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llvm-mirror/unittests/Analysis/LoopInfoTest.cpp
Whitney Tsang e5ca2592d4 [LoopNest] Consider loop nest with inner loop guard using outer loop
induction variable to be perfect

This patch allow more conditional branches to be considered as loop
guard, and so more loop nests can be considered perfect.

Reviewed By: bmahjour, sidbav

Differential Revision: https://reviews.llvm.org/D94717
2021-05-07 16:04:18 +00:00

1551 lines
58 KiB
C++

//===- LoopInfoTest.cpp - LoopInfo 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/LoopInfo.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Dominators.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
/// Build the loop info for the function and run the Test.
static void
runWithLoopInfo(Module &M, StringRef FuncName,
function_ref<void(Function &F, LoopInfo &LI)> Test) {
auto *F = M.getFunction(FuncName);
ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
// Compute the dominator tree and the loop info for the function.
DominatorTree DT(*F);
LoopInfo LI(DT);
Test(*F, LI);
}
/// Build the loop info and scalar evolution for the function and run the Test.
static void runWithLoopInfoPlus(
Module &M, StringRef FuncName,
function_ref<void(Function &F, LoopInfo &LI, ScalarEvolution &SE)> Test) {
auto *F = M.getFunction(FuncName);
ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
TargetLibraryInfoImpl TLII;
TargetLibraryInfo TLI(TLII);
AssumptionCache AC(*F);
DominatorTree DT(*F);
LoopInfo LI(DT);
ScalarEvolution SE(*F, TLI, AC, DT, LI);
Test(*F, LI, SE);
}
static std::unique_ptr<Module> makeLLVMModule(LLVMContext &Context,
const char *ModuleStr) {
SMDiagnostic Err;
return parseAssemblyString(ModuleStr, Err, Context);
}
// This tests that for a loop with a single latch, we get the loop id from
// its only latch, even in case the loop may not be in a simplified form.
TEST(LoopInfoTest, LoopWithSingleLatch) {
const char *ModuleStr =
"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
"define void @foo(i32 %n) {\n"
"entry:\n"
" br i1 undef, label %for.cond, label %for.end\n"
"for.cond:\n"
" %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]\n"
" %cmp = icmp slt i32 %i.0, %n\n"
" br i1 %cmp, label %for.inc, label %for.end\n"
"for.inc:\n"
" %inc = add nsw i32 %i.0, 1\n"
" br label %for.cond, !llvm.loop !0\n"
"for.end:\n"
" ret void\n"
"}\n"
"!0 = distinct !{!0, !1}\n"
"!1 = !{!\"llvm.loop.distribute.enable\", i1 true}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfo(*M, "foo", [&](Function &F, LoopInfo &LI) {
Function::iterator FI = F.begin();
// First basic block is entry - skip it.
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.cond");
Loop *L = LI.getLoopFor(Header);
// This loop is not in simplified form.
EXPECT_FALSE(L->isLoopSimplifyForm());
// Analyze the loop metadata id.
bool loopIDFoundAndSet = false;
// Try to get and set the metadata id for the loop.
if (MDNode *D = L->getLoopID()) {
L->setLoopID(D);
loopIDFoundAndSet = true;
}
// We must have successfully found and set the loop id in the
// only latch the loop has.
EXPECT_TRUE(loopIDFoundAndSet);
});
}
// Test loop id handling for a loop with multiple latches.
