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llvm-project/llvm/unittests/Analysis/ValueTrackingTest.cpp

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//===- ValueTrackingTest.cpp - ValueTracking tests ------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/KnownBits.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Transforms/Utils/Local.h"
#include "gtest/gtest.h"
using namespace llvm;
namespace {
static Instruction *findInstructionByNameOrNull(Function *F, StringRef Name) {
for (Instruction &I : instructions(F))
if (I.getName() == Name)
return &I;
return nullptr;
}
static Instruction &findInstructionByName(Function *F, StringRef Name) {
auto *I = findInstructionByNameOrNull(F, Name);
if (I)
return *I;
llvm_unreachable("Expected value not found");
}
class ValueTrackingTest : public testing::Test {
protected:
std::unique_ptr<Module> parseModule(StringRef Assembly) {
SMDiagnostic Error;
std::unique_ptr<Module> M = parseAssemblyString(Assembly, Error, Context);
std::string errMsg;
raw_string_ostream os(errMsg);
Error.print("", os);
EXPECT_TRUE(M) << os.str();
return M;
}
void parseAssembly(StringRef Assembly) {
M = parseModule(Assembly);
ASSERT_TRUE(M);
F = M->getFunction("test");
ASSERT_TRUE(F) << "Test must have a function @test";
if (!F)
return;
A = findInstructionByNameOrNull(F, "A");
ASSERT_TRUE(A) << "@test must have an instruction %A";
CxtI = findInstructionByNameOrNull(F, "CxtI");
CxtI2 = findInstructionByNameOrNull(F, "CxtI2");
CxtI3 = findInstructionByNameOrNull(F, "CxtI3");
}
LLVMContext Context;
std::unique_ptr<Module> M;
Function *F = nullptr;
Instruction *A = nullptr;
// Context instructions (optional)
Instruction *CxtI = nullptr, *CxtI2 = nullptr, *CxtI3 = nullptr;
};
class MatchSelectPatternTest : public ValueTrackingTest {
protected:
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);
}
};
class ComputeKnownBitsTest : public ValueTrackingTest {
protected:
void expectKnownBits(uint64_t Zero, uint64_t One) {
auto Known = computeKnownBits(A, M->getDataLayout());
ASSERT_FALSE(Known.hasConflict());
EXPECT_EQ(Known.One.getZExtValue(), One);
EXPECT_EQ(Known.Zero.getZExtValue(), Zero);
}
};
}
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, FMinMismatchConstantZero1) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp olt float -0.0, %a\n"
" %A = select i1 %1, float 0.0, float %a\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, true});
}
TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero2) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp ogt float %a, -0.0\n"
" %A = select i1 %1, float 0.0, float %a\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, false});
}
TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero3) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp olt float 0.0, %a\n"
" %A = select i1 %1, float -0.0, float %a\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, true});
}
TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero4) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp ogt float %a, 0.0\n"
" %A = select i1 %1, float -0.0, float %a\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, false});
}
TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero5) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp ogt float -0.0, %a\n"
" %A = select i1 %1, float %a, float 0.0\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, false});
}
TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero6) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp olt float %a, -0.0\n"
" %A = select i1 %1, float %a, float 0.0\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, true});
}
TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero7) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp ogt float 0.0, %a\n"
" %A = select i1 %1, float %a, float -0.0\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, false});
}
TEST_F(MatchSelectPatternTest, FMinMismatchConstantZero8) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp olt float %a, 0.0\n"
" %A = select i1 %1, float %a, float -0.0\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, true});
}
TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero1) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp ogt float -0.0, %a\n"
" %A = select i1 %1, float 0.0, float %a\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMAXNUM, SPNB_RETURNS_NAN, true});
}
TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero2) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp olt float %a, -0.0\n"
" %A = select i1 %1, float 0.0, float %a\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMAXNUM, SPNB_RETURNS_NAN, false});
}
TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero3) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp ogt float 0.0, %a\n"
" %A = select i1 %1, float -0.0, float %a\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMAXNUM, SPNB_RETURNS_NAN, true});
}
TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero4) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp olt float %a, 0.0\n"
" %A = select i1 %1, float -0.0, float %a\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMAXNUM, SPNB_RETURNS_NAN, false});
}
TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero5) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp olt float -0.0, %a\n"
" %A = select i1 %1, float %a, float 0.0\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, false});
}
TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero6) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp ogt float %a, -0.0\n"
" %A = select i1 %1, float %a, float 0.0\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, true});
}
TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero7) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp olt float 0.0, %a\n"
" %A = select i1 %1, float %a, float -0.0\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, false});
}
TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZero8) {
parseAssembly(
"define float @test(float %a) {\n"
" %1 = fcmp ogt float %a, 0.0\n"
" %A = select i1 %1, float %a, float -0.0\n"
" ret float %A\n"
"}\n");
// The sign of zero doesn't matter in fcmp.
expectPattern({SPF_FMAXNUM, SPNB_RETURNS_OTHER, true});
}
TEST_F(MatchSelectPatternTest, FMinMismatchConstantZeroVecUndef) {
parseAssembly(
"define <2 x float> @test(<2 x float> %a) {\n"
" %1 = fcmp ogt <2 x float> %a, <float -0.0, float -0.0>\n"
" %A = select <2 x i1> %1, <2 x float> <float undef, float 0.0>, <2 x float> %a\n"
" ret <2 x float> %A\n"
"}\n");
// An undef in a vector constant can not be back-propagated for this analysis.
expectPattern({SPF_UNKNOWN, SPNB_NA, false});
}
TEST_F(MatchSelectPatternTest, FMaxMismatchConstantZeroVecUndef) {
parseAssembly(
"define <2 x float> @test(<2 x float> %a) {\n"
" %1 = fcmp ogt <2 x float> %a, zeroinitializer\n"
" %A = select <2 x i1> %1, <2 x float> %a, <2 x float> <float -0.0, float undef>\n"
" ret <2 x float> %A\n"
"}\n");
// An undef in a vector constant can not be back-propagated for this analysis.
expectPattern({SPF_UNKNOWN, SPNB_NA, false});
}
TEST_F(MatchSelectPatternTest, VectorFMinimum) {
parseAssembly(
"define <4 x float> @test(<4 x float> %a) {\n"
" %1 = fcmp ule <4 x float> %a, \n"
" <float 5.0, float 5.0, float 5.0, float 5.0>\n"
" %A = select <4 x i1> %1, <4 x float> %a,\n"
" <4 x float> <float 5.0, float 5.0, float 5.0, float 5.0>\n"
" ret <4 x float> %A\n"
"}\n");
// Check that pattern matching works on vectors where each lane has the same
// unordered pattern.
expectPattern({SPF_FMINNUM, SPNB_RETURNS_NAN, false});
}
TEST_F(MatchSelectPatternTest, VectorFMinOtherOrdered) {
parseAssembly(
"define <4 x float> @test(<4 x float> %a) {\n"
" %1 = fcmp ole <4 x float> %a, \n"
" <float 5.0, float 5.0, float 5.0, float 5.0>\n"
" %A = select <4 x i1> %1, <4 x float> %a,\n"
" <4 x float> <float 5.0, float 5.0, float 5.0, float 5.0>\n"
" ret <4 x float> %A\n"
"}\n");
// Check that pattern matching works on vectors where each lane has the same
// ordered pattern.
