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1 //===- ScalarEvolutionsTest.cpp - ScalarEvolution unit tests --------------===//
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2 //
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3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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4 // See https://llvm.org/LICENSE.txt for license information.
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5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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6 //
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7 //===----------------------------------------------------------------------===//
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8
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9 #include "llvm/ADT/SmallVector.h"
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10 #include "llvm/Analysis/AssumptionCache.h"
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11 #include "llvm/Analysis/LoopInfo.h"
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12 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
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173
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13 #include "llvm/Analysis/ScalarEvolutionNormalization.h"
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150
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14 #include "llvm/Analysis/TargetLibraryInfo.h"
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15 #include "llvm/AsmParser/Parser.h"
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16 #include "llvm/IR/Constants.h"
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17 #include "llvm/IR/Dominators.h"
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18 #include "llvm/IR/GlobalVariable.h"
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19 #include "llvm/IR/IRBuilder.h"
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20 #include "llvm/IR/InstIterator.h"
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21 #include "llvm/IR/LLVMContext.h"
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22 #include "llvm/IR/LegacyPassManager.h"
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23 #include "llvm/IR/Module.h"
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24 #include "llvm/IR/Verifier.h"
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25 #include "llvm/Support/SourceMgr.h"
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26 #include "gtest/gtest.h"
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27
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28 namespace llvm {
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29
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30 // We use this fixture to ensure that we clean up ScalarEvolution before
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31 // deleting the PassManager.
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32 class ScalarEvolutionsTest : public testing::Test {
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33 protected:
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34 LLVMContext Context;
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35 Module M;
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36 TargetLibraryInfoImpl TLII;
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37 TargetLibraryInfo TLI;
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38
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39 std::unique_ptr<AssumptionCache> AC;
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40 std::unique_ptr<DominatorTree> DT;
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41 std::unique_ptr<LoopInfo> LI;
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42
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43 ScalarEvolutionsTest() : M("", Context), TLII(), TLI(TLII) {}
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44
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45 ScalarEvolution buildSE(Function &F) {
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46 AC.reset(new AssumptionCache(F));
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47 DT.reset(new DominatorTree(F));
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48 LI.reset(new LoopInfo(*DT));
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49 return ScalarEvolution(F, TLI, *AC, *DT, *LI);
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50 }
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51
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52 void runWithSE(
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53 Module &M, StringRef FuncName,
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54 function_ref<void(Function &F, LoopInfo &LI, ScalarEvolution &SE)> Test) {
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55 auto *F = M.getFunction(FuncName);
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56 ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
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57 ScalarEvolution SE = buildSE(*F);
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58 Test(*F, *LI, SE);
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59 }
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60
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61 static Optional<APInt> computeConstantDifference(ScalarEvolution &SE,
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62 const SCEV *LHS,
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63 const SCEV *RHS) {
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64 return SE.computeConstantDifference(LHS, RHS);
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65 }
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66 };
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67
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68 TEST_F(ScalarEvolutionsTest, SCEVUnknownRAUW) {
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69 FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context),
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70 std::vector<Type *>(), false);
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71 Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
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72 BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
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73 ReturnInst::Create(Context, nullptr, BB);
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74
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75 Type *Ty = Type::getInt1Ty(Context);
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76 Constant *Init = Constant::getNullValue(Ty);
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77 Value *V0 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V0");
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78 Value *V1 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V1");
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79 Value *V2 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V2");
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80
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81 ScalarEvolution SE = buildSE(*F);
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82
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83 const SCEV *S0 = SE.getSCEV(V0);
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84 const SCEV *S1 = SE.getSCEV(V1);
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85 const SCEV *S2 = SE.getSCEV(V2);
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86
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87 const SCEV *P0 = SE.getAddExpr(S0, S0);
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88 const SCEV *P1 = SE.getAddExpr(S1, S1);
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89 const SCEV *P2 = SE.getAddExpr(S2, S2);
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90
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91 const SCEVMulExpr *M0 = cast<SCEVMulExpr>(P0);
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92 const SCEVMulExpr *M1 = cast<SCEVMulExpr>(P1);
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93 const SCEVMulExpr *M2 = cast<SCEVMulExpr>(P2);
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94
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95 EXPECT_EQ(cast<SCEVConstant>(M0->getOperand(0))->getValue()->getZExtValue(),
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96 2u);
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97 EXPECT_EQ(cast<SCEVConstant>(M1->getOperand(0))->getValue()->getZExtValue(),
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98 2u);
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99 EXPECT_EQ(cast<SCEVConstant>(M2->getOperand(0))->getValue()->getZExtValue(),
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100 2u);
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101
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102 // Before the RAUWs, these are all pointing to separate values.
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103 EXPECT_EQ(cast<SCEVUnknown>(M0->getOperand(1))->getValue(), V0);
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104 EXPECT_EQ(cast<SCEVUnknown>(M1->getOperand(1))->getValue(), V1);
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105 EXPECT_EQ(cast<SCEVUnknown>(M2->getOperand(1))->getValue(), V2);
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106
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107 // Do some RAUWs.
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108 V2->replaceAllUsesWith(V1);
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109 V1->replaceAllUsesWith(V0);
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110
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111 // After the RAUWs, these should all be pointing to V0.
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112 EXPECT_EQ(cast<SCEVUnknown>(M0->getOperand(1))->getValue(), V0);
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113 EXPECT_EQ(cast<SCEVUnknown>(M1->getOperand(1))->getValue(), V0);
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114 EXPECT_EQ(cast<SCEVUnknown>(M2->getOperand(1))->getValue(), V0);
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115 }
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116
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117 TEST_F(ScalarEvolutionsTest, SimplifiedPHI) {
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118 FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context),
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119 std::vector<Type *>(), false);
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120 Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
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121 BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
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122 BasicBlock *LoopBB = BasicBlock::Create(Context, "loop", F);
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123 BasicBlock *ExitBB = BasicBlock::Create(Context, "exit", F);
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124 BranchInst::Create(LoopBB, EntryBB);
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125 BranchInst::Create(LoopBB, ExitBB, UndefValue::get(Type::getInt1Ty(Context)),
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126 LoopBB);
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127 ReturnInst::Create(Context, nullptr, ExitBB);
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128 auto *Ty = Type::getInt32Ty(Context);
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129 auto *PN = PHINode::Create(Ty, 2, "", &*LoopBB->begin());
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130 PN->addIncoming(Constant::getNullValue(Ty), EntryBB);
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131 PN->addIncoming(UndefValue::get(Ty), LoopBB);
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132 ScalarEvolution SE = buildSE(*F);
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133 auto *S1 = SE.getSCEV(PN);
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134 auto *S2 = SE.getSCEV(PN);
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135 auto *ZeroConst = SE.getConstant(Ty, 0);
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136
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137 // At some point, only the first call to getSCEV returned the simplified
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138 // SCEVConstant and later calls just returned a SCEVUnknown referencing the
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139 // PHI node.
