llvm-6502/include/llvm/Analysis/PostDominators.h

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//=- llvm/Analysis/PostDominators.h - Post Dominator Calculation-*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file exposes interfaces to post dominance information.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_POST_DOMINATORS_H
#define LLVM_ANALYSIS_POST_DOMINATORS_H
#include "llvm/Analysis/Dominators.h"
namespace llvm {
/// PostDominatorSet Class - Concrete subclass of DominatorSetBase that is used
/// to compute the post-dominator set. Because there can be multiple exit nodes
/// in an LLVM function, we calculate post dominators with a special null block
/// which is the virtual exit node that the real exit nodes all virtually branch
/// to. Clients should be prepared to see an entry in the dominator sets with a
/// null BasicBlock*.
///
struct PostDominatorSet : public DominatorSetBase {
PostDominatorSet() : DominatorSetBase(true) {}
virtual bool runOnFunction(Function &F);
// getAnalysisUsage - This pass does not modify the function at all.
//
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
}
};
//===-------------------------------------
// ImmediatePostDominators Class - Concrete subclass of ImmediateDominatorsBase
// that is used to compute the immediate post-dominators.
//
struct ImmediatePostDominators : public ImmediateDominatorsBase {
ImmediatePostDominators() : ImmediateDominatorsBase(true) {}
virtual bool runOnFunction(Function &F) {
IDoms.clear(); // Reset from the last time we were run...
PostDominatorSet &DS = getAnalysis<PostDominatorSet>();
Roots = DS.getRoots();
calcIDoms(DS);
return false;
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequired<PostDominatorSet>();
}
private:
void calcIDoms(const DominatorSetBase &DS);
};
//===-------------------------------------
// PostDominatorTree Class - Concrete subclass of DominatorTree that is used to
// compute the a post-dominator tree.
//
struct PostDominatorTree : public DominatorTreeBase {
PostDominatorTree() : DominatorTreeBase(true) {}
virtual bool runOnFunction(Function &F) {
reset(); // Reset from the last time we were run...
PostDominatorSet &DS = getAnalysis<PostDominatorSet>();
Roots = DS.getRoots();
calculate(DS);
return false;
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequired<PostDominatorSet>();
}
private:
void calculate(const PostDominatorSet &DS);
};
//===-------------------------------------
// PostDominanceFrontier Class - Concrete subclass of DominanceFrontier that is
// used to compute the a post-dominance frontier.
//
struct PostDominanceFrontier : public DominanceFrontierBase {
PostDominanceFrontier() : DominanceFrontierBase(true) {}
virtual bool runOnFunction(Function &) {
Frontiers.clear();
PostDominatorTree &DT = getAnalysis<PostDominatorTree>();
Roots = DT.getRoots();
if (const DominatorTree::Node *Root = DT.getRootNode())
calculate(DT, Root);
return false;
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequired<PostDominatorTree>();
}
// stub - dummy function, just ignore it
static void stub();
private:
const DomSetType &calculate(const PostDominatorTree &DT,
const DominatorTree::Node *Node);
};
// Make sure that any clients of this file link in PostDominators.cpp
static IncludeFile
POST_DOMINATOR_INCLUDE_FILE((void*)&PostDominanceFrontier::stub);
} // End llvm namespace
#endif