llvm-mirror/lib/CodeGen/MachineLoopRanges.cpp
2010-12-17 18:13:52 +00:00

117 lines
4.0 KiB
C++

//===- MachineLoopRanges.cpp - Ranges of machine loops --------------------===//
//
// 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 implementation of the MachineLoopRanges analysis.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineLoopRanges.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/Passes.h"
using namespace llvm;
char MachineLoopRanges::ID = 0;
INITIALIZE_PASS_BEGIN(MachineLoopRanges, "machine-loop-ranges",
"Machine Loop Ranges", true, true)
INITIALIZE_PASS_DEPENDENCY(SlotIndexes)
INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
INITIALIZE_PASS_END(MachineLoopRanges, "machine-loop-ranges",
"Machine Loop Ranges", true, true)
char &llvm::MachineLoopRangesID = MachineLoopRanges::ID;
void MachineLoopRanges::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequiredTransitive<SlotIndexes>();
AU.addRequiredTransitive<MachineLoopInfo>();
MachineFunctionPass::getAnalysisUsage(AU);
}
/// runOnMachineFunction - Don't do much, loop ranges are computed on demand.
bool MachineLoopRanges::runOnMachineFunction(MachineFunction &) {
releaseMemory();
Indexes = &getAnalysis<SlotIndexes>();
return false;
}
void MachineLoopRanges::releaseMemory() {
DeleteContainerSeconds(Cache);
Cache.clear();
}
MachineLoopRange *MachineLoopRanges::getLoopRange(const MachineLoop *Loop) {
MachineLoopRange *&Range = Cache[Loop];
if (!Range)
Range = new MachineLoopRange(Loop, Allocator, *Indexes);
return Range;
}
/// Create a MachineLoopRange, only accessible to MachineLoopRanges.
MachineLoopRange::MachineLoopRange(const MachineLoop *loop,
MachineLoopRange::Allocator &alloc,
SlotIndexes &Indexes)
: Loop(loop), Intervals(alloc), Area(0) {
// Compute loop coverage.
for (MachineLoop::block_iterator I = Loop->block_begin(),
E = Loop->block_end(); I != E; ++I) {
const std::pair<SlotIndex, SlotIndex> &Range = Indexes.getMBBRange(*I);
Intervals.insert(Range.first, Range.second, 1u);
Area += Range.first.distance(Range.second);
}
}
/// overlaps - Return true if this loop overlaps the given range of machine
/// instructions.
bool MachineLoopRange::overlaps(SlotIndex Start, SlotIndex Stop) {
Map::const_iterator I = Intervals.find(Start);
return I.valid() && Stop > I.start();
}
unsigned MachineLoopRange::getNumber() const {
return Loop->getHeader()->getNumber();
}
/// byNumber - Comparator for array_pod_sort that sorts a list of
/// MachineLoopRange pointers by number.
int MachineLoopRange::byNumber(const void *pa, const void *pb) {
const MachineLoopRange *a = *static_cast<MachineLoopRange *const *>(pa);
const MachineLoopRange *b = *static_cast<MachineLoopRange *const *>(pb);
unsigned na = a->getNumber();
unsigned nb = b->getNumber();
if (na < nb)
return -1;
if (na > nb)
return 1;
return 0;
}
/// byAreaDesc - Comparator for array_pod_sort that sorts a list of
/// MachineLoopRange pointers by:
/// 1. Descending area.
/// 2. Ascending number.
int MachineLoopRange::byAreaDesc(const void *pa, const void *pb) {
const MachineLoopRange *a = *static_cast<MachineLoopRange *const *>(pa);
const MachineLoopRange *b = *static_cast<MachineLoopRange *const *>(pb);
if (a->getArea() != b->getArea())
return a->getArea() > b->getArea() ? -1 : 1;
return byNumber(pa, pb);
}
void MachineLoopRange::print(raw_ostream &OS) const {
OS << "Loop#" << getNumber() << " =";
for (Map::const_iterator I = Intervals.begin(); I.valid(); ++I)
OS << " [" << I.start() << ';' << I.stop() << ')';
}
raw_ostream &llvm::operator<<(raw_ostream &OS, const MachineLoopRange &MLR) {
MLR.print(OS);
return OS;
}