llvm/lib/CodeGen/ExactHazardRecognizer.h
2010-04-07 18:19:32 +00:00

87 lines
2.6 KiB
C++

//=- llvm/CodeGen/ExactHazardRecognizer.h - Scheduling Support -*- C++ -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the ExactHazardRecognizer class, which
// implements hazard-avoidance heuristics for scheduling, based on the
// scheduling itineraries specified for the target.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_EXACTHAZARDRECOGNIZER_H
#define LLVM_CODEGEN_EXACTHAZARDRECOGNIZER_H
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
#include "llvm/CodeGen/ScheduleDAG.h"
#include "llvm/Target/TargetInstrItineraries.h"
namespace llvm {
class ExactHazardRecognizer : public ScheduleHazardRecognizer {
// ScoreBoard to track function unit usage. ScoreBoard[0] is a
// mask of the FUs in use in the cycle currently being
// schedule. ScoreBoard[1] is a mask for the next cycle. The
// ScoreBoard is used as a circular buffer with the current cycle
// indicated by Head.
class ScoreBoard {
unsigned *Data;
// The maximum number of cycles monitored by the Scoreboard. This
// value is determined based on the target itineraries to ensure
// that all hazards can be tracked.
size_t Depth;
// Indices into the Scoreboard that represent the current cycle.
size_t Head;
public:
ScoreBoard():Data(NULL), Depth(0), Head(0) { }
~ScoreBoard() {
delete[] Data;
}
size_t getDepth() const { return Depth; }
unsigned& operator[](size_t idx) const {
assert(Depth && "ScoreBoard was not initialized properly!");
return Data[(Head + idx) % Depth];
}
void reset(size_t d = 1) {
if (Data == NULL) {
Depth = d;
Data = new unsigned[Depth];
}
memset(Data, 0, Depth * sizeof(Data[0]));
Head = 0;
}
void advance() {
Head = (Head + 1) % Depth;
}
// Print the scoreboard.
void dump() const;
};
// Itinerary data for the target.
const InstrItineraryData &ItinData;
ScoreBoard ReservedScoreboard;
ScoreBoard RequiredScoreboard;
public:
ExactHazardRecognizer(const InstrItineraryData &ItinData);
virtual HazardType getHazardType(SUnit *SU);
virtual void Reset();
virtual void EmitInstruction(SUnit *SU);
virtual void AdvanceCycle();
};
}
#endif