llvm-6502/include/llvm/Analysis/PostDominators.h
Chris Lattner e93e311981 Switch the internal "Info" map from an std::map to a DenseMap. This
speeds up idom by about 45% and postidom by about 33%.

Some extra precautions must be taken not to invalidate densemap iterators.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40827 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-05 00:02:00 +00:00

87 lines
2.6 KiB
C++

//=- 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 {
/// PostDominatorTree Class - Concrete subclass of DominatorTree that is used to
/// compute the a post-dominator tree.
///
struct PostDominatorTree : public DominatorTreeBase {
static char ID; // Pass identification, replacement for typeid
PostDominatorTree() :
DominatorTreeBase((intptr_t)&ID, true) {}
virtual bool runOnFunction(Function &F) {
reset(); // Reset from the last time we were run...
calculate(F);
return false;
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
}
private:
void calculate(Function &F);
DomTreeNode *getNodeForBlock(BasicBlock *BB);
unsigned DFSPass(BasicBlock *V, unsigned N);
void Compress(BasicBlock *V, InfoRec &VInfo);
BasicBlock *Eval(BasicBlock *V);
void Link(BasicBlock *V, BasicBlock *W, InfoRec &WInfo);
inline BasicBlock *getIDom(BasicBlock *BB) const {
DenseMap<BasicBlock*, BasicBlock*>::const_iterator I = IDoms.find(BB);
return I != IDoms.end() ? I->second : 0;
}
};
/// PostDominanceFrontier Class - Concrete subclass of DominanceFrontier that is
/// used to compute the a post-dominance frontier.
///
struct PostDominanceFrontier : public DominanceFrontierBase {
static char ID;
PostDominanceFrontier()
: DominanceFrontierBase((intptr_t) &ID, true) {}
virtual bool runOnFunction(Function &) {
Frontiers.clear();
PostDominatorTree &DT = getAnalysis<PostDominatorTree>();
Roots = DT.getRoots();
if (const DomTreeNode *Root = DT.getRootNode())
calculate(DT, Root);
return false;
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequired<PostDominatorTree>();
}
private:
const DomSetType &calculate(const PostDominatorTree &DT,
const DomTreeNode *Node);
};
} // End llvm namespace
// Make sure that any clients of this file link in PostDominators.cpp
FORCE_DEFINING_FILE_TO_BE_LINKED(PostDominanceFrontier)
#endif