1 //===-- llvm/Target/TargetInstrItineraries.h - Scheduling -------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the James M. Laskey and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file describes the structures used for instruction itineraries and
11 // states. This is used by schedulers to determine instruction states and
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_TARGET_TARGETINSTRITINERARIES_H
17 #define LLVM_TARGET_TARGETINSTRITINERARIES_H
21 //===----------------------------------------------------------------------===//
22 // Instruction stage - These values represent a step in the execution of an
23 // instruction. The latency represents the number of discrete time slots used
24 // need to complete the stage. Units represent the choice of functional units
25 // that can be used to complete the stage. Eg. IntUnit1, IntUnit2.
28 unsigned Cycles; // Length of stage in machine cycles
29 unsigned Units; // Choice of functional units
33 //===----------------------------------------------------------------------===//
34 // Instruction itinerary - An itinerary represents a sequential series of steps
35 // required to complete an instruction. Itineraries are represented as
36 // sequences of instruction stages.
38 struct InstrItinerary {
39 unsigned First; // Index of first stage in itinerary
40 unsigned Last; // Index of last + 1 stage in itinerary
44 } // End llvm namespace