expectPattern({SPF_FMINNUM, SPNB_RETURNS_OTHER, true});
}
TEST_F(MatchSelectPatternTest, VectorNotFMinimum) {
parseAssembly(
"define <4 x float> @test(<4 x float> %a) {\n"
" %1 = fcmp ule <4 x float> %a, \n"
" <float 5.0, float 0x7ff8000000000000, float 5.0, float 5.0>\n"
" %A = select <4 x i1> %1, <4 x float> %a,\n"
" <4 x float> <float 5.0, float 0x7ff8000000000000, float 5.0, float "
"5.0>\n"
" ret <4 x float> %A\n"
"}\n");
// The lane that contains a NaN (0x7ff80...) behaves like a
// non-NaN-propagating min and the other lines behave like a NaN-propagating
// min, so check that neither is returned.
expectPattern({SPF_UNKNOWN, SPNB_NA, false});
}
TEST_F(MatchSelectPatternTest, VectorNotFMinZero) {
parseAssembly(
"define <4 x float> @test(<4 x float> %a) {\n"
" %1 = fcmp ule <4 x float> %a, \n"
" <float 5.0, float -0.0, float 5.0, float 5.0>\n"
" %A = select <4 x i1> %1, <4 x float> %a,\n"
" <4 x float> <float 5.0, float 0.0, float 5.0, float 5.0>\n"
" ret <4 x float> %A\n"
"}\n");
// Always selects the second lane of %a if it is positive or negative zero, so
// this is stricter than a min.
expectPattern({SPF_UNKNOWN, SPNB_NA, false});
}
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_F(MatchSelectPatternTest, NotNotSMin) {
parseAssembly(
"define i8 @test(i8 %a, i8 %b) {\n"
" %cmp = icmp sgt i8 %a, %b\n"
" %an = xor i8 %a, -1\n"
" %bn = xor i8 %b, -1\n"
" %A = select i1 %cmp, i8 %an, i8 %bn\n"
" ret i8 %A\n"
"}\n");
expectPattern({SPF_SMIN, SPNB_NA, false});
}
TEST_F(MatchSelectPatternTest, NotNotSMinSwap) {
parseAssembly(
"define <2 x i8> @test(<2 x i8> %a, <2 x i8> %b) {\n"
" %cmp = icmp slt <2 x i8> %a, %b\n"
" %an = xor <2 x i8> %a, <i8 -1, i8-1>\n"
" %bn = xor <2 x i8> %b, <i8 -1, i8-1>\n"
" %A = select <2 x i1> %cmp, <2 x i8> %bn, <2 x i8> %an\n"
" ret <2 x i8> %A\n"
"}\n");
expectPattern({SPF_SMIN, SPNB_NA, false});
}
TEST_F(MatchSelectPatternTest, NotNotSMax) {
parseAssembly(
"define i8 @test(i8 %a, i8 %b) {\n"
" %cmp = icmp slt i8 %a, %b\n"
" %an = xor i8 %a, -1\n"
" %bn = xor i8 %b, -1\n"
" %A = select i1 %cmp, i8 %an, i8 %bn\n"
" ret i8 %A\n"
"}\n");
expectPattern({SPF_SMAX, SPNB_NA, false});
}
TEST_F(MatchSelectPatternTest, NotNotSMaxSwap) {
parseAssembly(
"define <2 x i8> @test(<2 x i8> %a, <2 x i8> %b) {\n"
" %cmp = icmp sgt <2 x i8> %a, %b\n"
" %an = xor <2 x i8> %a, <i8 -1, i8-1>\n"
" %bn = xor <2 x i8> %b, <i8 -1, i8-1>\n"
" %A = select <2 x i1> %cmp, <2 x i8> %bn, <2 x i8> %an\n"
" ret <2 x i8> %A\n"
"}\n");
expectPattern({SPF_SMAX, SPNB_NA, false});
}
TEST_F(MatchSelectPatternTest, NotNotUMin) {
parseAssembly(
"define <2 x i8> @test(<2 x i8> %a, <2 x i8> %b) {\n"
" %cmp = icmp ugt <2 x i8> %a, %b\n"
" %an = xor <2 x i8> %a, <i8 -1, i8-1>\n"
" %bn = xor <2 x i8> %b, <i8 -1, i8-1>\n"
" %A = select <2 x i1> %cmp, <2 x i8> %an, <2 x i8> %bn\n"
" ret <2 x i8> %A\n"
"}\n");
expectPattern({SPF_UMIN, SPNB_NA, false});
}
TEST_F(MatchSelectPatternTest, NotNotUMinSwap) {
parseAssembly(
"define i8 @test(i8 %a, i8 %b) {\n"
" %cmp = icmp ult i8 %a, %b\n"
" %an = xor i8 %a, -1\n"
" %bn = xor i8 %b, -1\n"
" %A = select i1 %cmp, i8 %bn, i8 %an\n"
" ret i8 %A\n"
"}\n");
expectPattern({SPF_UMIN, SPNB_NA, false});
}
TEST_F(MatchSelectPatternTest, NotNotUMax) {
parseAssembly(
"define <2 x i8> @test(<2 x i8> %a, <2 x i8> %b) {\n"
" %cmp = icmp ult <2 x i8> %a, %b\n"
" %an = xor <2 x i8> %a, <i8 -1, i8-1>\n"
" %bn = xor <2 x i8> %b, <i8 -1, i8-1>\n"
" %A = select <2 x i1> %cmp, <2 x i8> %an, <2 x i8> %bn\n"
" ret <2 x i8> %A\n"
"}\n");
expectPattern({SPF_UMAX, SPNB_NA, false});
}
TEST_F(MatchSelectPatternTest, NotNotUMaxSwap) {
parseAssembly(
"define i8 @test(i8 %a, i8 %b) {\n"
" %cmp = icmp ugt i8 %a, %b\n"
" %an = xor i8 %a, -1\n"
" %bn = xor i8 %b, -1\n"
" %A = select i1 %cmp, i8 %bn, i8 %an\n"
" ret i8 %A\n"
"}\n");
expectPattern({SPF_UMAX, SPNB_NA, false});
}
TEST_F(MatchSelectPatternTest, NotNotEq) {
parseAssembly(
"define i8 @test(i8 %a, i8 %b) {\n"
" %cmp = icmp eq i8 %a, %b\n"
" %an = xor i8 %a, -1\n"
" %bn = xor i8 %b, -1\n"
" %A = select i1 %cmp, i8 %bn, i8 %an\n"
" ret i8 %A\n"
"}\n");
expectPattern({SPF_UNKNOWN, SPNB_NA, false});
}
TEST_F(MatchSelectPatternTest, NotNotNe) {
parseAssembly(
"define i8 @test(i8 %a, i8 %b) {\n"
" %cmp = icmp ne i8 %a, %b\n"
" %an = xor i8 %a, -1\n"
" %bn = xor i8 %b, -1\n"
" %A = select i1 %cmp, i8 %bn, i8 %an\n"
" ret i8 %A\n"
"}\n");
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 @nounwind_willreturn(i32*) nounwind willreturn"
" "
"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 "
" call void @nounwind_willreturn(i32* %p)"
" 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
true, // call void @nounwind_willreturn(i32* %p)
false, // ret void
};
int Index = 0;
for (auto &I : BB) {
EXPECT_EQ(isGuaranteedToTransferExecutionToSuccessor(&I),
ExpectedAnswers[Index])
<< "Incorrect answer at instruction " << Index << " = " << I;
Index++;
}
}
TEST_F(ValueTrackingTest, ComputeNumSignBits_PR32045) {
parseAssembly(
"define i32 @test(i32 %a) {\n"
" %A = ashr i32 %a, -1\n"
" ret i32 %A\n"
"}\n");
EXPECT_EQ(ComputeNumSignBits(A, M->getDataLayout()), 1u);
}
// No guarantees for canonical IR in this analysis, so this just bails out.
