llvm-6502/include/llvm/CodeGen/MachineLoopRanges.h
Jakob Stoklund Olesen f428eb6c1b Enable loop splitting in RegAllocGreedy.
The heuristics split around the largest loop where the current register may be
allocated without interference.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122106 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-17 23:16:32 +00:00

113 lines
3.4 KiB
C++

//===- MachineLoopRanges.h - Ranges of machine loops -----------*- c++ -*--===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides the interface to the MachineLoopRanges analysis.
//
// Provide on-demand information about the ranges of machine instructions
// covered by a loop.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_MACHINELOOPRANGES_H
#define LLVM_CODEGEN_MACHINELOOPRANGES_H
#include "llvm/ADT/IntervalMap.h"
#include "llvm/CodeGen/SlotIndexes.h"
namespace llvm {
class MachineLoop;
class MachineLoopInfo;
class raw_ostream;
/// MachineLoopRange - Range information for a single loop.
class MachineLoopRange {
friend class MachineLoopRanges;
public:
typedef IntervalMap<SlotIndex, unsigned, 4> Map;
typedef Map::Allocator Allocator;
private:
/// The mapped loop.
const MachineLoop *const Loop;
/// Map intervals to a bit mask.
/// Bit 0 = inside loop block.
Map Intervals;
/// Loop area as measured by SlotIndex::distance.
unsigned Area;
/// Create a MachineLoopRange, only accessible to MachineLoopRanges.
MachineLoopRange(const MachineLoop*, Allocator&, SlotIndexes&);
public:
/// getLoop - Return the mapped machine loop.
const MachineLoop *getLoop() const { return Loop; }
/// overlaps - Return true if this loop overlaps the given range of machine
/// inteructions.
bool overlaps(SlotIndex Start, SlotIndex Stop);
/// getNumber - Return the loop number. This is the same as the number of the
/// header block.
unsigned getNumber() const;
/// getArea - Return the loop area. This number is approximately proportional
/// to the number of instructions in the loop.
unsigned getArea() const { return Area; }
/// getMap - Allow public read-only access for IntervalMapOverlaps.
const Map &getMap() { return Intervals; }
/// print - Print loop ranges on OS.
void print(raw_ostream&) const;
/// byNumber - Comparator for array_pod_sort that sorts a list of
/// MachineLoopRange pointers by number.
static int byNumber(const void*, const void*);
/// byAreaDesc - Comparator for array_pod_sort that sorts a list of
/// MachineLoopRange pointers by descending area, then by number.
static int byAreaDesc(const void*, const void*);
};
raw_ostream &operator<<(raw_ostream&, const MachineLoopRange&);
/// MachineLoopRanges - Analysis pass that provides on-demand per-loop range
/// information.
class MachineLoopRanges : public MachineFunctionPass {
typedef DenseMap<const MachineLoop*, MachineLoopRange*> CacheMap;
typedef MachineLoopRange::Allocator MapAllocator;
MapAllocator Allocator;
SlotIndexes *Indexes;
CacheMap Cache;
public:
static char ID; // Pass identification, replacement for typeid
MachineLoopRanges() : MachineFunctionPass(ID), Indexes(0) {}
~MachineLoopRanges() { releaseMemory(); }
/// getLoopRange - Return the range of loop.
MachineLoopRange *getLoopRange(const MachineLoop *Loop);
private:
virtual bool runOnMachineFunction(MachineFunction&);
virtual void releaseMemory();
virtual void getAnalysisUsage(AnalysisUsage&) const;
};
} // end namespace llvm
#endif // LLVM_CODEGEN_MACHINELOOPRANGES_H