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//===- llvm/unittests/IR/DominatorTreeTest.cpp - Constants unit tests -----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include <random>
#include "llvm/Analysis/PostDominators.h"
#include "llvm/Analysis/IteratedDominanceFrontier.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 "CFGBuilder.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, PostDominatorTree *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);
PostDominatorTree PDT(*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, PHIs) {
StringRef ModuleString = R"(
define void @f() {
bb1:
br label %bb1
bb2:
%a = phi i32 [0, %bb1], [1, %bb2]
%b = phi i32 [2, %bb1], [%a, %bb2]
br label %bb2
};
)";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleString);
runWithDomTree(*M, "f",
[&](Function &F, DominatorTree *DT, PostDominatorTree *PDT) {
auto FI = F.begin();
++FI;
BasicBlock *BB2 = &*FI;
auto BI = BB2->begin();
Instruction *PhiA = &*BI++;
Instruction *PhiB = &*BI;
// Phis are thought to execute "instantly, together".
EXPECT_TRUE(DT->dominates(PhiA, PhiB));
EXPECT_TRUE(DT->dominates(PhiB, PhiA));
});
}
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, PostDominatorTree *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
DT->updateDFSNumbers();
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);
// Check levels before
EXPECT_EQ(DT->getNode(BB0)->getLevel(), 0U);
EXPECT_EQ(DT->getNode(BB1)->getLevel(), 1U);
EXPECT_EQ(DT->getNode(BB2)->getLevel(), 1U);
EXPECT_EQ(DT->getNode(BB4)->getLevel(), 1U);
// 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
DT->updateDFSNumbers();
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);
// Check levels after
EXPECT_EQ(DT->getNode(BB0)->getLevel(), 0U);
EXPECT_EQ(DT->getNode(BB1)->getLevel(), 1U);
EXPECT_EQ(DT->getNode(BB2)->getLevel(), 1U);
EXPECT_EQ(DT->getNode(BB3)->getLevel(), 2U);
EXPECT_EQ(DT->getNode(BB4)->getLevel(), 1U);
// Change root node
EXPECT_TRUE(DT->verify());
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);
EXPECT_TRUE(DT->verify());
});
}
TEST(DominatorTree, NonUniqueEdges) {
StringRef ModuleString =
"define i32 @f(i32 %i, i32 *%p) {\n"
"bb0:\n"
" store i32 %i, i32 *%p\n"
" switch i32 %i, label %bb2 [\n"
" i32 0, label %bb1\n"
" i32 1, label %bb1\n"
" ]\n"
" bb1:\n"
" ret i32 1\n"
" bb2:\n"
" ret i32 4\n"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleString);
runWithDomTree(
*M, "f", [&](Function &F, DominatorTree *DT, PostDominatorTree *PDT) {
Function::iterator FI = F.begin();
BasicBlock *BB0 = &*FI++;
BasicBlock *BB1 = &*FI++;
BasicBlock *BB2 = &*FI++;
const Instruction *TI = BB0->getTerminator();
assert(TI->getNumSuccessors() == 3 && "Switch has three successors");
BasicBlockEdge Edge_BB0_BB2(BB0, TI->getSuccessor(0));
assert(Edge_BB0_BB2.getEnd() == BB2 &&
"Default label is the 1st successor");
BasicBlockEdge Edge_BB0_BB1_a(BB0, TI->getSuccessor(1));
assert(Edge_BB0_BB1_a.getEnd() == BB1 && "BB1 is the 2nd successor");
BasicBlockEdge Edge_BB0_BB1_b(BB0, TI->getSuccessor(2));
assert(Edge_BB0_BB1_b.getEnd() == BB1 && "BB1 is the 3rd successor");
EXPECT_TRUE(DT->dominates(Edge_BB0_BB2, BB2));
EXPECT_FALSE(DT->dominates(Edge_BB0_BB2, BB1));
EXPECT_FALSE(DT->dominates(Edge_BB0_BB1_a, BB1));
EXPECT_FALSE(DT->dominates(Edge_BB0_BB1_b, BB1));
EXPECT_FALSE(DT->dominates(Edge_BB0_BB1_a, BB2));
EXPECT_FALSE(DT->dominates(Edge_BB0_BB1_b, BB2));
});
}
// Verify that the PDT is correctly updated in case an edge removal results
// in a new unreachable CFG node. Also make sure that the updated PDT is the
// same as a freshly recalculated one.
