llvm-6502/lib/Target/PowerPC/PPCInstrInfo.h
Hal Finkel b7c01bf403 [PowerPC] Mark all instructions as non-cheap for MachineLICM
MachineLICM uses a callback named hasLowDefLatency to determine if an
instruction def operand has a 'low' latency. If all relevant operands have a
'low' latency, the instruction is considered too cheap to hoist out of loops
even in low-register-pressure situations. On PowerPC cores, both the embedded
cores and the others, there is no reason to believe that this is a good choice:
all instructions have a cost inside a loop, and hoisting them when not limited
by register pressure is a reasonable default.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225471 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-08 22:11:49 +00:00

247 lines
10 KiB
C++

//===-- PPCInstrInfo.h - PowerPC Instruction Information --------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the PowerPC implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_POWERPC_PPCINSTRINFO_H
#define LLVM_LIB_TARGET_POWERPC_PPCINSTRINFO_H
#include "PPC.h"
#include "PPCRegisterInfo.h"
#include "llvm/Target/TargetInstrInfo.h"
#define GET_INSTRINFO_HEADER
#include "PPCGenInstrInfo.inc"
namespace llvm {
/// PPCII - This namespace holds all of the PowerPC target-specific
/// per-instruction flags. These must match the corresponding definitions in
/// PPC.td and PPCInstrFormats.td.
namespace PPCII {
enum {
// PPC970 Instruction Flags. These flags describe the characteristics of the
// PowerPC 970 (aka G5) dispatch groups and how they are formed out of
// raw machine instructions.
/// PPC970_First - This instruction starts a new dispatch group, so it will
/// always be the first one in the group.
PPC970_First = 0x1,
/// PPC970_Single - This instruction starts a new dispatch group and
/// terminates it, so it will be the sole instruction in the group.
PPC970_Single = 0x2,
/// PPC970_Cracked - This instruction is cracked into two pieces, requiring
/// two dispatch pipes to be available to issue.
PPC970_Cracked = 0x4,
/// PPC970_Mask/Shift - This is a bitmask that selects the pipeline type that
/// an instruction is issued to.
PPC970_Shift = 3,
PPC970_Mask = 0x07 << PPC970_Shift
};
enum PPC970_Unit {
/// These are the various PPC970 execution unit pipelines. Each instruction
/// is one of these.
PPC970_Pseudo = 0 << PPC970_Shift, // Pseudo instruction
PPC970_FXU = 1 << PPC970_Shift, // Fixed Point (aka Integer/ALU) Unit
PPC970_LSU = 2 << PPC970_Shift, // Load Store Unit
PPC970_FPU = 3 << PPC970_Shift, // Floating Point Unit
PPC970_CRU = 4 << PPC970_Shift, // Control Register Unit
PPC970_VALU = 5 << PPC970_Shift, // Vector ALU
PPC970_VPERM = 6 << PPC970_Shift, // Vector Permute Unit
PPC970_BRU = 7 << PPC970_Shift // Branch Unit
};
} // end namespace PPCII
class PPCInstrInfo : public PPCGenInstrInfo {
PPCSubtarget &Subtarget;
const PPCRegisterInfo RI;
bool StoreRegToStackSlot(MachineFunction &MF,
unsigned SrcReg, bool isKill, int FrameIdx,
const TargetRegisterClass *RC,
SmallVectorImpl<MachineInstr*> &NewMIs,
bool &NonRI, bool &SpillsVRS) const;
bool LoadRegFromStackSlot(MachineFunction &MF, DebugLoc DL,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC,
SmallVectorImpl<MachineInstr*> &NewMIs,
bool &NonRI, bool &SpillsVRS) const;
virtual void anchor();
public:
explicit PPCInstrInfo(PPCSubtarget &STI);
/// getRegisterInfo - TargetInstrInfo is a superset of MRegister info. As
/// such, whenever a client has an instance of instruction info, it should
/// always be able to get register info as well (through this method).
