llvm-6502/include/llvm/Target/TargetSchedule.td

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//===- TargetSchedule.td - Target Independent Scheduling ---*- tablegen -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the target-independent scheduling interfaces which should
// be implemented by each target which is using TableGen based scheduling.
//
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
// Processor functional unit - These values represent the function units
// available across all chip sets for the target. Eg., IntUnit, FPUnit, ...
// These may be independent values for each chip set or may be shared across
// all chip sets of the target. Each functional unit is treated as a resource
// during scheduling and has an affect instruction order based on availability
// during a time interval.
//
class FuncUnit;
//===----------------------------------------------------------------------===//
// Instruction stage - These values represent a non-pipelined step in
// the execution of an instruction. Cycles represents the number of
// discrete time slots needed to complete the stage. Units represent
// the choice of functional units that can be used to complete the
// stage. Eg. IntUnit1, IntUnit2. NextCycles indicates how many
// cycles should elapse from the start of this stage to the start of
// the next stage in the itinerary. For example:
//
// A stage is specified in one of two ways:
//
// InstrStage<1, [FU_x, FU_y]> - TimeInc defaults to Cycles
// InstrStage<1, [FU_x, FU_y], 0> - TimeInc explicit
//
class InstrStage<int cycles, list<FuncUnit> units, int timeinc = -1> {
int Cycles = cycles; // length of stage in machine cycles
list<FuncUnit> Units = units; // choice of functional units
int TimeInc = timeinc; // cycles till start of next stage
}
//===----------------------------------------------------------------------===//
// Instruction itinerary - An itinerary represents a sequential series of steps
// required to complete an instruction. Itineraries are represented as lists of
// instruction stages.
//
//===----------------------------------------------------------------------===//
// Instruction itinerary classes - These values represent 'named' instruction
// itinerary. Using named itineraries simplifies managing groups of
// instructions across chip sets. An instruction uses the same itinerary class
// across all chip sets. Thus a new chip set can be added without modifying
// instruction information.
//
class InstrItinClass;
def NoItinerary : InstrItinClass;
//===----------------------------------------------------------------------===//
// Instruction itinerary data - These values provide a runtime map of an
// instruction itinerary class (name) to it's itinerary data.
//
class InstrItinData<InstrItinClass Class, list<InstrStage> stages> {
InstrItinClass TheClass = Class;
list<InstrStage> Stages = stages;
}
//===----------------------------------------------------------------------===//
// Processor itineraries - These values represent the set of all itinerary
// classes for a given chip set.
//
class ProcessorItineraries<list<InstrItinData> iid> {
list<InstrItinData> IID = iid;
}
// NoItineraries - A marker that can be used by processors without schedule
// info.
def NoItineraries : ProcessorItineraries<[]>;