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//===- UnrollAnalyzerTest.cpp - UnrollAnalyzer 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/AsmParser/Parser.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Analysis/LoopUnrollAnalyzer.h"
#include "llvm/IR/Dominators.h"
#include "gtest/gtest.h"
using namespace llvm;
namespace llvm {
void initializeUnrollAnalyzerTestPass(PassRegistry &);
static SmallVector<DenseMap<Value *, Constant *>, 16> SimplifiedValuesVector;
static unsigned TripCount = 0;
namespace {
struct UnrollAnalyzerTest : public FunctionPass {
static char ID;
bool runOnFunction(Function &F) override {
LoopInfo *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
ScalarEvolution *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
Function::iterator FI = F.begin();
FI++; // First basic block is entry - skip it.
BasicBlock *Header = &*FI++;
Loop *L = LI->getLoopFor(Header);
BasicBlock *Exiting = L->getExitingBlock();
SimplifiedValuesVector.clear();
TripCount = SE->getSmallConstantTripCount(L, Exiting);
for (unsigned Iteration = 0; Iteration < TripCount; Iteration++) {
DenseMap<Value *, Constant *> SimplifiedValues;
UnrolledInstAnalyzer Analyzer(Iteration, SimplifiedValues, *SE, L);
for (auto *BB : L->getBlocks())
for (Instruction &I : *BB)
Analyzer.visit(I);
SimplifiedValuesVector.push_back(SimplifiedValues);
}
return false;
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addRequired<DominatorTreeWrapperPass>();
AU.addRequired<LoopInfoWrapperPass>();
AU.addRequired<ScalarEvolutionWrapperPass>();
AU.setPreservesAll();
}
UnrollAnalyzerTest() : FunctionPass(ID) {
initializeUnrollAnalyzerTestPass(*PassRegistry::getPassRegistry());
}
};
}
char UnrollAnalyzerTest::ID = 0;
std::unique_ptr<Module> makeLLVMModule(UnrollAnalyzerTest *P,
const char *ModuleStr) {
LLVMContext &C = getGlobalContext();
SMDiagnostic Err;
return parseAssemblyString(ModuleStr, Err, C);
}
TEST(UnrollAnalyzerTest, BasicSimplifications) {
const char *ModuleStr =
"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
"define i64 @propagate_loop_phis() {\n"
"entry:\n"
" br label %loop\n"
"loop:\n"
" %iv = phi i64 [ 0, %entry ], [ %inc, %loop ]\n"
" %x0 = phi i64 [ 0, %entry ], [ %x2, %loop ]\n"
" %x1 = or i64 %x0, 1\n"
" %x2 = or i64 %x1, 2\n"
" %inc = add nuw nsw i64 %iv, 1\n"
" %cond = icmp sge i64 %inc, 8\n"
" br i1 %cond, label %loop.end, label %loop\n"
"loop.end:\n"
" %x.lcssa = phi i64 [ %x2, %loop ]\n"
" ret i64 %x.lcssa\n"
"}\n";
UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
std::unique_ptr<Module> M = makeLLVMModule(P, ModuleStr);
legacy::PassManager Passes;
Passes.add(P);
Passes.run(*M);
// Perform checks
Module::iterator MI = M->begin();
Function *F = &*MI++;
Function::iterator FI = F->begin();
FI++; // First basic block is entry - skip it.
BasicBlock *Header = &*FI++;
BasicBlock::iterator BBI = Header->begin();
std::advance(BBI, 4);
Instruction *Y1 = &*BBI++;
Instruction *Y2 = &*BBI++;
// Check simplification expected on the 1st iteration.
// Check that "%inc = add nuw nsw i64 %iv, 1" is simplified to 1
auto I1 = SimplifiedValuesVector[0].find(Y1);
EXPECT_TRUE(I1 != SimplifiedValuesVector[0].end());
EXPECT_EQ(dyn_cast<ConstantInt>((*I1).second)->getZExtValue(), 1U);
// Check that "%cond = icmp sge i64 %inc, 10" is simplified to false
auto I2 = SimplifiedValuesVector[0].find(Y2);
EXPECT_TRUE(I2 != SimplifiedValuesVector[0].end());
EXPECT_FALSE(dyn_cast<ConstantInt>((*I2).second)->getZExtValue());
// Check simplification expected on the last iteration.
// Check that "%inc = add nuw nsw i64 %iv, 1" is simplified to 8
I1 = SimplifiedValuesVector[TripCount - 1].find(Y1);
EXPECT_TRUE(I1 != SimplifiedValuesVector[TripCount - 1].end());
EXPECT_EQ(dyn_cast<ConstantInt>((*I1).second)->getZExtValue(), TripCount);
// Check that "%cond = icmp sge i64 %inc, 10" is simplified to false
I2 = SimplifiedValuesVector[TripCount - 1].find(Y2);
EXPECT_TRUE(I2 != SimplifiedValuesVector[TripCount - 1].end());
EXPECT_TRUE(dyn_cast<ConstantInt>((*I2).second)->getZExtValue());
}
TEST(UnrollAnalyzerTest, OuterLoopSimplification) {
const char *ModuleStr =
"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
"define void @foo() {\n"
"entry:\n"
" br label %outer.loop\n"
"outer.loop:\n"
" %iv.outer = phi i64 [ 0, %entry ], [ %iv.outer.next, %outer.loop.latch ]\n"
" br label %inner.loop\n"
"inner.loop:\n"
" %iv.inner = phi i64 [ 0, %outer.loop ], [ %iv.inner.next, %inner.loop ]\n"
" %iv.inner.next = add nuw nsw i64 %iv.inner, 1\n"
" %exitcond.inner = icmp eq i64 %iv.inner.next, 1000\n"
" br i1 %exitcond.inner, label %outer.loop.latch, label %inner.loop\n"
"outer.loop.latch:\n"
" %iv.outer.next = add nuw nsw i64 %iv.outer, 1\n"
" %exitcond.outer = icmp eq i64 %iv.outer.next, 40\n"
" br i1 %exitcond.outer, label %exit, label %outer.loop\n"
"exit:\n"
" ret void\n"
"}\n";
UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
std::unique_ptr<Module> M = makeLLVMModule(P, ModuleStr);
legacy::PassManager Passes;
Passes.add(P);
Passes.run(*M);
Module::iterator MI = M->begin();
Function *F = &*MI++;
Function::iterator FI = F->begin();
FI++;
BasicBlock *Header = &*FI++;
BasicBlock *InnerBody = &*FI++;
BasicBlock::iterator BBI = Header->begin();
Instruction *Y1 = &*BBI++;
BBI = InnerBody->begin();
Instruction *Y2 = &*BBI++;
// Check that we can simplify IV of the outer loop, but can't simplify the IV
// of the inner loop if we only know the iteration number of the outer loop.
auto I1 = SimplifiedValuesVector[0].find(Y1);
EXPECT_TRUE(I1 != SimplifiedValuesVector[0].end());
auto I2 = SimplifiedValuesVector[0].find(Y2);
EXPECT_TRUE(I2 == SimplifiedValuesVector[0].end());
}
} // end namespace llvm
INITIALIZE_PASS_BEGIN(UnrollAnalyzerTest, "unrollanalyzertestpass",
"unrollanalyzertestpass", false, false)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
INITIALIZE_PASS_END(UnrollAnalyzerTest, "unrollanalyzertestpass",
"unrollanalyzertestpass", false, false)
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