TEST_F(ValueTrackingTest, ComputeNumSignBits_Shuffle) {
parseAssembly(
"define <2 x i32> @test() {\n"
" %A = shufflevector <2 x i32> undef, <2 x i32> undef, <2 x i32> <i32 0, i32 0>\n"
" ret <2 x i32> %A\n"
"}\n");
EXPECT_EQ(ComputeNumSignBits(A, M->getDataLayout()), 1u);
}
// No guarantees for canonical IR in this analysis, so a shuffle element that
// references an undef value means this can't return any extra information.
TEST_F(ValueTrackingTest, ComputeNumSignBits_Shuffle2) {
parseAssembly(
"define <2 x i32> @test(<2 x i1> %x) {\n"
" %sext = sext <2 x i1> %x to <2 x i32>\n"
" %A = shufflevector <2 x i32> %sext, <2 x i32> undef, <2 x i32> <i32 0, i32 2>\n"
" ret <2 x i32> %A\n"
"}\n");
EXPECT_EQ(ComputeNumSignBits(A, M->getDataLayout()), 1u);
}
TEST(ValueTracking, propagatesPoison) {
std::string AsmHead = "declare i32 @g(i32)\n"
"define void @f(i32 %x, i32 %y, float %fx, float %fy, "
"i1 %cond, i8* %p) {\n";
std::string AsmTail = " ret void\n}";
// (propagates poison?, IR instruction)
SmallVector<std::pair<bool, std::string>, 32> Data = {
{true, "add i32 %x, %y"},
{true, "add nsw nuw i32 %x, %y"},
{true, "ashr i32 %x, %y"},
{true, "lshr exact i32 %x, 31"},
{true, "fcmp oeq float %fx, %fy"},
{true, "icmp eq i32 %x, %y"},
{true, "getelementptr i8, i8* %p, i32 %x"},
{true, "getelementptr inbounds i8, i8* %p, i32 %x"},
{true, "bitcast float %fx to i32"},
{false, "select i1 %cond, i32 %x, i32 %y"},
{false, "freeze i32 %x"},
{true, "udiv i32 %x, %y"},
{true, "urem i32 %x, %y"},
{true, "sdiv exact i32 %x, %y"},
{true, "srem i32 %x, %y"},
{false, "call i32 @g(i32 %x)"}};
std::string AssemblyStr = AsmHead;
for (auto &Itm : Data)
AssemblyStr += Itm.second + "\n";
AssemblyStr += AsmTail;
LLVMContext Context;
SMDiagnostic Error;
auto M = parseAssemblyString(AssemblyStr, Error, Context);
assert(M && "Bad assembly?");
auto *F = M->getFunction("f");
assert(F && "Bad assembly?");
auto &BB = F->getEntryBlock();
int Index = 0;
for (auto &I : BB) {
if (isa<ReturnInst>(&I))
break;
EXPECT_EQ(propagatesPoison(cast<Operator>(&I)), Data[Index].first)
<< "Incorrect answer at instruction " << Index << " = " << I;
Index++;
}
}
TEST_F(ValueTrackingTest, programUndefinedIfPoison) {
parseAssembly("declare i32 @any_num()"
"define void @test(i32 %mask) {\n"
" %A = call i32 @any_num()\n"
" %B = or i32 %A, %mask\n"
" udiv i32 1, %B"
" ret void\n"
"}\n");
// If %A was poison, udiv raises UB regardless of %mask's value
EXPECT_EQ(programUndefinedIfPoison(A), true);
}
TEST_F(ValueTrackingTest, programUndefinedIfUndefOrPoison) {
parseAssembly("declare i32 @any_num()"
"define void @test(i32 %mask) {\n"
" %A = call i32 @any_num()\n"
" %B = or i32 %A, %mask\n"
" udiv i32 1, %B"
" ret void\n"
"}\n");
// If %A was undef and %mask was 1, udiv does not raise UB
EXPECT_EQ(programUndefinedIfUndefOrPoison(A), false);
}
TEST_F(ValueTrackingTest, isGuaranteedNotToBePoison_exploitBranchCond) {
parseAssembly("declare i1 @any_bool()"
"define void @test(i1 %y) {\n"
" %A = call i1 @any_bool()\n"
" %cond = and i1 %A, %y\n"
" br i1 %cond, label %BB1, label %BB2\n"
"BB1:\n"
" ret void\n"
"BB2:\n"
" ret void\n"
"}\n");
DominatorTree DT(*F);
for (auto &BB : *F) {
if (&BB == &F->getEntryBlock())
continue;
EXPECT_EQ(isGuaranteedNotToBePoison(A, nullptr, BB.getTerminator(), &DT),
true)
<< "isGuaranteedNotToBePoison does not hold at " << *BB.getTerminator();
}
}
TEST_F(ValueTrackingTest, isGuaranteedNotToBePoison_phi) {
parseAssembly("declare i32 @any_i32(i32)"
"define void @test() {\n"
"ENTRY:\n"
" br label %LOOP\n"
"LOOP:\n"
" %A = phi i32 [0, %ENTRY], [%A.next, %NEXT]\n"
" %A.next = call i32 @any_i32(i32 %A)\n"
" %cond = icmp eq i32 %A.next, 0\n"
" br i1 %cond, label %NEXT, label %EXIT\n"
"NEXT:\n"
" br label %LOOP\n"
"EXIT:\n"
" ret void\n"
"}\n");
DominatorTree DT(*F);
for (auto &BB : *F) {
if (BB.getName() == "LOOP") {
EXPECT_EQ(isGuaranteedNotToBePoison(A, nullptr, A, &DT), true)
<< "isGuaranteedNotToBePoison does not hold";
}
}
}
TEST_F(ValueTrackingTest, isGuaranteedNotToBeUndefOrPoison) {
parseAssembly("declare void @f(i32 noundef)"
"define void @test(i32 %x) {\n"
" %A = bitcast i32 %x to i32\n"
" call void @f(i32 noundef %x)\n"
" ret void\n"
"}\n");
EXPECT_EQ(isGuaranteedNotToBeUndefOrPoison(A), true);
}
TEST_F(ValueTrackingTest, isGuaranteedNotToBeUndefOrPoison_assume) {
parseAssembly("declare i1 @f_i1()\n"
"declare i32 @f_i32()\n"
"declare void @llvm.assume(i1)\n"
"define void @test() {\n"
" %A = call i32 @f_i32()\n"
" %cond = call i1 @f_i1()\n"
" %CxtI = add i32 0, 0\n"
" br i1 %cond, label %BB1, label %EXIT\n"
"BB1:\n"
" %CxtI2 = add i32 0, 0\n"
" %cond2 = call i1 @f_i1()\n"
" call void @llvm.assume(i1 true) [ \"noundef\"(i32 %A) ]\n"
" br i1 %cond2, label %BB2, label %EXIT\n"
"BB2:\n"
" %CxtI3 = add i32 0, 0\n"
" ret void\n"
"EXIT:\n"
" ret void\n"
"}");
AssumptionCache AC(*F);
DominatorTree DT(*F);
EXPECT_FALSE(isGuaranteedNotToBeUndefOrPoison(A, &AC, CxtI, &DT));
EXPECT_FALSE(isGuaranteedNotToBeUndefOrPoison(A, &AC, CxtI2, &DT));
EXPECT_TRUE(isGuaranteedNotToBeUndefOrPoison(A, &AC, CxtI3, &DT));
}
TEST(ValueTracking, canCreatePoisonOrUndef) {
std::string AsmHead =
"declare i32 @g(i32)\n"
"define void @f(i32 %x, i32 %y, float %fx, float %fy, i1 %cond, "