//
// For the following input code and initial PDT:
//
// CFG PDT
//
// A Exit
// | |
// _B D
// / | \ |
// ^ v \ B
// \ / D / \
// C \ C A
// v
// Exit
//
// we verify that CFG' and PDT-updated is obtained after removal of edge C -> B.
//
// CFG' PDT-updated
//
// A Exit
// | / | \
// B C B D
// | \ |
// v \ A
// / D
// C \
// | \
// unreachable Exit
//
// Both the blocks that end with ret and with unreachable become trivial
// PostDominatorTree roots, as they have no successors.
//
TEST(DominatorTree, DeletingEdgesIntroducesUnreachables) {
StringRef ModuleString =
"define void @f() {\n"
"A:\n"
" br label %B\n"
"B:\n"
" br i1 undef, label %D, label %C\n"
"C:\n"
" br label %B\n"
"D:\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, PostDominatorTree *PDT) {
Function::iterator FI = F.begin();
FI++;
BasicBlock *B = &*FI++;
BasicBlock *C = &*FI++;
BasicBlock *D = &*FI++;
ASSERT_TRUE(PDT->dominates(PDT->getNode(D), PDT->getNode(B)));
EXPECT_TRUE(DT->verify());
EXPECT_TRUE(PDT->verify());
C->getTerminator()->eraseFromParent();
new UnreachableInst(C->getContext(), C);
DT->deleteEdge(C, B);
PDT->deleteEdge(C, B);
EXPECT_TRUE(DT->verify());
EXPECT_TRUE(PDT->verify());
EXPECT_FALSE(PDT->dominates(PDT->getNode(D), PDT->getNode(B)));
EXPECT_NE(PDT->getNode(C), nullptr);
DominatorTree NDT(F);
EXPECT_EQ(DT->compare(NDT), 0);
PostDominatorTree NPDT(F);
EXPECT_EQ(PDT->compare(NPDT), 0);
});
}
// Verify that the PDT is correctly updated in case an edge removal results
// in an infinite loop. Also make sure that the updated PDT is the
// same as a freshly recalculated one.
//
// Test case:
//
// CFG PDT
//
// A Exit
// | |
// _B D
// / | \ |
// ^ v \ B
// \ / D / \
// C \ C A
// / \ v
// ^ v Exit
// \_/
//
// After deleting the edge C->B, C is part of an infinite reverse-unreachable
// loop:
//
// CFG' PDT'
//
// A Exit
// | / | \
// B C B D
// | \ |
// v \ A
// / D
// C \
// / \ v
// ^ v Exit
// \_/
//
// As C now becomes reverse-unreachable, it forms a new non-trivial root and
// gets connected to the virtual exit.
// D does not postdominate B anymore, because there are two forward paths from
// B to the virtual exit:
// - B -> C -> VirtualExit
// - B -> D -> VirtualExit.
