94 lines · cpp
1//===- LICMTest.cpp - LICM unit tests -------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "llvm/Analysis/ScalarEvolution.h"10#include "llvm/AsmParser/Parser.h"11#include "llvm/IR/Module.h"12#include "llvm/Passes/PassBuilder.h"13#include "llvm/Support/SourceMgr.h"14#include "llvm/Testing/Support/Error.h"15#include "llvm/Transforms/Scalar/LICM.h"16#include "gtest/gtest.h"17 18namespace llvm {19 20TEST(LICMTest, TestSCEVInvalidationOnHoisting) {21 LLVMContext Ctx;22 ModulePassManager MPM;23 PassBuilder PB;24 LoopAnalysisManager LAM;25 FunctionAnalysisManager FAM;26 CGSCCAnalysisManager CGAM;27 ModuleAnalysisManager MAM;28 29 PB.registerModuleAnalyses(MAM);30 PB.registerCGSCCAnalyses(CGAM);31 PB.registerFunctionAnalyses(FAM);32 PB.registerLoopAnalyses(LAM);33 PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);34 35 StringRef PipelineStr = "require<opt-remark-emit>,loop-mssa(licm)";36 ASSERT_THAT_ERROR(PB.parsePassPipeline(MPM, PipelineStr), Succeeded());37 38 SMDiagnostic Error;39 StringRef Text = R"(40 define void @foo(ptr %ptr) {41 entry:42 br label %loop43 44 loop:45 %iv = phi i64 [ 0, %entry ], [ %iv.inc, %loop ]46 %n = load i64, ptr %ptr, !invariant.load !047 %iv.inc = add i64 %iv, 148 %cmp = icmp ult i64 %iv.inc, %n49 br i1 %cmp, label %loop, label %exit50 51 exit:52 ret void53 }54 55 !0 = !{}56 )";57 58 std::unique_ptr<Module> M = parseAssemblyString(Text, Error, Ctx);59 ASSERT_TRUE(M);60 Function *F = M->getFunction("foo");61 ScalarEvolution &SE = FAM.getResult<ScalarEvolutionAnalysis>(*F);62 BasicBlock &EntryBB = F->getEntryBlock();63 BasicBlock *LoopBB = EntryBB.getUniqueSuccessor();64 65 // Select `load i64, ptr %ptr`.66 Instruction *IBefore = &*LoopBB->getFirstNonPHIIt();67 // Make sure the right instruction was selected.68 ASSERT_TRUE(isa<LoadInst>(IBefore));69 // Upon this query SCEV caches disposition of <load i64, ptr %ptr> SCEV.70 ASSERT_EQ(SE.getBlockDisposition(SE.getSCEV(IBefore), LoopBB),71 ScalarEvolution::BlockDisposition::DominatesBlock);72 73 MPM.run(*M, MAM);74 75 // Select `load i64, ptr %ptr` after it was hoisted.76 Instruction *IAfter = &*EntryBB.getFirstNonPHIIt();77 // Make sure the right instruction was selected.78 ASSERT_TRUE(isa<LoadInst>(IAfter));79 80 ScalarEvolution::BlockDisposition DispositionBeforeInvalidation =81 SE.getBlockDisposition(SE.getSCEV(IAfter), LoopBB);82 SE.forgetValue(IAfter);83 ScalarEvolution::BlockDisposition DispositionAfterInvalidation =84 SE.getBlockDisposition(SE.getSCEV(IAfter), LoopBB);85 86 // If LICM have properly invalidated SCEV,87 // 1. SCEV of <load i64, ptr %ptr> should properly dominate the "loop" BB,88 // 2. extra invalidation shouldn't change result of the query.89 EXPECT_EQ(DispositionBeforeInvalidation,90 ScalarEvolution::BlockDisposition::ProperlyDominatesBlock);91 EXPECT_EQ(DispositionBeforeInvalidation, DispositionAfterInvalidation);92}93}94