unittests/Analysis/OrderedInstructionsTest.cpp

   1 //===- OrderedInstructions.cpp - Unit tests for OrderedInstructions  ------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/Analysis/OrderedInstructions.h"
  11 #include "llvm/IR/BasicBlock.h"
  12 #include "llvm/IR/Dominators.h"
  13 #include "llvm/IR/IRBuilder.h"
  14 #include "llvm/IR/Instructions.h"
  15 #include "llvm/IR/LLVMContext.h"
  16 #include "llvm/IR/Module.h"
  17 #include "gtest/gtest.h"
  18
  19 using namespace llvm;
  20
  21 /// Check intra-basicblock and inter-basicblock dominance using
  22 /// OrderedInstruction.
  23 TEST(OrderedInstructionsTest, DominanceTest) {
  24   LLVMContext Ctx;
  25   Module M("test", Ctx);
  26   IRBuilder<> B(Ctx);
  27   FunctionType *FTy =
  28       FunctionType::get(Type::getVoidTy(Ctx), {B.getInt8PtrTy()}, false);
  29   Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
  30
  31   // Create the function as follow and check for dominance relation.
  32   //
  33   // test():
  34   //  bbx:
  35   //    loadx;
  36   //    loady;
  37   //  bby:
  38   //    loadz;
  39   //    return;
  40   //
  41   // More specifically, check for loadx -> (dominates) loady,
  42   // loady -> loadx and loady -> loadz.
  43   //
  44   // Create BBX with 2 loads.
  45   BasicBlock *BBX = BasicBlock::Create(Ctx, "bbx", F);
  46   B.SetInsertPoint(BBX);
  47   Argument *PointerArg = &*F->arg_begin();
  48   LoadInst *LoadInstX = B.CreateLoad(PointerArg);
  49   LoadInst *LoadInstY = B.CreateLoad(PointerArg);
  50
  51   // Create BBY with 1 load.
  52   BasicBlock *BBY = BasicBlock::Create(Ctx, "bby", F);
  53   B.SetInsertPoint(BBY);
  54   LoadInst *LoadInstZ = B.CreateLoad(PointerArg);
  55   B.CreateRet(LoadInstZ);
  56   std::unique_ptr<DominatorTree> DT(new DominatorTree(*F));
  57   OrderedInstructions OI(&*DT);
  58
  59   // Intra-BB dominance test.
  60   EXPECT_TRUE(OI.dominates(LoadInstX, LoadInstY));
  61   EXPECT_FALSE(OI.dominates(LoadInstY, LoadInstX));
  62
  63   // Inter-BB dominance test.
  64   EXPECT_TRUE(OI.dominates(LoadInstY, LoadInstZ));
  65 }