llvm-6502/lib/Target/X86/X86RegisterInfo.h
Jim Grosbach e45ab8a0a9 For aligned load/store instructions, it's only required to know whether a
function can support dynamic stack realignment. That's a much easier question
to answer at instruction selection stage than whether the function actually
will have dynamic alignment prologue. This allows the removal of the
stack alignment heuristic pass, and improves code quality for cases where
the heuristic would result in dynamic alignment code being generated when
it was not strictly necessary.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93885 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-19 18:31:11 +00:00

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5.8 KiB
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//===- X86RegisterInfo.h - X86 Register Information Impl --------*- 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 X86 implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#ifndef X86REGISTERINFO_H
#define X86REGISTERINFO_H
#include "llvm/Target/TargetRegisterInfo.h"
#include "X86GenRegisterInfo.h.inc"
namespace llvm {
class Type;
class TargetInstrInfo;
class X86TargetMachine;
/// N86 namespace - Native X86 register numbers
///
namespace N86 {
enum {
EAX = 0, ECX = 1, EDX = 2, EBX = 3, ESP = 4, EBP = 5, ESI = 6, EDI = 7
};
}
namespace X86 {
/// SubregIndex - The index of various sized subregister classes. Note that
/// these indices must be kept in sync with the class indices in the
/// X86RegisterInfo.td file.
enum SubregIndex {
SUBREG_8BIT = 1, SUBREG_8BIT_HI = 2, SUBREG_16BIT = 3, SUBREG_32BIT = 4
};
}
/// DWARFFlavour - Flavour of dwarf regnumbers
///
namespace DWARFFlavour {
enum {
X86_64 = 0, X86_32_DarwinEH = 1, X86_32_Generic = 2
};
}
class X86RegisterInfo : public X86GenRegisterInfo {
public:
X86TargetMachine &TM;
const TargetInstrInfo &TII;
private:
/// Is64Bit - Is the target 64-bits.
///
bool Is64Bit;
/// IsWin64 - Is the target on of win64 flavours
///
bool IsWin64;
/// SlotSize - Stack slot size in bytes.
///
unsigned SlotSize;
/// StackAlign - Default stack alignment.
///
unsigned StackAlign;
/// StackPtr - X86 physical register used as stack ptr.
///
unsigned StackPtr;
/// FramePtr - X86 physical register used as frame ptr.
///
unsigned FramePtr;
public:
X86RegisterInfo(X86TargetMachine &tm, const TargetInstrInfo &tii);
/// getX86RegNum - Returns the native X86 register number for the given LLVM
/// register identifier.
static unsigned getX86RegNum(unsigned RegNo);
unsigned getStackAlignment() const { return StackAlign; }
/// getDwarfRegNum - allows modification of X86GenRegisterInfo::getDwarfRegNum
/// (created by TableGen) for target dependencies.
int getDwarfRegNum(unsigned RegNum, bool isEH) const;
/// Code Generation virtual methods...
///
/// getMatchingSuperRegClass - Return a subclass of the specified register
/// class A so that each register in it has a sub-register of the
/// specified sub-register index which is in the specified register class B.
virtual const TargetRegisterClass *
getMatchingSuperRegClass(const TargetRegisterClass *A,
const TargetRegisterClass *B, unsigned Idx) const;
/// getPointerRegClass - Returns a TargetRegisterClass used for pointer
/// values.
const TargetRegisterClass *getPointerRegClass(unsigned Kind = 0) const;
/// getCrossCopyRegClass - Returns a legal register class to copy a register
/// in the specified class to or from. Returns NULL if it is possible to copy
/// between a two registers of the specified class.
const TargetRegisterClass *
getCrossCopyRegClass(const TargetRegisterClass *RC) const;
/// getCalleeSavedRegs - Return a null-terminated list of all of the
/// callee-save registers on this target.
const unsigned *getCalleeSavedRegs(const MachineFunction* MF = 0) const;
/// getCalleeSavedRegClasses - Return a null-terminated list of the preferred
/// register classes to spill each callee-saved register with. The order and
/// length of this list match the getCalleeSavedRegs() list.
const TargetRegisterClass* const*
getCalleeSavedRegClasses(const MachineFunction *MF = 0) const;
/// getReservedRegs - Returns a bitset indexed by physical register number
/// indicating if a register is a special register that has particular uses and
/// should be considered unavailable at all times, e.g. SP, RA. This is used by
/// register scavenger to determine what registers are free.
BitVector getReservedRegs(const MachineFunction &MF) const;
bool hasFP(const MachineFunction &MF) const;
bool canRealignStack(const MachineFunction &MF) const;
bool needsStackRealignment(const MachineFunction &MF) const;
bool hasReservedCallFrame(MachineFunction &MF) const;
bool hasReservedSpillSlot(MachineFunction &MF, unsigned Reg,
int &FrameIdx) const;
void eliminateCallFramePseudoInstr(MachineFunction &MF,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const;
unsigned eliminateFrameIndex(MachineBasicBlock::iterator MI,
int SPAdj, int *Value = NULL,
RegScavenger *RS = NULL) const;
void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
RegScavenger *RS = NULL) const;
void emitCalleeSavedFrameMoves(MachineFunction &MF, unsigned LabelId,
unsigned FramePtr) const;
void emitPrologue(MachineFunction &MF) const;
void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const;
// Debug information queries.
unsigned getRARegister() const;
unsigned getFrameRegister(const MachineFunction &MF) const;
int getFrameIndexOffset(MachineFunction &MF, int FI) const;
void getInitialFrameState(std::vector<MachineMove> &Moves) const;
// Exception handling queries.
unsigned getEHExceptionRegister() const;
unsigned getEHHandlerRegister() const;
};
// getX86SubSuperRegister - X86 utility function. It returns the sub or super
// register of a specific X86 register.
// e.g. getX86SubSuperRegister(X86::EAX, EVT::i16) return X86:AX
unsigned getX86SubSuperRegister(unsigned, EVT, bool High=false);
} // End llvm namespace
#endif