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llvm/unittests/Analysis/ScalarEvolutionTest.cpp
Matt Arsenault e0b3c335a2 Allow DataLayout to specify addrspace for allocas. 
LLVM makes several assumptions about address space 0. However,
alloca is presently constrained to always return this address space.
There's no real way to avoid using alloca, so without this
there is no way to opt out of these assumptions.

The problematic assumptions include:
- That the pointer size used for the stack is the same size as
  the code size pointer, which is also the maximum sized pointer.

- That 0 is an invalid, non-dereferencable pointer value.

These are problems for AMDGPU because alloca is used to
implement the private address space, which uses a 32-bit
index as the pointer value. Other pointers are 64-bit
and behave more like LLVM's notion of generic address
space. By changing the address space used for allocas,
we can change our generic pointer type to be LLVM's generic
pointer type which does have similar properties.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299888 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-10 22:27:50 +00:00

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//===- ScalarEvolutionsTest.cpp - ScalarEvolution unit 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/ScalarEvolutionExpander.h"
#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
namespace llvm {
namespace {
// We use this fixture to ensure that we clean up ScalarEvolution before
// deleting the PassManager.
class ScalarEvolutionsTest : public testing::Test {
protected:
LLVMContext Context;
Module M;
TargetLibraryInfoImpl TLII;
TargetLibraryInfo TLI;
std::unique_ptr<AssumptionCache> AC;
std::unique_ptr<DominatorTree> DT;
std::unique_ptr<LoopInfo> LI;
ScalarEvolutionsTest() : M("", Context), TLII(), TLI(TLII) {}
ScalarEvolution buildSE(Function &F) {
AC.reset(new AssumptionCache(F));
DT.reset(new DominatorTree(F));
LI.reset(new LoopInfo(*DT));
return ScalarEvolution(F, TLI, *AC, *DT, *LI);
}
void runWithFunctionAndSE(
Module &M, StringRef FuncName,
function_ref<void(Function &F, ScalarEvolution &SE)> Test) {
auto *F = M.getFunction(FuncName);
ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
ScalarEvolution SE = buildSE(*F);
Test(*F, SE);
}
};
TEST_F(ScalarEvolutionsTest, SCEVUnknownRAUW) {
FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context),
std::vector<Type *>(), false);
Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
ReturnInst::Create(Context, nullptr, BB);
Type *Ty = Type::getInt1Ty(Context);
Constant *Init = Constant::getNullValue(Ty);
Value *V0 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V0");
Value *V1 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V1");
Value *V2 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V2");
ScalarEvolution SE = buildSE(*F);
const SCEV *S0 = SE.getSCEV(V0);
const SCEV *S1 = SE.getSCEV(V1);
const SCEV *S2 = SE.getSCEV(V2);
const SCEV *P0 = SE.getAddExpr(S0, S0);
const SCEV *P1 = SE.getAddExpr(S1, S1);
const SCEV *P2 = SE.getAddExpr(S2, S2);
const SCEVMulExpr *M0 = cast<SCEVMulExpr>(P0);
const SCEVMulExpr *M1 = cast<SCEVMulExpr>(P1);
const SCEVMulExpr *M2 = cast<SCEVMulExpr>(P2);
EXPECT_EQ(cast<SCEVConstant>(M0->getOperand(0))->getValue()->getZExtValue(),
2u);
EXPECT_EQ(cast<SCEVConstant>(M1->getOperand(0))->getValue()->getZExtValue(),
2u);
EXPECT_EQ(cast<SCEVConstant>(M2->getOperand(0))->getValue()->getZExtValue(),
2u);
// Before the RAUWs, these are all pointing to separate values.
EXPECT_EQ(cast<SCEVUnknown>(M0->getOperand(1))->getValue(), V0);
EXPECT_EQ(cast<SCEVUnknown>(M1->getOperand(1))->getValue(), V1);
EXPECT_EQ(cast<SCEVUnknown>(M2->getOperand(1))->getValue(), V2);
// Do some RAUWs.
V2->replaceAllUsesWith(V1);
V1->replaceAllUsesWith(V0);
// After the RAUWs, these should all be pointing to V0.