TEST(LoopInfoTest, LoopWithMultipleLatches) {
const char *ModuleStr =
"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
"define void @foo(i32 %n) {\n"
"entry:\n"
" br i1 undef, label %for.cond, label %for.end\n"
"for.cond:\n"
" %i.0 = phi i32 [ 0, %entry ], [ %inc, %latch.1 ], [ %inc, %latch.2 ]\n"
" %inc = add nsw i32 %i.0, 1\n"
" %cmp = icmp slt i32 %i.0, %n\n"
" br i1 %cmp, label %latch.1, label %for.end\n"
"latch.1:\n"
" br i1 undef, label %for.cond, label %latch.2, !llvm.loop !0\n"
"latch.2:\n"
" br label %for.cond, !llvm.loop !0\n"
"for.end:\n"
" ret void\n"
"}\n"
"!0 = distinct !{!0, !1}\n"
"!1 = !{!\"llvm.loop.distribute.enable\", i1 true}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfo(*M, "foo", [&](Function &F, LoopInfo &LI) {
Function::iterator FI = F.begin();
// First basic block is entry - skip it.
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.cond");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
// This loop is not in simplified form.
EXPECT_FALSE(L->isLoopSimplifyForm());
// Try to get and set the metadata id for the loop.
MDNode *OldLoopID = L->getLoopID();
EXPECT_NE(OldLoopID, nullptr);
MDNode *NewLoopID = MDNode::get(Context, {nullptr});
// Set operand 0 to refer to the loop id itself.
NewLoopID->replaceOperandWith(0, NewLoopID);
L->setLoopID(NewLoopID);
EXPECT_EQ(L->getLoopID(), NewLoopID);
EXPECT_NE(L->getLoopID(), OldLoopID);
L->setLoopID(OldLoopID);
EXPECT_EQ(L->getLoopID(), OldLoopID);
EXPECT_NE(L->getLoopID(), NewLoopID);
});
}
TEST(LoopInfoTest, PreorderTraversals) {
const char *ModuleStr = "define void @f() {\n"
"entry:\n"
" br label %loop.0\n"
"loop.0:\n"
" br i1 undef, label %loop.0.0, label %loop.1\n"
"loop.0.0:\n"
" br i1 undef, label %loop.0.0, label %loop.0.1\n"
"loop.0.1:\n"
" br i1 undef, label %loop.0.1, label %loop.0.2\n"
"loop.0.2:\n"
" br i1 undef, label %loop.0.2, label %loop.0\n"
"loop.1:\n"
" br i1 undef, label %loop.1.0, label %end\n"
"loop.1.0:\n"
" br i1 undef, label %loop.1.0, label %loop.1.1\n"
"loop.1.1:\n"
" br i1 undef, label %loop.1.1, label %loop.1.2\n"
"loop.1.2:\n"
" br i1 undef, label %loop.1.2, label %loop.1\n"
"end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
Function &F = *M->begin();
DominatorTree DT(F);
LoopInfo LI;
LI.analyze(DT);
Function::iterator I = F.begin();
ASSERT_EQ("entry", I->getName());
++I;
Loop &L_0 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.0", L_0.getHeader()->getName());
Loop &L_0_0 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.0.0", L_0_0.getHeader()->getName());
Loop &L_0_1 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.0.1", L_0_1.getHeader()->getName());
Loop &L_0_2 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.0.2", L_0_2.getHeader()->getName());
Loop &L_1 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.1", L_1.getHeader()->getName());
Loop &L_1_0 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.1.0", L_1_0.getHeader()->getName());
Loop &L_1_1 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.1.1", L_1_1.getHeader()->getName());
Loop &L_1_2 = *LI.getLoopFor(&*I++);
ASSERT_EQ("loop.1.2", L_1_2.getHeader()->getName());
auto Preorder = LI.getLoopsInPreorder();
ASSERT_EQ(8u, Preorder.size());
EXPECT_EQ(&L_0, Preorder[0]);
EXPECT_EQ(&L_0_0, Preorder[1]);
EXPECT_EQ(&L_0_1, Preorder[2]);
EXPECT_EQ(&L_0_2, Preorder[3]);
EXPECT_EQ(&L_1, Preorder[4]);
EXPECT_EQ(&L_1_0, Preorder[5]);
EXPECT_EQ(&L_1_1, Preorder[6]);
EXPECT_EQ(&L_1_2, Preorder[7]);
auto ReverseSiblingPreorder = LI.getLoopsInReverseSiblingPreorder();
ASSERT_EQ(8u, ReverseSiblingPreorder.size());
EXPECT_EQ(&L_1, ReverseSiblingPreorder[0]);
EXPECT_EQ(&L_1_2, ReverseSiblingPreorder[1]);
EXPECT_EQ(&L_1_1, ReverseSiblingPreorder[2]);
EXPECT_EQ(&L_1_0, ReverseSiblingPreorder[3]);
EXPECT_EQ(&L_0, ReverseSiblingPreorder[4]);
EXPECT_EQ(&L_0_2, ReverseSiblingPreorder[5]);
EXPECT_EQ(&L_0_1, ReverseSiblingPreorder[6]);
EXPECT_EQ(&L_0_0, ReverseSiblingPreorder[7]);
}
TEST(LoopInfoTest, CanonicalLoop) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" %guardcmp = icmp slt i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp slt i32 %inc, %ub\n"