//
TEST(DominatorTree, DeletingEdgesIntroducesInfiniteLoop) {
StringRef ModuleString =
"define void @f() {\n"
"A:\n"
" br label %B\n"
"B:\n"
" br i1 undef, label %D, label %C\n"
"C:\n"
" switch i32 undef, label %C [\n"
" i32 0, label %B\n"
" ]\n"
"D:\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, PostDominatorTree *PDT) {
Function::iterator FI = F.begin();
FI++;
BasicBlock *B = &*FI++;
BasicBlock *C = &*FI++;
BasicBlock *D = &*FI++;
ASSERT_TRUE(PDT->dominates(PDT->getNode(D), PDT->getNode(B)));
EXPECT_TRUE(DT->verify());
EXPECT_TRUE(PDT->verify());
auto SwitchC = cast<SwitchInst>(C->getTerminator());
SwitchC->removeCase(SwitchC->case_begin());
DT->deleteEdge(C, B);
EXPECT_TRUE(DT->verify());
PDT->deleteEdge(C, B);
EXPECT_TRUE(PDT->verify());
EXPECT_FALSE(PDT->dominates(PDT->getNode(D), PDT->getNode(B)));
EXPECT_NE(PDT->getNode(C), nullptr);
DominatorTree NDT(F);
EXPECT_EQ(DT->compare(NDT), 0);
PostDominatorTree NPDT(F);
EXPECT_EQ(PDT->compare(NPDT), 0);
});
}
// Verify that the PDT is correctly updated in case an edge removal results
// in an infinite loop.
//
// Test case:
//
// CFG PDT
//
// A Exit
// | / | \
// B-- C2 B D
// | \ / |
// v \ C A
// / D
// C--C2 \
// / \ \ v
// ^ v --Exit
// \_/
//
// After deleting the edge C->E, C is part of an infinite reverse-unreachable
// loop:
//
// CFG' PDT'
//
// A Exit
// | / | \
// B C B D
// | \ |
// v \ A
// / D
// C \
// / \ v
// ^ v Exit
// \_/
//
// In PDT, D does not post-dominate B. After the edge C -> C2 is removed,
// C becomes a new nontrivial PDT root.
//
TEST(DominatorTree, DeletingEdgesIntroducesInfiniteLoop2) {
StringRef ModuleString =
"define void @f() {\n"
"A:\n"
" br label %B\n"
"B:\n"
" br i1 undef, label %D, label %C\n"
"C:\n"
" switch i32 undef, label %C [\n"
" i32 0, label %C2\n"
" ]\n"
"C2:\n"
" ret void\n"
"D:\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, PostDominatorTree *PDT) {
Function::iterator FI = F.begin();
FI++;
BasicBlock *B = &*FI++;
BasicBlock *C = &*FI++;
BasicBlock *C2 = &*FI++;
BasicBlock *D = &*FI++;
EXPECT_TRUE(DT->verify());
EXPECT_TRUE(PDT->verify());
auto SwitchC = cast<SwitchInst>(C->getTerminator());
SwitchC->removeCase(SwitchC->case_begin());
DT->deleteEdge(C, C2);
PDT->deleteEdge(C, C2);
C2->removeFromParent();
EXPECT_EQ(DT->getNode(C2), nullptr);
PDT->eraseNode(C2);
delete C2;
EXPECT_TRUE(DT->verify());
EXPECT_TRUE(PDT->verify());
EXPECT_FALSE(PDT->dominates(PDT->getNode(D), PDT->getNode(B)));
EXPECT_NE(PDT->getNode(C), nullptr);
DominatorTree NDT(F);
EXPECT_EQ(DT->compare(NDT), 0);
PostDominatorTree NPDT(F);
EXPECT_EQ(PDT->compare(NPDT), 0);
});
}
// Verify that the IDF returns blocks in a deterministic way.
//
// Test case:
//
// CFG
//
// (A)
// / \
// / \
// (B) (C)
// |\ /|
// | X |
// |/ \|
// (D) (E)
//
// IDF for block B is {D, E}, and the order of blocks in this list is defined by
// their 1) level in dom-tree and 2) DFSIn number if the level is the same.
