| //===- ValueTrackingTest.cpp - ValueTracking tests ------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Analysis/ValueTracking.h" |
| #include "llvm/AsmParser/Parser.h" |
| #include "llvm/IR/Function.h" |
| #include "llvm/IR/InstIterator.h" |
| #include "llvm/IR/LLVMContext.h" |
| #include "llvm/IR/Module.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/SourceMgr.h" |
| #include "llvm/Support/KnownBits.h" |
| #include "gtest/gtest.h" |
| |
| using namespace llvm; |
| |
| namespace { |
| |
| class MatchSelectPatternTest : public testing::Test { |
| protected: |
| void parseAssembly(const char *Assembly) { |
| SMDiagnostic Error; |
| M = parseAssemblyString(Assembly, Error, Context); |
| |
| std::string errMsg; |
| raw_string_ostream os(errMsg); |
| Error.print("", os); |
| |
| // A failure here means that the test itself is buggy. |
| if (!M) |
| report_fatal_error(os.str()); |
| |
| Function *F = M->getFunction("test"); |
| if (F == nullptr) |
| report_fatal_error("Test must have a function named @test"); |
| |
| A = nullptr; |
| for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) { |
| if (I->hasName()) { |
| if (I->getName() == "A") |
| A = &*I; |
| } |
| } |
| if (A == nullptr) |
| report_fatal_error("@test must have an instruction %A"); |
| } |
| |
| void expectPattern(const SelectPatternResult &P) { |
| Value *LHS, *RHS; |
| Instruction::CastOps CastOp; |
| SelectPatternResult R = matchSelectPattern(A, LHS, RHS, &CastOp); |
| EXPECT_EQ(P.Flavor, R.Flavor); |
| EXPECT_EQ(P.NaNBehavior, R.NaNBehavior); |
| EXPECT_EQ(P.Ordered, R.Ordered); |
| } |
| |
| LLVMContext Context; |
| std::unique_ptr<Module> M; |
| Instruction *A, *B; |
| }; |
| |
| } |
| |
| TEST_F(MatchSelectPatternTest, SimpleFMin) { |
| parseAssembly( |
| "define float @test(float %a) {\n" |
| " %1 = fcmp ult float %a, 5.0\n" |
| " %A = select i1 %1, float %a, float 5.0\n" |
| " ret float %A\n" |
| "}\n"); |
| expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, false}); |
| } |
| |
| TEST_F(MatchSelectPatternTest, SimpleFMax) { |
| parseAssembly( |
| "define float @test(float %a) {\n" |
| " %1 = fcmp ogt float %a, 5.0\n" |
| " %A = select i1 %1, float %a, float 5.0\n" |
| " ret float %A\n" |
| "}\n"); |
| expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, true}); |
| } |
| |
| TEST_F(MatchSelectPatternTest, SwappedFMax) { |
| parseAssembly( |
| "define float @test(float %a) {\n" |
| " %1 = fcmp olt float 5.0, %a\n" |
| " %A = select i1 %1, float %a, float 5.0\n" |
| " ret float %A\n" |
| "}\n"); |
| expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, false}); |
| } |
| |
| TEST_F(MatchSelectPatternTest, SwappedFMax2) { |
| parseAssembly( |
| "define float @test(float %a) {\n" |
| " %1 = fcmp olt float %a, 5.0\n" |
| " %A = select i1 %1, float 5.0, float %a\n" |
| " ret float %A\n" |
| "}\n"); |
| expectPattern({SPF_FMAXNUM, SPNB_RETURNS_NAN, false}); |
| } |
| |
| TEST_F(MatchSelectPatternTest, SwappedFMax3) { |
| parseAssembly( |
| "define float @test(float %a) {\n" |
| " %1 = fcmp ult float %a, 5.0\n" |
| " %A = select i1 %1, float 5.0, float %a\n" |
| " ret float %A\n" |
| "}\n"); |
| expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, true}); |
| } |
| |
| TEST_F(MatchSelectPatternTest, FastFMin) { |
| parseAssembly( |
| "define float @test(float %a) {\n" |
| " %1 = fcmp nnan olt float %a, 5.0\n" |
| " %A = select i1 %1, float %a, float 5.0\n" |
| " ret float %A\n" |
| "}\n"); |
| expectPattern({SPF_FMINNUM, SPNB_RETURNS_ANY, false}); |
| } |
| |
| TEST_F(MatchSelectPatternTest, FMinConstantZero) { |
| parseAssembly( |
| "define float @test(float %a) {\n" |
| " %1 = fcmp ole float %a, 0.0\n" |
| " %A = select i1 %1, float %a, float 0.0\n" |
| " ret float %A\n" |
| "}\n"); |
| // This shouldn't be matched, as %a could be -0.0. |
| expectPattern({SPF_UNKNOWN, SPNB_NA, false}); |
| } |
| |
| TEST_F(MatchSelectPatternTest, FMinConstantZeroNsz) { |
| parseAssembly( |
| "define float @test(float %a) {\n" |
| " %1 = fcmp nsz ole float %a, 0.0\n" |
| " %A = select i1 %1, float %a, float 0.0\n" |
| " ret float %A\n" |
| "}\n"); |
| // But this should be, because we've ignored signed zeroes. |
| expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, true}); |
| } |
| |
| TEST_F(MatchSelectPatternTest, DoubleCastU) { |
| parseAssembly( |
| "define i32 @test(i8 %a, i8 %b) {\n" |
| " %1 = icmp ult i8 %a, %b\n" |
| " %2 = zext i8 %a to i32\n" |
| " %3 = zext i8 %b to i32\n" |
| " %A = select i1 %1, i32 %2, i32 %3\n" |
| " ret i32 %A\n" |
| "}\n"); |
| // We should be able to look through the situation where we cast both operands |
| // to the select. |
| expectPattern({SPF_UMIN, SPNB_NA, false}); |
| } |
| |
| TEST_F(MatchSelectPatternTest, DoubleCastS) { |
| parseAssembly( |
| "define i32 @test(i8 %a, i8 %b) {\n" |
| " %1 = icmp slt i8 %a, %b\n" |
| " %2 = sext i8 %a to i32\n" |
| " %3 = sext i8 %b to i32\n" |
| " %A = select i1 %1, i32 %2, i32 %3\n" |
| " ret i32 %A\n" |
| "}\n"); |
| // We should be able to look through the situation where we cast both operands |
| // to the select. |
| expectPattern({SPF_SMIN, SPNB_NA, false}); |
| } |
| |
| TEST_F(MatchSelectPatternTest, DoubleCastBad) { |
| parseAssembly( |
| "define i32 @test(i8 %a, i8 %b) {\n" |
| " %1 = icmp ult i8 %a, %b\n" |
| " %2 = zext i8 %a to i32\n" |
| " %3 = sext i8 %b to i32\n" |
| " %A = select i1 %1, i32 %2, i32 %3\n" |
| " ret i32 %A\n" |
| "}\n"); |
| // The cast types here aren't the same, so we cannot match an UMIN. |
| expectPattern({SPF_UNKNOWN, SPNB_NA, false}); |
| } |
| |
| TEST(ValueTracking, GuaranteedToTransferExecutionToSuccessor) { |
| StringRef Assembly = |
| "declare void @nounwind_readonly(i32*) nounwind readonly " |
| "declare void @nounwind_argmemonly(i32*) nounwind argmemonly " |
| "declare void @throws_but_readonly(i32*) readonly " |
| "declare void @throws_but_argmemonly(i32*) argmemonly " |
| " " |
| "declare void @unknown(i32*) " |
| " " |
| "define void @f(i32* %p) { " |
| " call void @nounwind_readonly(i32* %p) " |
| " call void @nounwind_argmemonly(i32* %p) " |
| " call void @throws_but_readonly(i32* %p) " |
| " call void @throws_but_argmemonly(i32* %p) " |
| " call void @unknown(i32* %p) nounwind readonly " |
| " call void @unknown(i32* %p) nounwind argmemonly " |
| " call void @unknown(i32* %p) readonly " |
| " call void @unknown(i32* %p) argmemonly " |
| " ret void " |
| "} "; |
| |
| LLVMContext Context; |
| SMDiagnostic Error; |
| auto M = parseAssemblyString(Assembly, Error, Context); |
| assert(M && "Bad assembly?"); |
| |
| auto *F = M->getFunction("f"); |
| assert(F && "Bad assembly?"); |
| |
| auto &BB = F->getEntryBlock(); |
| bool ExpectedAnswers[] = { |
| true, // call void @nounwind_readonly(i32* %p) |
| true, // call void @nounwind_argmemonly(i32* %p) |
| false, // call void @throws_but_readonly(i32* %p) |
| false, // call void @throws_but_argmemonly(i32* %p) |
| true, // call void @unknown(i32* %p) nounwind readonly |
| true, // call void @unknown(i32* %p) nounwind argmemonly |
| false, // call void @unknown(i32* %p) readonly |
| false, // call void @unknown(i32* %p) argmemonly |
| false, // ret void |
| }; |
| |
| int Index = 0; |
| for (auto &I : BB) { |
| EXPECT_EQ(isGuaranteedToTransferExecutionToSuccessor(&I), |
| ExpectedAnswers[Index]) |
| << "Incorrect answer at instruction " << Index << " = " << I; |
| Index++; |
| } |
| } |
| |
| TEST(ValueTracking, ComputeNumSignBits_PR32045) { |
| StringRef Assembly = "define i32 @f(i32 %a) { " |
| " %val = ashr i32 %a, -1 " |
| " ret i32 %val " |
| "} "; |
| |
| LLVMContext Context; |
| SMDiagnostic Error; |
| auto M = parseAssemblyString(Assembly, Error, Context); |
| assert(M && "Bad assembly?"); |
| |
| auto *F = M->getFunction("f"); |
| assert(F && "Bad assembly?"); |
| |
| auto *RVal = |
| cast<ReturnInst>(F->getEntryBlock().getTerminator())->getOperand(0); |
| EXPECT_EQ(ComputeNumSignBits(RVal, M->getDataLayout()), 1u); |
| } |
| |
| TEST(ValueTracking, ComputeKnownBits) { |
| StringRef Assembly = "define i32 @f(i32 %a, i32 %b) { " |
| " %ash = mul i32 %a, 8 " |
| " %aad = add i32 %ash, 7 " |
| " %aan = and i32 %aad, 4095 " |
| " %bsh = shl i32 %b, 4 " |
| " %bad = or i32 %bsh, 6 " |
| " %ban = and i32 %bad, 4095 " |
| " %mul = mul i32 %aan, %ban " |
| " ret i32 %mul " |
| "} "; |
| |
| LLVMContext Context; |
| SMDiagnostic Error; |
| auto M = parseAssemblyString(Assembly, Error, Context); |
| assert(M && "Bad assembly?"); |
| |
| auto *F = M->getFunction("f"); |
| assert(F && "Bad assembly?"); |
| |
| auto *RVal = |
| cast<ReturnInst>(F->getEntryBlock().getTerminator())->getOperand(0); |
| auto Known = computeKnownBits(RVal, M->getDataLayout()); |
| ASSERT_FALSE(Known.hasConflict()); |
| EXPECT_EQ(Known.One.getZExtValue(), 10u); |
| EXPECT_EQ(Known.Zero.getZExtValue(), 4278190085u); |
| } |
| |
| TEST(ValueTracking, ComputeKnownMulBits) { |
| StringRef Assembly = "define i32 @f(i32 %a, i32 %b) { " |
| " %aa = shl i32 %a, 5 " |
| " %bb = shl i32 %b, 5 " |
| " %aaa = or i32 %aa, 24 " |
| " %bbb = or i32 %bb, 28 " |
| " %mul = mul i32 %aaa, %bbb " |
| " ret i32 %mul " |
| "} "; |
| |
| LLVMContext Context; |
| SMDiagnostic Error; |
| auto M = parseAssemblyString(Assembly, Error, Context); |
| assert(M && "Bad assembly?"); |
| |
| auto *F = M->getFunction("f"); |
| assert(F && "Bad assembly?"); |
| |
| auto *RVal = |
| cast<ReturnInst>(F->getEntryBlock().getTerminator())->getOperand(0); |
| auto Known = computeKnownBits(RVal, M->getDataLayout()); |
| ASSERT_FALSE(Known.hasConflict()); |
| EXPECT_EQ(Known.One.getZExtValue(), 32u); |
| EXPECT_EQ(Known.Zero.getZExtValue(), 95u); |
| } |