///
const PPCRegisterInfo &getRegisterInfo() const { return RI; }
ScheduleHazardRecognizer *
CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
const ScheduleDAG *DAG) const override;
ScheduleHazardRecognizer *
CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II,
const ScheduleDAG *DAG) const override;
int getOperandLatency(const InstrItineraryData *ItinData,
const MachineInstr *DefMI, unsigned DefIdx,
const MachineInstr *UseMI,
unsigned UseIdx) const override;
int getOperandLatency(const InstrItineraryData *ItinData,
SDNode *DefNode, unsigned DefIdx,
SDNode *UseNode, unsigned UseIdx) const override {
return PPCGenInstrInfo::getOperandLatency(ItinData, DefNode, DefIdx,
UseNode, UseIdx);
}
bool hasLowDefLatency(const InstrItineraryData *ItinData,
const MachineInstr *DefMI,
unsigned DefIdx) const override {
// Machine LICM should hoist all instructions in low-register-pressure
// situations; none are sufficiently free to justify leaving in a loop
// body.
return false;
}
bool isCoalescableExtInstr(const MachineInstr &MI,
unsigned &SrcReg, unsigned &DstReg,
unsigned &SubIdx) const override;
unsigned isLoadFromStackSlot(const MachineInstr *MI,
int &FrameIndex) const override;
unsigned isStoreToStackSlot(const MachineInstr *MI,
int &FrameIndex) const override;
// commuteInstruction - We can commute rlwimi instructions, but only if the
// rotate amt is zero. We also have to munge the immediates a bit.
MachineInstr *commuteInstruction(MachineInstr *MI, bool NewMI) const override;
bool findCommutedOpIndices(MachineInstr *MI, unsigned &SrcOpIdx1,
unsigned &SrcOpIdx2) const override;
void insertNoop(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const override;
// Branch analysis.
bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const override;
unsigned RemoveBranch(MachineBasicBlock &MBB) const override;
unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const SmallVectorImpl<MachineOperand> &Cond,
DebugLoc DL) const override;
// Select analysis.
bool canInsertSelect(const MachineBasicBlock&,
const SmallVectorImpl<MachineOperand> &Cond,
unsigned, unsigned, int&, int&, int&) const override;
void insertSelect(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI, DebugLoc DL,
unsigned DstReg,
const SmallVectorImpl<MachineOperand> &Cond,
unsigned TrueReg, unsigned FalseReg) const override;
void copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I, DebugLoc DL,
unsigned DestReg, unsigned SrcReg,
bool KillSrc) const override;
void storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
unsigned SrcReg, bool isKill, int FrameIndex,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const override;
void loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
unsigned DestReg, int FrameIndex,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const override;
bool
ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
bool FoldImmediate(MachineInstr *UseMI, MachineInstr *DefMI,
unsigned Reg, MachineRegisterInfo *MRI) const override;
// If conversion by predication (only supported by some branch instructions).
// All of the profitability checks always return true; it is always
// profitable to use the predicated branches.
bool isProfitableToIfCvt(MachineBasicBlock &MBB,
unsigned NumCycles, unsigned ExtraPredCycles,
const BranchProbability &Probability) const override {
return true;
}
bool isProfitableToIfCvt(MachineBasicBlock &TMBB,
unsigned NumT, unsigned ExtraT,
MachineBasicBlock &FMBB,
unsigned NumF, unsigned ExtraF,
const BranchProbability &Probability) const override;
bool isProfitableToDupForIfCvt(MachineBasicBlock &MBB,
unsigned NumCycles,
const BranchProbability
&Probability) const override {
return true;
}
bool isProfitableToUnpredicate(MachineBasicBlock &TMBB,
MachineBasicBlock &FMBB) const override {
return false;
}
// Predication support.
bool isPredicated(const MachineInstr *MI) const override;
bool isUnpredicatedTerminator(const MachineInstr *MI) const override;
bool PredicateInstruction(MachineInstr *MI,
const SmallVectorImpl<MachineOperand> &Pred) const override;
bool SubsumesPredicate(const SmallVectorImpl<MachineOperand> &Pred1,
const SmallVectorImpl<MachineOperand> &Pred2) const override;
bool DefinesPredicate(MachineInstr *MI,
std::vector<MachineOperand> &Pred) const override;
bool isPredicable(MachineInstr *MI) const override;
// Comparison optimization.
bool analyzeCompare(const MachineInstr *MI,
unsigned &SrcReg, unsigned &SrcReg2,
int &Mask, int &Value) const override;
bool optimizeCompareInstr(MachineInstr *CmpInstr,
unsigned SrcReg, unsigned SrcReg2,
int Mask, int Value,
const MachineRegisterInfo *MRI) const override;
/// GetInstSize - Return the number of bytes of code the specified
/// instruction may be. This returns the maximum number of bytes.
///
unsigned GetInstSizeInBytes(const MachineInstr *MI) const;
void getNoopForMachoTarget(MCInst &NopInst) const override;
};
}
#endif