llvm-project/llvm/unittests/IR/DominatorTreeTest.cpp

260 lines
9.2 KiB
C++

//===- llvm/unittests/IR/DominatorTreeTest.cpp - Constants 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/PostDominators.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
/// Build the dominator tree for the function and run the Test.
static void
runWithDomTree(Module &M, StringRef FuncName,
function_ref<void(Function &F, DominatorTree *DT,
DominatorTreeBase<BasicBlock> *PDT)>
Test) {
auto *F = M.getFunction(FuncName);
ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
// Compute the dominator tree for the function.
DominatorTree DT(*F);
DominatorTreeBase<BasicBlock> PDT(/*isPostDom*/ true);
PDT.recalculate(*F);
Test(*F, &DT, &PDT);
}
static std::unique_ptr<Module> makeLLVMModule(LLVMContext &Context,
StringRef ModuleStr) {
SMDiagnostic Err;
std::unique_ptr<Module> M = parseAssemblyString(ModuleStr, Err, Context);
assert(M && "Bad assembly?");
return M;
}
TEST(DominatorTree, Unreachable) {
StringRef ModuleString =
"declare i32 @g()\n"
"define void @f(i32 %x) personality i32 ()* @g {\n"
"bb0:\n"
" %y1 = add i32 %x, 1\n"
" %y2 = add i32 %x, 1\n"
" %y3 = invoke i32 @g() to label %bb1 unwind label %bb2\n"
"bb1:\n"
" %y4 = add i32 %x, 1\n"
" br label %bb4\n"
"bb2:\n"
" %y5 = landingpad i32\n"
" cleanup\n"
" br label %bb4\n"
"bb3:\n"
" %y6 = add i32 %x, 1\n"
" %y7 = add i32 %x, 1\n"
" ret void\n"
"bb4:\n"
" %y8 = phi i32 [0, %bb2], [%y4, %bb1]\n"
" %y9 = phi i32 [0, %bb2], [%y4, %bb1]\n"
" ret void\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleString);
runWithDomTree(
*M, "f",
[&](Function &F, DominatorTree *DT, DominatorTreeBase<BasicBlock> *PDT) {
Function::iterator FI = F.begin();
BasicBlock *BB0 = &*FI++;
BasicBlock::iterator BBI = BB0->begin();
Instruction *Y1 = &*BBI++;
Instruction *Y2 = &*BBI++;
Instruction *Y3 = &*BBI++;
BasicBlock *BB1 = &*FI++;
BBI = BB1->begin();
Instruction *Y4 = &*BBI++;
BasicBlock *BB2 = &*FI++;
BBI = BB2->begin();
Instruction *Y5 = &*BBI++;
BasicBlock *BB3 = &*FI++;
BBI = BB3->begin();
Instruction *Y6 = &*BBI++;
Instruction *Y7 = &*BBI++;
BasicBlock *BB4 = &*FI++;
BBI = BB4->begin();
Instruction *Y8 = &*BBI++;
Instruction *Y9 = &*BBI++;
// Reachability
EXPECT_TRUE(DT->isReachableFromEntry(BB0));
EXPECT_TRUE(DT->isReachableFromEntry(BB1));
EXPECT_TRUE(DT->isReachableFromEntry(BB2));
EXPECT_FALSE(DT->isReachableFromEntry(BB3));
EXPECT_TRUE(DT->isReachableFromEntry(BB4));
// BB dominance
EXPECT_TRUE(DT->dominates(BB0, BB0));
EXPECT_TRUE(DT->dominates(BB0, BB1));
EXPECT_TRUE(DT->dominates(BB0, BB2));
EXPECT_TRUE(DT->dominates(BB0, BB3));
