LLVM  6.0.0svn
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llvm::ScoreboardHazardRecognizer Class Reference

#include "llvm/CodeGen/ScoreboardHazardRecognizer.h"

Inheritance diagram for llvm::ScoreboardHazardRecognizer:
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Collaboration diagram for llvm::ScoreboardHazardRecognizer:
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Public Member Functions

 ScoreboardHazardRecognizer (const InstrItineraryData *ItinData, const ScheduleDAG *DAG, const char *ParentDebugType="")
 
bool atIssueLimit () const override
 atIssueLimit - Return true if no more instructions may be issued in this cycle. More...
 
HazardType getHazardType (SUnit *SU, int Stalls) override
 getHazardType - Return the hazard type of emitting this node. More...
 
void Reset () override
 Reset - This callback is invoked when a new block of instructions is about to be schedule. More...
 
void EmitInstruction (SUnit *SU) override
 EmitInstruction - This callback is invoked when an instruction is emitted, to advance the hazard state. More...
 
void AdvanceCycle () override
 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. More...
 
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. More...
 
- Public Member Functions inherited from llvm::ScheduleHazardRecognizer
 ScheduleHazardRecognizer ()=default
 
virtual ~ScheduleHazardRecognizer ()
 
unsigned getMaxLookAhead () const
 
bool isEnabled () const
 
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. More...
 
virtual unsigned PreEmitNoops (SUnit *)
 PreEmitNoops - This callback is invoked prior to emitting an instruction. More...
 
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. More...
 
virtual bool ShouldPreferAnother (SUnit *)
 ShouldPreferAnother - This callback may be invoked if getHazardType returns NoHazard. More...
 
virtual void EmitNoop ()
 EmitNoop - This callback is invoked when a noop was added to the instruction stream. More...
 

Additional Inherited Members

- Public Types inherited from llvm::ScheduleHazardRecognizer
enum  HazardType { NoHazard, Hazard, NoopHazard }
 
- Protected Attributes inherited from llvm::ScheduleHazardRecognizer
unsigned MaxLookAhead = 0
 MaxLookAhead - Indicate the number of cycles in the scoreboard state. More...
 

Detailed Description

Definition at line 30 of file ScoreboardHazardRecognizer.h.

Constructor & Destructor Documentation

◆ ScoreboardHazardRecognizer()

ScoreboardHazardRecognizer::ScoreboardHazardRecognizer ( const InstrItineraryData ItinData,
const ScheduleDAG DAG,
const char ParentDebugType = "" 
)

Member Function Documentation

◆ AdvanceCycle()

void ScoreboardHazardRecognizer::AdvanceCycle ( )
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.

Reimplemented in llvm::PPCDispatchGroupSBHazardRecognizer, and llvm::ARMHazardRecognizer.

Definition at line 230 of file ScoreboardHazardRecognizer.cpp.

Referenced by llvm::ARMHazardRecognizer::AdvanceCycle(), and llvm::PPCDispatchGroupSBHazardRecognizer::AdvanceCycle().

◆ atIssueLimit()

bool ScoreboardHazardRecognizer::atIssueLimit ( ) const
overridevirtual

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

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 104 of file ScoreboardHazardRecognizer.cpp.

◆ EmitInstruction()

void ScoreboardHazardRecognizer::EmitInstruction ( SUnit )
overridevirtual

◆ getHazardType()

ScheduleHazardRecognizer::HazardType ScoreboardHazardRecognizer::getHazardType ( SUnit m,
int  Stalls 
)
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.

Reimplemented in llvm::ARMHazardRecognizer, and llvm::PPCDispatchGroupSBHazardRecognizer.

Definition at line 112 of file ScoreboardHazardRecognizer.cpp.

References assert(), llvm::InstrItineraryData::beginStage(), llvm::dbgs(), DEBUG, llvm::ScheduleDAG::dumpNode(), E, llvm::InstrItineraryData::endStage(), llvm::ScheduleDAG::getInstrDesc(), llvm::MCInstrDesc::getSchedClass(), llvm::ScheduleHazardRecognizer::Hazard, llvm::InstrItineraryData::isEmpty(), LLVM_FALLTHROUGH, llvm::SUnit::NodeNum, llvm::ScheduleHazardRecognizer::NoHazard, llvm::InstrStage::Required, and llvm::InstrStage::Reserved.

Referenced by llvm::ARMHazardRecognizer::getHazardType(), and llvm::PPCDispatchGroupSBHazardRecognizer::getHazardType().

◆ RecedeCycle()

void ScoreboardHazardRecognizer::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.

Reimplemented in llvm::PPCDispatchGroupSBHazardRecognizer, and llvm::ARMHazardRecognizer.

Definition at line 236 of file ScoreboardHazardRecognizer.cpp.

◆ Reset()

void ScoreboardHazardRecognizer::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.

Reimplemented in llvm::PPCDispatchGroupSBHazardRecognizer, and llvm::ARMHazardRecognizer.

Definition at line 80 of file ScoreboardHazardRecognizer.cpp.

References llvm::dbgs(), llvm::Depth, dump(), and LLVM_DUMP_METHOD.

Referenced by llvm::ARMHazardRecognizer::Reset(), and llvm::PPCDispatchGroupSBHazardRecognizer::Reset().


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