mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-23 02:29:18 +00:00
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84244 91177308-0d34-0410-b5e6-96231b3b80d8
162 lines
5.1 KiB
C++
162 lines
5.1 KiB
C++
//===----- ExactHazardRecognizer.cpp - hazard recognizer -------- ---------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This implements a a hazard recognizer using the instructions itineraries
|
|
// defined for the current target.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#define DEBUG_TYPE "exact-hazards"
|
|
#include "ExactHazardRecognizer.h"
|
|
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/Support/ErrorHandling.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
#include "llvm/Target/TargetInstrItineraries.h"
|
|
|
|
using namespace llvm;
|
|
|
|
ExactHazardRecognizer::
|
|
ExactHazardRecognizer(const InstrItineraryData &LItinData) :
|
|
ScheduleHazardRecognizer(), ItinData(LItinData)
|
|
{
|
|
// Determine the maximum depth of any itinerary. This determines the
|
|
// depth of the scoreboard. We always make the scoreboard at least 1
|
|
// cycle deep to avoid dealing with the boundary condition.
|
|
ScoreboardDepth = 1;
|
|
if (!ItinData.isEmpty()) {
|
|
for (unsigned idx = 0; ; ++idx) {
|
|
if (ItinData.isEndMarker(idx))
|
|
break;
|
|
|
|
const InstrStage *IS = ItinData.beginStage(idx);
|
|
const InstrStage *E = ItinData.endStage(idx);
|
|
unsigned ItinDepth = 0;
|
|
for (; IS != E; ++IS)
|
|
ItinDepth += IS->getCycles();
|
|
|
|
ScoreboardDepth = std::max(ScoreboardDepth, ItinDepth);
|
|
}
|
|
}
|
|
|
|
Scoreboard = new unsigned[ScoreboardDepth];
|
|
ScoreboardHead = 0;
|
|
|
|
DEBUG(errs() << "Using exact hazard recognizer: ScoreboardDepth = "
|
|
<< ScoreboardDepth << '\n');
|
|
}
|
|
|
|
ExactHazardRecognizer::~ExactHazardRecognizer() {
|
|
delete [] Scoreboard;
|
|
}
|
|
|
|
void ExactHazardRecognizer::Reset() {
|
|
memset(Scoreboard, 0, ScoreboardDepth * sizeof(unsigned));
|
|
ScoreboardHead = 0;
|
|
}
|
|
|
|
unsigned ExactHazardRecognizer::getFutureIndex(unsigned offset) {
|
|
return (ScoreboardHead + offset) % ScoreboardDepth;
|
|
}
|
|
|
|
void ExactHazardRecognizer::dumpScoreboard() {
|
|
errs() << "Scoreboard:\n";
|
|
|
|
unsigned last = ScoreboardDepth - 1;
|
|
while ((last > 0) && (Scoreboard[getFutureIndex(last)] == 0))
|
|
last--;
|
|
|
|
for (unsigned i = 0; i <= last; i++) {
|
|
unsigned FUs = Scoreboard[getFutureIndex(i)];
|
|
errs() << "\t";
|
|
for (int j = 31; j >= 0; j--)
|
|
errs() << ((FUs & (1 << j)) ? '1' : '0');
|
|
errs() << '\n';
|
|
}
|
|
}
|
|
|
|
ExactHazardRecognizer::HazardType ExactHazardRecognizer::getHazardType(SUnit *SU) {
|
|
if (ItinData.isEmpty())
|
|
return NoHazard;
|
|
|
|
unsigned cycle = 0;
|
|
|
|
// Use the itinerary for the underlying instruction to check for
|
|
// free FU's in the scoreboard at the appropriate future cycles.
|
|
unsigned idx = SU->getInstr()->getDesc().getSchedClass();
|
|
for (const InstrStage *IS = ItinData.beginStage(idx),
|
|
*E = ItinData.endStage(idx); IS != E; ++IS) {
|
|
// We must find one of the stage's units free for every cycle the
|
|
// stage is occupied. FIXME it would be more accurate to find the
|
|
// same unit free in all the cycles.
|
|
for (unsigned int i = 0; i < IS->getCycles(); ++i) {
|
|
assert(((cycle + i) < ScoreboardDepth) &&
|
|
"Scoreboard depth exceeded!");
|
|
|
|
unsigned index = getFutureIndex(cycle + i);
|
|
unsigned freeUnits = IS->getUnits() & ~Scoreboard[index];
|
|
if (!freeUnits) {
|
|
DEBUG(errs() << "*** Hazard in cycle " << (cycle + i) << ", ");
|
|
DEBUG(errs() << "SU(" << SU->NodeNum << "): ");
|
|
DEBUG(SU->getInstr()->dump());
|
|
return Hazard;
|
|
}
|
|
}
|
|
|
|
// Advance the cycle to the next stage.
|
|
cycle += IS->getNextCycles();
|
|
}
|
|
|
|
return NoHazard;
|
|
}
|
|
|
|
void ExactHazardRecognizer::EmitInstruction(SUnit *SU) {
|
|
if (ItinData.isEmpty())
|
|
return;
|
|
|
|
unsigned cycle = 0;
|
|
|
|
// Use the itinerary for the underlying instruction to reserve FU's
|
|
// in the scoreboard at the appropriate future cycles.
|
|
unsigned idx = SU->getInstr()->getDesc().getSchedClass();
|
|
for (const InstrStage *IS = ItinData.beginStage(idx),
|
|
*E = ItinData.endStage(idx); IS != E; ++IS) {
|
|
// We must reserve one of the stage's units for every cycle the
|
|
// stage is occupied. FIXME it would be more accurate to reserve
|
|
// the same unit free in all the cycles.
|
|
for (unsigned int i = 0; i < IS->getCycles(); ++i) {
|
|
assert(((cycle + i) < ScoreboardDepth) &&
|
|
"Scoreboard depth exceeded!");
|
|
|
|
unsigned index = getFutureIndex(cycle + i);
|
|
unsigned freeUnits = IS->getUnits() & ~Scoreboard[index];
|
|
|
|
// reduce to a single unit
|
|
unsigned freeUnit = 0;
|
|
do {
|
|
freeUnit = freeUnits;
|
|
freeUnits = freeUnit & (freeUnit - 1);
|
|
} while (freeUnits);
|
|
|
|
assert(freeUnit && "No function unit available!");
|
|
Scoreboard[index] |= freeUnit;
|
|
}
|
|
|
|
// Advance the cycle to the next stage.
|
|
cycle += IS->getNextCycles();
|
|
}
|
|
|
|
DEBUG(dumpScoreboard());
|
|
}
|
|
|
|
void ExactHazardRecognizer::AdvanceCycle() {
|
|
Scoreboard[ScoreboardHead] = 0;
|
|
ScoreboardHead = getFutureIndex(1);
|
|
}
|