//
TEST(DominatorTree, IDFDeterminismTest) {
StringRef ModuleString =
"define void @f() {\n"
"A:\n"
" br i1 undef, label %B, label %C\n"
"B:\n"
" br i1 undef, label %D, label %E\n"
"C:\n"
" br i1 undef, label %D, label %E\n"
"D:\n"
" ret void\n"
"E:\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, PostDominatorTree *PDT) {
Function::iterator FI = F.begin();
BasicBlock *A = &*FI++;
BasicBlock *B = &*FI++;
BasicBlock *C = &*FI++;
BasicBlock *D = &*FI++;
BasicBlock *E = &*FI++;
(void)C;
DT->updateDFSNumbers();
ForwardIDFCalculator IDF(*DT);
SmallPtrSet<BasicBlock *, 1> DefBlocks;
DefBlocks.insert(B);
IDF.setDefiningBlocks(DefBlocks);
SmallVector<BasicBlock *, 32> IDFBlocks;
SmallPtrSet<BasicBlock *, 32> LiveInBlocks;
IDF.resetLiveInBlocks();
IDF.calculate(IDFBlocks);
EXPECT_EQ(IDFBlocks.size(), 2UL);
EXPECT_EQ(DT->getNode(A)->getDFSNumIn(), 0UL);
EXPECT_EQ(IDFBlocks[0], D);
EXPECT_EQ(IDFBlocks[1], E);
EXPECT_TRUE(DT->getNode(IDFBlocks[0])->getDFSNumIn() <
DT->getNode(IDFBlocks[1])->getDFSNumIn());
});
}
namespace {
const auto Insert = CFGBuilder::ActionKind::Insert;
const auto Delete = CFGBuilder::ActionKind::Delete;
bool CompUpdates(const CFGBuilder::Update &A, const CFGBuilder::Update &B) {
return std::tie(A.Action, A.Edge.From, A.Edge.To) <
std::tie(B.Action, B.Edge.From, B.Edge.To);
}
} // namespace
TEST(DominatorTree, InsertReachable) {
CFGHolder Holder;
std::vector<CFGBuilder::Arc> Arcs = {
{"1", "2"}, {"2", "3"}, {"3", "4"}, {"4", "5"}, {"5", "6"}, {"5", "7"},
{"3", "8"}, {"8", "9"}, {"9", "10"}, {"8", "11"}, {"11", "12"}};
std::vector<CFGBuilder::Update> Updates = {{Insert, {"12", "10"}},
{Insert, {"10", "9"}},
{Insert, {"7", "6"}},
{Insert, {"7", "5"}}};
CFGBuilder B(Holder.F, Arcs, Updates);
DominatorTree DT(*Holder.F);
EXPECT_TRUE(DT.verify());
PostDominatorTree PDT(*Holder.F);
EXPECT_TRUE(PDT.verify());
std::optional<CFGBuilder::Update> LastUpdate;
while ((LastUpdate = B.applyUpdate())) {
EXPECT_EQ(LastUpdate->Action, Insert);
BasicBlock *From = B.getOrAddBlock(LastUpdate->Edge.From);
BasicBlock *To = B.getOrAddBlock(LastUpdate->Edge.To);
DT.insertEdge(From, To);
EXPECT_TRUE(DT.verify());
PDT.insertEdge(From, To);
EXPECT_TRUE(PDT.verify());
}
}
TEST(DominatorTree, InsertReachable2) {
CFGHolder Holder;
std::vector<CFGBuilder::Arc> Arcs = {
{"1", "2"}, {"2", "3"}, {"3", "4"}, {"4", "5"}, {"5", "6"}, {"5", "7"},
{"7", "5"}, {"2", "8"}, {"8", "11"}, {"11", "12"}, {"12", "10"},
{"10", "9"}, {"9", "10"}};
std::vector<CFGBuilder::Update> Updates = {{Insert, {"10", "7"}}};
CFGBuilder B(Holder.F, Arcs, Updates);
DominatorTree DT(*Holder.F);
