LLVM: llvm::PPCHazardRecognizer970 Class Reference (original) (raw)

PPCHazardRecognizer970 - This class defines a finite state automata that models the dispatch logic on the PowerPC 970 (aka G5) processor. More...

#include "[Target/PowerPC/PPCHazardRecognizers.h](PPCHazardRecognizers%5F8h%5Fsource.html)"

Public Member Functions
PPCHazardRecognizer970 (const ScheduleDAG &DAG)
HazardType getHazardType (SUnit *SU, int Stalls) override
getHazardType - We return hazard for any non-branch instruction that would terminate the dispatch group.
void EmitInstruction (SUnit *SU) override
EmitInstruction - This callback is invoked when an instruction is emitted, to advance the hazard state.
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.
void Reset () override
Reset - This callback is invoked when a new block of instructions is about to be schedule.
Public Member Functions inherited from llvm::ScheduleHazardRecognizer
ScheduleHazardRecognizer ()=default
virtual ~ScheduleHazardRecognizer ()
unsigned getMaxLookAhead () const
bool isEnabled () const
virtual bool atIssueLimit () const
atIssueLimit - Return true if no more instructions may be issued in this cycle.
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.
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.
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.

PPCHazardRecognizer970 - This class defines a finite state automata that models the dispatch logic on the PowerPC 970 (aka G5) processor.

This promotes good dispatch group formation and implements noop insertion to avoid structural hazards that cause significant performance penalties (e.g. setting the CTR register then branching through it within a dispatch group), or storing then loading from the same address within a dispatch group.

Definition at line 55 of file PPCHazardRecognizers.h.

◆ AdvanceCycle()

void PPCHazardRecognizer970::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.

Definition at line 425 of file PPCHazardRecognizers.cpp.

References assert().

◆ EmitInstruction()

void PPCHazardRecognizer970::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 386 of file PPCHazardRecognizers.cpp.

References llvm::SUnit::getInstr(), llvm::MachineMemOperand::getOffset(), llvm::MachineMemOperand::getSize(), llvm::LocationSize::getValue(), llvm::MachineMemOperand::getValue(), isLoad(), isStore(), MI, llvm::PPCII::PPC970_BRU, and llvm::PPCII::PPC970_Pseudo.

◆ getHazardType()

getHazardType - We return hazard for any non-branch instruction that would terminate the dispatch group.

We turn NoopHazard for any instructions that wouldn't terminate the dispatch group that would cause a pipeline flush.

Reimplemented from llvm::ScheduleHazardRecognizer.

Definition at line 324 of file PPCHazardRecognizers.cpp.

References assert(), llvm::SUnit::getInstr(), llvm::MachineMemOperand::getOffset(), llvm::MachineMemOperand::getSize(), llvm::LocationSize::getValue(), llvm::MachineMemOperand::getValue(), llvm::LocationSize::hasValue(), llvm::ScheduleHazardRecognizer::Hazard, isLoad(), isStore(), llvm_unreachable, MI, llvm::ScheduleHazardRecognizer::NoHazard, llvm::ScheduleHazardRecognizer::NoopHazard, llvm::PPCII::PPC970_BRU, llvm::PPCII::PPC970_CRU, llvm::PPCII::PPC970_FPU, llvm::PPCII::PPC970_FXU, llvm::PPCII::PPC970_LSU, llvm::PPCII::PPC970_Pseudo, llvm::PPCII::PPC970_VALU, and llvm::PPCII::PPC970_VPERM.

◆ Reset()

void PPCHazardRecognizer970::Reset ( ) overridevirtual

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