" br i1 %cmp, label %for.body, label %for.exit\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, LoopWithInverseGuardSuccs) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" %guardcmp = icmp sge i32 0, %ub\n"
" br i1 %guardcmp, label %for.end, label %for.preheader\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp slt i32 %inc, %ub\n"
" br i1 %cmp, label %for.body, label %for.exit\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, LoopWithSwappedGuardCmp) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" %guardcmp = icmp sgt i32 %ub, 0\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp sge i32 %inc, %ub\n"
" br i1 %cmp, label %for.exit, label %for.body\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, LoopWithInverseLatchSuccs) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" %guardcmp = icmp slt i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp sge i32 %inc, %ub\n"
" br i1 %cmp, label %for.exit, label %for.body\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, LoopWithLatchCmpNE) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" %guardcmp = icmp slt i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp ne i32 %i, %ub\n"
" br i1 %cmp, label %for.body, label %for.exit\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, LoopWithGuardCmpSLE) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" %ubPlusOne = add i32 %ub, 1\n"
" %guardcmp = icmp sle i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp ne i32 %i, %ubPlusOne\n"
" br i1 %cmp, label %for.body, label %for.exit\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ubPlusOne");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, LoopNonConstantStep) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub, i32 %step) {\n"
"entry:\n"
" %guardcmp = icmp slt i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = zext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, %step\n"
" %cmp = icmp slt i32 %inc, %ub\n"
" br i1 %cmp, label %for.body, label %for.exit\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
EXPECT_EQ(Bounds->getStepValue()->getName(), "step");
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(), Loop::LoopBounds::Direction::Unknown);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, LoopUnsignedBounds) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" %guardcmp = icmp ult i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = zext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add i32 %i, 1\n"
" %cmp = icmp ult i32 %inc, %ub\n"
" br i1 %cmp, label %for.body, label %for.exit\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_ULT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, DecreasingLoop) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" %guardcmp = icmp slt i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ %ub, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = sub nsw i32 %i, 1\n"
" %cmp = icmp sgt i32 %inc, 0\n"
" br i1 %cmp, label %for.body, label %for.exit\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
EXPECT_EQ(Bounds->getInitialIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_EQ(StepValue, nullptr);
ConstantInt *FinalIVValue =
dyn_cast<ConstantInt>(&Bounds->getFinalIVValue());
EXPECT_TRUE(FinalIVValue && FinalIVValue->isZero());
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SGT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Decreasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, CannotFindDirection) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub, i32 %step) {\n"
"entry:\n"
" %guardcmp = icmp slt i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, %step\n"
" %cmp = icmp ne i32 %i, %ub\n"
" br i1 %cmp, label %for.body, label %for.exit\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader
// - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
EXPECT_EQ(Bounds->getStepValue()->getName(), "step");
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(),
ICmpInst::BAD_ICMP_PREDICATE);