EXPECT_TRUE(DT.verify());
PostDominatorTree PDT(*Holder.F);
EXPECT_TRUE(PDT.verify());
std::optional<CFGBuilder::Update> LastUpdate = B.applyUpdate();
EXPECT_TRUE(LastUpdate);
EXPECT_EQ(LastUpdate->Action, Insert);
BasicBlock *From = B.getOrAddBlock(LastUpdate->Edge.From);
BasicBlock *To = B.getOrAddBlock(LastUpdate->Edge.To);
DT.insertEdge(From, To);
EXPECT_TRUE(DT.verify());
PDT.insertEdge(From, To);
EXPECT_TRUE(PDT.verify());
}
TEST(DominatorTree, InsertUnreachable) {
CFGHolder Holder;
std::vector<CFGBuilder::Arc> Arcs = {{"1", "2"}, {"2", "3"}, {"3", "4"},
{"5", "6"}, {"5", "7"}, {"3", "8"},
{"9", "10"}, {"11", "12"}};
std::vector<CFGBuilder::Update> Updates = {{Insert, {"4", "5"}},
{Insert, {"8", "9"}},
{Insert, {"10", "12"}},
{Insert, {"10", "11"}}};
CFGBuilder B(Holder.F, Arcs, Updates);
DominatorTree DT(*Holder.F);
EXPECT_TRUE(DT.verify());
PostDominatorTree PDT(*Holder.F);
EXPECT_TRUE(PDT.verify());
std::optional<CFGBuilder::Update> LastUpdate;
while ((LastUpdate = B.applyUpdate())) {
EXPECT_EQ(LastUpdate->Action, Insert);
BasicBlock *From = B.getOrAddBlock(LastUpdate->Edge.From);
BasicBlock *To = B.getOrAddBlock(LastUpdate->Edge.To);
DT.insertEdge(From, To);
EXPECT_TRUE(DT.verify());
PDT.insertEdge(From, To);
EXPECT_TRUE(PDT.verify());
}
}
TEST(DominatorTree, InsertFromUnreachable) {
CFGHolder Holder;
std::vector<CFGBuilder::Arc> Arcs = {{"1", "2"}, {"2", "3"}, {"3", "4"}};
std::vector<CFGBuilder::Update> Updates = {{Insert, {"3", "5"}}};
CFGBuilder B(Holder.F, Arcs, Updates);
PostDominatorTree PDT(*Holder.F);
EXPECT_TRUE(PDT.verify());
std::optional<CFGBuilder::Update> LastUpdate = B.applyUpdate();
EXPECT_TRUE(LastUpdate);
EXPECT_EQ(LastUpdate->Action, Insert);
BasicBlock *From = B.getOrAddBlock(LastUpdate->Edge.From);
BasicBlock *To = B.getOrAddBlock(LastUpdate->Edge.To);
PDT.insertEdge(From, To);
EXPECT_TRUE(PDT.verify());
EXPECT_EQ(PDT.root_size(), 2UL);
// Make sure we can use a const pointer with getNode.
const BasicBlock *BB5 = B.getOrAddBlock("5");
EXPECT_NE(PDT.getNode(BB5), nullptr);
}
TEST(DominatorTree, InsertMixed) {
CFGHolder Holder;
std::vector<CFGBuilder::Arc> Arcs = {
{"1", "2"}, {"2", "3"}, {"3", "4"}, {"5", "6"}, {"5", "7"},
{"8", "9"}, {"9", "10"}, {"8", "11"}, {"11", "12"}, {"7", "3"}};
std::vector<CFGBuilder::Update> Updates = {
{Insert, {"4", "5"}}, {Insert, {"2", "5"}}, {Insert, {"10", "9"}},
{Insert, {"12", "10"}}, {Insert, {"12", "10"}}, {Insert, {"7", "8"}},
{Insert, {"7", "5"}}};
CFGBuilder B(Holder.F, Arcs, Updates);
DominatorTree DT(*Holder.F);
EXPECT_TRUE(DT.verify());
PostDominatorTree PDT(*Holder.F);
EXPECT_TRUE(PDT.verify());