"<4 x i32> %vx, <4 x i32> %vx2, <vscale x 4 x i32> %svx, i8* %p) {\n";
std::string AsmTail = " ret void\n}";
// (can create poison?, can create undef?, IR instruction)
SmallVector<std::pair<std::pair<bool, bool>, std::string>, 32> Data = {
{{false, false}, "add i32 %x, %y"},
{{true, false}, "add nsw nuw i32 %x, %y"},
{{true, false}, "shl i32 %x, %y"},
{{true, false}, "shl <4 x i32> %vx, %vx2"},
{{true, false}, "shl nsw i32 %x, %y"},
{{true, false}, "shl nsw <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 3>"},
{{false, false}, "shl i32 %x, 31"},
{{true, false}, "shl i32 %x, 32"},
{{false, false}, "shl <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 3>"},
{{true, false}, "shl <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 32>"},
{{true, false}, "ashr i32 %x, %y"},
{{true, false}, "ashr exact i32 %x, %y"},
{{false, false}, "ashr i32 %x, 31"},
{{true, false}, "ashr exact i32 %x, 31"},
{{false, false}, "ashr <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 3>"},
{{true, false}, "ashr <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 32>"},
{{true, false}, "ashr exact <4 x i32> %vx, <i32 0, i32 1, i32 2, i32 3>"},
{{true, false}, "lshr i32 %x, %y"},
{{true, false}, "lshr exact i32 %x, 31"},
{{false, false}, "udiv i32 %x, %y"},
{{true, false}, "udiv exact i32 %x, %y"},
{{false, false}, "getelementptr i8, i8* %p, i32 %x"},
{{true, false}, "getelementptr inbounds i8, i8* %p, i32 %x"},
{{true, false}, "fneg nnan float %fx"},
{{false, false}, "fneg float %fx"},
{{false, false}, "fadd float %fx, %fy"},
{{true, false}, "fadd nnan float %fx, %fy"},
{{false, false}, "urem i32 %x, %y"},
{{true, false}, "fptoui float %fx to i32"},
{{true, false}, "fptosi float %fx to i32"},
{{false, false}, "bitcast float %fx to i32"},
{{false, false}, "select i1 %cond, i32 %x, i32 %y"},
{{true, false}, "select nnan i1 %cond, float %fx, float %fy"},
{{true, false}, "extractelement <4 x i32> %vx, i32 %x"},
{{false, false}, "extractelement <4 x i32> %vx, i32 3"},
{{true, false}, "extractelement <vscale x 4 x i32> %svx, i32 4"},
{{true, false}, "insertelement <4 x i32> %vx, i32 %x, i32 %y"},
{{false, false}, "insertelement <4 x i32> %vx, i32 %x, i32 3"},
{{true, false}, "insertelement <vscale x 4 x i32> %svx, i32 %x, i32 4"},
{{false, false}, "freeze i32 %x"},
{{false, false},
"shufflevector <4 x i32> %vx, <4 x i32> %vx2, "
"<4 x i32> <i32 0, i32 1, i32 2, i32 3>"},
{{false, true},
"shufflevector <4 x i32> %vx, <4 x i32> %vx2, "
"<4 x i32> <i32 0, i32 1, i32 2, i32 undef>"},
{{false, true},
"shufflevector <vscale x 4 x i32> %svx, "
"<vscale x 4 x i32> %svx, <vscale x 4 x i32> undef"},
{{true, false}, "call i32 @g(i32 %x)"},
{{false, false}, "call noundef i32 @g(i32 %x)"},
{{true, false}, "fcmp nnan oeq float %fx, %fy"},
{{false, false}, "fcmp oeq float %fx, %fy"}};
std::string AssemblyStr = AsmHead;
for (auto &Itm : Data)
AssemblyStr += Itm.second + "\n";
AssemblyStr += AsmTail;
LLVMContext Context;
SMDiagnostic Error;
auto M = parseAssemblyString(AssemblyStr, Error, Context);
assert(M && "Bad assembly?");
auto *F = M->getFunction("f");
assert(F && "Bad assembly?");
auto &BB = F->getEntryBlock();
int Index = 0;
for (auto &I : BB) {
if (isa<ReturnInst>(&I))
break;
bool Poison = Data[Index].first.first;
bool Undef = Data[Index].first.second;
EXPECT_EQ(canCreatePoison(cast<Operator>(&I)), Poison)
<< "Incorrect answer of canCreatePoison at instruction " << Index
<< " = " << I;
EXPECT_EQ(canCreateUndefOrPoison(cast<Operator>(&I)), Undef || Poison)
<< "Incorrect answer of canCreateUndef at instruction " << Index
<< " = " << I;
Index++;
}
}
TEST_F(ValueTrackingTest, computePtrAlignment) {
parseAssembly("declare i1 @f_i1()\n"
"declare i8* @f_i8p()\n"
"declare void @llvm.assume(i1)\n"
"define void @test() {\n"
" %A = call i8* @f_i8p()\n"
" %cond = call i1 @f_i1()\n"
" %CxtI = add i32 0, 0\n"
" br i1 %cond, label %BB1, label %EXIT\n"
"BB1:\n"
" %CxtI2 = add i32 0, 0\n"
" %cond2 = call i1 @f_i1()\n"
" call void @llvm.assume(i1 true) [ \"align\"(i8* %A, i64 16) ]\n"
" br i1 %cond2, label %BB2, label %EXIT\n"
"BB2:\n"
" %CxtI3 = add i32 0, 0\n"
" ret void\n"
"EXIT:\n"
" ret void\n"
"}");
AssumptionCache AC(*F);
DominatorTree DT(*F);
DataLayout DL = M->getDataLayout();
EXPECT_EQ(getKnownAlignment(A, DL, CxtI, &AC, &DT), Align(1));
EXPECT_EQ(getKnownAlignment(A, DL, CxtI2, &AC, &DT), Align(1));
EXPECT_EQ(getKnownAlignment(A, DL, CxtI3, &AC, &DT), Align(16));
}
TEST_F(ComputeKnownBitsTest, ComputeKnownBits) {
parseAssembly(
"define i32 @test(i32 %a, i32 %b) {\n"
" %ash = mul i32 %a, 8\n"
" %aad = add i32 %ash, 7\n"
" %aan = and i32 %aad, 4095\n"
" %bsh = shl i32 %b, 4\n"
" %bad = or i32 %bsh, 6\n"
" %ban = and i32 %bad, 4095\n"
" %A = mul i32 %aan, %ban\n"
" ret i32 %A\n"
"}\n");
expectKnownBits(/*zero*/ 4278190085u, /*one*/ 10u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownMulBits) {
parseAssembly(
"define i32 @test(i32 %a, i32 %b) {\n"
" %aa = shl i32 %a, 5\n"
" %bb = shl i32 %b, 5\n"
" %aaa = or i32 %aa, 24\n"
" %bbb = or i32 %bb, 28\n"
" %A = mul i32 %aaa, %bbb\n"
" ret i32 %A\n"
"}\n");
expectKnownBits(/*zero*/ 95u, /*one*/ 32u);
}
TEST_F(ComputeKnownBitsTest, KnownNonZeroShift) {
// %q is known nonzero without known bits.