EXPECT_EQ(cast<SCEVUnknown>(M0->getOperand(1))->getValue(), V0);
EXPECT_EQ(cast<SCEVUnknown>(M1->getOperand(1))->getValue(), V0);
EXPECT_EQ(cast<SCEVUnknown>(M2->getOperand(1))->getValue(), V0);
}
TEST_F(ScalarEvolutionsTest, SCEVMultiplyAddRecs) {
Type *Ty = Type::getInt32Ty(Context);
SmallVector<Type *, 10> Types;
Types.append(10, Ty);
FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context), Types, false);
Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
ReturnInst::Create(Context, nullptr, BB);
ScalarEvolution SE = buildSE(*F);
// It's possible to produce an empty loop through the default constructor,
// but you can't add any blocks to it without a LoopInfo pass.
Loop L;
const_cast<std::vector<BasicBlock*>&>(L.getBlocks()).push_back(BB);
Function::arg_iterator AI = F->arg_begin();
SmallVector<const SCEV *, 5> A;
A.push_back(SE.getSCEV(&*AI++));
A.push_back(SE.getSCEV(&*AI++));
A.push_back(SE.getSCEV(&*AI++));
A.push_back(SE.getSCEV(&*AI++));
A.push_back(SE.getSCEV(&*AI++));
const SCEV *A_rec = SE.getAddRecExpr(A, &L, SCEV::FlagAnyWrap);
SmallVector<const SCEV *, 5> B;
B.push_back(SE.getSCEV(&*AI++));
B.push_back(SE.getSCEV(&*AI++));
B.push_back(SE.getSCEV(&*AI++));
B.push_back(SE.getSCEV(&*AI++));
B.push_back(SE.getSCEV(&*AI++));
const SCEV *B_rec = SE.getAddRecExpr(B, &L, SCEV::FlagAnyWrap);
/* Spot check that we perform this transformation:
{A0,+,A1,+,A2,+,A3,+,A4} * {B0,+,B1,+,B2,+,B3,+,B4} =
{A0*B0,+,
A1*B0 + A0*B1 + A1*B1,+,
A2*B0 + 2A1*B1 + A0*B2 + 2A2*B1 + 2A1*B2 + A2*B2,+,
A3*B0 + 3A2*B1 + 3A1*B2 + A0*B3 + 3A3*B1 + 6A2*B2 + 3A1*B3 + 3A3*B2 +
3A2*B3 + A3*B3,+,
A4*B0 + 4A3*B1 + 6A2*B2 + 4A1*B3 + A0*B4 + 4A4*B1 + 12A3*B2 + 12A2*B3 +
4A1*B4 + 6A4*B2 + 12A3*B3 + 6A2*B4 + 4A4*B3 + 4A3*B4 + A4*B4,+,
5A4*B1 + 10A3*B2 + 10A2*B3 + 5A1*B4 + 20A4*B2 + 30A3*B3 + 20A2*B4 +
30A4*B3 + 30A3*B4 + 20A4*B4,+,
15A4*B2 + 20A3*B3 + 15A2*B4 + 60A4*B3 + 60A3*B4 + 90A4*B4,+,
35A4*B3 + 35A3*B4 + 140A4*B4,+,
70A4*B4}
*/
const SCEVAddRecExpr *Product =
dyn_cast<SCEVAddRecExpr>(SE.getMulExpr(A_rec, B_rec));
ASSERT_TRUE(Product);
ASSERT_EQ(Product->getNumOperands(), 9u);
SmallVector<const SCEV *, 16> Sum;
Sum.push_back(SE.getMulExpr(A[0], B[0]));
EXPECT_EQ(Product->getOperand(0), SE.getAddExpr(Sum));
Sum.clear();
// SCEV produces different an equal but different expression for these.
// Re-enable when PR11052 is fixed.
