114 lines
3.6 KiB
C++
114 lines
3.6 KiB
C++
//===- PostDominators.cpp - Post-Dominator Calculation --------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the post-dominator construction algorithms.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Analysis/PostDominators.h"
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#include "llvm/IR/Function.h"
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#include "llvm/IR/Instructions.h"
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#include "llvm/IR/PassManager.h"
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#include "llvm/InitializePasses.h"
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#include "llvm/Pass.h"
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#include "llvm/Support/raw_ostream.h"
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using namespace llvm;
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#define DEBUG_TYPE "postdomtree"
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#ifdef EXPENSIVE_CHECKS
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static constexpr bool ExpensiveChecksEnabled = true;
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#else
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static constexpr bool ExpensiveChecksEnabled = false;
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#endif
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//===----------------------------------------------------------------------===//
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// PostDominatorTree Implementation
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//===----------------------------------------------------------------------===//
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char PostDominatorTreeWrapperPass::ID = 0;
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PostDominatorTreeWrapperPass::PostDominatorTreeWrapperPass()
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: FunctionPass(ID) {
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initializePostDominatorTreeWrapperPassPass(*PassRegistry::getPassRegistry());
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}
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INITIALIZE_PASS(PostDominatorTreeWrapperPass, "postdomtree",
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"Post-Dominator Tree Construction", true, true)
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bool PostDominatorTree::invalidate(Function &F, const PreservedAnalyses &PA,
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FunctionAnalysisManager::Invalidator &) {
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// Check whether the analysis, all analyses on functions, or the function's
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// CFG have been preserved.
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auto PAC = PA.getChecker<PostDominatorTreeAnalysis>();
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return !(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Function>>() ||
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PAC.preservedSet<CFGAnalyses>());
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}
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bool PostDominatorTree::dominates(const Instruction *I1,
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const Instruction *I2) const {
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assert(I1 && I2 && "Expecting valid I1 and I2");
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const BasicBlock *BB1 = I1->getParent();
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const BasicBlock *BB2 = I2->getParent();
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if (BB1 != BB2)
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return Base::dominates(BB1, BB2);
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// PHINodes in a block are unordered.
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if (isa<PHINode>(I1) && isa<PHINode>(I2))
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return false;
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// Loop through the basic block until we find I1 or I2.
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BasicBlock::const_iterator I = BB1->begin();
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for (; &*I != I1 && &*I != I2; ++I)
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/*empty*/;
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return &*I == I2;
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}
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bool PostDominatorTreeWrapperPass::runOnFunction(Function &F) {
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DT.recalculate(F);
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return false;
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}
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void PostDominatorTreeWrapperPass::verifyAnalysis() const {
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if (VerifyDomInfo)
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assert(DT.verify(PostDominatorTree::VerificationLevel::Full));
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else if (ExpensiveChecksEnabled)
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assert(DT.verify(PostDominatorTree::VerificationLevel::Basic));
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}
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void PostDominatorTreeWrapperPass::print(raw_ostream &OS, const Module *) const {
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DT.print(OS);
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}
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FunctionPass* llvm::createPostDomTree() {
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return new PostDominatorTreeWrapperPass();
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}
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AnalysisKey PostDominatorTreeAnalysis::Key;
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PostDominatorTree PostDominatorTreeAnalysis::run(Function &F,
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FunctionAnalysisManager &) {
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PostDominatorTree PDT(F);
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return PDT;
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}
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PostDominatorTreePrinterPass::PostDominatorTreePrinterPass(raw_ostream &OS)
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: OS(OS) {}
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PreservedAnalyses
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PostDominatorTreePrinterPass::run(Function &F, FunctionAnalysisManager &AM) {
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OS << "PostDominatorTree for function: " << F.getName() << "\n";
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AM.getResult<PostDominatorTreeAnalysis>(F).print(OS);
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return PreservedAnalyses::all();
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}
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