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140 EXPECT_EQ(S1, ZeroConst);
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141 EXPECT_EQ(S1, S2);
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142 }
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143
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144
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145 static Instruction *getInstructionByName(Function &F, StringRef Name) {
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146 for (auto &I : instructions(F))
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147 if (I.getName() == Name)
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148 return &I;
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149 llvm_unreachable("Expected to find instruction!");
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150 }
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151
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152 TEST_F(ScalarEvolutionsTest, CommutativeExprOperandOrder) {
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153 LLVMContext C;
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154 SMDiagnostic Err;
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155 std::unique_ptr<Module> M = parseAssemblyString(
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156 "target datalayout = \"e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128\" "
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157 " "
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158 "@var_0 = external global i32, align 4"
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159 "@var_1 = external global i32, align 4"
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160 "@var_2 = external global i32, align 4"
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161 " "
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162 "declare i32 @unknown(i32, i32, i32)"
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163 " "
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164 "define void @f_1(i8* nocapture %arr, i32 %n, i32* %A, i32* %B) "
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165 " local_unnamed_addr { "
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166 "entry: "
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167 " %entrycond = icmp sgt i32 %n, 0 "
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168 " br i1 %entrycond, label %loop.ph, label %for.end "
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169 " "
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170 "loop.ph: "
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171 " %a = load i32, i32* %A, align 4 "
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172 " %b = load i32, i32* %B, align 4 "
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173 " %mul = mul nsw i32 %b, %a "
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174 " %iv0.init = getelementptr inbounds i8, i8* %arr, i32 %mul "
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175 " br label %loop "
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176 " "
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177 "loop: "
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178 " %iv0 = phi i8* [ %iv0.inc, %loop ], [ %iv0.init, %loop.ph ] "
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179 " %iv1 = phi i32 [ %iv1.inc, %loop ], [ 0, %loop.ph ] "
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180 " %conv = trunc i32 %iv1 to i8 "
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181 " store i8 %conv, i8* %iv0, align 1 "
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182 " %iv0.inc = getelementptr inbounds i8, i8* %iv0, i32 %b "
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183 " %iv1.inc = add nuw nsw i32 %iv1, 1 "
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184 " %exitcond = icmp eq i32 %iv1.inc, %n "
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185 " br i1 %exitcond, label %for.end.loopexit, label %loop "
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186 " "
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187 "for.end.loopexit: "
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188 " br label %for.end "
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189 " "
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190 "for.end: "
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191 " ret void "
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192 "} "
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193 " "
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194 "define void @f_2(i32* %X, i32* %Y, i32* %Z) { "
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195 " %x = load i32, i32* %X "
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196 " %y = load i32, i32* %Y "
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197 " %z = load i32, i32* %Z "
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198 " ret void "
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199 "} "
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200 " "
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201 "define void @f_3() { "
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202 " %x = load i32, i32* @var_0"
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203 " %y = load i32, i32* @var_1"
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204 " %z = load i32, i32* @var_2"
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205 " ret void"
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206 "} "
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207 " "
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208 "define void @f_4(i32 %a, i32 %b, i32 %c) { "
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209 " %x = call i32 @unknown(i32 %a, i32 %b, i32 %c)"
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210 " %y = call i32 @unknown(i32 %b, i32 %c, i32 %a)"
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211 " %z = call i32 @unknown(i32 %c, i32 %a, i32 %b)"
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212 " ret void"
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213 "} "
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214 ,
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215 Err, C);
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216
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217 assert(M && "Could not parse module?");
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218 assert(!verifyModule(*M) && "Must have been well formed!");
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219
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220 runWithSE(*M, "f_1", [&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
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221 auto *IV0 = getInstructionByName(F, "iv0");
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222 auto *IV0Inc = getInstructionByName(F, "iv0.inc");
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223
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224 auto *FirstExprForIV0 = SE.getSCEV(IV0);
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225 auto *FirstExprForIV0Inc = SE.getSCEV(IV0Inc);
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226 auto *SecondExprForIV0 = SE.getSCEV(IV0);
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227
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228 EXPECT_TRUE(isa<SCEVAddRecExpr>(FirstExprForIV0));
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229 EXPECT_TRUE(isa<SCEVAddRecExpr>(FirstExprForIV0Inc));
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230 EXPECT_TRUE(isa<SCEVAddRecExpr>(SecondExprForIV0));
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231 });
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232
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233 auto CheckCommutativeMulExprs = [&](ScalarEvolution &SE, const SCEV *A,
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234 const SCEV *B, const SCEV *C) {
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235 EXPECT_EQ(SE.getMulExpr(A, B), SE.getMulExpr(B, A));
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236 EXPECT_EQ(SE.getMulExpr(B, C), SE.getMulExpr(C, B));
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237 EXPECT_EQ(SE.getMulExpr(A, C), SE.getMulExpr(C, A));
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238
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239 SmallVector<const SCEV *, 3> Ops0 = {A, B, C};
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240 SmallVector<const SCEV *, 3> Ops1 = {A, C, B};
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241 SmallVector<const SCEV *, 3> Ops2 = {B, A, C};
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242 SmallVector<const SCEV *, 3> Ops3 = {B, C, A};
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243 SmallVector<const SCEV *, 3> Ops4 = {C, B, A};
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244 SmallVector<const SCEV *, 3> Ops5 = {C, A, B};
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245
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246 auto *Mul0 = SE.getMulExpr(Ops0);
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247 auto *Mul1 = SE.getMulExpr(Ops1);
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248 auto *Mul2 = SE.getMulExpr(Ops2);
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249 auto *Mul3 = SE.getMulExpr(Ops3);
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250 auto *Mul4 = SE.getMulExpr(Ops4);
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251 auto *Mul5 = SE.getMulExpr(Ops5);
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252
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253 EXPECT_EQ(Mul0, Mul1) << "Expected " << *Mul0 << " == " << *Mul1;
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254 EXPECT_EQ(Mul1, Mul2) << "Expected " << *Mul1 << " == " << *Mul2;
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255 EXPECT_EQ(Mul2, Mul3) << "Expected " << *Mul2 << " == " << *Mul3;
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256 EXPECT_EQ(Mul3, Mul4) << "Expected " << *Mul3 << " == " << *Mul4;
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257 EXPECT_EQ(Mul4, Mul5) << "Expected " << *Mul4 << " == " << *Mul5;
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258 };
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259
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260 for (StringRef FuncName : {"f_2", "f_3", "f_4"})
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261 runWithSE(
