetCompareTy(LHS), 1); 2129210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (CmpInst::isFalseWhenEqual(Pred)) 2130210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::get(GetCompareTy(LHS), 0); 2131210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 213212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2133210c5d4880b525e064088b6fec713260128c16ebChris Lattner // Handle fcmp with constant RHS 2134210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (Constant *RHSC = dyn_cast<Constant>(RHS)) { 2135210c5d4880b525e064088b6fec713260128c16ebChris Lattner // If the constant is a nan, see if we can fold the comparison based on it. 2136210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (ConstantFP *CFP = dyn_cast<ConstantFP>(RHSC)) { 2137210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (CFP->getValueAPF().isNaN()) { 2138210c5d4880b525e064088b6fec713260128c16ebChris Lattner if (FCmpInst::isOrdered(Pred)) // True "if ordered and foo" 2139210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::getFalse(CFP->getContext()); 2140210c5d4880b525e064088b6fec713260128c16ebChris Lattner assert(FCmpInst::isUnordered(Pred) && 2141210c5d4880b525e064088b6fec713260128c16ebChris Lattner "Comparison must be either ordered or unordered!"); 2142210c5d4880b525e064088b6fec713260128c16ebChris Lattner // True if unordered. 2143210c5d4880b525e064088b6fec713260128c16ebChris Lattner return ConstantInt::getTrue(CFP->getContext()); 2144210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 21456b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // Check whether the constant is an infinity. 21466b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman if (CFP->getValueAPF().isInfinity()) { 21476b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman if (CFP->getValueAPF().isNegative()) { 21486b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman switch (Pred) { 21496b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman case FCmpInst::FCMP_OLT: 21506b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // No value is ordered and less than negative infinity. 21516b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman return ConstantInt::getFalse(CFP->getContext()); 21526b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman case FCmpInst::FCMP_UGE: 21536b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // All values are unordered with or at least negative infinity. 21546b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman return ConstantInt::getTrue(CFP->getContext()); 21556b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman default: 21566b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman break; 21576b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } 21586b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } else { 21596b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman switch (Pred) { 21606b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman case FCmpInst::FCMP_OGT: 21616b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // No value is ordered and greater than infinity. 21626b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman return ConstantInt::getFalse(CFP->getContext()); 21636b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman case FCmpInst::FCMP_ULE: 21646b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman // All values are unordered with and at most infinity. 21656b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman return ConstantInt::getTrue(CFP->getContext()); 21666b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman default: 21676b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman break; 21686b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } 21696b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } 21706b617a7213e159097a7e5c7216ed9b04921de4e1Dan Gohman } 2171210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 2172210c5d4880b525e064088b6fec713260128c16ebChris Lattner } 217312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 217492826def593df7a422c7b07f09342febce81ddd3Duncan Sands // If the comparison is with the result of a select instruction, check whether 217592826def593df7a422c7b07f09342febce81ddd3Duncan Sands // comparing with either branch of the select always yields the same value. 21760312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS)) 21770312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (Value *V = ThreadCmpOverSelect(Pred, LHS, RHS, TD, DT, MaxRecurse)) 2178a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 2179a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 2180a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the comparison is with the result of a phi instruction, check whether 2181a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // doing the compare with each incoming phi value yields a common result. 21820312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(LHS) || isa<PHINode>(RHS)) 21830312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (Value *V = ThreadCmpOverPHI(Pred, LHS, RHS, TD, DT, MaxRecurse)) 21843bbb0cc42b67b4bf2c488285666999963bab0f7eDuncan Sands return V; 218592826def593df7a422c7b07f09342febce81ddd3Duncan Sands 21869f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner return 0; 21879f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner} 21889f3c25aeb3df77a336693308dc0f19a4983c99afChris Lattner 2189a74a58c83be492b7d5b7383656f049909394cff4Duncan SandsValue *llvm::SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS, 21901845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT) { 21911845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return ::SimplifyFCmpInst(Predicate, LHS, RHS, TD, DT, RecursionLimit); 2192a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 2193a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 2194047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner/// SimplifySelectInst - Given operands for a SelectInst, see if we can fold 2195047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner/// the result. If not, this returns null. 2196124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan SandsValue *llvm::SimplifySelectInst(Value *CondVal, Value *TrueVal, Value *FalseVal, 2197124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands const TargetData *TD, const DominatorTree *) { 2198047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner // select true, X, Y -> X 2199047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner // select false, X, Y -> Y 2200047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner if (ConstantInt *CB = dyn_cast<ConstantInt>(CondVal)) 2201047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return CB->getZExtValue() ? TrueVal : FalseVal; 220212a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2203047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner // select C, X, X -> X 2204124708d9b47cc53cb11d8bfed75b241b6eec86d4Duncan Sands if (TrueVal == FalseVal) 2205047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return TrueVal; 220612a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2207047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner if (isa<UndefValue>(CondVal)) { // select undef, X, Y -> X or Y 2208047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner if (isa<Constant>(TrueVal)) 2209047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return TrueVal; 2210047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return FalseVal; 2211047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner } 221268c0dbc14fb7599987fb3e27be4e12c1ac36535eDan Gohman if (isa<UndefValue>(TrueVal)) // select C, undef, X -> X 221368c0dbc14fb7599987fb3e27be4e12c1ac36535eDan Gohman return FalseVal; 221468c0dbc14fb7599987fb3e27be4e12c1ac36535eDan Gohman if (isa<UndefValue>(FalseVal)) // select C, X, undef -> X 221568c0dbc14fb7599987fb3e27be4e12c1ac36535eDan Gohman return TrueVal; 221612a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2217047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner return 0; 2218047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner} 2219047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner 2220c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner/// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can 2221c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner/// fold the result. If not, this returns null. 2222c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris LattnerValue *llvm::SimplifyGEPInst(Value *const *Ops, unsigned NumOps, 22231845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *) { 222485bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands // The type of the GEP pointer operand. 222585bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands const PointerType *PtrTy = cast<PointerType>(Ops[0]->getType()); 222685bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands 2227c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner // getelementptr P -> P. 2228c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner if (NumOps == 1) 2229c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner return Ops[0]; 2230c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner 223185bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands if (isa<UndefValue>(Ops[0])) { 223285bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands // Compute the (pointer) type returned by the GEP instruction. 223385bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands const Type *LastType = GetElementPtrInst::getIndexedType(PtrTy, &Ops[1], 223485bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands NumOps-1); 223585bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands const Type *GEPTy = PointerType::get(LastType, PtrTy->getAddressSpace()); 223685bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands return UndefValue::get(GEPTy); 223785bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands } 2238c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner 2239e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands if (NumOps == 2) { 2240e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands // getelementptr P, 0 -> P. 2241c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner if (ConstantInt *C = dyn_cast<ConstantInt>(Ops[1])) 2242c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner if (C->isZero()) 2243c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner return Ops[0]; 2244e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands // getelementptr P, N -> P if P points to a type of zero size. 2245e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands if (TD) { 224685bbff6c94695f07cc1a9765b4d384ed18d2fd7cDuncan Sands const Type *Ty = PtrTy->getElementType(); 2247a63395a30f9227bde826749d3480046301b47332Duncan Sands if (Ty->isSized() && TD->getTypeAllocSize(Ty) == 0) 2248e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands return Ops[0]; 2249e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands } 2250e60d79faf7ef7bc4847f9e5d067af00b98dced7bDuncan Sands } 225112a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2252c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner // Check to see if this is constant foldable. 2253c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner for (unsigned i = 0; i != NumOps; ++i) 2254c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner if (!isa<Constant>(Ops[i])) 2255c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner return 0; 225612a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2257c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner return ConstantExpr::getGetElementPtr(cast<Constant>(Ops[0]), 2258c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner (Constant *const*)Ops+1, NumOps-1); 2259c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner} 2260c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner 2261ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands/// SimplifyPHINode - See if we can fold the given phi. If not, returns null. 2262ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sandsstatic Value *SimplifyPHINode(PHINode *PN, const DominatorTree *DT) { 2263ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If all of the PHI's incoming values are the same then replace the PHI node 2264ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // with the common value. 