EXPECT_EQ(Bounds->getDirection(), Loop::LoopBounds::Direction::Unknown);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, ZextIndVar) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" %guardcmp = icmp slt i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %indvars.iv = phi i64 [ 0, %for.preheader ], [ %indvars.iv.next, %for.body ]\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1\n"
" %inc = add nsw i32 %i, 1\n"
" %wide.trip.count = zext i32 %ub to i64\n"
" %exitcond = icmp ne i64 %indvars.iv.next, %wide.trip.count\n"
" br i1 %exitcond, label %for.body, label %for.exit\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "indvars.iv.next");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "wide.trip.count");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_NE);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "indvars.iv");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, MultiExitingLoop) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub, i1 %cond) {\n"
"entry:\n"
" %guardcmp = icmp slt i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body.1 ]\n"
" br i1 %cond, label %for.body.1, label %for.exit\n"
"for.body.1:\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp slt i32 %inc, %ub\n"
" br i1 %cmp, label %for.body, label %for.exit\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
});
}
TEST(LoopInfoTest, MultiExitLoop) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub, i1 %cond) {\n"
"entry:\n"
" %guardcmp = icmp slt i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body.1 ]\n"
" br i1 %cond, label %for.body.1, label %for.exit\n"
"for.body.1:\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp slt i32 %inc, %ub\n"
" br i1 %cmp, label %for.body, label %for.exit.1\n"
"for.exit:\n"
" br label %for.end\n"
"for.exit.1:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), nullptr);
EXPECT_FALSE(L->isGuarded());
});
}
TEST(LoopInfoTest, UnguardedLoop) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %entry ], [ %inc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp slt i32 %inc, %ub\n"
" br i1 %cmp, label %for.body, label %for.exit\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
// First basic block is entry - skip it.
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), nullptr);
EXPECT_FALSE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, UnguardedLoopWithControlFlow) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub, i1 %cond) {\n"
"entry:\n"
" br i1 %cond, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp slt i32 %inc, %ub\n"
" br i1 %cmp, label %for.body, label %for.exit\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, LoopNest) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" %guardcmp = icmp slt i32 0, %ub\n"
" br i1 %guardcmp, label %for.outer.preheader, label %for.end\n"
"for.outer.preheader:\n"
" br label %for.outer\n"
"for.outer:\n"
" %j = phi i32 [ 0, %for.outer.preheader ], [ %inc.outer, %for.outer.latch ]\n"
" br i1 %guardcmp, label %for.inner.preheader, label %for.outer.latch\n"
"for.inner.preheader:\n"
" br label %for.inner\n"
"for.inner:\n"
" %i = phi i32 [ 0, %for.inner.preheader ], [ %inc, %for.inner ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp slt i32 %inc, %ub\n"
" br i1 %cmp, label %for.inner, label %for.inner.exit\n"
"for.inner.exit:\n"
" br label %for.outer.latch\n"
"for.outer.latch:\n"
" %inc.outer = add nsw i32 %j, 1\n"
" %cmp.outer = icmp slt i32 %inc.outer, %ub\n"
" br i1 %cmp.outer, label %for.outer, label %for.outer.exit\n"
"for.outer.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *OuterGuard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.outer.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.outer");
BranchInst *InnerGuard = dyn_cast<BranchInst>(Header->getTerminator());
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc.outer");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "j");
EXPECT_EQ(L->getLoopGuardBranch(), OuterGuard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
// Next two basic blocks are for.outer and for.inner.preheader - skip
// them.
