unittests/Analysis/UnrollAnalyzer.cpp - llvm - Git at Google

 //===- 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/Analysis/LoopUnrollAnalyzer.h"
 #include "llvm/AsmParser/Parser.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/Support/SourceMgr.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(LLVMContext &Context,
                                        const char *ModuleStr) {
   SMDiagnostic Err;
   return parseAssemblyString(ModuleStr, Err, Context);
 }

 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();
   LLVMContext Context;
   std::unique_ptr<Module> M = makeLLVMModule(Context, 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(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(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(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(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"
       "  %iv.outer.next = add nuw nsw i64 %iv.outer, 1\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"
       "  %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();
   LLVMContext Context;
   std::unique_ptr<Module> M = makeLLVMModule(Context, 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();
   BBI++;
   Instruction *Y1 = &*BBI;
   BBI = InnerBody->begin();
   BBI++;
   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.
   //
   //  Y1 is %iv.outer.next, Y2 is %iv.inner.next
   auto I1 = SimplifiedValuesVector[0].find(Y1);
   EXPECT_TRUE(I1 != SimplifiedValuesVector[0].end());
   auto I2 = SimplifiedValuesVector[0].find(Y2);
   EXPECT_TRUE(I2 == SimplifiedValuesVector[0].end());
 }
 TEST(UnrollAnalyzerTest, CmpSimplifications) {
   const char *ModuleStr =
       "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
       "define void @branch_iv_trunc() {\n"
       "entry:\n"
       "  br label %for.body\n"
       "for.body:\n"
       "  %indvars.iv = phi i64 [ 0, %entry ], [ %tmp3, %for.body ]\n"
       "  %tmp2 = trunc i64 %indvars.iv to i32\n"
       "  %cmp3 = icmp eq i32 %tmp2, 5\n"
       "  %tmp3 = add nuw nsw i64 %indvars.iv, 1\n"
       "  %exitcond = icmp eq i64 %tmp3, 10\n"
       "  br i1 %exitcond, label %for.end, label %for.body\n"
       "for.end:\n"
       "  ret void\n"
       "}\n";
   UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
   LLVMContext Context;
   std::unique_ptr<Module> M = makeLLVMModule(Context, 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();
   BBI++;
   Instruction *Y1 = &*BBI++;
   Instruction *Y2 = &*BBI++;
   // Check simplification expected on the 5th iteration.
   // Check that "%tmp2 = trunc i64 %indvars.iv to i32" is simplified to 5
   // and "%cmp3 = icmp eq i32 %tmp2, 5" is simplified to 1 (i.e. true).
   auto I1 = SimplifiedValuesVector[5].find(Y1);
   EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end());
   EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 5U);
   auto I2 = SimplifiedValuesVector[5].find(Y2);
   EXPECT_TRUE(I2 != SimplifiedValuesVector[5].end());
   EXPECT_EQ(cast<ConstantInt>((*I2).second)->getZExtValue(), 1U);
 }
 TEST(UnrollAnalyzerTest, PtrCmpSimplifications) {
   const char *ModuleStr =
       "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
       "define void @ptr_cmp(i8 *%a) {\n"
       "entry:\n"
       "  %limit = getelementptr i8, i8* %a, i64 40\n"
       "  %start.iv2 = getelementptr i8, i8* %a, i64 7\n"
       "  br label %loop.body\n"
       "loop.body:\n"
       "  %iv.0 = phi i8* [ %a, %entry ], [ %iv.1, %loop.body ]\n"
       "  %iv2.0 = phi i8* [ %start.iv2, %entry ], [ %iv2.1, %loop.body ]\n"
       "  %cmp = icmp eq i8* %iv2.0, %iv.0\n"
       "  %iv.1 = getelementptr inbounds i8, i8* %iv.0, i64 1\n"
       "  %iv2.1 = getelementptr inbounds i8, i8* %iv2.0, i64 1\n"
       "  %exitcond = icmp ne i8* %iv.1, %limit\n"
       "  br i1 %exitcond, label %loop.body, label %loop.exit\n"
       "loop.exit:\n"
       "  ret void\n"
       "}\n";
   UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
   LLVMContext Context;
   std::unique_ptr<Module> M = makeLLVMModule(Context, 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, 2);
   Instruction *Y1 = &*BBI;
   // Check simplification expected on the 5th iteration.
   // Check that "%cmp = icmp eq i8* %iv2.0, %iv.0" is simplified to 0.
   auto I1 = SimplifiedValuesVector[5].find(Y1);
   EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end());
   EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 0U);
 }
 TEST(UnrollAnalyzerTest, CastSimplifications) {
   const char *ModuleStr =
       "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
       "@known_constant = internal unnamed_addr constant [10 x i32] [i32 0, i32 1, i32 0, i32 1, i32 0, i32 259, i32 0, i32 1, i32 0, i32 1], align 16\n"
       "define void @const_load_cast() {\n"
       "entry:\n"
       "  br label %loop\n"
       "\n"
       "loop:\n"
       "  %iv = phi i64 [ 0, %entry ], [ %inc, %loop ]\n"
       "  %array_const_idx = getelementptr inbounds [10 x i32], [10 x i32]* @known_constant, i64 0, i64 %iv\n"
       "  %const_array_element = load i32, i32* %array_const_idx, align 4\n"
       "  %se = sext i32 %const_array_element to i64\n"
       "  %ze = zext i32 %const_array_element to i64\n"
       "  %tr = trunc i32 %const_array_element to i8\n"
       "  %inc = add nuw nsw i64 %iv, 1\n"
       "  %exitcond86.i = icmp eq i64 %inc, 10\n"
       "  br i1 %exitcond86.i, label %loop.end, label %loop\n"
       "\n"
       "loop.end:\n"
       "  ret void\n"
       "}\n";

   UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
   LLVMContext Context;
   std::unique_ptr<Module> M = makeLLVMModule(Context, 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, 3);
   Instruction *Y1 = &*BBI++;
   Instruction *Y2 = &*BBI++;
   Instruction *Y3 = &*BBI++;
   // Check simplification expected on the 5th iteration.
   // "%se = sext i32 %const_array_element to i64" should be simplified to 259,
   // "%ze = zext i32 %const_array_element to i64" should be simplified to 259,
   // "%tr = trunc i32 %const_array_element to i8" should be simplified to 3.
   auto I1 = SimplifiedValuesVector[5].find(Y1);
   EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end());
   EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 259U);
   auto I2 = SimplifiedValuesVector[5].find(Y2);
   EXPECT_TRUE(I2 != SimplifiedValuesVector[5].end());
   EXPECT_EQ(cast<ConstantInt>((*I2).second)->getZExtValue(), 259U);
   auto I3 = SimplifiedValuesVector[5].find(Y3);
   EXPECT_TRUE(I3 != SimplifiedValuesVector[5].end());
   EXPECT_EQ(cast<ConstantInt>((*I3).second)->getZExtValue(), 3U);
 }

 } // 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)
	//===- 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/Analysis/LoopUnrollAnalyzer.h"
	#include "llvm/AsmParser/Parser.h"
	#include "llvm/IR/Dominators.h"
	#include "llvm/IR/LegacyPassManager.h"
	#include "llvm/Support/SourceMgr.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(LLVMContext &Context,
	const char *ModuleStr) {
	SMDiagnostic Err;
	return parseAssemblyString(ModuleStr, Err, Context);
	}

