llvm-6502/include/llvm/Target/TargetInstrItineraries.h

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//===-- llvm/Target/TargetInstrItineraries.h - Scheduling -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file describes the structures used for instruction itineraries and
// states. This is used by schedulers to determine instruction states and
// latencies.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TARGET_TARGETINSTRITINERARIES_H
#define LLVM_TARGET_TARGETINSTRITINERARIES_H
namespace llvm {
//===----------------------------------------------------------------------===//
// Instruction stage - These values represent a step in the execution of an
// instruction. The latency represents the number of discrete time slots used
// need to complete the stage. Units represent the choice of functional units
// that can be used to complete the stage. Eg. IntUnit1, IntUnit2.
//
struct InstrStage {
unsigned Cycles; // Length of stage in machine cycles
unsigned Units; // Choice of functional units
};
//===----------------------------------------------------------------------===//
// Instruction itinerary - An itinerary represents a sequential series of steps
// required to complete an instruction. Itineraries are represented as
// sequences of instruction stages.
//
struct InstrItinerary {
unsigned First; // Index of first stage in itinerary
unsigned Last; // Index of last + 1 stage in itinerary
};
//===----------------------------------------------------------------------===//
// Instruction itinerary Data - Itinerary data supplied by a subtarget to be
// used by a target.
//
struct InstrItineraryData {
const InstrStage *Stages; // Array of stages selected
const InstrItinerary *Itineratries; // Array of itineraries selected
//
// Ctors.
//
InstrItineraryData() : Stages(0), Itineratries(0) {}
InstrItineraryData(const InstrStage *S, const InstrItinerary *I)
: Stages(S), Itineratries(I) {}
//
// isEmpty - Returns true if there are no itineraries.
//
inline bool isEmpty() const { return Itineratries == 0; }
//
// begin - Return the first stage of the itinerary.
//
inline const InstrStage *begin(unsigned ItinClassIndx) const {
unsigned StageIdx = Itineratries[ItinClassIndx].First;
return Stages + StageIdx;
}
//
// end - Return the last+1 stage of the itinerary.
//
inline const InstrStage *end(unsigned ItinClassIndx) const {
unsigned StageIdx = Itineratries[ItinClassIndx].Last;
return Stages + StageIdx;
}
};
} // End llvm namespace
#endif