++FI;
Header = &*(++FI);
assert(Header->getName() == "for.inner");
L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> InnerBounds = L->getBounds(SE);
EXPECT_NE(InnerBounds, None);
InitialIVValue =
dyn_cast<ConstantInt>(&InnerBounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(InnerBounds->getStepInst().getName(), "inc");
StepValue = dyn_cast_or_null<ConstantInt>(InnerBounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(InnerBounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(InnerBounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(InnerBounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
EXPECT_EQ(L->getLoopGuardBranch(), InnerGuard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, AuxiliaryIV) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" %guardcmp = icmp slt i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %aux = phi i32 [ 0, %for.preheader ], [ %auxinc, %for.body ]\n"
" %loopvariant = phi i32 [ 0, %for.preheader ], [ %loopvariantinc, %for.body ]\n"
" %usedoutside = phi i32 [ 0, %for.preheader ], [ %usedoutsideinc, %for.body ]\n"
" %mulopcode = phi i32 [ 0, %for.preheader ], [ %mulopcodeinc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %mulopcodeinc = mul nsw i32 %mulopcode, 5\n"
" %usedoutsideinc = add nsw i32 %usedoutside, 5\n"
" %loopvariantinc = add nsw i32 %loopvariant, %i\n"
" %auxinc = add nsw i32 %aux, 5\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp slt i32 %inc, %ub\n"
" br i1 %cmp, label %for.body, label %for.exit\n"
"for.exit:\n"
" %lcssa = phi i32 [ %usedoutside, %for.body ]\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
BasicBlock *Entry = &*(FI);
BranchInst *Guard = dyn_cast<BranchInst>(Entry->getTerminator());
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.body");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
Optional<Loop::LoopBounds> Bounds = L->getBounds(SE);
EXPECT_NE(Bounds, None);
ConstantInt *InitialIVValue =
dyn_cast<ConstantInt>(&Bounds->getInitialIVValue());
EXPECT_TRUE(InitialIVValue && InitialIVValue->isZero());
EXPECT_EQ(Bounds->getStepInst().getName(), "inc");
ConstantInt *StepValue =
dyn_cast_or_null<ConstantInt>(Bounds->getStepValue());
EXPECT_TRUE(StepValue && StepValue->isOne());
EXPECT_EQ(Bounds->getFinalIVValue().getName(), "ub");
EXPECT_EQ(Bounds->getCanonicalPredicate(), ICmpInst::ICMP_SLT);
EXPECT_EQ(Bounds->getDirection(),
Loop::LoopBounds::Direction::Increasing);
EXPECT_EQ(L->getInductionVariable(SE)->getName(), "i");
BasicBlock::iterator II = Header->begin();
PHINode &Instruction_i = cast<PHINode>(*(II));
EXPECT_TRUE(L->isAuxiliaryInductionVariable(Instruction_i, SE));
PHINode &Instruction_aux = cast<PHINode>(*(++II));
EXPECT_TRUE(L->isAuxiliaryInductionVariable(Instruction_aux, SE));
PHINode &Instruction_loopvariant = cast<PHINode>(*(++II));
EXPECT_FALSE(
L->isAuxiliaryInductionVariable(Instruction_loopvariant, SE));
PHINode &Instruction_usedoutside = cast<PHINode>(*(++II));
EXPECT_FALSE(
L->isAuxiliaryInductionVariable(Instruction_usedoutside, SE));
PHINode &Instruction_mulopcode = cast<PHINode>(*(++II));
EXPECT_FALSE(
L->isAuxiliaryInductionVariable(Instruction_mulopcode, SE));
EXPECT_EQ(L->getLoopGuardBranch(), Guard);
EXPECT_TRUE(L->isGuarded());
EXPECT_TRUE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, LoopNotInSimplifyForm) {
const char *ModuleStr =
"define void @foo(i32 %n) {\n"
"entry:\n"
" %guard.cmp = icmp sgt i32 %n, 0\n"
" br i1 %guard.cmp, label %for.cond, label %for.end\n"
"for.cond:\n"
" %i.0 = phi i32 [ 0, %entry ], [ %inc, %latch.1 ], [ %inc, %latch.2 ]\n"
" %inc = add nsw i32 %i.0, 1\n"
" %cmp = icmp slt i32 %i.0, %n\n"
" br i1 %cmp, label %latch.1, label %for.end\n"
"latch.1:\n"
" br i1 undef, label %for.cond, label %latch.2\n"
"latch.2:\n"
" br label %for.cond\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfo(*M, "foo", [&](Function &F, LoopInfo &LI) {
Function::iterator FI = F.begin();
// First basic block is entry - skip it.
