LLVM  6.0.0svn
Public Types | Public Member Functions | Public Attributes | List of all members
llvm::InstrStage Struct Reference

These values represent a non-pipelined step in the execution of an instruction. More...

#include "llvm/MC/MCInstrItineraries.h"

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Public Types

enum  ReservationKinds { Required = 0, Reserved = 1 }
 

Public Member Functions

unsigned getCycles () const
 Returns the number of cycles the stage is occupied. More...
 
unsigned getUnits () const
 Returns the choice of FUs. More...
 
ReservationKinds getReservationKind () const
 
unsigned getNextCycles () const
 Returns the number of cycles from the start of this stage to the start of the next stage in the itinerary. More...
 

Public Attributes

unsigned Cycles_
 Length of stage in machine cycles. More...
 
unsigned Units_
 Choice of functional units. More...
 
int NextCycles_
 Number of machine cycles to next stage. More...
 
ReservationKinds Kind_
 Kind of the FU reservation. More...
 

Detailed Description

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. A value of -1 indicates that the next stage should start immediately after the current one. For example:

{ 1, x, -1 } indicates that the stage occupies FU x for 1 cycle and that the next stage starts immediately after this one.

{ 2, x|y, 1 } indicates that the stage occupies either FU x or FU y for 2 consecutive cycles and that the next stage starts one cycle after this stage starts. That is, the stage requirements overlap in time.

{ 1, x, 0 } indicates that the stage occupies FU x for 1 cycle and that the next stage starts in this same cycle. This can be used to indicate that the instruction requires multiple stages at the same time.

FU reservation can be of two different kinds:

Definition at line 59 of file MCInstrItineraries.h.

Member Enumeration Documentation

◆ ReservationKinds

Enumerator
Required 
Reserved 

Definition at line 60 of file MCInstrItineraries.h.

Member Function Documentation

◆ getCycles()

unsigned llvm::InstrStage::getCycles ( ) const
inline

Returns the number of cycles the stage is occupied.

Definition at line 71 of file MCInstrItineraries.h.

References Cycles_.

Referenced by llvm::ScoreboardHazardRecognizer::ScoreboardHazardRecognizer().

◆ getNextCycles()

unsigned llvm::InstrStage::getNextCycles ( ) const
inline

Returns the number of cycles from the start of this stage to the start of the next stage in the itinerary.

Definition at line 86 of file MCInstrItineraries.h.

Referenced by llvm::ScoreboardHazardRecognizer::ScoreboardHazardRecognizer().

◆ getReservationKind()

ReservationKinds llvm::InstrStage::getReservationKind ( ) const
inline

Definition at line 80 of file MCInstrItineraries.h.

References Kind_.

◆ getUnits()

unsigned llvm::InstrStage::getUnits ( ) const
inline

Returns the choice of FUs.

Definition at line 76 of file MCInstrItineraries.h.

References Units_.

Referenced by llvm::HexagonInstrInfo::getUnits().

Member Data Documentation

◆ Cycles_

unsigned llvm::InstrStage::Cycles_

Length of stage in machine cycles.

Definition at line 65 of file MCInstrItineraries.h.

Referenced by getCycles().

◆ Kind_

ReservationKinds llvm::InstrStage::Kind_

Kind of the FU reservation.

Definition at line 68 of file MCInstrItineraries.h.

Referenced by getReservationKind().

◆ NextCycles_

int llvm::InstrStage::NextCycles_

Number of machine cycles to next stage.

Definition at line 67 of file MCInstrItineraries.h.

◆ Units_

unsigned llvm::InstrStage::Units_

Choice of functional units.

Definition at line 66 of file MCInstrItineraries.h.

Referenced by getUnits().


The documentation for this struct was generated from the following file: