1 //===- PostDominators.cpp - Post-Dominator Calculation --------------------===//
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 // This file implements the post-dominator construction algorithms.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/Analysis/PostDominators.h"
15 #include "llvm/ADT/DepthFirstIterator.h"
16 #include "llvm/ADT/SetOperations.h"
17 #include "llvm/IR/CFG.h"
18 #include "llvm/IR/Instructions.h"
19 #include "llvm/IR/PassManager.h"
20 #include "llvm/Support/Debug.h"
21 #include "llvm/Support/GenericDomTreeConstruction.h"
22 using namespace llvm;
23 
24 #define DEBUG_TYPE "postdomtree"
25 
26 template class llvm::DominatorTreeBase<BasicBlock, true>; // PostDomTreeBase
27 
28 //===----------------------------------------------------------------------===//
29 //  PostDominatorTree Implementation
30 //===----------------------------------------------------------------------===//
31 
32 char PostDominatorTreeWrapperPass::ID = 0;
33 INITIALIZE_PASS(PostDominatorTreeWrapperPass, "postdomtree",
34                 "Post-Dominator Tree Construction", true, true)
35 
36 bool PostDominatorTree::invalidate(Function &F, const PreservedAnalyses &PA,
37                                    FunctionAnalysisManager::Invalidator &) {
38   // Check whether the analysis, all analyses on functions, or the function's
39   // CFG have been preserved.
40   auto PAC = PA.getChecker<PostDominatorTreeAnalysis>();
41   return !(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Function>>() ||
42            PAC.preservedSet<CFGAnalyses>());
43 }
44 
45 bool PostDominatorTreeWrapperPass::runOnFunction(Function &F) {
46   DT.recalculate(F);
47   return false;
48 }
49 
50 void PostDominatorTreeWrapperPass::print(raw_ostream &OS, const Module *) const {
51   DT.print(OS);
52 }
53 
54 FunctionPass* llvm::createPostDomTree() {
55   return new PostDominatorTreeWrapperPass();
56 }
57 
58 AnalysisKey PostDominatorTreeAnalysis::Key;
59 
60 PostDominatorTree PostDominatorTreeAnalysis::run(Function &F,
61                                                  FunctionAnalysisManager &) {
62   PostDominatorTree PDT;
63   PDT.recalculate(F);
64   return PDT;
65 }
66 
67 PostDominatorTreePrinterPass::PostDominatorTreePrinterPass(raw_ostream &OS)
68   : OS(OS) {}
69 
70 PreservedAnalyses
71 PostDominatorTreePrinterPass::run(Function &F, FunctionAnalysisManager &AM) {
72   OS << "PostDominatorTree for function: " << F.getName() << "\n";
73   AM.getResult<PostDominatorTreeAnalysis>(F).print(OS);
74 
75   return PreservedAnalyses::all();
76 }
77