unittests/Analysis/OrderedInstructionsTest.cpp

   1 //===- OrderedInstructions.cpp - Unit tests for OrderedInstructions  ------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/Analysis/OrderedInstructions.h"
  10 #include "llvm/IR/BasicBlock.h"
  11 #include "llvm/IR/Dominators.h"
  12 #include "llvm/IR/IRBuilder.h"
  13 #include "llvm/IR/Instructions.h"
  14 #include "llvm/IR/LLVMContext.h"
  15 #include "llvm/IR/Module.h"
  16 #include "gtest/gtest.h"
  17
  18 using namespace llvm;
  19
  20 /// Check intra-basicblock and inter-basicblock dominance using
  21 /// OrderedInstruction.
  22 TEST(OrderedInstructionsTest, DominanceTest) {
  23   LLVMContext Ctx;
  24   Module M("test", Ctx);
  25   IRBuilder<> B(Ctx);
  26   FunctionType *FTy =
  27       FunctionType::get(Type::getVoidTy(Ctx), {B.getInt8PtrTy()}, false);
  28   Function *F = Function::Create(FTy, Function::ExternalLinkage, "f", M);
  29
  30   // Create the function as follow and check for dominance relation.
  31   //
  32   // test():
  33   //  bbx:
  34   //    loadx;
  35   //    loady;
  36   //  bby:
  37   //    loadz;
  38   //    return;
  39   //
  40   // More specifically, check for loadx -> (dominates) loady,
  41   // loady -> loadx and loady -> loadz.
  42   //
  43   // Create BBX with 2 loads.
  44   BasicBlock *BBX = BasicBlock::Create(Ctx, "bbx", F);
  45   B.SetInsertPoint(BBX);
  46   Argument *PointerArg = &*F->arg_begin();
  47   LoadInst *LoadInstX = B.CreateLoad(B.getInt8Ty(), PointerArg);
  48   LoadInst *LoadInstY = B.CreateLoad(B.getInt8Ty(), PointerArg);
  49
  50   // Create BBY with 1 load.
  51   BasicBlock *BBY = BasicBlock::Create(Ctx, "bby", F);
  52   B.SetInsertPoint(BBY);
  53   LoadInst *LoadInstZ = B.CreateLoad(B.getInt8Ty(), PointerArg);
  54   B.CreateRet(LoadInstZ);
  55   std::unique_ptr<DominatorTree> DT(new DominatorTree(*F));
  56   OrderedInstructions OI(&*DT);
  57
  58   // Intra-BB dominance test.
  59   EXPECT_TRUE(OI.dominates(LoadInstX, LoadInstY));
  60   EXPECT_FALSE(OI.dominates(LoadInstY, LoadInstX));
  61
  62   // Inter-BB dominance test.
  63   EXPECT_TRUE(OI.dominates(LoadInstY, LoadInstZ));
  64 }