2265ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands Value *CommonValue = 0; 2266ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands bool HasUndefInput = false; 2267ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { 2268ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands Value *Incoming = PN->getIncomingValue(i); 2269ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If the incoming value is the phi node itself, it can safely be skipped. 2270ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (Incoming == PN) continue; 2271ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (isa<UndefValue>(Incoming)) { 2272ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // Remember that we saw an undef value, but otherwise ignore them. 2273ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands HasUndefInput = true; 2274ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands continue; 2275ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands } 2276ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (CommonValue && Incoming != CommonValue) 2277ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands return 0; // Not the same, bail out. 2278ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands CommonValue = Incoming; 2279ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands } 2280ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands 2281ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If CommonValue is null then all of the incoming values were either undef or 2282ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // equal to the phi node itself. 2283ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (!CommonValue) 2284ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands return UndefValue::get(PN->getType()); 2285ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands 2286ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // If we have a PHI node like phi(X, undef, X), where X is defined by some 2287ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // instruction, we cannot return X as the result of the PHI node unless it 2288ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands // dominates the PHI block. 2289ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands if (HasUndefInput) 2290ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands return ValueDominatesPHI(CommonValue, PN, DT) ? CommonValue : 0; 2291ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands 2292ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands return CommonValue; 2293ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands} 2294ff10341183adf74760e6118a55cbd1debf50f90fDuncan Sands 2295c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner 2296d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner//=== Helper functions for higher up the class hierarchy. 22979dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 2298d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner/// SimplifyBinOp - Given operands for a BinaryOperator, see if we can 2299d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner/// fold the result. If not, this returns null. 2300a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, 23011845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT, 23021845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 2303d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner switch (Opcode) { 230481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner case Instruction::Add: 2305ffeb98ad3becfbb8e26270ef8751e37e4b6b0cd1Duncan Sands return SimplifyAddInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false, 230681a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner TD, DT, MaxRecurse); 230781a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner case Instruction::Sub: 2308ffeb98ad3becfbb8e26270ef8751e37e4b6b0cd1Duncan Sands return SimplifySubInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false, 230981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner TD, DT, MaxRecurse); 231081a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner case Instruction::Mul: return SimplifyMulInst (LHS, RHS, TD, DT, MaxRecurse); 2311593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands case Instruction::SDiv: return SimplifySDivInst(LHS, RHS, TD, DT, MaxRecurse); 2312593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands case Instruction::UDiv: return SimplifyUDivInst(LHS, RHS, TD, DT, MaxRecurse); 23131fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel case Instruction::FDiv: return SimplifyFDivInst(LHS, RHS, TD, DT, MaxRecurse); 2314f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands case Instruction::SRem: return SimplifySRemInst(LHS, RHS, TD, DT, MaxRecurse); 2315f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands case Instruction::URem: return SimplifyURemInst(LHS, RHS, TD, DT, MaxRecurse); 2316f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands case Instruction::FRem: return SimplifyFRemInst(LHS, RHS, TD, DT, MaxRecurse); 231781a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner case Instruction::Shl: 2318ffeb98ad3becfbb8e26270ef8751e37e4b6b0cd1Duncan Sands return SimplifyShlInst(LHS, RHS, /*isNSW*/false, /*isNUW*/false, 231981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner TD, DT, MaxRecurse); 232081a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner case Instruction::LShr: 2321ffeb98ad3becfbb8e26270ef8751e37e4b6b0cd1Duncan Sands return SimplifyLShrInst(LHS, RHS, /*isExact*/false, TD, DT, MaxRecurse); 232281a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner case Instruction::AShr: 2323ffeb98ad3becfbb8e26270ef8751e37e4b6b0cd1Duncan Sands return SimplifyAShrInst(LHS, RHS, /*isExact*/false, TD, DT, MaxRecurse); 232482fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands case Instruction::And: return SimplifyAndInst(LHS, RHS, TD, DT, MaxRecurse); 232581a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner case Instruction::Or: return SimplifyOrInst (LHS, RHS, TD, DT, MaxRecurse); 232682fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands case Instruction::Xor: return SimplifyXorInst(LHS, RHS, TD, DT, MaxRecurse); 2327d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner default: 2328d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CLHS = dyn_cast<Constant>(LHS)) 2329d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner if (Constant *CRHS = dyn_cast<Constant>(RHS)) { 2330d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner Constant *COps[] = {CLHS, CRHS}; 2331d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return ConstantFoldInstOperands(Opcode, LHS->getType(), COps, 2, TD); 2332d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 2333b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 2334566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands // If the operation is associative, try some generic simplifications. 2335566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Instruction::isAssociative(Opcode)) 2336566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands if (Value *V = SimplifyAssociativeBinOp(Opcode, LHS, RHS, TD, DT, 2337566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands MaxRecurse)) 2338566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands return V; 2339566edb04b890cebca8f2eefa37af7371a1e756c9Duncan Sands 2340b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // If the operation is with the result of a select instruction, check whether 2341b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands // operating on either branch of the select always yields the same value. 23420312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<SelectInst>(LHS) || isa<SelectInst>(RHS)) 23431845009290e4d804ad377927bd8a08cca3036adcDuncan Sands if (Value *V = ThreadBinOpOverSelect(Opcode, LHS, RHS, TD, DT, 23440312a93693abc2eb682b2b101c889959888fd883Duncan Sands MaxRecurse)) 2345a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands return V; 2346a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 2347a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // If the operation is with the result of a phi instruction, check whether 2348a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands // operating on all incoming values of the phi always yields the same value. 23490312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (isa<PHINode>(LHS) || isa<PHINode>(RHS)) 23500312a93693abc2eb682b2b101c889959888fd883Duncan Sands if (Value *V = ThreadBinOpOverPHI(Opcode, LHS, RHS, TD, DT, MaxRecurse)) 2351b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands return V; 2352b2cbdc35ba85c04df15b0e991d9be371691ab08cDuncan Sands 2353d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner return 0; 2354d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner } 2355d06094f0682f2ede03caff4892b1a57469896d48Chris Lattner} 23569dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 235712a86f5b3199e72e6d967781acc76340f5920e46Duncan SandsValue *llvm::SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS, 23581845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT) { 23591845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return ::SimplifyBinOp(Opcode, LHS, RHS, TD, DT, RecursionLimit); 2360a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 2361a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands 23629dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// SimplifyCmpInst - Given operands for a CmpInst, see if we can 23639dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner/// fold the result. 2364a74a58c83be492b7d5b7383656f049909394cff4Duncan Sandsstatic Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS, 23651845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT, 23661845009290e4d804ad377927bd8a08cca3036adcDuncan Sands unsigned MaxRecurse) { 23679dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner if (CmpInst::isIntPredicate((CmpInst::Predicate)Predicate)) 23681845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return SimplifyICmpInst(Predicate, LHS, RHS, TD, DT, MaxRecurse); 23691845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return SimplifyFCmpInst(Predicate, LHS, RHS, TD, DT, MaxRecurse); 23709dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner} 23719dbb42944c4d7caddab21016b24cca31019a3fafChris Lattner 2372a74a58c83be492b7d5b7383656f049909394cff4Duncan SandsValue *llvm::SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS, 23731845009290e4d804ad377927bd8a08cca3036adcDuncan Sands const TargetData *TD, const DominatorTree *DT) { 23741845009290e4d804ad377927bd8a08cca3036adcDuncan Sands return ::SimplifyCmpInst(Predicate, LHS, RHS, TD, DT, RecursionLimit); 2375a74a58c83be492b7d5b7383656f049909394cff4Duncan Sands} 2376e34537856a544c83513e390ac9552a8bc3823346Chris Lattner 2377e34537856a544c83513e390ac9552a8bc3823346Chris Lattner/// SimplifyInstruction - See if we can compute a simplified version of this 2378e34537856a544c83513e390ac9552a8bc3823346Chris Lattner/// instruction. If not, this returns null. 2379eff0581583ef10e2872e9baf537a04b67d992101Duncan SandsValue *llvm::SimplifyInstruction(Instruction *I, const TargetData *TD, 2380eff0581583ef10e2872e9baf537a04b67d992101Duncan Sands const DominatorTree *DT) { 2381d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Value *Result; 2382d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands 2383e34537856a544c83513e390ac9552a8bc3823346Chris Lattner switch (I->getOpcode()) { 2384e34537856a544c83513e390ac9552a8bc3823346Chris Lattner default: 2385d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = ConstantFoldInstruction(I, TD); 2386d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 23878aee8efc0c2e387faa7dae39fdf613a22889b566Chris Lattner case Instruction::Add: 2388d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyAddInst(I->getOperand(0), I->getOperand(1), 2389d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands cast<BinaryOperator>(I)->hasNoSignedWrap(), 2390d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands cast<BinaryOperator>(I)->hasNoUnsignedWrap(), 2391d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands TD, DT); 2392d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2393fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands case Instruction::Sub: 2394fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands Result = SimplifySubInst(I->getOperand(0), I->getOperand(1), 2395fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands cast<BinaryOperator>(I)->hasNoSignedWrap(), 2396fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands cast<BinaryOperator>(I)->hasNoUnsignedWrap(), 2397fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands TD, DT); 2398fea3b218d61708ea3577f4ef14c8f7677a94db95Duncan Sands break; 239982fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands case Instruction::Mul: 240082fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands Result = SimplifyMulInst(I->getOperand(0), I->getOperand(1), TD, DT); 240182fdab335881cd90f8f7ab3ad1f1ca0bb3ee886aDuncan Sands break; 2402593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands case Instruction::SDiv: 2403593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands Result = SimplifySDivInst(I->getOperand(0), I->getOperand(1), TD, DT); 2404593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands break; 2405593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands case Instruction::UDiv: 2406593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands Result = SimplifyUDivInst(I->getOperand(0), I->getOperand(1), TD, DT); 2407593faa53fa6d89841e601cc4571d143a6a05f0b4Duncan Sands break; 24081fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel case Instruction::FDiv: 24091fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel Result = SimplifyFDivInst(I->getOperand(0), I->getOperand(1), TD, DT); 24101fca2c32cc99197215d3fd32a4ad05214c74edd1Frits van Bommel break; 2411f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands case Instruction::SRem: 2412f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands Result = SimplifySRemInst(I->getOperand(0), I->getOperand(1), TD, DT); 2413f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands break; 2414f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands case Instruction::URem: 2415f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands Result = SimplifyURemInst(I->getOperand(0), I->getOperand(1), TD, DT); 2416f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands break; 2417f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands case Instruction::FRem: 2418f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands Result = SimplifyFRemInst(I->getOperand(0), I->getOperand(1), TD, DT); 2419f24ed77d2416b66178d8ff1d807858dfab37ca18Duncan Sands break; 2420c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands case Instruction::Shl: 242181a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Result = SimplifyShlInst(I->getOperand(0), I->getOperand(1), 242281a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<BinaryOperator>(I)->hasNoSignedWrap(), 242381a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<BinaryOperator>(I)->hasNoUnsignedWrap(), 242481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner TD, DT); 2425c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands break; 2426c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands case Instruction::LShr: 242781a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Result = SimplifyLShrInst(I->getOperand(0), I->getOperand(1), 242881a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<BinaryOperator>(I)->isExact(), 242981a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner TD, DT); 2430c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands break; 2431c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands case Instruction::AShr: 243281a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner Result = SimplifyAShrInst(I->getOperand(0), I->getOperand(1), 243381a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner cast<BinaryOperator>(I)->isExact(), 243481a0dc911586c77421c2255aa417dc9b350b9e20Chris Lattner TD, DT); 2435c43cee3fbb3098f0647e50dd2c13bc55b027a228Duncan Sands break; 2436e34537856a544c83513e390ac9552a8bc3823346Chris Lattner case Instruction::And: 2437d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyAndInst(I->getOperand(0), I->getOperand(1), TD, DT); 2438d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2439e34537856a544c83513e390ac9552a8bc3823346Chris Lattner case Instruction::Or: 2440d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyOrInst(I->getOperand(0), I->getOperand(1), TD, DT); 2441d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 24422b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands case Instruction::Xor: 24432b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands Result = SimplifyXorInst(I->getOperand(0), I->getOperand(1), TD, DT); 24442b749870d0488c3b049edf5d0c8875f56f5b1bedDuncan Sands break; 2445e34537856a544c83513e390ac9552a8bc3823346Chris Lattner case Instruction::ICmp: 2446d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyICmpInst(cast<ICmpInst>(I)->getPredicate(), 2447d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands I->getOperand(0), I->getOperand(1), TD, DT); 2448d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2449e34537856a544c83513e390ac9552a8bc3823346Chris Lattner case Instruction::FCmp: 2450d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyFCmpInst(cast<FCmpInst>(I)->getPredicate(), 2451d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands I->getOperand(0), I->getOperand(1), TD, DT); 2452d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2453047542669a20505fc7c5f2d93caa5610aa3db2c5Chris Lattner case Instruction::Select: 2454d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifySelectInst(I->getOperand(0), I->getOperand(1), 2455d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands I->getOperand(2), TD, DT); 2456d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2457c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner case Instruction::GetElementPtr: { 2458c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner SmallVector<Value*, 8> Ops(I->op_begin(), I->op_end()); 2459d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyGEPInst(&Ops[0], Ops.size(), TD, DT); 2460d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2461c514c1f5218b8fe7499a0b9a4737860344cf4c43Chris Lattner } 2462cd6636c737a82949ad13db2d0d918af6424fb78bDuncan Sands case Instruction::PHI: 2463d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands Result = SimplifyPHINode(cast<PHINode>(I), DT); 2464d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands break; 2465e34537856a544c83513e390ac9552a8bc3823346Chris Lattner } 2466d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands 2467d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands /// If called on unreachable code, the above logic may report that the 2468d261dc650a01ac5c51ab10f97f1e35aa6a770721Duncan Sands /// instruction simplified to itself. Make life easier for users by 2469f8b1a5ea9602bb65a5cf59d3d34f2851a08cdc3eDuncan Sands /// detecting that case here, returning a safe value instead. 