std::optional<CFGBuilder::Update> LastUpdate;
while ((LastUpdate = B.applyUpdate())) {
EXPECT_EQ(LastUpdate->Action, Insert);
BasicBlock *From = B.getOrAddBlock(LastUpdate->Edge.From);
BasicBlock *To = B.getOrAddBlock(LastUpdate->Edge.To);
DT.insertEdge(From, To);
EXPECT_TRUE(DT.verify());
PDT.insertEdge(From, To);
EXPECT_TRUE(PDT.verify());
}
}
TEST(DominatorTree, InsertPermut) {
std::vector<CFGBuilder::Arc> Arcs = {
{"1", "2"}, {"2", "3"}, {"3", "4"}, {"5", "6"}, {"5", "7"},
{"8", "9"}, {"9", "10"}, {"8", "11"}, {"11", "12"}, {"7", "3"}};
std::vector<CFGBuilder::Update> Updates = {{Insert, {"4", "5"}},
{Insert, {"2", "5"}},
{Insert, {"10", "9"}},
{Insert, {"12", "10"}}};
while (std::next_permutation(Updates.begin(), Updates.end(), CompUpdates)) {
CFGHolder Holder;
CFGBuilder B(Holder.F, Arcs, Updates);
DominatorTree DT(*Holder.F);
EXPECT_TRUE(DT.verify());
PostDominatorTree PDT(*Holder.F);
EXPECT_TRUE(PDT.verify());
std::optional<CFGBuilder::Update> LastUpdate;
while ((LastUpdate = B.applyUpdate())) {
EXPECT_EQ(LastUpdate->Action, Insert);
BasicBlock *From = B.getOrAddBlock(LastUpdate->Edge.From);
BasicBlock *To = B.getOrAddBlock(LastUpdate->Edge.To);
DT.insertEdge(From, To);
EXPECT_TRUE(DT.verify());
PDT.insertEdge(From, To);
EXPECT_TRUE(PDT.verify());
}
}
}
TEST(DominatorTree, DeleteReachable) {
CFGHolder Holder;
std::vector<CFGBuilder::Arc> Arcs = {
{"1", "2"}, {"2", "3"}, {"2", "4"}, {"3", "4"}, {"4", "5"}, {"5", "6"},
{"5", "7"}, {"7", "8"}, {"3", "8"}, {"8", "9"}, {"9", "10"}, {"10", "2"}};
std::vector<CFGBuilder::Update> Updates = {
{Delete, {"2", "4"}}, {Delete, {"7", "8"}}, {Delete, {"10", "2"}}};
CFGBuilder B(Holder.F, Arcs, Updates);
DominatorTree DT(*Holder.F);
EXPECT_TRUE(DT.verify());
PostDominatorTree PDT(*Holder.F);
EXPECT_TRUE(PDT.verify());
std::optional<CFGBuilder::Update> LastUpdate;
while ((LastUpdate = B.applyUpdate())) {
EXPECT_EQ(LastUpdate->Action, Delete);
BasicBlock *From = B.getOrAddBlock(LastUpdate->Edge.From);
BasicBlock *To = B.getOrAddBlock(LastUpdate->Edge.To);
DT.deleteEdge(From, To);
EXPECT_TRUE(DT.verify());
PDT.deleteEdge(From, To);
EXPECT_TRUE(PDT.verify());
}
}
TEST(DominatorTree, DeleteUnreachable) {
CFGHolder Holder;
std::vector<CFGBuilder::Arc> Arcs = {
{"1", "2"}, {"2", "3"}, {"3", "4"}, {"4", "5"}, {"5", "6"}, {"5", "7"},
{"7", "8"}, {"3", "8"}, {"8", "9"}, {"9", "10"}, {"10", "2"}};
std::vector<CFGBuilder::Update> Updates = {
{Delete, {"8", "9"}}, {Delete, {"7", "8"}}, {Delete, {"3", "4"}}};
CFGBuilder B(Holder.F, Arcs, Updates);
DominatorTree DT(*Holder.F);
EXPECT_TRUE(DT.verify());
PostDominatorTree PDT(*Holder.F);
