135 lines · cpp
1//=======- CaptureTrackingTest.cpp - Unit test for the Capture Tracking ---===//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/CaptureTracking.h"10#include "llvm/AsmParser/Parser.h"11#include "llvm/IR/Dominators.h"12#include "llvm/IR/Instructions.h"13#include "llvm/IR/LLVMContext.h"14#include "llvm/IR/Module.h"15#include "llvm/Support/SourceMgr.h"16#include "gtest/gtest.h"17 18using namespace llvm;19 20TEST(CaptureTracking, MaxUsesToExplore) {21 StringRef Assembly = R"(22 ; Function Attrs: nounwind ssp uwtable23 declare void @doesnt_capture(ptr nocapture, ptr nocapture, ptr nocapture,24 ptr nocapture, ptr nocapture)25 26 ; %arg has 5 uses27 define void @test_few_uses(ptr %arg) {28 call void @doesnt_capture(ptr %arg, ptr %arg, ptr %arg, ptr %arg, ptr %arg)29 ret void30 }31 32 ; %arg has 50 uses33 define void @test_many_uses(ptr %arg) {34 call void @doesnt_capture(ptr %arg, ptr %arg, ptr %arg, ptr %arg, ptr %arg)35 call void @doesnt_capture(ptr %arg, ptr %arg, ptr %arg, ptr %arg, ptr %arg)36 call void @doesnt_capture(ptr %arg, ptr %arg, ptr %arg, ptr %arg, ptr %arg)37 call void @doesnt_capture(ptr %arg, ptr %arg, ptr %arg, ptr %arg, ptr %arg)38 call void @doesnt_capture(ptr %arg, ptr %arg, ptr %arg, ptr %arg, ptr %arg)39 call void @doesnt_capture(ptr %arg, ptr %arg, ptr %arg, ptr %arg, ptr %arg)40 call void @doesnt_capture(ptr %arg, ptr %arg, ptr %arg, ptr %arg, ptr %arg)41 call void @doesnt_capture(ptr %arg, ptr %arg, ptr %arg, ptr %arg, ptr %arg)42 call void @doesnt_capture(ptr %arg, ptr %arg, ptr %arg, ptr %arg, ptr %arg)43 call void @doesnt_capture(ptr %arg, ptr %arg, ptr %arg, ptr %arg, ptr %arg)44 ret void45 }46 )";47 48 LLVMContext Context;49 SMDiagnostic Error;50 auto M = parseAssemblyString(Assembly, Error, Context);51 ASSERT_TRUE(M) << "Bad assembly?";52 53 auto Test = [&M](const char *FName, unsigned FalseMaxUsesLimit,54 unsigned TrueMaxUsesLimit) {55 Function *F = M->getFunction(FName);56 ASSERT_NE(F, nullptr);57 Value *Arg = &*F->arg_begin();58 ASSERT_NE(Arg, nullptr);59 ASSERT_FALSE(PointerMayBeCaptured(Arg, true, FalseMaxUsesLimit));60 ASSERT_TRUE(PointerMayBeCaptured(Arg, true, TrueMaxUsesLimit));61 62 BasicBlock *EntryBB = &F->getEntryBlock();63 DominatorTree DT(*F);64 65 Instruction *Ret = EntryBB->getTerminator();66 ASSERT_TRUE(isa<ReturnInst>(Ret));67 ASSERT_FALSE(PointerMayBeCapturedBefore(Arg, true, Ret, &DT, false,68 FalseMaxUsesLimit));69 ASSERT_TRUE(PointerMayBeCapturedBefore(Arg, true, Ret, &DT, false,70 TrueMaxUsesLimit));71 };72 73 Test("test_few_uses", 6, 4);74 Test("test_many_uses", 50, 30);75}76 77struct CollectingCaptureTracker : public CaptureTracker {78 SmallVector<const Use *, 4> Captures;79 void tooManyUses() override { }80 Action captured(const Use *U, UseCaptureInfo CI) override {81 Captures.push_back(U);82 return Continue;83 }84};85 86TEST(CaptureTracking, MultipleUsesInSameInstruction) {87 StringRef Assembly = R"(88 declare void @call(ptr, ptr, ptr)89 90 define void @test(ptr %arg, ptr %ptr) {91 call void @call(ptr %arg, ptr nocapture %arg, ptr %arg) [ "bundle"(ptr %arg) ]92 cmpxchg ptr %ptr, ptr %arg, ptr %arg acq_rel monotonic93 icmp eq ptr %arg, %arg94 ret void95 }96 )";97 98 LLVMContext Context;99 SMDiagnostic Error;100 auto M = parseAssemblyString(Assembly, Error, Context);101 ASSERT_TRUE(M) << "Bad assembly?";102 103 Function *F = M->getFunction("test");104 Value *Arg = &*F->arg_begin();105 BasicBlock *BB = &F->getEntryBlock();106 Instruction *Call = &*BB->begin();107 Instruction *CmpXChg = Call->getNextNode();108 Instruction *ICmp = CmpXChg->getNextNode();109 110 CollectingCaptureTracker CT;111 PointerMayBeCaptured(Arg, &CT);112 EXPECT_EQ(7u, CT.Captures.size());113 // Call arg 1114 EXPECT_EQ(Call, CT.Captures[0]->getUser());115 EXPECT_EQ(0u, CT.Captures[0]->getOperandNo());116 // Call arg 3117 EXPECT_EQ(Call, CT.Captures[1]->getUser());118 EXPECT_EQ(2u, CT.Captures[1]->getOperandNo());119 // Operand bundle arg120 EXPECT_EQ(Call, CT.Captures[2]->getUser());121 EXPECT_EQ(3u, CT.Captures[2]->getOperandNo());122 // Cmpxchg compare operand123 EXPECT_EQ(CmpXChg, CT.Captures[3]->getUser());124 EXPECT_EQ(1u, CT.Captures[3]->getOperandNo());125 // Cmpxchg new value operand126 EXPECT_EQ(CmpXChg, CT.Captures[4]->getUser());127 EXPECT_EQ(2u, CT.Captures[4]->getOperandNo());128 // ICmp first operand129 EXPECT_EQ(ICmp, CT.Captures[5]->getUser());130 EXPECT_EQ(0u, CT.Captures[5]->getOperandNo());131 // ICmp second operand132 EXPECT_EQ(ICmp, CT.Captures[6]->getUser());133 EXPECT_EQ(1u, CT.Captures[6]->getOperandNo());134}135