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
17using namespace llvm;
18
19TEST(Local, RecursivelyDeleteDeadPHINodes) {
20  LLVMContext C;
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
62TEST(Local, RemoveDuplicatePHINodes) {
63  LLVMContext C;
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}
98