EXPECT_TRUE(PDT.verify());
std::optional<CFGBuilder::Update> LastUpdate;
while ((LastUpdate = B.applyUpdate())) {
EXPECT_EQ(LastUpdate->Action, Delete);
BasicBlock *From = B.getOrAddBlock(LastUpdate->Edge.From);
BasicBlock *To = B.getOrAddBlock(LastUpdate->Edge.To);
DT.deleteEdge(From, To);
EXPECT_TRUE(DT.verify());
PDT.deleteEdge(From, To);
EXPECT_TRUE(PDT.verify());
}
}
TEST(DominatorTree, InsertDelete) {
std::vector<CFGBuilder::Arc> Arcs = {
{"1", "2"}, {"2", "3"}, {"3", "4"}, {"4", "5"}, {"5", "6"}, {"5", "7"},
{"3", "8"}, {"8", "9"}, {"9", "10"}, {"8", "11"}, {"11", "12"}};
std::vector<CFGBuilder::Update> Updates = {
{Insert, {"2", "4"}}, {Insert, {"12", "10"}}, {Insert, {"10", "9"}},
{Insert, {"7", "6"}}, {Insert, {"7", "5"}}, {Delete, {"3", "8"}},
{Insert, {"10", "7"}}, {Insert, {"2", "8"}}, {Delete, {"3", "4"}},
{Delete, {"8", "9"}}, {Delete, {"11", "12"}}};
CFGHolder Holder;
CFGBuilder B(Holder.F, Arcs, Updates);
DominatorTree DT(*Holder.F);
EXPECT_TRUE(DT.verify());
PostDominatorTree PDT(*Holder.F);
EXPECT_TRUE(PDT.verify());
std::optional<CFGBuilder::Update> LastUpdate;
while ((LastUpdate = B.applyUpdate())) {
BasicBlock *From = B.getOrAddBlock(LastUpdate->Edge.From);
BasicBlock *To = B.getOrAddBlock(LastUpdate->Edge.To);
if (LastUpdate->Action == Insert) {
DT.insertEdge(From, To);
PDT.insertEdge(From, To);
} else {
DT.deleteEdge(From, To);
PDT.deleteEdge(From, To);
}
EXPECT_TRUE(DT.verify());
EXPECT_TRUE(PDT.verify());
}
}
TEST(DominatorTree, InsertDeleteExhaustive) {
std::vector<CFGBuilder::Arc> Arcs = {
{"1", "2"}, {"2", "3"}, {"3", "4"}, {"4", "5"}, {"5", "6"}, {"5", "7"},
{"3", "8"}, {"8", "9"}, {"9", "10"}, {"8", "11"}, {"11", "12"}};
std::vector<CFGBuilder::Update> Updates = {
{Insert, {"2", "4"}}, {Insert, {"12", "10"}}, {Insert, {"10", "9"}},
{Insert, {"7", "6"}}, {Insert, {"7", "5"}}, {Delete, {"3", "8"}},
{Insert, {"10", "7"}}, {Insert, {"2", "8"}}, {Delete, {"3", "4"}},
{Delete, {"8", "9"}}, {Delete, {"11", "12"}}};
std::mt19937 Generator(0);
for (unsigned i = 0; i < 16; ++i) {
std::shuffle(Updates.begin(), Updates.end(), Generator);
CFGHolder Holder;
CFGBuilder B(Holder.F, Arcs, Updates);
DominatorTree DT(*Holder.F);
EXPECT_TRUE(DT.verify());
PostDominatorTree PDT(*Holder.F);
EXPECT_TRUE(PDT.verify());
std::optional<CFGBuilder::Update> LastUpdate;
while ((LastUpdate = B.applyUpdate())) {
BasicBlock *From = B.getOrAddBlock(LastUpdate->Edge.From);
BasicBlock *To = B.getOrAddBlock(LastUpdate->Edge.To);
if (LastUpdate->Action == Insert) {
DT.insertEdge(From, To);
PDT.insertEdge(From, To);
} else {
DT.deleteEdge(From, To);
