llvm-6502/lib/Target/PowerPC/PPCHazardRecognizers.h
Dan Gohman 2836c283bb Initial hazard recognizer support in post-pass scheduling. This includes
a new toy hazard recognizier heuristic which attempts to direct the
scheduler to avoid clumping large groups of loads or stores too densely.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62291 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-16 01:33:36 +00:00

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2.6 KiB
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//===-- 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 PPCHAZRECS_H
#define PPCHAZRECS_H
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "PPCInstrInfo.h"
namespace llvm {
/// 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 TargetInstrInfo &TII;
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.
SDValue StorePtr1[4], StorePtr2[4];
unsigned StoreSize[4];
unsigned NumStores;
public:
PPCHazardRecognizer970(const TargetInstrInfo &TII);
virtual HazardType getHazardType(SUnit *SU);
virtual void EmitInstruction(SUnit *SU);
virtual void AdvanceCycle();
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(unsigned LoadSize,
SDValue Ptr1, SDValue Ptr2) const;
};
} // end namespace llvm
#endif