	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();
	LLVMContext Context;
	std::unique_ptr<Module> M = makeLLVMModule(Context, 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(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(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(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(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"
	" %iv.outer.next = add nuw nsw i64 %iv.outer, 1\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"
	" %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();
	LLVMContext Context;
	std::unique_ptr<Module> M = makeLLVMModule(Context, 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();
	BBI++;
	Instruction Y1 = &BBI;
	BBI = InnerBody->begin();
	BBI++;
	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.
	//
	// Y1 is %iv.outer.next, Y2 is %iv.inner.next
	auto I1 = SimplifiedValuesVector[0].find(Y1);
	EXPECT_TRUE(I1 != SimplifiedValuesVector[0].end());
	auto I2 = SimplifiedValuesVector[0].find(Y2);
	EXPECT_TRUE(I2 == SimplifiedValuesVector[0].end());
	}
	TEST(UnrollAnalyzerTest, CmpSimplifications) {
	const char *ModuleStr =
	"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
	"define void @branch_iv_trunc() {\n"
	"entry:\n"
	" br label %for.body\n"
	"for.body:\n"
	" %indvars.iv = phi i64 [ 0, %entry ], [ %tmp3, %for.body ]\n"
	" %tmp2 = trunc i64 %indvars.iv to i32\n"
	" %cmp3 = icmp eq i32 %tmp2, 5\n"
	" %tmp3 = add nuw nsw i64 %indvars.iv, 1\n"
	" %exitcond = icmp eq i64 %tmp3, 10\n"
	" br i1 %exitcond, label %for.end, label %for.body\n"
	"for.end:\n"
	" ret void\n"
	"}\n";
	UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
	LLVMContext Context;
	std::unique_ptr<Module> M = makeLLVMModule(Context, 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();
	BBI++;
	Instruction Y1 = &BBI++;
	Instruction Y2 = &BBI++;
	// Check simplification expected on the 5th iteration.
	// Check that "%tmp2 = trunc i64 %indvars.iv to i32" is simplified to 5
	// and "%cmp3 = icmp eq i32 %tmp2, 5" is simplified to 1 (i.e. true).
	auto I1 = SimplifiedValuesVector[5].find(Y1);
	EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end());
	EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 5U);
	auto I2 = SimplifiedValuesVector[5].find(Y2);
	EXPECT_TRUE(I2 != SimplifiedValuesVector[5].end());
	EXPECT_EQ(cast<ConstantInt>((*I2).second)->getZExtValue(), 1U);
	}
	TEST(UnrollAnalyzerTest, PtrCmpSimplifications) {
	const char *ModuleStr =
	"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
	"define void @ptr_cmp(i8 *%a) {\n"
	"entry:\n"
	" %limit = getelementptr i8, i8* %a, i64 40\n"
	" %start.iv2 = getelementptr i8, i8* %a, i64 7\n"
	" br label %loop.body\n"
	"loop.body:\n"
	" %iv.0 = phi i8* [ %a, %entry ], [ %iv.1, %loop.body ]\n"
	" %iv2.0 = phi i8* [ %start.iv2, %entry ], [ %iv2.1, %loop.body ]\n"
	" %cmp = icmp eq i8* %iv2.0, %iv.0\n"
	" %iv.1 = getelementptr inbounds i8, i8* %iv.0, i64 1\n"
	" %iv2.1 = getelementptr inbounds i8, i8* %iv2.0, i64 1\n"
	" %exitcond = icmp ne i8* %iv.1, %limit\n"
	" br i1 %exitcond, label %loop.body, label %loop.exit\n"
	"loop.exit:\n"
	" ret void\n"
	"}\n";
	UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
	LLVMContext Context;
	std::unique_ptr<Module> M = makeLLVMModule(Context, 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, 2);
	Instruction Y1 = &BBI;
	// Check simplification expected on the 5th iteration.
	// Check that "%cmp = icmp eq i8* %iv2.0, %iv.0" is simplified to 0.
	auto I1 = SimplifiedValuesVector[5].find(Y1);
	EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end());
	EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 0U);
	}
	TEST(UnrollAnalyzerTest, CastSimplifications) {
	const char *ModuleStr =
	"target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
	"@known_constant = internal unnamed_addr constant [10 x i32] [i32 0, i32 1, i32 0, i32 1, i32 0, i32 259, i32 0, i32 1, i32 0, i32 1], align 16\n"
	"define void @const_load_cast() {\n"
	"entry:\n"
	" br label %loop\n"
	"\n"
	"loop:\n"
	" %iv = phi i64 [ 0, %entry ], [ %inc, %loop ]\n"
	" %array_const_idx = getelementptr inbounds [10 x i32], [10 x i32]* @known_constant, i64 0, i64 %iv\n"
	" %const_array_element = load i32, i32* %array_const_idx, align 4\n"
	" %se = sext i32 %const_array_element to i64\n"
	" %ze = zext i32 %const_array_element to i64\n"
	" %tr = trunc i32 %const_array_element to i8\n"
	" %inc = add nuw nsw i64 %iv, 1\n"
	" %exitcond86.i = icmp eq i64 %inc, 10\n"
	" br i1 %exitcond86.i, label %loop.end, label %loop\n"
	"\n"
	"loop.end:\n"
	" ret void\n"
	"}\n";

	UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
	LLVMContext Context;
	std::unique_ptr<Module> M = makeLLVMModule(Context, 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, 3);
	Instruction Y1 = &BBI++;
	Instruction Y2 = &BBI++;
	Instruction Y3 = &BBI++;
	// Check simplification expected on the 5th iteration.
	// "%se = sext i32 %const_array_element to i64" should be simplified to 259,
	// "%ze = zext i32 %const_array_element to i64" should be simplified to 259,
	// "%tr = trunc i32 %const_array_element to i8" should be simplified to 3.
	auto I1 = SimplifiedValuesVector[5].find(Y1);
	EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end());
	EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 259U);
	auto I2 = SimplifiedValuesVector[5].find(Y2);
	EXPECT_TRUE(I2 != SimplifiedValuesVector[5].end());
	EXPECT_EQ(cast<ConstantInt>((*I2).second)->getZExtValue(), 259U);
	auto I3 = SimplifiedValuesVector[5].find(Y3);
	EXPECT_TRUE(I3 != SimplifiedValuesVector[5].end());
	EXPECT_EQ(cast<ConstantInt>((*I3).second)->getZExtValue(), 3U);
	}

	} // 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)