PDT.deleteEdge(From, To);
}
EXPECT_TRUE(DT.verify());
EXPECT_TRUE(PDT.verify());
}
}
}
TEST(DominatorTree, InsertIntoIrreducible) {
std::vector<CFGBuilder::Arc> Arcs = {
{"0", "1"},
{"1", "27"}, {"1", "7"},
{"10", "18"},
{"13", "10"},
{"18", "13"}, {"18", "23"},
{"23", "13"}, {"23", "24"},
{"24", "1"}, {"24", "18"},
{"27", "24"}};
CFGHolder Holder;
CFGBuilder B(Holder.F, Arcs, {{Insert, {"7", "23"}}});
DominatorTree DT(*Holder.F);
EXPECT_TRUE(DT.verify());
B.applyUpdate();
BasicBlock *From = B.getOrAddBlock("7");
BasicBlock *To = B.getOrAddBlock("23");
DT.insertEdge(From, To);
EXPECT_TRUE(DT.verify());
}
TEST(DominatorTree, EdgeDomination) {
StringRef ModuleString = "define i32 @f(i1 %cond) {\n"
" bb0:\n"
" br i1 %cond, label %bb1, label %bb2\n"
" bb1:\n"
" br label %bb3\n"
" bb2:\n"
" br label %bb3\n"
" bb3:\n"
" ret i32 4"
"}\n";
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleString);
runWithDomTree(*M, "f",
[&](Function &F, DominatorTree *DT, PostDominatorTree *PDT) {
Function::iterator FI = F.begin();
BasicBlock *BB0 = &*FI++;
BasicBlock *BB1 = &*FI++;
BasicBlock *BB2 = &*FI++;
BasicBlock *BB3 = &*FI++;
BasicBlockEdge E01(BB0, BB1);
BasicBlockEdge E02(BB0, BB2);
BasicBlockEdge E13(BB1, BB3);
BasicBlockEdge E23(BB2, BB3);
EXPECT_TRUE(DT->dominates(E01, E01));
EXPECT_FALSE(DT->dominates(E01, E02));
EXPECT_TRUE(DT->dominates(E01, E13));
EXPECT_FALSE(DT->dominates(E01, E23));
EXPECT_FALSE(DT->dominates(E02, E01));
EXPECT_TRUE(DT->dominates(E02, E02));
EXPECT_FALSE(DT->dominates(E02, E13));
EXPECT_TRUE(DT->dominates(E02, E23));
EXPECT_FALSE(DT->dominates(E13, E01));
EXPECT_FALSE(DT->dominates(E13, E02));
EXPECT_TRUE(DT->dominates(E13, E13));
EXPECT_FALSE(DT->dominates(E13, E23));
EXPECT_FALSE(DT->dominates(E23, E01));
EXPECT_FALSE(DT->dominates(E23, E02));
EXPECT_FALSE(DT->dominates(E23, E13));
EXPECT_TRUE(DT->dominates(E23, E23));
});
}
TEST(DominatorTree, ValueDomination) {
StringRef ModuleString = R"(
@foo = global i8 0
define i8 @f(i8 %arg) {
ret i8 %arg
}
)";
LLVMContext Context;
std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleString);
runWithDomTree(*M, "f",
[&](Function &F, DominatorTree *DT, PostDominatorTree *PDT) {
Argument *A = F.getArg(0);
GlobalValue *G = M->getNamedValue("foo");
Constant *C = ConstantInt::getNullValue(Type::getInt8Ty(Context));
Instruction *I = F.getEntryBlock().getTerminator();
EXPECT_TRUE(DT->dominates(A, I));
EXPECT_TRUE(DT->dominates(G, I));
EXPECT_TRUE(DT->dominates(C, I));
const Use &U = I->getOperandUse(0);
EXPECT_TRUE(DT->dominates(A, U));
EXPECT_TRUE(DT->dominates(G, U));
EXPECT_TRUE(DT->dominates(C, U));
});
}