llvm-6502/lib/Target/TargetSchedule.td
2005-10-18 16:23:40 +00:00

75 lines
3.3 KiB
TableGen

//===- TargetSchedule.td - Target Independent Scheduling ---*- tablegen -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by James M. Laskey and 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 chip sets - These values represent each of the chip sets supported
// by the scheduler. Each Processor definition requires corresponding
// instruction itineraries.
//
class Processor;
//===----------------------------------------------------------------------===//
// 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 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.
//
class InstrStage<int latency, list<FuncUnit> units> {
int Latency = latency; // length of stage in machine cycles
list<FuncUnit> Units = units; // choice of functional units
}
//===----------------------------------------------------------------------===//
// 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;
//===----------------------------------------------------------------------===//
// 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<Processor proc, list<InstrItinData> iid> {
Processor Proc = proc;
list<InstrItinData> IID = iid;
}