unittests/Transforms/Utils/Local.cpp

   1 //===- Local.cpp - Unit tests for Local -----------------------------------===//
   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/Transforms/Utils/Local.h"
  11 #include "llvm/IR/BasicBlock.h"
  12 #include "llvm/IR/IRBuilder.h"
  13 #include "llvm/IR/Instructions.h"
  14 #include "llvm/IR/LLVMContext.h"
  15 #include "gtest/gtest.h"
  16
  17 using namespace llvm;
  18
  19 TEST(Local, RecursivelyDeleteDeadPHINodes) {
  20   LLVMContext &C(getGlobalContext());
  21
  22   IRBuilder<> builder(C);
  23
  24   // Make blocks
  25   BasicBlock *bb0 = BasicBlock::Create(C);
  26   BasicBlock *bb1 = BasicBlock::Create(C);
  27
  28   builder.SetInsertPoint(bb0);
  29   PHINode    *phi = builder.CreatePHI(Type::getInt32Ty(C), 2);
  30   BranchInst *br0 = builder.CreateCondBr(builder.getTrue(), bb0, bb1);
  31
  32   builder.SetInsertPoint(bb1);
  33   BranchInst *br1 = builder.CreateBr(bb0);
  34
  35   phi->addIncoming(phi, bb0);
  36   phi->addIncoming(phi, bb1);
  37
  38   // The PHI will be removed
  39   EXPECT_TRUE(RecursivelyDeleteDeadPHINode(phi));
  40
  41   // Make sure the blocks only contain the branches
  42   EXPECT_EQ(&bb0->front(), br0);
  43   EXPECT_EQ(&bb1->front(), br1);
  44
  45   builder.SetInsertPoint(bb0);
  46   phi = builder.CreatePHI(Type::getInt32Ty(C), 0);
  47
  48   EXPECT_TRUE(RecursivelyDeleteDeadPHINode(phi));
  49
  50   builder.SetInsertPoint(bb0);
  51   phi = builder.CreatePHI(Type::getInt32Ty(C), 0);
  52   builder.CreateAdd(phi, phi);
  53
  54   EXPECT_TRUE(RecursivelyDeleteDeadPHINode(phi));
  55
  56   bb0->dropAllReferences();
  57   bb1->dropAllReferences();
  58   delete bb0;
  59   delete bb1;
  60 }
  61
  62 TEST(Local, RemoveDuplicatePHINodes) {
  63   LLVMContext &C(getGlobalContext());
  64   IRBuilder<> B(C);
  65
  66   std::unique_ptr<Function> F(
  67       Function::Create(FunctionType::get(B.getVoidTy(), false),
  68                        GlobalValue::ExternalLinkage, "F"));
  69   BasicBlock *Entry(BasicBlock::Create(C, "", F.get()));
  70   BasicBlock *BB(BasicBlock::Create(C, "", F.get()));
  71   BranchInst::Create(BB, Entry);
  72
  73   B.SetInsertPoint(BB);
  74
  75   AssertingVH<PHINode> P1 = B.CreatePHI(Type::getInt32Ty(C), 2);
  76   P1->addIncoming(B.getInt32(42), Entry);
  77
  78   PHINode *P2 = B.CreatePHI(Type::getInt32Ty(C), 2);
  79   P2->addIncoming(B.getInt32(42), Entry);
  80
  81   AssertingVH<PHINode> P3 = B.CreatePHI(Type::getInt32Ty(C), 2);
  82   P3->addIncoming(B.getInt32(42), Entry);
  83   P3->addIncoming(B.getInt32(23), BB);
  84
  85   PHINode *P4 = B.CreatePHI(Type::getInt32Ty(C), 2);
  86   P4->addIncoming(B.getInt32(42), Entry);
  87   P4->addIncoming(B.getInt32(23), BB);
  88
  89   P1->addIncoming(P3, BB);
  90   P2->addIncoming(P4, BB);
  91   BranchInst::Create(BB, BB);
  92
  93   // Verify that we can eliminate PHIs that become duplicates after chaning PHIs
  94   // downstream.
  95   EXPECT_TRUE(EliminateDuplicatePHINodes(BB));
  96   EXPECT_EQ(3U, BB->size());
  97 }