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//===- LoadsTest.cpp - local load analysis unit 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/Loads.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
static std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
SMDiagnostic Err;
std::unique_ptr<Module> Mod = parseAssemblyString(IR, Err, C);
if (!Mod)
Err.print("AnalysisTests", errs());
return Mod;
}
TEST(LoadsTest, FindAvailableLoadedValueSameBasePtrConstantOffsetsNullAA) {
LLVMContext C;
std::unique_ptr<Module> M = parseIR(C,
R"IR(
target datalayout = "p:64:64:64:32"
%class = type <{ i32, i32 }>
define i32 @f() {
entry:
%o = alloca %class
%f1 = getelementptr inbounds %class, %class* %o, i32 0, i32 0
store i32 42, i32* %f1
%f2 = getelementptr inbounds %class, %class* %o, i32 0, i32 1
store i32 43, i32* %f2
%v = load i32, i32* %f1
ret i32 %v
}
)IR");
auto *GV = M->getNamedValue("f");
ASSERT_TRUE(GV);
auto *F = dyn_cast<Function>(GV);
ASSERT_TRUE(F);
Instruction *Inst = &F->front().front();
auto *AI = dyn_cast<AllocaInst>(Inst);
ASSERT_TRUE(AI);
Inst = &*++F->front().rbegin();
auto *LI = dyn_cast<LoadInst>(Inst);
ASSERT_TRUE(LI);
BasicBlock::iterator BBI(LI);
Value *Loaded = FindAvailableLoadedValue(
LI, LI->getParent(), BBI, 0, nullptr, nullptr);
ASSERT_TRUE(Loaded);
auto *CI = dyn_cast<ConstantInt>(Loaded);
ASSERT_TRUE(CI);
ASSERT_TRUE(CI->equalsInt(42));
}
TEST(LoadsTest, CanReplacePointersIfEqual) {
LLVMContext C;
std::unique_ptr<Module> M = parseIR(C,
R"IR(
@y = common global [1 x i32] zeroinitializer, align 4
@x = common global [1 x i32] zeroinitializer, align 4
declare void @use(i32*)
define void @f(i32* %p) {
call void @use(i32* getelementptr inbounds ([1 x i32], [1 x i32]* @y, i64 0, i64 0))
call void @use(i32* getelementptr inbounds (i32, i32* getelementptr inbounds ([1 x i32], [1 x i32]* @x, i64 0, i64 0), i64 1))
ret void
}
)IR");
const auto &DL = M->getDataLayout();
auto *GV = M->getNamedValue("f");
ASSERT_TRUE(GV);
auto *F = dyn_cast<Function>(GV);
ASSERT_TRUE(F);
// NOTE: the implementation of canReplacePointersIfEqual is incomplete.
// Currently the only the cases it returns false for are really sound and
// returning true means unknown.
Value *P = &*F->arg_begin();
auto InstIter = F->front().begin();
Value *ConstDerefPtr = *cast<CallInst>(&*InstIter)->arg_begin();
// ConstDerefPtr is a constant pointer that is provably de-referenceable. We
// can replace an arbitrary pointer with it.
EXPECT_TRUE(canReplacePointersIfEqual(P, ConstDerefPtr, DL, nullptr));
++InstIter;
Value *ConstUnDerefPtr = *cast<CallInst>(&*InstIter)->arg_begin();
// ConstUndDerefPtr is a constant pointer that is provably not
// de-referenceable. We cannot replace an arbitrary pointer with it.
EXPECT_FALSE(
canReplacePointersIfEqual(ConstDerefPtr, ConstUnDerefPtr, DL, nullptr));
}
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