#if 0
Sum.push_back(SE.getMulExpr(A[1], B[0]));
Sum.push_back(SE.getMulExpr(A[0], B[1]));
Sum.push_back(SE.getMulExpr(A[1], B[1]));
EXPECT_EQ(Product->getOperand(1), SE.getAddExpr(Sum));
Sum.clear();
Sum.push_back(SE.getMulExpr(A[2], B[0]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 2), A[1], B[1]));
Sum.push_back(SE.getMulExpr(A[0], B[2]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 2), A[2], B[1]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 2), A[1], B[2]));
Sum.push_back(SE.getMulExpr(A[2], B[2]));
EXPECT_EQ(Product->getOperand(2), SE.getAddExpr(Sum));
Sum.clear();
Sum.push_back(SE.getMulExpr(A[3], B[0]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 3), A[2], B[1]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 3), A[1], B[2]));
Sum.push_back(SE.getMulExpr(A[0], B[3]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 3), A[3], B[1]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 6), A[2], B[2]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 3), A[1], B[3]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 3), A[3], B[2]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 3), A[2], B[3]));
Sum.push_back(SE.getMulExpr(A[3], B[3]));
EXPECT_EQ(Product->getOperand(3), SE.getAddExpr(Sum));
Sum.clear();
Sum.push_back(SE.getMulExpr(A[4], B[0]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 4), A[3], B[1]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 6), A[2], B[2]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 4), A[1], B[3]));
Sum.push_back(SE.getMulExpr(A[0], B[4]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 4), A[4], B[1]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 12), A[3], B[2]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 12), A[2], B[3]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 4), A[1], B[4]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 6), A[4], B[2]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 12), A[3], B[3]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 6), A[2], B[4]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 4), A[4], B[3]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 4), A[3], B[4]));
Sum.push_back(SE.getMulExpr(A[4], B[4]));
EXPECT_EQ(Product->getOperand(4), SE.getAddExpr(Sum));
Sum.clear();
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 5), A[4], B[1]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 10), A[3], B[2]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 10), A[2], B[3]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 5), A[1], B[4]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 20), A[4], B[2]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 30), A[3], B[3]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 20), A[2], B[4]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 30), A[4], B[3]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 30), A[3], B[4]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 20), A[4], B[4]));
EXPECT_EQ(Product->getOperand(5), SE.getAddExpr(Sum));
Sum.clear();
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 15), A[4], B[2]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 20), A[3], B[3]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 15), A[2], B[4]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 60), A[4], B[3]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 60), A[3], B[4]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 90), A[4], B[4]));
EXPECT_EQ(Product->getOperand(6), SE.getAddExpr(Sum));
Sum.clear();
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 35), A[4], B[3]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 35), A[3], B[4]));
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 140), A[4], B[4]));
EXPECT_EQ(Product->getOperand(7), SE.getAddExpr(Sum));
Sum.clear();
#endif
Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 70), A[4], B[4]));
EXPECT_EQ(Product->getOperand(8), SE.getAddExpr(Sum));
}
TEST_F(ScalarEvolutionsTest, SimplifiedPHI) {
FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context),
std::vector<Type *>(), false);
Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
BasicBlock *LoopBB = BasicBlock::Create(Context, "loop", F);
BasicBlock *ExitBB = BasicBlock::Create(Context, "exit", F);
BranchInst::Create(LoopBB, EntryBB);
BranchInst::Create(LoopBB, ExitBB, UndefValue::get(Type::getInt1Ty(Context)),
LoopBB);
ReturnInst::Create(Context, nullptr, ExitBB);
auto *Ty = Type::getInt32Ty(Context);
auto *PN = PHINode::Create(Ty, 2, "", &*LoopBB->begin());
PN->addIncoming(Constant::getNullValue(Ty), EntryBB);
PN->addIncoming(UndefValue::get(Ty), LoopBB);
ScalarEvolution SE = buildSE(*F);
auto *S1 = SE.getSCEV(PN);
auto *S2 = SE.getSCEV(PN);
auto *ZeroConst = SE.getConstant(Ty, 0);
// At some point, only the first call to getSCEV returned the simplified
// SCEVConstant and later calls just returned a SCEVUnknown referencing the
// PHI node.
