llvm-6502/lib/Target/X86/X86RegisterInfo.h

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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"
#define GET_REGINFO_HEADER
#include "X86GenRegisterInfo.inc"
namespace llvm {
class Type;
class TargetInstrInfo;
class X86TargetMachine;
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;
/// StackPtr - X86 physical register used as stack ptr.
///
unsigned StackPtr;
/// FramePtr - X86 physical register used as frame ptr.
///
unsigned FramePtr;
/// BasePtr - X86 physical register used as a base ptr in complex stack
/// frames. I.e., when we need a 3rd base, not just SP and FP, due to
/// variable size stack objects.
unsigned BasePtr;
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);
// FIXME: This should be tablegen'd like getDwarfRegNum is
int getSEHRegNum(unsigned i) const;
/// getCompactUnwindRegNum - This function maps the register to the number for
/// compact unwind encoding. Return -1 if the register isn't valid.
int getCompactUnwindRegNum(unsigned RegNum, bool isEH) const;
/// Code Generation virtual methods...
This patch fixes a problem which arose when using the Post-RA scheduler on X86 Atom. Some of our tests failed because the tail merging part of the BranchFolding pass was creating new basic blocks which did not contain live-in information. When the anti-dependency code in the Post-RA scheduler ran, it would sometimes rename the register containing the function return value because the fact that the return value was live-in to the subsequent block had been lost. To fix this, it is necessary to run the RegisterScavenging code in the BranchFolding pass. This patch makes sure that the register scavenging code is invoked in the X86 subtarget only when post-RA scheduling is being done. Post RA scheduling in the X86 subtarget is only done for Atom. This patch adds a new function to the TargetRegisterClass to control whether or not live-ins should be preserved during branch folding. This is necessary in order for the anti-dependency optimizations done during the PostRASchedulerList pass to work properly when doing Post-RA scheduling for the X86 in general and for the Intel Atom in particular. The patch adds and invokes the new function trackLivenessAfterRegAlloc() instead of using the existing requiresRegisterScavenging(). It changes BranchFolding.cpp to call trackLivenessAfterRegAlloc() instead of requiresRegisterScavenging(). It changes the all the targets that implemented requiresRegisterScavenging() to also implement trackLivenessAfterRegAlloc(). It adds an assertion in the Post RA scheduler to make sure that post RA liveness information is available when it is needed. It changes the X86 break-anti-dependencies test to use –mcpu=atom, in order to avoid running into the added assertion. Finally, this patch restores the use of anti-dependency checking (which was turned off temporarily for the 3.1 release) for Intel Atom in the Post RA scheduler. Patch by Andy Zhang! Thanks to Jakob and Anton for their reviews. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155395 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-23 21:39:35 +00:00
///
virtual bool trackLivenessAfterRegAlloc(const MachineFunction &MF) const;
/// 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;
virtual const TargetRegisterClass *
getSubClassWithSubReg(const TargetRegisterClass *RC, unsigned Idx) const;
const TargetRegisterClass*
getLargestLegalSuperClass(const TargetRegisterClass *RC) const;
/// getPointerRegClass - Returns a TargetRegisterClass used for pointer
/// values.
const TargetRegisterClass *
getPointerRegClass(const MachineFunction &MF, 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;
unsigned getRegPressureLimit(const TargetRegisterClass *RC,
MachineFunction &MF) const;
/// getCalleeSavedRegs - Return a null-terminated list of all of the
/// callee-save registers on this target.
const uint16_t *getCalleeSavedRegs(const MachineFunction* MF = 0) const;
const uint32_t *getCallPreservedMask(CallingConv::ID) 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 hasBasePointer(const MachineFunction &MF) const;
bool canRealignStack(const MachineFunction &MF) const;
bool needsStackRealignment(const MachineFunction &MF) const;
bool hasReservedSpillSlot(const MachineFunction &MF, unsigned Reg,
int &FrameIdx) const;
void eliminateCallFramePseudoInstr(MachineFunction &MF,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const;
void eliminateFrameIndex(MachineBasicBlock::iterator MI,
int SPAdj, RegScavenger *RS = NULL) const;
// Debug information queries.
unsigned getFrameRegister(const MachineFunction &MF) const;
unsigned getStackRegister() const { return StackPtr; }
unsigned getBaseRegister() const { return BasePtr; }
// FIXME: Move to FrameInfok
unsigned getSlotSize() const { return SlotSize; }
// 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