// Because %q is nonzero, %A[0] is known to be zero.
parseAssembly(
"define i8 @test(i8 %p, i8* %pq) {\n"
" %q = load i8, i8* %pq, !range !0\n"
" %A = shl i8 %p, %q\n"
" ret i8 %A\n"
"}\n"
"!0 = !{ i8 1, i8 5 }\n");
expectKnownBits(/*zero*/ 1u, /*one*/ 0u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownFshl) {
// fshl(....1111....0000, 00..1111........, 6)
// = 11....000000..11
parseAssembly(
"define i16 @test(i16 %a, i16 %b) {\n"
" %aa = shl i16 %a, 4\n"
" %bb = lshr i16 %b, 2\n"
" %aaa = or i16 %aa, 3840\n"
" %bbb = or i16 %bb, 3840\n"
" %A = call i16 @llvm.fshl.i16(i16 %aaa, i16 %bbb, i16 6)\n"
" ret i16 %A\n"
"}\n"
"declare i16 @llvm.fshl.i16(i16, i16, i16)\n");
expectKnownBits(/*zero*/ 1008u, /*one*/ 49155u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownFshr) {
// fshr(....1111....0000, 00..1111........, 26)
// = 11....000000..11
parseAssembly(
"define i16 @test(i16 %a, i16 %b) {\n"
" %aa = shl i16 %a, 4\n"
" %bb = lshr i16 %b, 2\n"
" %aaa = or i16 %aa, 3840\n"
" %bbb = or i16 %bb, 3840\n"
" %A = call i16 @llvm.fshr.i16(i16 %aaa, i16 %bbb, i16 26)\n"
" ret i16 %A\n"
"}\n"
"declare i16 @llvm.fshr.i16(i16, i16, i16)\n");
expectKnownBits(/*zero*/ 1008u, /*one*/ 49155u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownFshlZero) {
// fshl(....1111....0000, 00..1111........, 0)
// = ....1111....0000
parseAssembly(
"define i16 @test(i16 %a, i16 %b) {\n"
" %aa = shl i16 %a, 4\n"
" %bb = lshr i16 %b, 2\n"
" %aaa = or i16 %aa, 3840\n"
" %bbb = or i16 %bb, 3840\n"
" %A = call i16 @llvm.fshl.i16(i16 %aaa, i16 %bbb, i16 0)\n"
" ret i16 %A\n"
"}\n"
"declare i16 @llvm.fshl.i16(i16, i16, i16)\n");
expectKnownBits(/*zero*/ 15u, /*one*/ 3840u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownUAddSatLeadingOnes) {
// uadd.sat(1111...1, ........)
// = 1111....
parseAssembly(
"define i8 @test(i8 %a, i8 %b) {\n"
" %aa = or i8 %a, 241\n"
" %A = call i8 @llvm.uadd.sat.i8(i8 %aa, i8 %b)\n"
" ret i8 %A\n"
"}\n"
"declare i8 @llvm.uadd.sat.i8(i8, i8)\n");
expectKnownBits(/*zero*/ 0u, /*one*/ 240u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownUAddSatOnesPreserved) {
// uadd.sat(00...011, .1...110)
// = .......1
parseAssembly(
"define i8 @test(i8 %a, i8 %b) {\n"
" %aa = or i8 %a, 3\n"
" %aaa = and i8 %aa, 59\n"
" %bb = or i8 %b, 70\n"
" %bbb = and i8 %bb, 254\n"
" %A = call i8 @llvm.uadd.sat.i8(i8 %aaa, i8 %bbb)\n"
" ret i8 %A\n"
"}\n"
"declare i8 @llvm.uadd.sat.i8(i8, i8)\n");
expectKnownBits(/*zero*/ 0u, /*one*/ 1u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownUSubSatLHSLeadingZeros) {
// usub.sat(0000...0, ........)
// = 0000....
parseAssembly(
"define i8 @test(i8 %a, i8 %b) {\n"
" %aa = and i8 %a, 14\n"
" %A = call i8 @llvm.usub.sat.i8(i8 %aa, i8 %b)\n"
" ret i8 %A\n"
"}\n"
"declare i8 @llvm.usub.sat.i8(i8, i8)\n");
expectKnownBits(/*zero*/ 240u, /*one*/ 0u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownUSubSatRHSLeadingOnes) {
// usub.sat(........, 1111...1)
// = 0000....
parseAssembly(
"define i8 @test(i8 %a, i8 %b) {\n"
" %bb = or i8 %a, 241\n"
" %A = call i8 @llvm.usub.sat.i8(i8 %a, i8 %bb)\n"
" ret i8 %A\n"
"}\n"
"declare i8 @llvm.usub.sat.i8(i8, i8)\n");
expectKnownBits(/*zero*/ 240u, /*one*/ 0u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownUSubSatZerosPreserved) {
// usub.sat(11...011, .1...110)
// = ......0.
parseAssembly(
"define i8 @test(i8 %a, i8 %b) {\n"
" %aa = or i8 %a, 195\n"
" %aaa = and i8 %aa, 251\n"
" %bb = or i8 %b, 70\n"
" %bbb = and i8 %bb, 254\n"
" %A = call i8 @llvm.usub.sat.i8(i8 %aaa, i8 %bbb)\n"
" ret i8 %A\n"
"}\n"
"declare i8 @llvm.usub.sat.i8(i8, i8)\n");
expectKnownBits(/*zero*/ 2u, /*one*/ 0u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownBitsPtrToIntTrunc) {
// ptrtoint truncates the pointer type.
parseAssembly(
"define void @test(i8** %p) {\n"
" %A = load i8*, i8** %p\n"
" %i = ptrtoint i8* %A to i32\n"
" %m = and i32 %i, 31\n"
" %c = icmp eq i32 %m, 0\n"
" call void @llvm.assume(i1 %c)\n"
" ret void\n"
"}\n"
"declare void @llvm.assume(i1)\n");
AssumptionCache AC(*F);
KnownBits Known = computeKnownBits(
A, M->getDataLayout(), /* Depth */ 0, &AC, F->front().getTerminator());
EXPECT_EQ(Known.Zero.getZExtValue(), 31u);
EXPECT_EQ(Known.One.getZExtValue(), 0u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownBitsPtrToIntZext) {
// ptrtoint zero extends the pointer type.
parseAssembly(
"define void @test(i8** %p) {\n"
" %A = load i8*, i8** %p\n"
" %i = ptrtoint i8* %A to i128\n"
" %m = and i128 %i, 31\n"
" %c = icmp eq i128 %m, 0\n"
" call void @llvm.assume(i1 %c)\n"
" ret void\n"
"}\n"
"declare void @llvm.assume(i1)\n");
AssumptionCache AC(*F);
KnownBits Known = computeKnownBits(
A, M->getDataLayout(), /* Depth */ 0, &AC, F->front().getTerminator());
EXPECT_EQ(Known.Zero.getZExtValue(), 31u);
EXPECT_EQ(Known.One.getZExtValue(), 0u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownBitsFreeze) {
parseAssembly("define void @test() {\n"
" %m = call i32 @any_num()\n"
" %A = freeze i32 %m\n"
" %n = and i32 %m, 31\n"
" %c = icmp eq i32 %n, 0\n"
" call void @llvm.assume(i1 %c)\n"
" ret void\n"
"}\n"
"declare void @llvm.assume(i1)\n"
"declare i32 @any_num()\n");
AssumptionCache AC(*F);
KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC,
F->front().getTerminator());
EXPECT_EQ(Known.Zero.getZExtValue(), 31u);
EXPECT_EQ(Known.One.getZExtValue(), 0u);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownBitsAddWithRange) {
parseAssembly("define void @test(i64* %p) {\n"
" %A = load i64, i64* %p, !range !{i64 64, i64 65536}\n"
" %APlus512 = add i64 %A, 512\n"
" %c = icmp ugt i64 %APlus512, 523\n"
" call void @llvm.assume(i1 %c)\n"
" ret void\n"
"}\n"
"declare void @llvm.assume(i1)\n");
AssumptionCache AC(*F);
KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC,
F->front().getTerminator());
EXPECT_EQ(Known.Zero.getZExtValue(), ~(65536llu - 1));
EXPECT_EQ(Known.One.getZExtValue(), 0u);
Instruction &APlus512 = findInstructionByName(F, "APlus512");
Known = computeKnownBits(&APlus512, M->getDataLayout(), /* Depth */ 0, &AC,
F->front().getTerminator());
// We know of one less zero because 512 may have produced a 1 that
// got carried all the way to the first trailing zero.
EXPECT_EQ(Known.Zero.getZExtValue(), (~(65536llu - 1)) << 1);
EXPECT_EQ(Known.One.getZExtValue(), 0u);
// The known range is not precise given computeKnownBits works
// with the masks of zeros and ones, not the ranges.
EXPECT_EQ(Known.getMinValue(), 0u);
EXPECT_EQ(Known.getMaxValue(), 131071);
}
// 512 + [32, 64) doesn't produce overlapping bits.
// Make sure we get all the individual bits properly.
TEST_F(ComputeKnownBitsTest, ComputeKnownBitsAddWithRangeNoOverlap) {
parseAssembly("define void @test(i64* %p) {\n"
" %A = load i64, i64* %p, !range !{i64 32, i64 64}\n"
" %APlus512 = add i64 %A, 512\n"
" %c = icmp ugt i64 %APlus512, 523\n"
" call void @llvm.assume(i1 %c)\n"
" ret void\n"
"}\n"
"declare void @llvm.assume(i1)\n");
AssumptionCache AC(*F);
KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC,
F->front().getTerminator());
EXPECT_EQ(Known.Zero.getZExtValue(), ~(64llu - 1));
EXPECT_EQ(Known.One.getZExtValue(), 32u);
Instruction &APlus512 = findInstructionByName(F, "APlus512");
Known = computeKnownBits(&APlus512, M->getDataLayout(), /* Depth */ 0, &AC,
F->front().getTerminator());
EXPECT_EQ(Known.Zero.getZExtValue(), ~512llu & ~(64llu - 1));
EXPECT_EQ(Known.One.getZExtValue(), 512u | 32u);
// The known range is not precise given computeKnownBits works
// with the masks of zeros and ones, not the ranges.
EXPECT_EQ(Known.getMinValue(), 544);
EXPECT_EQ(Known.getMaxValue(), 575);
}
TEST_F(ComputeKnownBitsTest, ComputeKnownBitsGEPWithRange) {
parseAssembly(
"define void @test(i64* %p) {\n"
" %A = load i64, i64* %p, !range !{i64 64, i64 65536}\n"
" %APtr = inttoptr i64 %A to float*"
" %APtrPlus512 = getelementptr float, float* %APtr, i32 128\n"
" %c = icmp ugt float* %APtrPlus512, inttoptr (i32 523 to float*)\n"
" call void @llvm.assume(i1 %c)\n"
" ret void\n"
"}\n"
"declare void @llvm.assume(i1)\n");
AssumptionCache AC(*F);
KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC,
F->front().getTerminator());
EXPECT_EQ(Known.Zero.getZExtValue(), ~(65536llu - 1));
EXPECT_EQ(Known.One.getZExtValue(), 0u);
Instruction &APtrPlus512 = findInstructionByName(F, "APtrPlus512");
Known = computeKnownBits(&APtrPlus512, M->getDataLayout(), /* Depth */ 0, &AC,
F->front().getTerminator());
// We know of one less zero because 512 may have produced a 1 that
// got carried all the way to the first trailing zero.
EXPECT_EQ(Known.Zero.getZExtValue(), ~(65536llu - 1) << 1);
EXPECT_EQ(Known.One.getZExtValue(), 0u);
// The known range is not precise given computeKnownBits works
// with the masks of zeros and ones, not the ranges.
EXPECT_EQ(Known.getMinValue(), 0u);
EXPECT_EQ(Known.getMaxValue(), 131071);
}
// 4*128 + [32, 64) doesn't produce overlapping bits.
// Make sure we get all the individual bits properly.
// This test is useful to check that we account for the scaling factor
// in the gep. Indeed, gep float, [32,64), 128 is not 128 + [32,64).
TEST_F(ComputeKnownBitsTest, ComputeKnownBitsGEPWithRangeNoOverlap) {
parseAssembly(
"define void @test(i64* %p) {\n"
" %A = load i64, i64* %p, !range !{i64 32, i64 64}\n"
" %APtr = inttoptr i64 %A to float*"
" %APtrPlus512 = getelementptr float, float* %APtr, i32 128\n"
" %c = icmp ugt float* %APtrPlus512, inttoptr (i32 523 to float*)\n"
" call void @llvm.assume(i1 %c)\n"
" ret void\n"
"}\n"
"declare void @llvm.assume(i1)\n");
AssumptionCache AC(*F);
KnownBits Known = computeKnownBits(A, M->getDataLayout(), /* Depth */ 0, &AC,
F->front().getTerminator());
EXPECT_EQ(Known.Zero.getZExtValue(), ~(64llu - 1));
EXPECT_EQ(Known.One.getZExtValue(), 32u);
Instruction &APtrPlus512 = findInstructionByName(F, "APtrPlus512");
Known = computeKnownBits(&APtrPlus512, M->getDataLayout(), /* Depth */ 0, &AC,
F->front().getTerminator());
EXPECT_EQ(Known.Zero.getZExtValue(), ~512llu & ~(64llu - 1));
EXPECT_EQ(Known.One.getZExtValue(), 512u | 32u);
// The known range is not precise given computeKnownBits works
// with the masks of zeros and ones, not the ranges.
EXPECT_EQ(Known.getMinValue(), 544);
EXPECT_EQ(Known.getMaxValue(), 575);
}
class IsBytewiseValueTest : public ValueTrackingTest,
public ::testing::WithParamInterface<
std::pair<const char *, const char *>> {
protected:
};
const std::pair<const char *, const char *> IsBytewiseValueTests[] = {
{
"i8 0",
"i48* null",
},
{
"i8 undef",
"i48* undef",
},
{
"i8 0",
"i8 zeroinitializer",
},
{
"i8 0",
"i8 0",
},
{
"i8 -86",
"i8 -86",
},
{
"i8 -1",
"i8 -1",
},
{
"i8 undef",
"i16 undef",
},
{
"i8 0",
"i16 0",
},
{
"",
"i16 7",
},
{
"i8 -86",
"i16 -21846",
},
{
"i8 -1",
"i16 -1",
},
{
"i8 0",
"i48 0",
},
{
"i8 -1",
"i48 -1",
},
{
"i8 0",
"i49 0",
},
{
"",
"i49 -1",
},
{
"i8 0",
"half 0xH0000",
},
{
"i8 -85",
"half 0xHABAB",
},
{
"i8 0",
"float 0.0",
},
{
"i8 -1",
"float 0xFFFFFFFFE0000000",
},
{
"i8 0",
"double 0.0",
},
{
"i8 -15",
"double 0xF1F1F1F1F1F1F1F1",
},
{
"i8 undef",
"i16* undef",
},
{
"i8 0",
"i16* inttoptr (i64 0 to i16*)",
},
{
"i8 -1",
"i16* inttoptr (i64 -1 to i16*)",
},
{
"i8 -86",
"i16* inttoptr (i64 -6148914691236517206 to i16*)",
},
{
"",
"i16* inttoptr (i48 -1 to i16*)",
},
{
"i8 -1",
"i16* inttoptr (i96 -1 to i16*)",
},
{
"i8 undef",
"[0 x i8] zeroinitializer",
},
{
"i8 undef",
"[0 x i8] undef",
},
{
"i8 undef",
"[5 x [0 x i8]] zeroinitializer",
},
{
"i8 undef",
"[5 x [0 x i8]] undef",
},
{
"i8 0",
"[6 x i8] zeroinitializer",
},
{
"i8 undef",
"[6 x i8] undef",
},
{
"i8 1",
"[5 x i8] [i8 1, i8 1, i8 1, i8 1, i8 1]",
},
{
"",
"[5 x i64] [i64 1, i64 1, i64 1, i64 1, i64 1]",
},
{
"i8 -1",
"[5 x i64] [i64 -1, i64 -1, i64 -1, i64 -1, i64 -1]",
},
{
"",
"[4 x i8] [i8 1, i8 2, i8 1, i8 1]",
},
{
"i8 1",
"[4 x i8] [i8 1, i8 undef, i8 1, i8 1]",
},
{
"i8 0",
"<6 x i8> zeroinitializer",
},
{
"i8 undef",
"<6 x i8> undef",
},
{
"i8 1",
"<5 x i8> <i8 1, i8 1, i8 1, i8 1, i8 1>",
},
{
"",
"<5 x i64> <i64 1, i64 1, i64 1, i64 1, i64 1>",
},
{
"i8 -1",
"<5 x i64> <i64 -1, i64 -1, i64 -1, i64 -1, i64 -1>",
},
{
"",
"<4 x i8> <i8 1, i8 1, i8 2, i8 1>",
},
{
"i8 5",
"<2 x i8> < i8 5, i8 undef >",
},
{
"i8 0",
"[2 x [2 x i16]] zeroinitializer",
},
{
"i8 undef",
"[2 x [2 x i16]] undef",
},
{
"i8 -86",
"[2 x [2 x i16]] [[2 x i16] [i16 -21846, i16 -21846], "
"[2 x i16] [i16 -21846, i16 -21846]]",
},
{
"",
"[2 x [2 x i16]] [[2 x i16] [i16 -21846, i16 -21846], "
"[2 x i16] [i16 -21836, i16 -21846]]",
},
{
"i8 undef",
"{ } zeroinitializer",
},
{
"i8 undef",
"{ } undef",
},
{
"i8 undef",
"{ {}, {} } zeroinitializer",
},
{
"i8 undef",
"{ {}, {} } undef",
},
{
"i8 0",
"{i8, i64, i16*} zeroinitializer",
},
{
"i8 undef",
"{i8, i64, i16*} undef",
},
{
"i8 -86",
"{i8, i64, i16*} {i8 -86, i64 -6148914691236517206, i16* undef}",
},
{
"",
"{i8, i64, i16*} {i8 86, i64 -6148914691236517206, i16* undef}",
},
};
INSTANTIATE_TEST_CASE_P(IsBytewiseValueParamTests, IsBytewiseValueTest,
::testing::ValuesIn(IsBytewiseValueTests),);
TEST_P(IsBytewiseValueTest, IsBytewiseValue) {
auto M = parseModule(std::string("@test = global ") + GetParam().second);
GlobalVariable *GV = dyn_cast<GlobalVariable>(M->getNamedValue("test"));
Value *Actual = isBytewiseValue(GV->getInitializer(), M->getDataLayout());
std::string Buff;
raw_string_ostream S(Buff);
if (Actual)
S << *Actual;
EXPECT_EQ(GetParam().first, S.str());
}
TEST_F(ValueTrackingTest, ComputeConstantRange) {
{
// Assumptions:
// * stride >= 5
// * stride < 10
//
// stride = [5, 10)
auto M = parseModule(R"(
declare void @llvm.assume(i1)
define i32 @test(i32 %stride) {
%gt = icmp uge i32 %stride, 5
call void @llvm.assume(i1 %gt)
%lt = icmp ult i32 %stride, 10
call void @llvm.assume(i1 %lt)
%stride.plus.one = add nsw nuw i32 %stride, 1
ret i32 %stride.plus.one
})");
Function *F = M->getFunction("test");
AssumptionCache AC(*F);
Value *Stride = &*F->arg_begin();
ConstantRange CR1 = computeConstantRange(Stride, true, &AC, nullptr);
EXPECT_TRUE(CR1.isFullSet());
Instruction *I = &findInstructionByName(F, "stride.plus.one");
ConstantRange CR2 = computeConstantRange(Stride, true, &AC, I);
EXPECT_EQ(5, CR2.getLower());
EXPECT_EQ(10, CR2.getUpper());
}
{
// Assumptions:
// * stride >= 5
// * stride < 200
// * stride == 99
//
// stride = [99, 100)
auto M = parseModule(R"(
declare void @llvm.assume(i1)
define i32 @test(i32 %stride) {
%gt = icmp uge i32 %stride, 5
call void @llvm.assume(i1 %gt)
%lt = icmp ult i32 %stride, 200
call void @llvm.assume(i1 %lt)
%eq = icmp eq i32 %stride, 99
call void @llvm.assume(i1 %eq)
%stride.plus.one = add nsw nuw i32 %stride, 1
ret i32 %stride.plus.one
})");
Function *F = M->getFunction("test");
AssumptionCache AC(*F);
Value *Stride = &*F->arg_begin();
Instruction *I = &findInstructionByName(F, "stride.plus.one");
ConstantRange CR = computeConstantRange(Stride, true, &AC, I);
EXPECT_EQ(99, *CR.getSingleElement());
}
{
// Assumptions:
// * stride >= 5
// * stride >= 50
// * stride < 100
// * stride < 200
//
// stride = [50, 100)
auto M = parseModule(R"(
declare void @llvm.assume(i1)
define i32 @test(i32 %stride, i1 %cond) {
%gt = icmp uge i32 %stride, 5
call void @llvm.assume(i1 %gt)
%gt.2 = icmp uge i32 %stride, 50
call void @llvm.assume(i1 %gt.2)
br i1 %cond, label %bb1, label %bb2
bb1:
%lt = icmp ult i32 %stride, 200
call void @llvm.assume(i1 %lt)
%lt.2 = icmp ult i32 %stride, 100
call void @llvm.assume(i1 %lt.2)
%stride.plus.one = add nsw nuw i32 %stride, 1
ret i32 %stride.plus.one
bb2:
ret i32 0
})");
Function *F = M->getFunction("test");
AssumptionCache AC(*F);
Value *Stride = &*F->arg_begin();
Instruction *GT2 = &findInstructionByName(F, "gt.2");
ConstantRange CR = computeConstantRange(Stride, true, &AC, GT2);
EXPECT_EQ(5, CR.getLower());
EXPECT_EQ(0, CR.getUpper());
Instruction *I = &findInstructionByName(F, "stride.plus.one");
ConstantRange CR2 = computeConstantRange(Stride, true, &AC, I);
EXPECT_EQ(50, CR2.getLower());
EXPECT_EQ(100, CR2.getUpper());
}
{
// Assumptions:
// * stride > 5
// * stride < 5
//
// stride = empty range, as the assumptions contradict each other.