EXPECT_EQ(S1, ZeroConst);
EXPECT_EQ(S1, S2);
}
TEST_F(ScalarEvolutionsTest, ExpandPtrTypeSCEV) {
// It is to test the fix for PR30213. It exercises the branch in scev
// expansion when the value in ValueOffsetPair is a ptr and the offset
// is not divisible by the elem type size of value.
auto *I8Ty = Type::getInt8Ty(Context);
auto *I8PtrTy = Type::getInt8PtrTy(Context);
auto *I32Ty = Type::getInt32Ty(Context);
auto *I32PtrTy = Type::getInt32PtrTy(Context);
FunctionType *FTy =
FunctionType::get(Type::getVoidTy(Context), std::vector<Type *>(), false);
Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
BasicBlock *LoopBB = BasicBlock::Create(Context, "loop", F);
BasicBlock *ExitBB = BasicBlock::Create(Context, "exit", F);
BranchInst::Create(LoopBB, EntryBB);
ReturnInst::Create(Context, nullptr, ExitBB);
// loop: ; preds = %loop, %entry
// %alloca = alloca i32
// %gep0 = getelementptr i32, i32* %alloca, i32 1
// %bitcast1 = bitcast i32* %gep0 to i8*
// %gep1 = getelementptr i8, i8* %bitcast1, i32 1
// %gep2 = getelementptr i8, i8* undef, i32 1
// %cmp = icmp ult i8* undef, %bitcast1
// %select = select i1 %cmp, i8* %gep1, i8* %gep2
// %bitcast2 = bitcast i8* %select to i32*
// br i1 undef, label %loop, label %exit
const DataLayout &DL = F->getParent()->getDataLayout();
BranchInst *Br = BranchInst::Create(
LoopBB, ExitBB, UndefValue::get(Type::getInt1Ty(Context)), LoopBB);
AllocaInst *Alloca = new AllocaInst(I32Ty, DL.getAllocaAddrSpace(),
"alloca", Br);
ConstantInt *Ci32 = ConstantInt::get(Context, APInt(32, 1));
GetElementPtrInst *Gep0 =
GetElementPtrInst::Create(I32Ty, Alloca, Ci32, "gep0", Br);
CastInst *CastA =
CastInst::CreateBitOrPointerCast(Gep0, I8PtrTy, "bitcast1", Br);
GetElementPtrInst *Gep1 =
GetElementPtrInst::Create(I8Ty, CastA, Ci32, "gep1", Br);
GetElementPtrInst *Gep2 = GetElementPtrInst::Create(
I8Ty, UndefValue::get(I8PtrTy), Ci32, "gep2", Br);
CmpInst *Cmp = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_ULT,
UndefValue::get(I8PtrTy), CastA, "cmp", Br);
SelectInst *Sel = SelectInst::Create(Cmp, Gep1, Gep2, "select", Br);
CastInst *CastB =
CastInst::CreateBitOrPointerCast(Sel, I32PtrTy, "bitcast2", Br);
ScalarEvolution SE = buildSE(*F);
auto *S = SE.getSCEV(CastB);
SCEVExpander Exp(SE, M.getDataLayout(), "expander");
Value *V =
Exp.expandCodeFor(cast<SCEVAddExpr>(S)->getOperand(1), nullptr, Br);
// Expect the expansion code contains:
// %0 = bitcast i32* %bitcast2 to i8*
// %uglygep = getelementptr i8, i8* %0, i64 -1
// %1 = bitcast i8* %uglygep to i32*
EXPECT_TRUE(isa<BitCastInst>(V));
Instruction *Gep = cast<Instruction>(V)->getPrevNode();
EXPECT_TRUE(isa<GetElementPtrInst>(Gep));
EXPECT_TRUE(isa<ConstantInt>(Gep->getOperand(1)));
EXPECT_EQ(cast<ConstantInt>(Gep->getOperand(1))->getSExtValue(), -1);
EXPECT_TRUE(isa<BitCastInst>(Gep->getPrevNode()));
}
static Instruction *getInstructionByName(Function &F, StringRef Name) {
for (auto &I : instructions(F))
if (I.getName() == Name)
return &I;
llvm_unreachable("Expected to find instruction!");
}
