text: //===- 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)
  