BasicBlock *Header = &*(++FI);
assert(Header && "No header");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
EXPECT_FALSE(L->isLoopSimplifyForm());
// No loop guard because loop in not in simplify form.
EXPECT_EQ(L->getLoopGuardBranch(), nullptr);
EXPECT_FALSE(L->isGuarded());
});
}
TEST(LoopInfoTest, LoopLatchNotExiting) {
const char *ModuleStr =
"define void @foo(i32* %A, i32 %ub) {\n"
"entry:\n"
" %guardcmp = icmp slt i32 0, %ub\n"
" br i1 %guardcmp, label %for.preheader, label %for.end\n"
"for.preheader:\n"
" br label %for.body\n"
"for.body:\n"
" %i = phi i32 [ 0, %for.preheader ], [ %inc, %for.body ]\n"
" %idxprom = sext i32 %i to i64\n"
" %arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom\n"
" store i32 %i, i32* %arrayidx, align 4\n"
" %inc = add nsw i32 %i, 1\n"
" %cmp = icmp slt i32 %inc, %ub\n"
" br i1 %cmp, label %for.latch, label %for.exit\n"
"for.latch:\n"
" br label %for.body\n"
"for.exit:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfoPlus(
*M, "foo",
[&](Function &F, LoopInfo &LI, ScalarEvolution &SE) {
Function::iterator FI = F.begin();
// First two basic block are entry and for.preheader - skip them.
++FI;
BasicBlock *Header = &*(++FI);
BasicBlock *Latch = &*(++FI);
assert(Header && "No header");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
EXPECT_TRUE(L->isLoopSimplifyForm());
EXPECT_EQ(L->getLoopLatch(), Latch);
EXPECT_FALSE(L->isLoopExiting(Latch));
// No loop guard becuase loop is not exiting on latch.
EXPECT_EQ(L->getLoopGuardBranch(), nullptr);
EXPECT_FALSE(L->isGuarded());
});
}
// Examine getUniqueExitBlocks/getUniqueNonLatchExitBlocks functions.
TEST(LoopInfoTest, LoopUniqueExitBlocks) {
const char *ModuleStr =
"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
"define void @foo(i32 %n, i1 %cond) {\n"
"entry:\n"
" br label %for.cond\n"
"for.cond:\n"
" %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]\n"
" %cmp = icmp slt i32 %i.0, %n\n"
" br i1 %cond, label %for.inc, label %for.end1\n"
"for.inc:\n"
" %inc = add nsw i32 %i.0, 1\n"
" br i1 %cmp, label %for.cond, label %for.end2, !llvm.loop !0\n"
"for.end1:\n"
" br label %for.end\n"
"for.end2:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n"
"!0 = distinct !{!0, !1}\n"
"!1 = !{!\"llvm.loop.distribute.enable\", i1 true}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfo(*M, "foo", [&](Function &F, LoopInfo &LI) {
Function::iterator FI = F.begin();
// First basic block is entry - skip it.
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.cond");
Loop *L = LI.getLoopFor(Header);
SmallVector<BasicBlock *, 2> Exits;
// This loop has 2 unique exits.
L->getUniqueExitBlocks(Exits);
EXPECT_TRUE(Exits.size() == 2);
// And one unique non latch exit.
Exits.clear();
L->getUniqueNonLatchExitBlocks(Exits);
EXPECT_TRUE(Exits.size() == 1);
});
}
// Regression test for getUniqueNonLatchExitBlocks functions.
// It should detect the exit if it comes from both latch and non-latch blocks.