TEST_F(ScalarEvolutionsTest, CommutativeExprOperandOrder) {
LLVMContext C;
SMDiagnostic Err;
std::unique_ptr<Module> M = parseAssemblyString(
"target datalayout = \"e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128\" "
" "
"@var_0 = external global i32, align 4"
"@var_1 = external global i32, align 4"
"@var_2 = external global i32, align 4"
" "
"declare i32 @unknown(i32, i32, i32)"
" "
"define void @f_1(i8* nocapture %arr, i32 %n, i32* %A, i32* %B) "
" local_unnamed_addr { "
"entry: "
" %entrycond = icmp sgt i32 %n, 0 "
" br i1 %entrycond, label %loop.ph, label %for.end "
" "
"loop.ph: "
" %a = load i32, i32* %A, align 4 "
" %b = load i32, i32* %B, align 4 "
" %mul = mul nsw i32 %b, %a "
" %iv0.init = getelementptr inbounds i8, i8* %arr, i32 %mul "
" br label %loop "
" "
"loop: "
" %iv0 = phi i8* [ %iv0.inc, %loop ], [ %iv0.init, %loop.ph ] "
" %iv1 = phi i32 [ %iv1.inc, %loop ], [ 0, %loop.ph ] "
" %conv = trunc i32 %iv1 to i8 "
" store i8 %conv, i8* %iv0, align 1 "
" %iv0.inc = getelementptr inbounds i8, i8* %iv0, i32 %b "
" %iv1.inc = add nuw nsw i32 %iv1, 1 "
" %exitcond = icmp eq i32 %iv1.inc, %n "
" br i1 %exitcond, label %for.end.loopexit, label %loop "
" "
"for.end.loopexit: "
" br label %for.end "
" "
"for.end: "
" ret void "
"} "
" "
"define void @f_2(i32* %X, i32* %Y, i32* %Z) { "
" %x = load i32, i32* %X "
" %y = load i32, i32* %Y "
" %z = load i32, i32* %Z "
" ret void "
"} "
" "
"define void @f_3() { "
" %x = load i32, i32* @var_0"
" %y = load i32, i32* @var_1"
" %z = load i32, i32* @var_2"
" ret void"
"} "
" "
"define void @f_4(i32 %a, i32 %b, i32 %c) { "
" %x = call i32 @unknown(i32 %a, i32 %b, i32 %c)"
" %y = call i32 @unknown(i32 %b, i32 %c, i32 %a)"
" %z = call i32 @unknown(i32 %c, i32 %a, i32 %b)"
" ret void"
"} "
,
Err, C);
assert(M && "Could not parse module?");
assert(!verifyModule(*M) && "Must have been well formed!");
runWithFunctionAndSE(*M, "f_1", [&](Function &F, ScalarEvolution &SE) {
auto *IV0 = getInstructionByName(F, "iv0");
auto *IV0Inc = getInstructionByName(F, "iv0.inc");
auto *FirstExprForIV0 = SE.getSCEV(IV0);
auto *FirstExprForIV0Inc = SE.getSCEV(IV0Inc);
auto *SecondExprForIV0 = SE.getSCEV(IV0);
EXPECT_TRUE(isa<SCEVAddRecExpr>(FirstExprForIV0));
EXPECT_TRUE(isa<SCEVAddRecExpr>(FirstExprForIV0Inc));
EXPECT_TRUE(isa<SCEVAddRecExpr>(SecondExprForIV0));
});
auto CheckCommutativeMulExprs = [&](ScalarEvolution &SE, const SCEV *A,
const SCEV *B, const SCEV *C) {
EXPECT_EQ(SE.getMulExpr(A, B), SE.getMulExpr(B, A));
EXPECT_EQ(SE.getMulExpr(B, C), SE.getMulExpr(C, B));
EXPECT_EQ(SE.getMulExpr(A, C), SE.getMulExpr(C, A));
SmallVector<const SCEV *, 3> Ops0 = {A, B, C};
SmallVector<const SCEV *, 3> Ops1 = {A, C, B};
SmallVector<const SCEV *, 3> Ops2 = {B, A, C};
SmallVector<const SCEV *, 3> Ops3 = {B, C, A};
SmallVector<const SCEV *, 3> Ops4 = {C, B, A};
SmallVector<const SCEV *, 3> Ops5 = {C, A, B};
auto *Mul0 = SE.getMulExpr(Ops0);
auto *Mul1 = SE.getMulExpr(Ops1);
auto *Mul2 = SE.getMulExpr(Ops2);
auto *Mul3 = SE.getMulExpr(Ops3);
auto *Mul4 = SE.getMulExpr(Ops4);
