llvm/lib/Target/PowerPC/PPCHazardRecognizers.h
2014-08-30 16:48:34 +00:00

103 lines
3.8 KiB
C++

//===-- PPCHazardRecognizers.h - PowerPC Hazard Recognizers -----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines hazard recognizers for scheduling on PowerPC processors.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_POWERPC_PPCHAZARDRECOGNIZERS_H
#define LLVM_LIB_TARGET_POWERPC_PPCHAZARDRECOGNIZERS_H
#include "PPCInstrInfo.h"
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
#include "llvm/CodeGen/ScoreboardHazardRecognizer.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
namespace llvm {
/// PPCDispatchGroupSBHazardRecognizer - This class implements a scoreboard-based
/// hazard recognizer for PPC ooo processors with dispatch-group hazards.
class PPCDispatchGroupSBHazardRecognizer : public ScoreboardHazardRecognizer {
const ScheduleDAG *DAG;
SmallVector<SUnit *, 7> CurGroup;
unsigned CurSlots, CurBranches;
bool isLoadAfterStore(SUnit *SU);
bool isBCTRAfterSet(SUnit *SU);
bool mustComeFirst(const MCInstrDesc *MCID, unsigned &NSlots);
public:
PPCDispatchGroupSBHazardRecognizer(const InstrItineraryData *ItinData,
const ScheduleDAG *DAG_) :
ScoreboardHazardRecognizer(ItinData, DAG_), DAG(DAG_),
CurSlots(0), CurBranches(0) {}
HazardType getHazardType(SUnit *SU, int Stalls) override;
bool ShouldPreferAnother(SUnit* SU) override;
unsigned PreEmitNoops(SUnit *SU) override;
void EmitInstruction(SUnit *SU) override;
void AdvanceCycle() override;
void RecedeCycle() override;
void Reset() override;
void EmitNoop() override;
};
/// 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.
class PPCHazardRecognizer970 : public ScheduleHazardRecognizer {
const ScheduleDAG &DAG;
unsigned NumIssued; // Number of insts issued, including advanced cycles.
// Various things that can cause a structural hazard.
// HasCTRSet - If the CTR register is set in this group, disallow BCTRL.
bool HasCTRSet;
// StoredPtr - Keep track of the address of any store. If we see a load from
// the same address (or one that aliases it), disallow the store. We can have
// up to four stores in one dispatch group, hence we track up to 4.
//
// This is null if we haven't seen a store yet. We keep track of both
// operands of the store here, since we support [r+r] and [r+i] addressing.
const Value *StoreValue[4];
int64_t StoreOffset[4];
uint64_t StoreSize[4];
unsigned NumStores;
public:
PPCHazardRecognizer970(const ScheduleDAG &DAG);
HazardType getHazardType(SUnit *SU, int Stalls) override;
void EmitInstruction(SUnit *SU) override;
void AdvanceCycle() override;
void Reset() override;
private:
/// EndDispatchGroup - Called when we are finishing a new dispatch group.
///
void EndDispatchGroup();
/// GetInstrType - Classify the specified powerpc opcode according to its
/// pipeline.
PPCII::PPC970_Unit GetInstrType(unsigned Opcode,
bool &isFirst, bool &isSingle,bool &isCracked,
bool &isLoad, bool &isStore);
bool isLoadOfStoredAddress(uint64_t LoadSize, int64_t LoadOffset,
const Value *LoadValue) const;
};
} // end namespace llvm
#endif