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262 *M, FuncName, [&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
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263 CheckCommutativeMulExprs(SE, SE.getSCEV(getInstructionByName(F, "x")),
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264 SE.getSCEV(getInstructionByName(F, "y")),
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265 SE.getSCEV(getInstructionByName(F, "z")));
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266 });
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267 }
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268
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269 TEST_F(ScalarEvolutionsTest, CompareSCEVComplexity) {
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270 FunctionType *FTy =
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271 FunctionType::get(Type::getVoidTy(Context), std::vector<Type *>(), false);
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272 Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
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273 BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
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274 BasicBlock *LoopBB = BasicBlock::Create(Context, "bb1", F);
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275 BranchInst::Create(LoopBB, EntryBB);
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276
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277 auto *Ty = Type::getInt32Ty(Context);
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278 SmallVector<Instruction*, 8> Muls(8), Acc(8), NextAcc(8);
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279
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280 Acc[0] = PHINode::Create(Ty, 2, "", LoopBB);
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281 Acc[1] = PHINode::Create(Ty, 2, "", LoopBB);
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282 Acc[2] = PHINode::Create(Ty, 2, "", LoopBB);
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283 Acc[3] = PHINode::Create(Ty, 2, "", LoopBB);
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284 Acc[4] = PHINode::Create(Ty, 2, "", LoopBB);
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285 Acc[5] = PHINode::Create(Ty, 2, "", LoopBB);
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286 Acc[6] = PHINode::Create(Ty, 2, "", LoopBB);
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287 Acc[7] = PHINode::Create(Ty, 2, "", LoopBB);
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288
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289 for (int i = 0; i < 20; i++) {
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290 Muls[0] = BinaryOperator::CreateMul(Acc[0], Acc[0], "", LoopBB);
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291 NextAcc[0] = BinaryOperator::CreateAdd(Muls[0], Acc[4], "", LoopBB);
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292 Muls[1] = BinaryOperator::CreateMul(Acc[1], Acc[1], "", LoopBB);
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293 NextAcc[1] = BinaryOperator::CreateAdd(Muls[1], Acc[5], "", LoopBB);
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294 Muls[2] = BinaryOperator::CreateMul(Acc[2], Acc[2], "", LoopBB);
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295 NextAcc[2] = BinaryOperator::CreateAdd(Muls[2], Acc[6], "", LoopBB);
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296 Muls[3] = BinaryOperator::CreateMul(Acc[3], Acc[3], "", LoopBB);
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297 NextAcc[3] = BinaryOperator::CreateAdd(Muls[3], Acc[7], "", LoopBB);
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298
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299 Muls[4] = BinaryOperator::CreateMul(Acc[4], Acc[4], "", LoopBB);
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300 NextAcc[4] = BinaryOperator::CreateAdd(Muls[4], Acc[0], "", LoopBB);
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301 Muls[5] = BinaryOperator::CreateMul(Acc[5], Acc[5], "", LoopBB);
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302 NextAcc[5] = BinaryOperator::CreateAdd(Muls[5], Acc[1], "", LoopBB);
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303 Muls[6] = BinaryOperator::CreateMul(Acc[6], Acc[6], "", LoopBB);
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304 NextAcc[6] = BinaryOperator::CreateAdd(Muls[6], Acc[2], "", LoopBB);
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305 Muls[7] = BinaryOperator::CreateMul(Acc[7], Acc[7], "", LoopBB);
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306 NextAcc[7] = BinaryOperator::CreateAdd(Muls[7], Acc[3], "", LoopBB);
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307 Acc = NextAcc;
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308 }
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309
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310 auto II = LoopBB->begin();
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311 for (int i = 0; i < 8; i++) {
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312 PHINode *Phi = cast<PHINode>(&*II++);
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313 Phi->addIncoming(Acc[i], LoopBB);
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314 Phi->addIncoming(UndefValue::get(Ty), EntryBB);
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315 }
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316
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317 BasicBlock *ExitBB = BasicBlock::Create(Context, "bb2", F);
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318 BranchInst::Create(LoopBB, ExitBB, UndefValue::get(Type::getInt1Ty(Context)),
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319 LoopBB);
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320
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321 Acc[0] = BinaryOperator::CreateAdd(Acc[0], Acc[1], "", ExitBB);
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322 Acc[1] = BinaryOperator::CreateAdd(Acc[2], Acc[3], "", ExitBB);
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323 Acc[2] = BinaryOperator::CreateAdd(Acc[4], Acc[5], "", ExitBB);
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324 Acc[3] = BinaryOperator::CreateAdd(Acc[6], Acc[7], "", ExitBB);
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325 Acc[0] = BinaryOperator::CreateAdd(Acc[0], Acc[1], "", ExitBB);
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|
|
326 Acc[1] = BinaryOperator::CreateAdd(Acc[2], Acc[3], "", ExitBB);
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|
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327 Acc[0] = BinaryOperator::CreateAdd(Acc[0], Acc[1], "", ExitBB);
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328
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|
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329 ReturnInst::Create(Context, nullptr, ExitBB);
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330
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|
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331 ScalarEvolution SE = buildSE(*F);
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332
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333 EXPECT_NE(nullptr, SE.getSCEV(Acc[0]));
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|
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334 }
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335
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|
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336 TEST_F(ScalarEvolutionsTest, CompareValueComplexity) {
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337 IntegerType *IntPtrTy = M.getDataLayout().getIntPtrType(Context);
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338 PointerType *IntPtrPtrTy = IntPtrTy->getPointerTo();
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339
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|
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340 FunctionType *FTy =
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341 FunctionType::get(Type::getVoidTy(Context), {IntPtrTy, IntPtrTy}, false);
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342 Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
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343 BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
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344
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345 Value *X = &*F->arg_begin();
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346 Value *Y = &*std::next(F->arg_begin());
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347
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|
|
348 const int ValueDepth = 10;
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|
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349 for (int i = 0; i < ValueDepth; i++) {
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350 X = new LoadInst(IntPtrTy, new IntToPtrInst(X, IntPtrPtrTy, "", EntryBB),
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351 "",
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|
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352 /*isVolatile*/ false, EntryBB);
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353 Y = new LoadInst(IntPtrTy, new IntToPtrInst(Y, IntPtrPtrTy, "", EntryBB),
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354 "",
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|
|
355 /*isVolatile*/ false, EntryBB);
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|
|
356 }
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|
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357
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358 auto *MulA = BinaryOperator::CreateMul(X, Y, "", EntryBB);
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359 auto *MulB = BinaryOperator::CreateMul(Y, X, "", EntryBB);
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360 ReturnInst::Create(Context, nullptr, EntryBB);
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361
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362 // This test isn't checking for correctness. Today making A and B resolve to
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363 // the same SCEV would require deeper searching in CompareValueComplexity,
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364 // which will slow down compilation. However, this test can fail (with LLVM's
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|
|
365 // behavior still being correct) if we ever have a smarter
|
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366 // CompareValueComplexity that is both fast and more accurate.
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367
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368 ScalarEvolution SE = buildSE(*F);
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369 auto *A = SE.getSCEV(MulA);
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370 auto *B = SE.getSCEV(MulB);
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|
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371 EXPECT_NE(A, B);
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|
|
372 }
|
|
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373
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|
|
374 TEST_F(ScalarEvolutionsTest, SCEVAddExpr) {
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375 Type *Ty32 = Type::getInt32Ty(Context);
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376 Type *ArgTys[] = {Type::getInt64Ty(Context), Ty32};
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377
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|
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378 FunctionType *FTy =
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379 FunctionType::get(Type::getVoidTy(Context), ArgTys, false);
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|
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380 Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
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381
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|
382 Argument *A1 = &*F->arg_begin();
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383 Argument *A2 = &*(std::next(F->arg_begin()));
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|
384 BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
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385
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|
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386 Instruction *Trunc = CastInst::CreateTruncOrBitCast(A1, Ty32, "", EntryBB);
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|
|
387 Instruction *Mul1 = BinaryOperator::CreateMul(Trunc, A2, "", EntryBB);
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|
|
388 Instruction *Add1 = BinaryOperator::CreateAdd(Mul1, Trunc, "", EntryBB);
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|
389 Mul1 = BinaryOperator::CreateMul(Add1, Trunc, "", EntryBB);
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|
|
390 Instruction *Add2 = BinaryOperator::CreateAdd(Mul1, Add1, "", EntryBB);
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|
|
391 // FIXME: The size of this is arbitrary and doesn't seem to change the
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|
|
392 // result, but SCEV will do quadratic work for these so a large number here
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|
|
393 // will be extremely slow. We should revisit what and how this is testing
|
|
|
394 // SCEV.
|
|
|
395 for (int i = 0; i < 10; i++) {
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|
|
396 Mul1 = BinaryOperator::CreateMul(Add2, Add1, "", EntryBB);
|
|
|
397 Add1 = Add2;
|
|
|
398 Add2 = BinaryOperator::CreateAdd(Mul1, Add1, "", EntryBB);
|
|
|
399 }
|
|
|
400
|
|
|
401 ReturnInst::Create(Context, nullptr, EntryBB);
|
|
|
402 ScalarEvolution SE = buildSE(*F);
|
|
|
403 EXPECT_NE(nullptr, SE.getSCEV(Mul1));
|
|
|
404 }
|
|
|
405
|
|
|
406 static Instruction &GetInstByName(Function &F, StringRef Name) {
|
|
|
407 for (auto &I : instructions(F))
|
|
|
408 if (I.getName() == Name)
|
|
|
409 return I;
|
|
|
410 llvm_unreachable("Could not find instructions!");
|
|
|
411 }
|
|
|
412
|
|
|
413 TEST_F(ScalarEvolutionsTest, SCEVNormalization) {
|
|
|
414 LLVMContext C;
|
|
|
415 SMDiagnostic Err;
|
|
|
416 std::unique_ptr<Module> M = parseAssemblyString(
|
|
|
417 "target datalayout = \"e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128\" "
|
|
|
418 " "
|
|
|
419 "@var_0 = external global i32, align 4"
|
|
|
420 "@var_1 = external global i32, align 4"
|
|
|
421 "@var_2 = external global i32, align 4"
|
|
|
422 " "
|
|
|
423 "declare i32 @unknown(i32, i32, i32)"
|
|
|
424 " "
|
|
|
425 "define void @f_1(i8* nocapture %arr, i32 %n, i32* %A, i32* %B) "
|
|
|
426 " local_unnamed_addr { "
|
|
|
427 "entry: "
|
|
|
428 " br label %loop.ph "
|
|
|
429 " "
|
|
|
430 "loop.ph: "
|
|
|
431 " br label %loop "
|
|
|
432 " "
|
|
|
433 "loop: "
|
|
|
434 " %iv0 = phi i32 [ %iv0.inc, %loop ], [ 0, %loop.ph ] "
|
|
|
435 " %iv1 = phi i32 [ %iv1.inc, %loop ], [ -2147483648, %loop.ph ] "
|
|
|
436 " %iv0.inc = add i32 %iv0, 1 "
|
|
|
437 " %iv1.inc = add i32 %iv1, 3 "
|
|
|
438 " br i1 undef, label %for.end.loopexit, label %loop "
|
|
|
439 " "
|
|
|
440 "for.end.loopexit: "
|
|
|
441 " ret void "
|
|
|
442 "} "
|
|
|
443 " "
|
|
|
444 "define void @f_2(i32 %a, i32 %b, i32 %c, i32 %d) "
|
|
|
445 " local_unnamed_addr { "
|
|
|
446 "entry: "
|
|
|
447 " br label %loop_0 "
|
|
|
448 " "
|
|
|
449 "loop_0: "
|
|
|
450 " br i1 undef, label %loop_0, label %loop_1 "
|
|
|
451 " "
|
|
|
452 "loop_1: "
|
|
|
453 " br i1 undef, label %loop_2, label %loop_1 "
|
|
|
454 " "
|
|
|
455 " "
|
|
|
456 "loop_2: "
|
|
|
457 " br i1 undef, label %end, label %loop_2 "
|
|
|
458 " "
|
|
|
459 "end: "
|
|
|
460 " ret void "
|
|
|
461 "} "
|
|
|
462 ,
|
|
|
463 Err, C);
|
|
|
464
|
|
|
465 assert(M && "Could not parse module?");
|
|
|
466 assert(!verifyModule(*M) && "Must have been well formed!");
|
|
|
467
|
|
|
468 runWithSE(*M, "f_1", [&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
|
|
|
469 auto &I0 = GetInstByName(F, "iv0");
|
|
|
470 auto &I1 = *I0.getNextNode();
|
|
|
471
|
|
|
472 auto *S0 = cast<SCEVAddRecExpr>(SE.getSCEV(&I0));
|
|
|
473 PostIncLoopSet Loops;
|
|
|
474 Loops.insert(S0->getLoop());
|
|
|
475 auto *N0 = normalizeForPostIncUse(S0, Loops, SE);
|
|
|
476 auto *D0 = denormalizeForPostIncUse(N0, Loops, SE);
|
|
|
477 EXPECT_EQ(S0, D0) << *S0 << " " << *D0;
|
|
|
478
|
|
|
479 auto *S1 = cast<SCEVAddRecExpr>(SE.getSCEV(&I1));
|
|
|
480 Loops.clear();
|
|
|
481 Loops.insert(S1->getLoop());
|
|
|
482 auto *N1 = normalizeForPostIncUse(S1, Loops, SE);
|
|
|
483 auto *D1 = denormalizeForPostIncUse(N1, Loops, SE);
|
|
|
484 EXPECT_EQ(S1, D1) << *S1 << " " << *D1;
|
|
|
485 });
|
|
|
486
|
|
|
487 runWithSE(*M, "f_2", [&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
|
|
|
488 auto *L2 = *LI.begin();
|
|
|
489 auto *L1 = *std::next(LI.begin());
|
|
|
490 auto *L0 = *std::next(LI.begin(), 2);
|
|
|
491
|
|
|
492 auto GetAddRec = [&SE](const Loop *L, std::initializer_list<const SCEV *> Ops) {
|
|
|
493 SmallVector<const SCEV *, 4> OpsCopy(Ops);
|
|
|
494 return SE.getAddRecExpr(OpsCopy, L, SCEV::FlagAnyWrap);
|
|
|
495 };
|
|
|
496
|
|
|
497 auto GetAdd = [&SE](std::initializer_list<const SCEV *> Ops) {
|
|
|
498 SmallVector<const SCEV *, 4> OpsCopy(Ops);
|
|
|
499 return SE.getAddExpr(OpsCopy, SCEV::FlagAnyWrap);
|
|
|
500 };
|
|
|
501
|
|
|
502 // We first populate the AddRecs vector with a few "interesting" SCEV
|
|
|
503 // expressions, and then we go through the list and assert that each
|
|
|
504 // expression in it has an invertible normalization.
|
|
|
505
|
|
|
506 std::vector<const SCEV *> Exprs;
|
|
|
507 {
|
|
|
508 const SCEV *V0 = SE.getSCEV(&*F.arg_begin());
|
|
|
509 const SCEV *V1 = SE.getSCEV(&*std::next(F.arg_begin(), 1));
|
|
|
510 const SCEV *V2 = SE.getSCEV(&*std::next(F.arg_begin(), 2));
|
|
|
511 const SCEV *V3 = SE.getSCEV(&*std::next(F.arg_begin(), 3));
|
|
|
512
|
|
|
513 Exprs.push_back(GetAddRec(L0, {V0})); // 0
|
|
|
514 Exprs.push_back(GetAddRec(L0, {V0, V1})); // 1
|
|
|
515 Exprs.push_back(GetAddRec(L0, {V0, V1, V2})); // 2
|
|
|
516 Exprs.push_back(GetAddRec(L0, {V0, V1, V2, V3})); // 3
|
|
|
517
|
|
|
518 Exprs.push_back(
|
|
|
519 GetAddRec(L1, {Exprs[1], Exprs[2], Exprs[3], Exprs[0]})); // 4
|
|
|
520 Exprs.push_back(
|
|
|
521 GetAddRec(L1, {Exprs[1], Exprs[2], Exprs[0], Exprs[3]})); // 5
|
|
|
522 Exprs.push_back(
|
|
|
523 GetAddRec(L1, {Exprs[1], Exprs[3], Exprs[3], Exprs[1]})); // 6
|
|
|
524
|
|
|
525 Exprs.push_back(GetAdd({Exprs[6], Exprs[3], V2})); // 7
|
|
|
526
|
|
|
527 Exprs.push_back(
|
|
|
528 GetAddRec(L2, {Exprs[4], Exprs[3], Exprs[3], Exprs[5]})); // 8
|
|
|
529
|
|
|
530 Exprs.push_back(
|
|
|
531 GetAddRec(L2, {Exprs[4], Exprs[6], Exprs[7], Exprs[3], V0})); // 9
|
|
|
532 }
|
|
|
533
|
|
|
534 std::vector<PostIncLoopSet> LoopSets;
|
|
|
535 for (int i = 0; i < 8; i++) {
|
|
|
536 LoopSets.emplace_back();
|
|
|
537 if (i & 1)
|
|
|
538 LoopSets.back().insert(L0);
|
|
|
539 if (i & 2)
|
|
|
540 LoopSets.back().insert(L1);
|
|
|
541 if (i & 4)
|
|
|
542 LoopSets.back().insert(L2);
|
|
|
543 }
|
|
|
544
|
|
|
545 for (const auto &LoopSet : LoopSets)
|
|
|
546 for (auto *S : Exprs) {
|
|
|
547 {
|
|
|
548 auto *N = llvm::normalizeForPostIncUse(S, LoopSet, SE);
|
|
|
549 auto *D = llvm::denormalizeForPostIncUse(N, LoopSet, SE);
|
|
|
550
|
|
|
551 // Normalization and then denormalizing better give us back the same
|
|
|
552 // value.
|
|
|
553 EXPECT_EQ(S, D) << "S = " << *S << " D = " << *D << " N = " << *N;
|
|
|
554 }
|
|
|
555 {
|
|
|
556 auto *D = llvm::denormalizeForPostIncUse(S, LoopSet, SE);
|
|
|
557 auto *N = llvm::normalizeForPostIncUse(D, LoopSet, SE);
|
|
|
558
|
|
|
559 // Denormalization and then normalizing better give us back the same
|
|
|
560 // value.
|
|
|
561 EXPECT_EQ(S, N) << "S = " << *S << " N = " << *N;
|
|
|
562 }
|
|
|
563 }
|
|
|
564 });
|
|
|
565 }
|
|
|
566
|
|
|
567 // Expect the call of getZeroExtendExpr will not cost exponential time.
|
|
|
568 TEST_F(ScalarEvolutionsTest, SCEVZeroExtendExpr) {
|
|
|
569 LLVMContext C;
|
|
|
570 SMDiagnostic Err;
|
|
|
571
|
|
|
572 // Generate a function like below:
|
|
|
573 // define void @foo() {
|
|
|
574 // entry:
|
|
|
575 // br label %for.cond
|
|
|
576 //
|
|
|
577 // for.cond:
|
|
|
578 // %0 = phi i64 [ 100, %entry ], [ %dec, %for.inc ]
|
|
|
579 // %cmp = icmp sgt i64 %0, 90
|
|
|
580 // br i1 %cmp, label %for.inc, label %for.cond1
|
|
|
581 //
|
|
|
582 // for.inc:
|
|
|
583 // %dec = add nsw i64 %0, -1
|
|
|
584 // br label %for.cond
|
|
|
585 //
|
|
|
586 // for.cond1:
|
|
|
587 // %1 = phi i64 [ 100, %for.cond ], [ %dec5, %for.inc2 ]
|
|
|
588 // %cmp3 = icmp sgt i64 %1, 90
|
|
|
589 // br i1 %cmp3, label %for.inc2, label %for.cond4
|
|
|
590 //
|
|
|
591 // for.inc2:
|
|
|
592 // %dec5 = add nsw i64 %1, -1
|
|
|
593 // br label %for.cond1
|
|
|
594 //
|
|
|
595 // ......
|
|
|
596 //
|
|
|
597 // for.cond89:
|
|
|
598 // %19 = phi i64 [ 100, %for.cond84 ], [ %dec94, %for.inc92 ]
|
|
|
599 // %cmp93 = icmp sgt i64 %19, 90
|
|
|
600 // br i1 %cmp93, label %for.inc92, label %for.end
|
|
|
601 //
|
|
|
602 // for.inc92:
|
|
|
603 // %dec94 = add nsw i64 %19, -1
|
|
|
604 // br label %for.cond89
|
|
|
605 //
|
|
|
606 // for.end:
|
|
|
607 // %gep = getelementptr i8, i8* null, i64 %dec
|
|
|
608 // %gep6 = getelementptr i8, i8* %gep, i64 %dec5
|
|
|
609 // ......
|
|
|
610 // %gep95 = getelementptr i8, i8* %gep91, i64 %dec94
|
|
|
611 // ret void
|
|
|
612 // }
|
|
|
613 FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context), {}, false);
|
|
|
614 Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", M);
|
|
|
615
|
|
|
616 BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
|
|
|
617 BasicBlock *CondBB = BasicBlock::Create(Context, "for.cond", F);
|
|
|
618 BasicBlock *EndBB = BasicBlock::Create(Context, "for.end", F);
|
|
|
619 BranchInst::Create(CondBB, EntryBB);
|
|
|
620 BasicBlock *PrevBB = EntryBB;
|
|
|
621
|
|
|
622 Type *I64Ty = Type::getInt64Ty(Context);
|
|
|
623 Type *I8Ty = Type::getInt8Ty(Context);
|
|
|
624 Type *I8PtrTy = Type::getInt8PtrTy(Context);
|
|
|
625 Value *Accum = Constant::getNullValue(I8PtrTy);
|
|
|
626 int Iters = 20;
|
|
|
627 for (int i = 0; i < Iters; i++) {
|
|
|
628 BasicBlock *IncBB = BasicBlock::Create(Context, "for.inc", F, EndBB);
|
|
|
629 auto *PN = PHINode::Create(I64Ty, 2, "", CondBB);
|
|
|
630 PN->addIncoming(ConstantInt::get(Context, APInt(64, 100)), PrevBB);
|
|
|
631 auto *Cmp = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_SGT, PN,
|
|
|
632 ConstantInt::get(Context, APInt(64, 90)), "cmp",
|
|
|
633 CondBB);
|
|
|
634 BasicBlock *NextBB;
|
|
|
635 if (i != Iters - 1)
|
|
|
636 NextBB = BasicBlock::Create(Context, "for.cond", F, EndBB);
|
|
|
637 else
|
|
|
638 NextBB = EndBB;
|
|
|
639 BranchInst::Create(IncBB, NextBB, Cmp, CondBB);
|
|
|
640 auto *Dec = BinaryOperator::CreateNSWAdd(
|
|
|
641 PN, ConstantInt::get(Context, APInt(64, -1)), "dec", IncBB);
|
|
|
642 PN->addIncoming(Dec, IncBB);
|
|
|
643 BranchInst::Create(CondBB, IncBB);
|
|
|
644
|
|
|
645 Accum = GetElementPtrInst::Create(I8Ty, Accum, PN, "gep", EndBB);
|
|
|
646
|
|
|
647 PrevBB = CondBB;
|
|
|
648 CondBB = NextBB;
|
|
|
649 }
|
|
|
650 ReturnInst::Create(Context, nullptr, EndBB);
|
|
|
651 ScalarEvolution SE = buildSE(*F);
|
|
|
652 const SCEV *S = SE.getSCEV(Accum);
|
|
|
653 Type *I128Ty = Type::getInt128Ty(Context);
|
|
|
654 SE.getZeroExtendExpr(S, I128Ty);
|
|
|
655 }
|
|
|
656
|
|
|
657 // Make sure that SCEV invalidates exit limits after invalidating the values it
|
|
|
658 // depends on when we forget a loop.
|
|
|
659 TEST_F(ScalarEvolutionsTest, SCEVExitLimitForgetLoop) {
|
|
|
660 /*
|
|
|
661 * Create the following code:
|
|
|
662 * func(i64 addrspace(10)* %arg)
|
|
|
663 * top:
|
|
|
664 * br label %L.ph
|
|
|
665 * L.ph:
|
|
|
666 * br label %L
|
|
|
667 * L:
|
|
|
668 * %phi = phi i64 [i64 0, %L.ph], [ %add, %L2 ]
|
|
|
669 * %add = add i64 %phi2, 1
|
|
|
670 * %cond = icmp slt i64 %add, 1000; then becomes 2000.
|
|
|
671 * br i1 %cond, label %post, label %L2
|
|
|
672 * post:
|
|
|
673 * ret void
|
|
|
674 *
|
|
|
675 */
|
|
|
676
|
|
|
677 // Create a module with non-integral pointers in it's datalayout
|
|
|
678 Module NIM("nonintegral", Context);
|
|
|
679 std::string DataLayout = M.getDataLayoutStr();
|
|
|
680 if (!DataLayout.empty())
|
|
|
681 DataLayout += "-";
|
|
|
682 DataLayout += "ni:10";
|
|
|
683 NIM.setDataLayout(DataLayout);
|
|
|
684
|
|
|
685 Type *T_int64 = Type::getInt64Ty(Context);
|
|
|
686 Type *T_pint64 = T_int64->getPointerTo(10);
|
|
|
687
|
|
|
688 FunctionType *FTy =
|
|
|
689 FunctionType::get(Type::getVoidTy(Context), {T_pint64}, false);
|
|
|
690 Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", NIM);
|
|
|
691
|
|
|
692 BasicBlock *Top = BasicBlock::Create(Context, "top", F);
|
|
|
693 BasicBlock *LPh = BasicBlock::Create(Context, "L.ph", F);
|
|
|
694 BasicBlock *L = BasicBlock::Create(Context, "L", F);
|
|
|
695 BasicBlock *Post = BasicBlock::Create(Context, "post", F);
|
|
|
696
|
|
|
697 IRBuilder<> Builder(Top);
|
|
|
698 Builder.CreateBr(LPh);
|
|
|
699
|
|
|
700 Builder.SetInsertPoint(LPh);
|
|
|
701 Builder.CreateBr(L);
|
|
|
702
|
|
|
703 Builder.SetInsertPoint(L);
|
|
|
704 PHINode *Phi = Builder.CreatePHI(T_int64, 2);
|
|
|
705 auto *Add = cast<Instruction>(
|
|
|
706 Builder.CreateAdd(Phi, ConstantInt::get(T_int64, 1), "add"));
|
|
|
707 auto *Limit = ConstantInt::get(T_int64, 1000);
|
|
|
708 auto *Cond = cast<Instruction>(
|
|
|
709 Builder.CreateICmp(ICmpInst::ICMP_SLT, Add, Limit, "cond"));
|
|
|
710 auto *Br = cast<Instruction>(Builder.CreateCondBr(Cond, L, Post));
|
|
|
711 Phi->addIncoming(ConstantInt::get(T_int64, 0), LPh);
|
|
|
712 Phi->addIncoming(Add, L);
|
|
|
713
|
|
|
714 Builder.SetInsertPoint(Post);
|
|
|
715 Builder.CreateRetVoid();
|
|
|
716
|
|
|
717 ScalarEvolution SE = buildSE(*F);
|
|
|
718 auto *Loop = LI->getLoopFor(L);
|
|
|
719 const SCEV *EC = SE.getBackedgeTakenCount(Loop);
|
|
|
720 EXPECT_FALSE(isa<SCEVCouldNotCompute>(EC));
|
|
|
721 EXPECT_TRUE(isa<SCEVConstant>(EC));
|
|
|
722 EXPECT_EQ(cast<SCEVConstant>(EC)->getAPInt().getLimitedValue(), 999u);
|
|
|
723
|
|
|
724 // The add recurrence {5,+,1} does not correspond to any PHI in the IR, and
|
|
|
725 // that is relevant to this test.
|
|
|
726 auto *Five = SE.getConstant(APInt(/*numBits=*/64, 5));
|
|
|
727 auto *AR =
|
|
|
728 SE.getAddRecExpr(Five, SE.getOne(T_int64), Loop, SCEV::FlagAnyWrap);
|
|
|
729 const SCEV *ARAtLoopExit = SE.getSCEVAtScope(AR, nullptr);
|
|
|
730 EXPECT_FALSE(isa<SCEVCouldNotCompute>(ARAtLoopExit));
|
|
|
731 EXPECT_TRUE(isa<SCEVConstant>(ARAtLoopExit));
|
|
|
732 EXPECT_EQ(cast<SCEVConstant>(ARAtLoopExit)->getAPInt().getLimitedValue(),
|
|
|
733 1004u);
|
|
|
734
|
|
|
735 SE.forgetLoop(Loop);
|
|
|
736 Br->eraseFromParent();
|
|
|
737 Cond->eraseFromParent();
|
|
|
738
|
|
|
739 Builder.SetInsertPoint(L);
|
|
|
740 auto *NewCond = Builder.CreateICmp(
|
|
|
741 ICmpInst::ICMP_SLT, Add, ConstantInt::get(T_int64, 2000), "new.cond");
|
|
|
742 Builder.CreateCondBr(NewCond, L, Post);
|
|
|
743 const SCEV *NewEC = SE.getBackedgeTakenCount(Loop);
|
|
|
744 EXPECT_FALSE(isa<SCEVCouldNotCompute>(NewEC));
|
|
|
745 EXPECT_TRUE(isa<SCEVConstant>(NewEC));
|
|
|
746 EXPECT_EQ(cast<SCEVConstant>(NewEC)->getAPInt().getLimitedValue(), 1999u);
|
|
|
747 const SCEV *NewARAtLoopExit = SE.getSCEVAtScope(AR, nullptr);
|
|
|
748 EXPECT_FALSE(isa<SCEVCouldNotCompute>(NewARAtLoopExit));
|
|
|
749 EXPECT_TRUE(isa<SCEVConstant>(NewARAtLoopExit));
|
|
|
750 EXPECT_EQ(cast<SCEVConstant>(NewARAtLoopExit)->getAPInt().getLimitedValue(),
|
|
|
751 2004u);
|
|
|
752 }
|
|
|
753
|
|
|
754 // Make sure that SCEV invalidates exit limits after invalidating the values it
|
|
|
755 // depends on when we forget a value.
|
|
|
756 TEST_F(ScalarEvolutionsTest, SCEVExitLimitForgetValue) {
|
|
|
757 /*
|
|
|
758 * Create the following code:
|
|
|
759 * func(i64 addrspace(10)* %arg)
|
|
|
760 * top:
|
|
|
761 * br label %L.ph
|
|
|
762 * L.ph:
|
|
|
763 * %load = load i64 addrspace(10)* %arg
|
|
|
764 * br label %L
|
|
|
765 * L:
|
|
|
766 * %phi = phi i64 [i64 0, %L.ph], [ %add, %L2 ]
|
|
|
767 * %add = add i64 %phi2, 1
|
|
|
768 * %cond = icmp slt i64 %add, %load ; then becomes 2000.
|
|
|
769 * br i1 %cond, label %post, label %L2
|
|
|
770 * post:
|
|
|
771 * ret void
|
|
|
772 *
|
|
|
773 */
|
|
|
774
|
|
|
775 // Create a module with non-integral pointers in it's datalayout
|
|
|
776 Module NIM("nonintegral", Context);
|
|
|
777 std::string DataLayout = M.getDataLayoutStr();
|
|
|
778 if (!DataLayout.empty())
|
|
|
779 DataLayout += "-";
|
|
|
780 DataLayout += "ni:10";
|
|
|
781 NIM.setDataLayout(DataLayout);
|
|
|
782
|
|
|
783 Type *T_int64 = Type::getInt64Ty(Context);
|
|
|
784 Type *T_pint64 = T_int64->getPointerTo(10);
|
|
|
785
|
|
|
786 FunctionType *FTy =
|
|
|
787 FunctionType::get(Type::getVoidTy(Context), {T_pint64}, false);
|
|
|
788 Function *F = Function::Create(FTy, Function::ExternalLinkage, "foo", NIM);
|
|
|
789
|
|
|
790 Argument *Arg = &*F->arg_begin();
|
|
|
791
|
|
|
792 BasicBlock *Top = BasicBlock::Create(Context, "top", F);
|
|
|
793 BasicBlock *LPh = BasicBlock::Create(Context, "L.ph", F);
|
|
|
794 BasicBlock *L = BasicBlock::Create(Context, "L", F);
|
|
|
795 BasicBlock *Post = BasicBlock::Create(Context, "post", F);
|
|
|
796
|
|
|
797 IRBuilder<> Builder(Top);
|
|
|
798 Builder.CreateBr(LPh);
|
|
|
799
|
|
|
800 Builder.SetInsertPoint(LPh);
|
|
|
801 auto *Load = cast<Instruction>(Builder.CreateLoad(T_int64, Arg, "load"));
|
|
|
802 Builder.CreateBr(L);
|
|
|
803
|
|
|
804 Builder.SetInsertPoint(L);
|
|
|
805 PHINode *Phi = Builder.CreatePHI(T_int64, 2);
|
|
|
806 auto *Add = cast<Instruction>(
|
|
|
807 Builder.CreateAdd(Phi, ConstantInt::get(T_int64, 1), "add"));
|
|
|
808 auto *Cond = cast<Instruction>(
|
|
|
809 Builder.CreateICmp(ICmpInst::ICMP_SLT, Add, Load, "cond"));
|
|
|
810 auto *Br = cast<Instruction>(Builder.CreateCondBr(Cond, L, Post));
|
|
|
811 Phi->addIncoming(ConstantInt::get(T_int64, 0), LPh);
|
|
|
812 Phi->addIncoming(Add, L);
|
|
|
813
|
|
|
814 Builder.SetInsertPoint(Post);
|
|
|
815 Builder.CreateRetVoid();
|
|
|
816
|
|
|
817 ScalarEvolution SE = buildSE(*F);
|
|
|
818 auto *Loop = LI->getLoopFor(L);
|
|
|
819 const SCEV *EC = SE.getBackedgeTakenCount(Loop);
|
|
|
820 EXPECT_FALSE(isa<SCEVCouldNotCompute>(EC));
|
|
|
821 EXPECT_FALSE(isa<SCEVConstant>(EC));
|
|
|
822
|
|
|
823 SE.forgetValue(Load);
|
|
|
824 Br->eraseFromParent();
|
|
|
825 Cond->eraseFromParent();
|
|
|
826 Load->eraseFromParent();
|
|
|
827
|
|
|
828 Builder.SetInsertPoint(L);
|
|
|
829 auto *NewCond = Builder.CreateICmp(
|
|
|
830 ICmpInst::ICMP_SLT, Add, ConstantInt::get(T_int64, 2000), "new.cond");
|
|
|
831 Builder.CreateCondBr(NewCond, L, Post);
|
|
|
832 const SCEV *NewEC = SE.getBackedgeTakenCount(Loop);
|
|
|
833 EXPECT_FALSE(isa<SCEVCouldNotCompute>(NewEC));
|
|
|
834 EXPECT_TRUE(isa<SCEVConstant>(NewEC));
|
|
|
835 EXPECT_EQ(cast<SCEVConstant>(NewEC)->getAPInt().getLimitedValue(), 1999u);
|
|
|
836 }
|
|
|
837
|
|
|
838 TEST_F(ScalarEvolutionsTest, SCEVAddRecFromPHIwithLargeConstants) {
|
|
|
839 // Reference: https://reviews.llvm.org/D37265
|
|
|
840 // Make sure that SCEV does not blow up when constructing an AddRec
|
|
|
841 // with predicates for a phi with the update pattern:
|
|
|
842 // (SExt/ZExt ix (Trunc iy (%SymbolicPHI) to ix) to iy) + InvariantAccum
|
|
|
843 // when either the initial value of the Phi or the InvariantAccum are
|
|
|
844 // constants that are too large to fit in an ix but are zero when truncated to
|
|
|
845 // ix.
|
|
|
846 FunctionType *FTy =
|
|
|
847 FunctionType::get(Type::getVoidTy(Context), std::vector<Type *>(), false);
|
|
|
848 Function *F =
|
|
|
849 Function::Create(FTy, Function::ExternalLinkage, "addrecphitest", M);
|
|
|
850
|
|
|
851 /*
|
|
|
852 Create IR:
|
|
|
853 entry:
|
|
|
854 br label %loop
|
|
|
855 loop:
|
|
|
856 %0 = phi i64 [-9223372036854775808, %entry], [%3, %loop]
|
|
|
857 %1 = shl i64 %0, 32
|
|
|
858 %2 = ashr exact i64 %1, 32
|
|
|
859 %3 = add i64 %2, -9223372036854775808
|
|
|
860 br i1 undef, label %exit, label %loop
|
|
|
861 exit:
|
|
|
862 ret void
|
|
|
863 */
|
|
|
864 BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
|
|
|
865 BasicBlock *LoopBB = BasicBlock::Create(Context, "loop", F);
|
|
|
866 BasicBlock *ExitBB = BasicBlock::Create(Context, "exit", F);
|
|
|
867
|
|
|
868 // entry:
|
|
|
869 BranchInst::Create(LoopBB, EntryBB);
|
|
|
870 // loop:
|
|
|
871 auto *MinInt64 =
|
|
|
872 ConstantInt::get(Context, APInt(64, 0x8000000000000000U, true));
|
|
|
873 auto *Int64_32 = ConstantInt::get(Context, APInt(64, 32));
|
|
|
874 auto *Br = BranchInst::Create(
|
|
|
875 LoopBB, ExitBB, UndefValue::get(Type::getInt1Ty(Context)), LoopBB);
|
|
|
876 auto *Phi = PHINode::Create(Type::getInt64Ty(Context), 2, "", Br);
|
|
|
877 auto *Shl = BinaryOperator::CreateShl(Phi, Int64_32, "", Br);
|
|
|
878 auto *AShr = BinaryOperator::CreateExactAShr(Shl, Int64_32, "", Br);
|
|
|
879 auto *Add = BinaryOperator::CreateAdd(AShr, MinInt64, "", Br);
|
|
|
880 Phi->addIncoming(MinInt64, EntryBB);
|
|
|
881 Phi->addIncoming(Add, LoopBB);
|
|
|
882 // exit:
|
|
|
883 ReturnInst::Create(Context, nullptr, ExitBB);
|
|
|
884
|
|
|
885 // Make sure that SCEV doesn't blow up
|
|
|
886 ScalarEvolution SE = buildSE(*F);
|
|
|
887 SCEVUnionPredicate Preds;
|
|
|
888 const SCEV *Expr = SE.getSCEV(Phi);
|
|
|
889 EXPECT_NE(nullptr, Expr);
|
|
|
890 EXPECT_TRUE(isa<SCEVUnknown>(Expr));
|
|
|
891 auto Result = SE.createAddRecFromPHIWithCasts(cast<SCEVUnknown>(Expr));
|
|
|
892 }
|
|
|
893
|
|
|
894 TEST_F(ScalarEvolutionsTest, SCEVAddRecFromPHIwithLargeConstantAccum) {
|
|
|
895 // Make sure that SCEV does not blow up when constructing an AddRec
|
|
|
896 // with predicates for a phi with the update pattern:
|
|
|
897 // (SExt/ZExt ix (Trunc iy (%SymbolicPHI) to ix) to iy) + InvariantAccum
|
|
|
898 // when the InvariantAccum is a constant that is too large to fit in an
|
|
|
899 // ix but are zero when truncated to ix, and the initial value of the
|
|
|
900 // phi is not a constant.
|
|
|
901 Type *Int32Ty = Type::getInt32Ty(Context);
|
|
|
902 SmallVector<Type *, 1> Types;
|
|
|
903 Types.push_back(Int32Ty);
|
|
|
904 FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context), Types, false);
|
|
|
905 Function *F =
|
|
|
906 Function::Create(FTy, Function::ExternalLinkage, "addrecphitest", M);
|
|
|
907
|
|
|
908 /*
|
|
|
909 Create IR:
|
|
|
910 define @addrecphitest(i32)
|
|
|
911 entry:
|
|
|
912 br label %loop
|
|
|
913 loop:
|
|
|
914 %1 = phi i32 [%0, %entry], [%4, %loop]
|
|
|
915 %2 = shl i32 %1, 16
|
|
|
916 %3 = ashr exact i32 %2, 16
|
|
|
917 %4 = add i32 %3, -2147483648
|
|
|
918 br i1 undef, label %exit, label %loop
|
|
|
919 exit:
|
|
|
920 ret void
|
|
|
921 */
|
|
|
922 BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
|
|
|
923 BasicBlock *LoopBB = BasicBlock::Create(Context, "loop", F);
|
|
|
924 BasicBlock *ExitBB = BasicBlock::Create(Context, "exit", F);
|
|
|
925
|
|
|
926 // entry:
|
|
|
927 BranchInst::Create(LoopBB, EntryBB);
|
|
|
928 // loop:
|
|
|
929 auto *MinInt32 = ConstantInt::get(Context, APInt(32, 0x80000000U, true));
|
|
|
930 auto *Int32_16 = ConstantInt::get(Context, APInt(32, 16));
|
|
|
931 auto *Br = BranchInst::Create(
|
|
|
932 LoopBB, ExitBB, UndefValue::get(Type::getInt1Ty(Context)), LoopBB);
|
|
|
933 auto *Phi = PHINode::Create(Int32Ty, 2, "", Br);
|
|
|
934 auto *Shl = BinaryOperator::CreateShl(Phi, Int32_16, "", Br);
|
|
|
935 auto *AShr = BinaryOperator::CreateExactAShr(Shl, Int32_16, "", Br);
|
|
|
936 auto *Add = BinaryOperator::CreateAdd(AShr, MinInt32, "", Br);
|
|
|
937 auto *Arg = &*(F->arg_begin());
|
|
|
938 Phi->addIncoming(Arg, EntryBB);
|
|
|
939 Phi->addIncoming(Add, LoopBB);
|
|
|
940 // exit:
|
|
|
941 ReturnInst::Create(Context, nullptr, ExitBB);
|
|
|
942
|
|
|
943 // Make sure that SCEV doesn't blow up
|
|
|
944 ScalarEvolution SE = buildSE(*F);
|
|
|
945 SCEVUnionPredicate Preds;
|
|
|
946 const SCEV *Expr = SE.getSCEV(Phi);
|
|
|
947 EXPECT_NE(nullptr, Expr);
|
|
|
948 EXPECT_TRUE(isa<SCEVUnknown>(Expr));
|
|
|
949 auto Result = SE.createAddRecFromPHIWithCasts(cast<SCEVUnknown>(Expr));
|
|
|
950 }
|
|
|
951
|
|
|
952 TEST_F(ScalarEvolutionsTest, SCEVFoldSumOfTruncs) {
|
|
|
953 // Verify that the following SCEV gets folded to a zero:
|
|
|
954 // (-1 * (trunc i64 (-1 * %0) to i32)) + (-1 * (trunc i64 %0 to i32)
|
|
|
955 Type *ArgTy = Type::getInt64Ty(Context);
|
|
|
956 Type *Int32Ty = Type::getInt32Ty(Context);
|
|
|
957 SmallVector<Type *, 1> Types;
|
|
|
958 Types.push_back(ArgTy);
|
|
|
959 FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context), Types, false);
|
|
|
960 Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
|
|
|
961 BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
|
|
|
962 ReturnInst::Create(Context, nullptr, BB);
|
|
|
963
|
|
|
964 ScalarEvolution SE = buildSE(*F);
|
|
|
965
|
|
|
966 auto *Arg = &*(F->arg_begin());
|
|
|
967 const auto *ArgSCEV = SE.getSCEV(Arg);
|
|
|
968
|
|
|
969 // Build the SCEV
|
|
|
970 const auto *A0 = SE.getNegativeSCEV(ArgSCEV);
|
|
|
971 const auto *A1 = SE.getTruncateExpr(A0, Int32Ty);
|
|
|
972 const auto *A = SE.getNegativeSCEV(A1);
|
|
|
973
|
|
|
974 const auto *B0 = SE.getTruncateExpr(ArgSCEV, Int32Ty);
|
|
|
975 const auto *B = SE.getNegativeSCEV(B0);
|
|
|
976
|
|
|
977 const auto *Expr = SE.getAddExpr(A, B);
|
|
|
978 // Verify that the SCEV was folded to 0
|
|
|
979 const auto *ZeroConst = SE.getConstant(Int32Ty, 0);
|
|
|
980 EXPECT_EQ(Expr, ZeroConst);
|
|
|
981 }
|
|
|
982
|
|
|
983 // Check logic of SCEV expression size computation.
|
|
|
984 TEST_F(ScalarEvolutionsTest, SCEVComputeExpressionSize) {
|
|
|
985 /*
|
|
|
986 * Create the following code:
|
|
|
987 * void func(i64 %a, i64 %b)
|
|
|
988 * entry:
|
|
|
989 * %s1 = add i64 %a, 1
|
|
|
990 * %s2 = udiv i64 %s1, %b
|
|
|
991 * br label %exit
|
|
|
992 * exit:
|
|
|
993 * ret
|
|
|
994 */
|
|
|
995
|
|
|
996 // Create a module.
|
|
|
997 Module M("SCEVComputeExpressionSize", Context);
|
|
|
998
|
|
|
999 Type *T_int64 = Type::getInt64Ty(Context);
|
|
|
1000
|
|
|
1001 FunctionType *FTy =
|
|
|
1002 FunctionType::get(Type::getVoidTy(Context), { T_int64, T_int64 }, false);
|
|
|
1003 Function *F = Function::Create(FTy, Function::ExternalLinkage, "func", M);
|
|
|
1004 Argument *A = &*F->arg_begin();
|
|
|
1005 Argument *B = &*std::next(F->arg_begin());
|
|
|
1006 ConstantInt *C = ConstantInt::get(Context, APInt(64, 1));
|
|
|
1007
|
|
|
1008 BasicBlock *Entry = BasicBlock::Create(Context, "entry", F);
|
|
|
1009 BasicBlock *Exit = BasicBlock::Create(Context, "exit", F);
|
|
|
1010
|
|
|
1011 IRBuilder<> Builder(Entry);
|
|
|
1012 auto *S1 = cast<Instruction>(Builder.CreateAdd(A, C, "s1"));
|
|
|
1013 auto *S2 = cast<Instruction>(Builder.CreateUDiv(S1, B, "s2"));
|
|
|
1014 Builder.CreateBr(Exit);
|
|
|
1015
|
|
|
1016 Builder.SetInsertPoint(Exit);
|
|
|
1017 Builder.CreateRetVoid();
|
|
|
1018
|
|
|
1019 ScalarEvolution SE = buildSE(*F);
|
|
|
1020 // Get S2 first to move it to cache.
|
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1021 const SCEV *AS = SE.getSCEV(A);
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1022 const SCEV *BS = SE.getSCEV(B);
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1023 const SCEV *CS = SE.getSCEV(C);
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1024 const SCEV *S1S = SE.getSCEV(S1);
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1025 const SCEV *S2S = SE.getSCEV(S2);
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1026 EXPECT_EQ(AS->getExpressionSize(), 1u);
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1027 EXPECT_EQ(BS->getExpressionSize(), 1u);
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1028 EXPECT_EQ(CS->getExpressionSize(), 1u);
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1029 EXPECT_EQ(S1S->getExpressionSize(), 3u);
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1030 EXPECT_EQ(S2S->getExpressionSize(), 5u);
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1031 }
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1032
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1033 TEST_F(ScalarEvolutionsTest, SCEVLoopDecIntrinsic) {
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1034 LLVMContext C;
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1035 SMDiagnostic Err;
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1036 std::unique_ptr<Module> M = parseAssemblyString(
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1037 "define void @foo(i32 %N) { "
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1038 "entry: "
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1039 " %cmp3 = icmp sgt i32 %N, 0 "
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1040 " br i1 %cmp3, label %for.body, label %for.cond.cleanup "
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1041 "for.cond.cleanup: "
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1042 " ret void "
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1043 "for.body: "
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1044 " %i.04 = phi i32 [ %inc, %for.body ], [ 100, %entry ] "
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1045 " %inc = call i32 @llvm.loop.decrement.reg.i32.i32.i32(i32 %i.04, i32 1) "
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1046 " %exitcond = icmp ne i32 %inc, 0 "
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1047 " br i1 %exitcond, label %for.cond.cleanup, label %for.body "
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1048 "} "
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1049 "declare i32 @llvm.loop.decrement.reg.i32.i32.i32(i32, i32) ",
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1050 Err, C);
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1051
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1052 ASSERT_TRUE(M && "Could not parse module?");
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1053 ASSERT_TRUE(!verifyModule(*M) && "Must have been well formed!");
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1054
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1055 runWithSE(*M, "foo", [&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
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1056 auto *ScevInc = SE.getSCEV(getInstructionByName(F, "inc"));
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1057 EXPECT_TRUE(isa<SCEVAddRecExpr>(ScevInc));
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1058 });
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1059 }
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1060
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1061 TEST_F(ScalarEvolutionsTest, SCEVComputeConstantDifference) {
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1062 LLVMContext C;
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1063 SMDiagnostic Err;
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1064 std::unique_ptr<Module> M = parseAssemblyString(
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1065 "define void @foo(i32 %sz, i32 %pp) { "
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1066 "entry: "
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1067 " %v0 = add i32 %pp, 0 "
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1068 " %v3 = add i32 %pp, 3 "
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1069 " br label %loop.body "
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1070 "loop.body: "
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1071 " %iv = phi i32 [ %iv.next, %loop.body ], [ 0, %entry ] "
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1072 " %xa = add nsw i32 %iv, %v0 "
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1073 " %yy = add nsw i32 %iv, %v3 "
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1074 " %xb = sub nsw i32 %yy, 3 "
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1075 " %iv.next = add nsw i32 %iv, 1 "
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1076 " %cmp = icmp sle i32 %iv.next, %sz "
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1077 " br i1 %cmp, label %loop.body, label %exit "
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1078 "exit: "
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1079 " ret void "
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1080 "} ",
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1081 Err, C);
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1082
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1083 ASSERT_TRUE(M && "Could not parse module?");
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1084 ASSERT_TRUE(!verifyModule(*M) && "Must have been well formed!");
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|
1085
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1086 runWithSE(*M, "foo", [](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
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1087 auto *ScevV0 = SE.getSCEV(getInstructionByName(F, "v0")); // %pp
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1088 auto *ScevV3 = SE.getSCEV(getInstructionByName(F, "v3")); // (3 + %pp)
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1089 auto *ScevIV = SE.getSCEV(getInstructionByName(F, "iv")); // {0,+,1}
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1090 auto *ScevXA = SE.getSCEV(getInstructionByName(F, "xa")); // {%pp,+,1}
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1091 auto *ScevYY = SE.getSCEV(getInstructionByName(F, "yy")); // {(3 + %pp),+,1}
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1092 auto *ScevXB = SE.getSCEV(getInstructionByName(F, "xb")); // {%pp,+,1}
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1093 auto *ScevIVNext = SE.getSCEV(getInstructionByName(F, "iv.next")); // {1,+,1}
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|
|
1094
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|
1095 auto diff = [&SE](const SCEV *LHS, const SCEV *RHS) -> Optional<int> {
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|
|
1096 auto ConstantDiffOrNone = computeConstantDifference(SE, LHS, RHS);
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|
|
1097 if (!ConstantDiffOrNone)
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|
|
1098 return None;
|
|
|
1099
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|
1100 auto ExtDiff = ConstantDiffOrNone->getSExtValue();
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|
1101 int Diff = ExtDiff;
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1102 assert(Diff == ExtDiff && "Integer overflow");
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|
|
1103 return Diff;
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|
1104 };
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|
|
1105
|
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|
1106 EXPECT_EQ(diff(ScevV3, ScevV0), 3);
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|
1107 EXPECT_EQ(diff(ScevV0, ScevV3), -3);
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|
|
1108 EXPECT_EQ(diff(ScevV0, ScevV0), 0);
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|
|
1109 EXPECT_EQ(diff(ScevV3, ScevV3), 0);
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|
|
1110 EXPECT_EQ(diff(ScevIV, ScevIV), 0);
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|
1111 EXPECT_EQ(diff(ScevXA, ScevXB), 0);
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|
|
1112 EXPECT_EQ(diff(ScevXA, ScevYY), -3);
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|
|
1113 EXPECT_EQ(diff(ScevYY, ScevXB), 3);
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|
|
1114 EXPECT_EQ(diff(ScevIV, ScevIVNext), -1);
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|
|
1115 EXPECT_EQ(diff(ScevIVNext, ScevIV), 1);
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|
|
1116 EXPECT_EQ(diff(ScevIVNext, ScevIVNext), 0);
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|
|
1117 EXPECT_EQ(diff(ScevV0, ScevIV), None);
|
|
|
1118 EXPECT_EQ(diff(ScevIVNext, ScevV3), None);
|
|
|
1119 EXPECT_EQ(diff(ScevYY, ScevV3), None);
|
|
|
1120 });
|
|
|
1121 }
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|
|
1122
|
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1123 } // end namespace llvm
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