llvm-6502/include/llvm/Analysis/IntervalPartition.h
Devang Patel 3e15bf33e0 Use 'static const char' instead of 'static const int'.
Due to darwin gcc bug, one version of darwin linker coalesces
static const int, which defauts PassID based pass identification.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36652 91177308-0d34-0410-b5e6-96231b3b80d8
2007-05-02 21:39:20 +00:00

115 lines
4.2 KiB
C++

//===- IntervalPartition.h - Interval partition 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 contains the declaration of the IntervalPartition class, which
// calculates and represents the interval partition of a function, or a
// preexisting interval partition.
//
// In this way, the interval partition may be used to reduce a flow graph down
// to its degenerate single node interval partition (unless it is irreducible).
//
// TODO: The IntervalPartition class should take a bool parameter that tells
// whether it should add the "tails" of an interval to an interval itself or if
// they should be represented as distinct intervals.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_INTERVAL_PARTITION_H
#define LLVM_INTERVAL_PARTITION_H
#include "llvm/Analysis/Interval.h"
#include "llvm/Pass.h"
namespace llvm {
//===----------------------------------------------------------------------===//
//
// IntervalPartition - This class builds and holds an "interval partition" for
// a function. This partition divides the control flow graph into a set of
// maximal intervals, as defined with the properties above. Intuitively, a
// BasicBlock is a (possibly nonexistent) loop with a "tail" of non looping
// nodes following it.
//
class IntervalPartition : public FunctionPass {
typedef std::map<BasicBlock*, Interval*> IntervalMapTy;
IntervalMapTy IntervalMap;
typedef std::vector<Interval*> IntervalListTy;
Interval *RootInterval;
std::vector<Interval*> Intervals;
public:
static const char ID; // Pass identifcation, replacement for typeid
IntervalPartition() : FunctionPass((intptr_t)&ID), RootInterval(0) {}
// run - Calculate the interval partition for this function
virtual bool runOnFunction(Function &F);
// IntervalPartition ctor - Build a reduced interval partition from an
// existing interval graph. This takes an additional boolean parameter to
// distinguish it from a copy constructor. Always pass in false for now.
//
IntervalPartition(IntervalPartition &I, bool);
// Destructor - Free memory
~IntervalPartition() { destroy(); }
// print - Show contents in human readable format...
virtual void print(std::ostream &O, const Module* = 0) const;
void print(std::ostream *O, const Module* M = 0) const {
if (O) print(*O, M);
}
// getRootInterval() - Return the root interval that contains the starting
// block of the function.
inline Interval *getRootInterval() { return RootInterval; }
// isDegeneratePartition() - Returns true if the interval partition contains
// a single interval, and thus cannot be simplified anymore.
bool isDegeneratePartition() { return Intervals.size() == 1; }
// TODO: isIrreducible - look for triangle graph.
// getBlockInterval - Return the interval that a basic block exists in.
inline Interval *getBlockInterval(BasicBlock *BB) {
IntervalMapTy::iterator I = IntervalMap.find(BB);
return I != IntervalMap.end() ? I->second : 0;
}
// getAnalysisUsage - Implement the Pass API
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
}
// Interface to Intervals vector...
const std::vector<Interval*> &getIntervals() const { return Intervals; }
private:
// destroy - Reset state back to before function was analyzed
void destroy();
// addIntervalToPartition - Add an interval to the internal list of intervals,
// and then add mappings from all of the basic blocks in the interval to the
// interval itself (in the IntervalMap).
//
void addIntervalToPartition(Interval *I);
// updatePredecessors - Interval generation only sets the successor fields of
// the interval data structures. After interval generation is complete,
// run through all of the intervals and propagate successor info as
// predecessor info.
//
void updatePredecessors(Interval *Int);
};
} // End llvm namespace
#endif