2470f8b1a5ea9602bb65a5cf59d3d34f2851a08cdc3eDuncan Sands return Result == I ? UndefValue::get(I->getType()) : Result; 2471e34537856a544c83513e390ac9552a8bc3823346Chris Lattner} 2472e34537856a544c83513e390ac9552a8bc3823346Chris Lattner 247340d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// ReplaceAndSimplifyAllUses - Perform From->replaceAllUsesWith(To) and then 247440d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// delete the From instruction. In addition to a basic RAUW, this does a 247540d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// recursive simplification of the newly formed instructions. This catches 247640d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// things where one simplification exposes other opportunities. This only 247740d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// simplifies and deletes scalar operations, it does not change the CFG. 247840d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner/// 247940d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattnervoid llvm::ReplaceAndSimplifyAllUses(Instruction *From, Value *To, 2480eff0581583ef10e2872e9baf537a04b67d992101Duncan Sands const TargetData *TD, 2481eff0581583ef10e2872e9baf537a04b67d992101Duncan Sands const DominatorTree *DT) { 248240d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner assert(From != To && "ReplaceAndSimplifyAllUses(X,X) is not valid!"); 248312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2484d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // FromHandle/ToHandle - This keeps a WeakVH on the from/to values so that 2485d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // we can know if it gets deleted out from under us or replaced in a 2486d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // recursive simplification. 248740d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner WeakVH FromHandle(From); 2488d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner WeakVH ToHandle(To); 248912a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 249040d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner while (!From->use_empty()) { 249140d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner // Update the instruction to use the new value. 2492d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner Use &TheUse = From->use_begin().getUse(); 2493d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner Instruction *User = cast<Instruction>(TheUse.getUser()); 2494d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner TheUse = To; 2495d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner 2496d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // Check to see if the instruction can be folded due to the operand 2497d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // replacement. For example changing (or X, Y) into (or X, -1) can replace 2498d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // the 'or' with -1. 2499d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner Value *SimplifiedVal; 2500d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner { 2501d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // Sanity check to make sure 'User' doesn't dangle across 2502d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // SimplifyInstruction. 2503d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner AssertingVH<> UserHandle(User); 250412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2505eff0581583ef10e2872e9baf537a04b67d992101Duncan Sands SimplifiedVal = SimplifyInstruction(User, TD, DT); 2506d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner if (SimplifiedVal == 0) continue; 250740d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner } 250812a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2509d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // Recursively simplify this user to the new value. 2510eff0581583ef10e2872e9baf537a04b67d992101Duncan Sands ReplaceAndSimplifyAllUses(User, SimplifiedVal, TD, DT); 2511d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner From = dyn_cast_or_null<Instruction>((Value*)FromHandle); 2512d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner To = ToHandle; 251312a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2514d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner assert(ToHandle && "To value deleted by recursive simplification?"); 251512a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2516d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // If the recursive simplification ended up revisiting and deleting 2517d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // 'From' then we're done. 2518d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner if (From == 0) 2519d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner return; 252040d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner } 252112a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 2522d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner // If 'From' has value handles referring to it, do a real RAUW to update them. 2523d2bfe54b0a9f28c021d4f0790bdb5224d5579447Chris Lattner From->replaceAllUsesWith(To); 252412a86f5b3199e72e6d967781acc76340f5920e46Duncan Sands 252540d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner From->eraseFromParent(); 252640d8c28b27377199b7465ba2c5a2c59c6fd12fa9Chris Lattner} 2527