auto M = parseModule(R"(
declare void @llvm.assume(i1)
define i32 @test(i32 %stride, i1 %cond) {
%gt = icmp ugt i32 %stride, 5
call void @llvm.assume(i1 %gt)
%lt = icmp ult i32 %stride, 5
call void @llvm.assume(i1 %lt)
%stride.plus.one = add nsw nuw i32 %stride, 1
ret i32 %stride.plus.one
})");
Function *F = M->getFunction("test");
AssumptionCache AC(*F);
Value *Stride = &*F->arg_begin();
Instruction *I = &findInstructionByName(F, "stride.plus.one");
ConstantRange CR = computeConstantRange(Stride, true, &AC, I);
EXPECT_TRUE(CR.isEmptySet());
}
{
// Assumptions:
// * x.1 >= 5
// * x.2 < x.1
//
// stride = [0, 5)
auto M = parseModule(R"(
declare void @llvm.assume(i1)
define i32 @test(i32 %x.1, i32 %x.2) {
%gt = icmp uge i32 %x.1, 5
call void @llvm.assume(i1 %gt)
%lt = icmp ult i32 %x.2, %x.1
call void @llvm.assume(i1 %lt)
%stride.plus.one = add nsw nuw i32 %x.1, 1
ret i32 %stride.plus.one
})");
Function *F = M->getFunction("test");
AssumptionCache AC(*F);
Value *X2 = &*std::next(F->arg_begin());
Instruction *I = &findInstructionByName(F, "stride.plus.one");
ConstantRange CR1 = computeConstantRange(X2, true, &AC, I);
EXPECT_EQ(0, CR1.getLower());
EXPECT_EQ(5, CR1.getUpper());
// Check the depth cutoff results in a conservative result (full set) by
// passing Depth == MaxDepth == 6.
ConstantRange CR2 = computeConstantRange(X2, true, &AC, I, 6);
EXPECT_TRUE(CR2.isFullSet());
}
}
struct FindAllocaForValueTestParams {
const char *IR;
bool AnyOffsetResult;
bool ZeroOffsetResult;
};
class FindAllocaForValueTest
: public ValueTrackingTest,
public ::testing::WithParamInterface<FindAllocaForValueTestParams> {
protected:
};
const FindAllocaForValueTestParams FindAllocaForValueTests[] = {
{R"(
define void @test() {
%a = alloca i64
%r = bitcast i64* %a to i32*
ret void
})",
true, true},
{R"(
define void @test() {
%a = alloca i32
%r = getelementptr i32, i32* %a, i32 1
ret void
})",
true, false},
{R"(
define void @test() {
%a = alloca i32
%r = getelementptr i32, i32* %a, i32 0
ret void
})",
true, true},
{R"(
define void @test(i1 %cond) {
entry:
%a = alloca i32
br label %bb1
bb1:
%r = phi i32* [ %a, %entry ], [ %r, %bb1 ]
br i1 %cond, label %bb1, label %exit
exit:
ret void
})",
true, true},
{R"(
define void @test(i1 %cond) {
%a = alloca i32
%r = select i1 %cond, i32* %a, i32* %a
ret void
})",
true, true},
{R"(
define void @test(i1 %cond) {
%a = alloca i32
%b = alloca i32
%r = select i1 %cond, i32* %a, i32* %b
ret void
})",
false, false},
{R"(
define void @test(i1 %cond) {
entry:
%a = alloca i64
%a32 = bitcast i64* %a to i32*
br label %bb1
bb1:
%x = phi i32* [ %a32, %entry ], [ %x, %bb1 ]
%r = getelementptr i32, i32* %x, i32 1
br i1 %cond, label %bb1, label %exit
exit:
ret void
})",
true, false},
{R"(
define void @test(i1 %cond) {
entry:
%a = alloca i64
%a32 = bitcast i64* %a to i32*
br label %bb1
bb1:
%x = phi i32* [ %a32, %entry ], [ %r, %bb1 ]
%r = getelementptr i32, i32* %x, i32 1
br i1 %cond, label %bb1, label %exit
exit:
ret void
})",
true, false},
{R"(
define void @test(i1 %cond, i64* %a) {
entry:
%r = bitcast i64* %a to i32*
ret void
})",
false, false},
{R"(
define void @test(i1 %cond) {
entry:
%a = alloca i32
%b = alloca i32
br label %bb1
bb1:
%r = phi i32* [ %a, %entry ], [ %b, %bb1 ]
br i1 %cond, label %bb1, label %exit
exit:
ret void
})",
false, false},
};
TEST_P(FindAllocaForValueTest, findAllocaForValue) {
auto M = parseModule(GetParam().IR);
Function *F = M->getFunction("test");
Instruction *I = &findInstructionByName(F, "r");
const AllocaInst *AI = findAllocaForValue(I);
EXPECT_EQ(!!AI, GetParam().AnyOffsetResult);
}
TEST_P(FindAllocaForValueTest, findAllocaForValueZeroOffset) {
auto M = parseModule(GetParam().IR);
Function *F = M->getFunction("test");
Instruction *I = &findInstructionByName(F, "r");
const AllocaInst *AI = findAllocaForValue(I, true);
EXPECT_EQ(!!AI, GetParam().ZeroOffsetResult);
}
INSTANTIATE_TEST_CASE_P(FindAllocaForValueTest, FindAllocaForValueTest,
::testing::ValuesIn(FindAllocaForValueTests), );
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