auto *Mul5 = SE.getMulExpr(Ops5);
EXPECT_EQ(Mul0, Mul1) << "Expected " << *Mul0 << " == " << *Mul1;
EXPECT_EQ(Mul1, Mul2) << "Expected " << *Mul1 << " == " << *Mul2;
EXPECT_EQ(Mul2, Mul3) << "Expected " << *Mul2 << " == " << *Mul3;
EXPECT_EQ(Mul3, Mul4) << "Expected " << *Mul3 << " == " << *Mul4;
EXPECT_EQ(Mul4, Mul5) << "Expected " << *Mul4 << " == " << *Mul5;
};
for (StringRef FuncName : {"f_2", "f_3", "f_4"})
runWithFunctionAndSE(*M, FuncName, [&](Function &F, ScalarEvolution &SE) {
CheckCommutativeMulExprs(SE, SE.getSCEV(getInstructionByName(F, "x")),
SE.getSCEV(getInstructionByName(F, "y")),
SE.getSCEV(getInstructionByName(F, "z")));
});
}
TEST_F(ScalarEvolutionsTest, CompareSCEVComplexity) {
FunctionType *FTy =
FunctionType::get(Type::getVoidTy(Context), std::vector<Type *>(), false);
Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
BasicBlock *LoopBB = BasicBlock::Create(Context, "bb1", F);
BranchInst::Create(LoopBB, EntryBB);
auto *Ty = Type::getInt32Ty(Context);
SmallVector<Instruction*, 8> Muls(8), Acc(8), NextAcc(8);
Acc[0] = PHINode::Create(Ty, 2, "", LoopBB);
Acc[1] = PHINode::Create(Ty, 2, "", LoopBB);
Acc[2] = PHINode::Create(Ty, 2, "", LoopBB);
Acc[3] = PHINode::Create(Ty, 2, "", LoopBB);
Acc[4] = PHINode::Create(Ty, 2, "", LoopBB);
Acc[5] = PHINode::Create(Ty, 2, "", LoopBB);
Acc[6] = PHINode::Create(Ty, 2, "", LoopBB);
Acc[7] = PHINode::Create(Ty, 2, "", LoopBB);
for (int i = 0; i < 20; i++) {
Muls[0] = BinaryOperator::CreateMul(Acc[0], Acc[0], "", LoopBB);
NextAcc[0] = BinaryOperator::CreateAdd(Muls[0], Acc[4], "", LoopBB);
Muls[1] = BinaryOperator::CreateMul(Acc[1], Acc[1], "", LoopBB);
NextAcc[1] = BinaryOperator::CreateAdd(Muls[1], Acc[5], "", LoopBB);
Muls[2] = BinaryOperator::CreateMul(Acc[2], Acc[2], "", LoopBB);
NextAcc[2] = BinaryOperator::CreateAdd(Muls[2], Acc[6], "", LoopBB);
Muls[3] = BinaryOperator::CreateMul(Acc[3], Acc[3], "", LoopBB);
NextAcc[3] = BinaryOperator::CreateAdd(Muls[3], Acc[7], "", LoopBB);
Muls[4] = BinaryOperator::CreateMul(Acc[4], Acc[4], "", LoopBB);
NextAcc[4] = BinaryOperator::CreateAdd(Muls[4], Acc[0], "", LoopBB);
Muls[5] = BinaryOperator::CreateMul(Acc[5], Acc[5], "", LoopBB);
NextAcc[5] = BinaryOperator::CreateAdd(Muls[5], Acc[1], "", LoopBB);
Muls[6] = BinaryOperator::CreateMul(Acc[6], Acc[6], "", LoopBB);
NextAcc[6] = BinaryOperator::CreateAdd(Muls[6], Acc[2], "", LoopBB);
Muls[7] = BinaryOperator::CreateMul(Acc[7], Acc[7], "", LoopBB);
NextAcc[7] = BinaryOperator::CreateAdd(Muls[7], Acc[3], "", LoopBB);
Acc = NextAcc;
}
auto II = LoopBB->begin();
for (int i = 0; i < 8; i++) {
PHINode *Phi = cast<PHINode>(&*II++);
Phi->addIncoming(Acc[i], LoopBB);
Phi->addIncoming(UndefValue::get(Ty), EntryBB);
}
BasicBlock *ExitBB = BasicBlock::Create(Context, "bb2", F);
BranchInst::Create(LoopBB, ExitBB, UndefValue::get(Type::getInt1Ty(Context)),
LoopBB);
Acc[0] = BinaryOperator::CreateAdd(Acc[0], Acc[1], "", ExitBB);
Acc[1] = BinaryOperator::CreateAdd(Acc[2], Acc[3], "", ExitBB);
Acc[2] = BinaryOperator::CreateAdd(Acc[4], Acc[5], "", ExitBB);
Acc[3] = BinaryOperator::CreateAdd(Acc[6], Acc[7], "", ExitBB);
Acc[0] = BinaryOperator::CreateAdd(Acc[0], Acc[1], "", ExitBB);
Acc[1] = BinaryOperator::CreateAdd(Acc[2], Acc[3], "", ExitBB);
Acc[0] = BinaryOperator::CreateAdd(Acc[0], Acc[1], "", ExitBB);
ReturnInst::Create(Context, nullptr, ExitBB);
ScalarEvolution SE = buildSE(*F);
EXPECT_NE(nullptr, SE.getSCEV(Acc[0]));
}
TEST_F(ScalarEvolutionsTest, CompareValueComplexity) {
IntegerType *IntPtrTy = M.getDataLayout().getIntPtrType(Context);
PointerType *IntPtrPtrTy = IntPtrTy->getPointerTo();
FunctionType *FTy =
FunctionType::get(Type::getVoidTy(Context), {IntPtrTy, IntPtrTy}, false);
Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
Value *X = &*F->arg_begin();
Value *Y = &*std::next(F->arg_begin());
const int ValueDepth = 10;
for (int i = 0; i < ValueDepth; i++) {
X = new LoadInst(new IntToPtrInst(X, IntPtrPtrTy, "", EntryBB), "",
/*isVolatile*/ false, EntryBB);
Y = new LoadInst(new IntToPtrInst(Y, IntPtrPtrTy, "", EntryBB), "",
/*isVolatile*/ false, EntryBB);
}
auto *MulA = BinaryOperator::CreateMul(X, Y, "", EntryBB);
auto *MulB = BinaryOperator::CreateMul(Y, X, "", EntryBB);
ReturnInst::Create(Context, nullptr, EntryBB);
// This test isn't checking for correctness. Today making A and B resolve to
// the same SCEV would require deeper searching in CompareValueComplexity,
// which will slow down compilation. However, this test can fail (with LLVM's
// behavior still being correct) if we ever have a smarter
// CompareValueComplexity that is both fast and more accurate.
ScalarEvolution SE = buildSE(*F);
auto *A = SE.getSCEV(MulA);
auto *B = SE.getSCEV(MulB);
EXPECT_NE(A, B);
}
TEST_F(ScalarEvolutionsTest, SCEVAddExpr) {
Type *Ty32 = Type::getInt32Ty(Context);
Type *ArgTys[] = {Type::getInt64Ty(Context), Ty32};
FunctionType *FTy =
FunctionType::get(Type::getVoidTy(Context), ArgTys, false);
Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
Argument *A1 = &*F->arg_begin();
Argument *A2 = &*(std::next(F->arg_begin()));
BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F);
Instruction *Trunc = CastInst::CreateTruncOrBitCast(A1, Ty32, "", EntryBB);
Instruction *Mul1 = BinaryOperator::CreateMul(Trunc, A2, "", EntryBB);
Instruction *Add1 = BinaryOperator::CreateAdd(Mul1, Trunc, "", EntryBB);
Mul1 = BinaryOperator::CreateMul(Add1, Trunc, "", EntryBB);
Instruction *Add2 = BinaryOperator::CreateAdd(Mul1, Add1, "", EntryBB);
// FIXME: The size of this is arbitrary and doesn't seem to change the
// result, but SCEV will do quadratic work for these so a large number here
// will be extremely slow. We should revisit what and how this is testing
// SCEV.
for (int i = 0; i < 10; i++) {
Mul1 = BinaryOperator::CreateMul(Add2, Add1, "", EntryBB);
Add1 = Add2;
Add2 = BinaryOperator::CreateAdd(Mul1, Add1, "", EntryBB);
}
ReturnInst::Create(Context, nullptr, EntryBB);
ScalarEvolution SE = buildSE(*F);
EXPECT_NE(nullptr, SE.getSCEV(Mul1));
}
} // end anonymous namespace
} // end namespace llvm
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