LLVM 17.0.0git
llvm::MultiHazardRecognizer Class Reference

#include "llvm/CodeGen/MultiHazardRecognizer.h"

Inheritance diagram for llvm::MultiHazardRecognizer:
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Collaboration diagram for llvm::MultiHazardRecognizer:
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## Public Member Functions

MultiHazardRecognizer ()=default

void AddHazardRecognizer (std::unique_ptr< ScheduleHazardRecognizer > &&)

bool atIssueLimit () const override
atIssueLimit - Return true if no more instructions may be issued in this cycle.

HazardType getHazardType (SUnit *, int Stalls=0) override
getHazardType - Return the hazard type of emitting this node.

void Reset () override
Reset - This callback is invoked when a new block of instructions is about to be schedule.

void EmitInstruction (SUnit *) override
EmitInstruction - This callback is invoked when an instruction is emitted, to advance the hazard state.

void EmitInstruction (MachineInstr *) override
This overload will be used when the hazard recognizer is being used by a non-scheduling pass, which does not use SUnits.

unsigned PreEmitNoops (SUnit *) override
PreEmitNoops - This callback is invoked prior to emitting an instruction.

unsigned PreEmitNoops (MachineInstr *) override
This overload will be used when the hazard recognizer is being used by a non-scheduling pass, which does not use SUnits.

bool ShouldPreferAnother (SUnit *) override
ShouldPreferAnother - This callback may be invoked if getHazardType returns NoHazard.

AdvanceCycle - This callback is invoked whenever the next top-down instruction to be scheduled cannot issue in the current cycle, either because of latency or resource conflicts.

void RecedeCycle () override
RecedeCycle - This callback is invoked whenever the next bottom-up instruction to be scheduled cannot issue in the current cycle, either because of latency or resource conflicts.

void EmitNoop () override
EmitNoop - This callback is invoked when a noop was added to the instruction stream.

Public Member Functions inherited from llvm::ScheduleHazardRecognizer
ScheduleHazardRecognizer ()=default

virtual ~ScheduleHazardRecognizer ()

bool isEnabled () const

virtual bool atIssueLimit () const
atIssueLimit - Return true if no more instructions may be issued in this cycle.

virtual HazardType getHazardType (SUnit *, int Stalls=0)
getHazardType - Return the hazard type of emitting this node.

virtual void Reset ()
Reset - This callback is invoked when a new block of instructions is about to be schedule.

virtual void EmitInstruction (SUnit *)
EmitInstruction - This callback is invoked when an instruction is emitted, to advance the hazard state.

virtual void EmitInstruction (MachineInstr *)
This overload will be used when the hazard recognizer is being used by a non-scheduling pass, which does not use SUnits.

virtual unsigned PreEmitNoops (SUnit *)
PreEmitNoops - This callback is invoked prior to emitting an instruction.

virtual unsigned PreEmitNoops (MachineInstr *)
This overload will be used when the hazard recognizer is being used by a non-scheduling pass, which does not use SUnits.

virtual bool ShouldPreferAnother (SUnit *)
ShouldPreferAnother - This callback may be invoked if getHazardType returns NoHazard.

AdvanceCycle - This callback is invoked whenever the next top-down instruction to be scheduled cannot issue in the current cycle, either because of latency or resource conflicts.

virtual void RecedeCycle ()
RecedeCycle - This callback is invoked whenever the next bottom-up instruction to be scheduled cannot issue in the current cycle, either because of latency or resource conflicts.

virtual void EmitNoop ()
EmitNoop - This callback is invoked when a noop was added to the instruction stream.

virtual void EmitNoops (unsigned Quantity)
EmitNoops - This callback is invoked when noops were added to the instruction stream.

Public Types inherited from llvm::ScheduleHazardRecognizer
enum  HazardType { NoHazard , Hazard , NoopHazard }

Protected Attributes inherited from llvm::ScheduleHazardRecognizer
MaxLookAhead - Indicate the number of cycles in the scoreboard state.

## Detailed Description

Definition at line 25 of file MultiHazardRecognizer.h.