EXPECT_TRUE(DT->dominates(BB0, BB4));
EXPECT_FALSE(DT->dominates(BB1, BB0));
EXPECT_TRUE(DT->dominates(BB1, BB1));
EXPECT_FALSE(DT->dominates(BB1, BB2));
EXPECT_TRUE(DT->dominates(BB1, BB3));
EXPECT_FALSE(DT->dominates(BB1, BB4));
EXPECT_FALSE(DT->dominates(BB2, BB0));
EXPECT_FALSE(DT->dominates(BB2, BB1));
EXPECT_TRUE(DT->dominates(BB2, BB2));
EXPECT_TRUE(DT->dominates(BB2, BB3));
EXPECT_FALSE(DT->dominates(BB2, BB4));
EXPECT_FALSE(DT->dominates(BB3, BB0));
EXPECT_FALSE(DT->dominates(BB3, BB1));
EXPECT_FALSE(DT->dominates(BB3, BB2));
EXPECT_TRUE(DT->dominates(BB3, BB3));
EXPECT_FALSE(DT->dominates(BB3, BB4));
// BB proper dominance
EXPECT_FALSE(DT->properlyDominates(BB0, BB0));
EXPECT_TRUE(DT->properlyDominates(BB0, BB1));
EXPECT_TRUE(DT->properlyDominates(BB0, BB2));
EXPECT_TRUE(DT->properlyDominates(BB0, BB3));
EXPECT_FALSE(DT->properlyDominates(BB1, BB0));
EXPECT_FALSE(DT->properlyDominates(BB1, BB1));
EXPECT_FALSE(DT->properlyDominates(BB1, BB2));
EXPECT_TRUE(DT->properlyDominates(BB1, BB3));
EXPECT_FALSE(DT->properlyDominates(BB2, BB0));
EXPECT_FALSE(DT->properlyDominates(BB2, BB1));
EXPECT_FALSE(DT->properlyDominates(BB2, BB2));
EXPECT_TRUE(DT->properlyDominates(BB2, BB3));
EXPECT_FALSE(DT->properlyDominates(BB3, BB0));
EXPECT_FALSE(DT->properlyDominates(BB3, BB1));
EXPECT_FALSE(DT->properlyDominates(BB3, BB2));
EXPECT_FALSE(DT->properlyDominates(BB3, BB3));
// Instruction dominance in the same reachable BB
EXPECT_FALSE(DT->dominates(Y1, Y1));
EXPECT_TRUE(DT->dominates(Y1, Y2));
EXPECT_FALSE(DT->dominates(Y2, Y1));
EXPECT_FALSE(DT->dominates(Y2, Y2));
// Instruction dominance in the same unreachable BB
EXPECT_TRUE(DT->dominates(Y6, Y6));
EXPECT_TRUE(DT->dominates(Y6, Y7));
EXPECT_TRUE(DT->dominates(Y7, Y6));
EXPECT_TRUE(DT->dominates(Y7, Y7));
// Invoke
EXPECT_TRUE(DT->dominates(Y3, Y4));
EXPECT_FALSE(DT->dominates(Y3, Y5));
// Phi
EXPECT_TRUE(DT->dominates(Y2, Y9));
EXPECT_FALSE(DT->dominates(Y3, Y9));
EXPECT_FALSE(DT->dominates(Y8, Y9));
// Anything dominates unreachable
EXPECT_TRUE(DT->dominates(Y1, Y6));
EXPECT_TRUE(DT->dominates(Y3, Y6));
// Unreachable doesn't dominate reachable
EXPECT_FALSE(DT->dominates(Y6, Y1));
// Instruction, BB dominance
EXPECT_FALSE(DT->dominates(Y1, BB0));
EXPECT_TRUE(DT->dominates(Y1, BB1));
EXPECT_TRUE(DT->dominates(Y1, BB2));
EXPECT_TRUE(DT->dominates(Y1, BB3));
EXPECT_TRUE(DT->dominates(Y1, BB4));
EXPECT_FALSE(DT->dominates(Y3, BB0));
EXPECT_TRUE(DT->dominates(Y3, BB1));
EXPECT_FALSE(DT->dominates(Y3, BB2));
EXPECT_TRUE(DT->dominates(Y3, BB3));
EXPECT_FALSE(DT->dominates(Y3, BB4));
EXPECT_TRUE(DT->dominates(Y6, BB3));
// Post dominance.
EXPECT_TRUE(PDT->dominates(BB0, BB0));
EXPECT_FALSE(PDT->dominates(BB1, BB0));
EXPECT_FALSE(PDT->dominates(BB2, BB0));
EXPECT_FALSE(PDT->dominates(BB3, BB0));
EXPECT_TRUE(PDT->dominates(BB4, BB1));
// Dominance descendants.
SmallVector<BasicBlock *, 8> DominatedBBs, PostDominatedBBs;
DT->getDescendants(BB0, DominatedBBs);
PDT->getDescendants(BB0, PostDominatedBBs);
EXPECT_EQ(DominatedBBs.size(), 4UL);
EXPECT_EQ(PostDominatedBBs.size(), 1UL);
// BB3 is unreachable. It should have no dominators nor postdominators.
DominatedBBs.clear();
PostDominatedBBs.clear();
DT->getDescendants(BB3, DominatedBBs);
DT->getDescendants(BB3, PostDominatedBBs);
EXPECT_EQ(DominatedBBs.size(), 0UL);
EXPECT_EQ(PostDominatedBBs.size(), 0UL);
// Check DFS Numbers before
EXPECT_EQ(DT->getNode(BB0)->getDFSNumIn(), 0UL);
EXPECT_EQ(DT->getNode(BB0)->getDFSNumOut(), 7UL);
EXPECT_EQ(DT->getNode(BB1)->getDFSNumIn(), 1UL);
EXPECT_EQ(DT->getNode(BB1)->getDFSNumOut(), 2UL);
EXPECT_EQ(DT->getNode(BB2)->getDFSNumIn(), 5UL);
EXPECT_EQ(DT->getNode(BB2)->getDFSNumOut(), 6UL);
EXPECT_EQ(DT->getNode(BB4)->getDFSNumIn(), 3UL);
EXPECT_EQ(DT->getNode(BB4)->getDFSNumOut(), 4UL);
// Reattach block 3 to block 1 and recalculate
BB1->getTerminator()->eraseFromParent();
BranchInst::Create(BB4, BB3, ConstantInt::getTrue(F.getContext()), BB1);
DT->recalculate(F);
// Check DFS Numbers after
EXPECT_EQ(DT->getNode(BB0)->getDFSNumIn(), 0UL);
EXPECT_EQ(DT->getNode(BB0)->getDFSNumOut(), 9UL);
EXPECT_EQ(DT->getNode(BB1)->getDFSNumIn(), 1UL);
EXPECT_EQ(DT->getNode(BB1)->getDFSNumOut(), 4UL);
EXPECT_EQ(DT->getNode(BB2)->getDFSNumIn(), 7UL);
EXPECT_EQ(DT->getNode(BB2)->getDFSNumOut(), 8UL);
EXPECT_EQ(DT->getNode(BB3)->getDFSNumIn(), 2UL);
EXPECT_EQ(DT->getNode(BB3)->getDFSNumOut(), 3UL);
EXPECT_EQ(DT->getNode(BB4)->getDFSNumIn(), 5UL);
EXPECT_EQ(DT->getNode(BB4)->getDFSNumOut(), 6UL);
// Change root node
DT->verifyDomTree();
BasicBlock *NewEntry =
BasicBlock::Create(F.getContext(), "new_entry", &F, BB0);
BranchInst::Create(BB0, NewEntry);
EXPECT_EQ(F.begin()->getName(), NewEntry->getName());
EXPECT_TRUE(&F.getEntryBlock() == NewEntry);
DT->setNewRoot(NewEntry);
DT->verifyDomTree();
});
}