TEST(LoopInfoTest, LoopNonLatchUniqueExitBlocks) {
const char *ModuleStr =
"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
"define void @foo(i32 %n, i1 %cond) {\n"
"entry:\n"
" br label %for.cond\n"
"for.cond:\n"
" %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]\n"
" %cmp = icmp slt i32 %i.0, %n\n"
" br i1 %cond, label %for.inc, label %for.end\n"
"for.inc:\n"
" %inc = add nsw i32 %i.0, 1\n"
" br i1 %cmp, label %for.cond, label %for.end, !llvm.loop !0\n"
"for.end:\n"
" ret void\n"
"}\n"
"!0 = distinct !{!0, !1}\n"
"!1 = !{!\"llvm.loop.distribute.enable\", i1 true}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfo(*M, "foo", [&](Function &F, LoopInfo &LI) {
Function::iterator FI = F.begin();
// First basic block is entry - skip it.
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.cond");
Loop *L = LI.getLoopFor(Header);
SmallVector<BasicBlock *, 2> Exits;
// This loop has 1 unique exit.
L->getUniqueExitBlocks(Exits);
EXPECT_TRUE(Exits.size() == 1);
// And one unique non latch exit.
Exits.clear();
L->getUniqueNonLatchExitBlocks(Exits);
EXPECT_TRUE(Exits.size() == 1);
});
}
// Test that a pointer-chasing loop is not rotated.
TEST(LoopInfoTest, LoopNotRotated) {
const char *ModuleStr =
"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
"define void @foo(i32* %elem) {\n"
"entry:\n"
" br label %while.cond\n"
"while.cond:\n"
" %elem.addr.0 = phi i32* [ %elem, %entry ], [ %incdec.ptr, %while.body "
"]\n"
" %tobool = icmp eq i32* %elem.addr.0, null\n"
" br i1 %tobool, label %while.end, label %while.body\n"
"while.body:\n"
" %incdec.ptr = getelementptr inbounds i32, i32* %elem.addr.0, i64 1\n"
" br label %while.cond\n"
"while.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfo(*M, "foo", [&](Function &F, LoopInfo &LI) {
Function::iterator FI = F.begin();
// First basic block is entry - skip it.
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "while.cond");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
// This loop is in simplified form.
EXPECT_TRUE(L->isLoopSimplifyForm());
// This loop is not rotated.
EXPECT_FALSE(L->isRotatedForm());
});
}
TEST(LoopInfoTest, LoopUserBranch) {
const char *ModuleStr =
"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
"define void @foo(i32* %B, i64 signext %nx, i1 %cond) {\n"
"entry:\n"
" br i1 %cond, label %bb, label %guard\n"
"guard:\n"
" %cmp.guard = icmp slt i64 0, %nx\n"
" br i1 %cmp.guard, label %for.i.preheader, label %for.end\n"
"for.i.preheader:\n"
" br label %for.i\n"
"for.i:\n"
" %i = phi i64 [ 0, %for.i.preheader ], [ %inc13, %for.i ]\n"
" %Bi = getelementptr inbounds i32, i32* %B, i64 %i\n"
" store i32 0, i32* %Bi, align 4\n"
" %inc13 = add nsw i64 %i, 1\n"
" %cmp = icmp slt i64 %inc13, %nx\n"
" br i1 %cmp, label %for.i, label %for.i.exit\n"
"for.i.exit:\n"
" br label %bb\n"
"bb:\n"
" br label %for.end\n"
"for.end:\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
runWithLoopInfo(*M, "foo", [&](Function &F, LoopInfo &LI) {
Function::iterator FI = F.begin();
FI = ++FI;
BasicBlock *Guard = &*FI;
assert(Guard->getName() == "guard");
FI = ++FI;
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.i");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
// L should not have a guard branch
EXPECT_EQ(L->getLoopGuardBranch(), nullptr);
});
}