## ◆ MultiHazardRecognizer()

 llvm::MultiHazardRecognizer::MultiHazardRecognizer ( )
default

## Member Function Documentation

 void MultiHazardRecognizer::AddHazardRecognizer ( std::unique_ptr< ScheduleHazardRecognizer > && R )

overridevirtual

AdvanceCycle - This callback is invoked whenever the next top-down instruction to be scheduled cannot issue in the current cycle, either because of latency or resource conflicts.

This should increment the internal state of the hazard recognizer so that previously "Hazard" instructions will now not be hazards.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 79 of file MultiHazardRecognizer.cpp.

## ◆ atIssueLimit()

 bool MultiHazardRecognizer::atIssueLimit ( ) const
overridevirtual

atIssueLimit - Return true if no more instructions may be issued in this cycle.

FIXME: remove this once MachineScheduler is the only client.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 28 of file MultiHazardRecognizer.cpp.

References llvm::any_of(), and llvm::ScheduleHazardRecognizer::atIssueLimit().

## ◆ EmitInstruction() [1/2]

 void MultiHazardRecognizer::EmitInstruction ( MachineInstr * )
overridevirtual

This overload will be used when the hazard recognizer is being used by a non-scheduling pass, which does not use SUnits.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 53 of file MultiHazardRecognizer.cpp.

References MI.

## ◆ EmitInstruction() [2/2]

 void MultiHazardRecognizer::EmitInstruction ( SUnit * )
overridevirtual

EmitInstruction - This callback is invoked when an instruction is emitted, to advance the hazard state.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 48 of file MultiHazardRecognizer.cpp.

## ◆ EmitNoop()

 void MultiHazardRecognizer::EmitNoop ( )
overridevirtual

EmitNoop - This callback is invoked when a noop was added to the instruction stream.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 89 of file MultiHazardRecognizer.cpp.

## ◆ getHazardType()

 ScheduleHazardRecognizer::HazardType MultiHazardRecognizer::getHazardType ( SUnit * , int Stalls = 0 )
overridevirtual

getHazardType - Return the hazard type of emitting this node.

There are three possible results. Either:

• NoHazard: it is legal to issue this instruction on this cycle.
• Hazard: issuing this instruction would stall the machine. If some other instruction is available, issue it first.
• NoopHazard: issuing this instruction would break the program. If some other instruction can be issued, do so, otherwise issue a noop.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 34 of file MultiHazardRecognizer.cpp.

References llvm::ScheduleHazardRecognizer::NoHazard.

## ◆ PreEmitNoops() [1/2]

 unsigned MultiHazardRecognizer::PreEmitNoops ( MachineInstr * )
overridevirtual

This overload will be used when the hazard recognizer is being used by a non-scheduling pass, which does not use SUnits.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 65 of file MultiHazardRecognizer.cpp.

References MI.

## ◆ PreEmitNoops() [2/2]

 unsigned MultiHazardRecognizer::PreEmitNoops ( SUnit * )
overridevirtual

PreEmitNoops - This callback is invoked prior to emitting an instruction.

It should return the number of noops to emit prior to the provided instruction. Note: This is only used during PostRA scheduling. EmitNoop is not called for these noops.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 58 of file MultiHazardRecognizer.cpp.

## ◆ RecedeCycle()

 void MultiHazardRecognizer::RecedeCycle ( )
overridevirtual

RecedeCycle - This callback is invoked whenever the next bottom-up instruction to be scheduled cannot issue in the current cycle, either because of latency or resource conflicts.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 84 of file MultiHazardRecognizer.cpp.

## ◆ Reset()

 void MultiHazardRecognizer::Reset ( )
overridevirtual

Reset - This callback is invoked when a new block of instructions is about to be schedule.

The hazard state should be set to an initialized state.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 43 of file MultiHazardRecognizer.cpp.

## ◆ ShouldPreferAnother()

 bool MultiHazardRecognizer::ShouldPreferAnother ( SUnit * )
overridevirtual

ShouldPreferAnother - This callback may be invoked if getHazardType returns NoHazard.

If, even though there is no hazard, it would be better to schedule another available instruction, this callback should return true.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 72 of file MultiHazardRecognizer.cpp.

References llvm::any_of().

The documentation for this class was generated from the following files: