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port X86InstrInfo::determineREX over to the new encoder.

llvm-svn: 95440
This commit is contained in:
Chris Lattner 2010-02-05 22:10:22 +00:00
parent 670458b3be
commit 8db3500688
3 changed files with 109 additions and 10 deletions

View File

@ -3015,11 +3015,10 @@ isSafeToMoveRegClassDefs(const TargetRegisterClass *RC) const {
}
/// isX86_64ExtendedReg - Is the MachineOperand a x86-64 extended register?
/// e.g. r8, xmm8, etc.
bool X86InstrInfo::isX86_64ExtendedReg(const MachineOperand &MO) {
if (!MO.isReg()) return false;
switch (MO.getReg()) {
/// isX86_64ExtendedReg - Is the MachineOperand a x86-64 extended (r8 or higher)
/// register? e.g. r8, xmm8, xmm13, etc.
bool X86InstrInfo::isX86_64ExtendedReg(unsigned RegNo) {
switch (RegNo) {
default: break;
case X86::R8: case X86::R9: case X86::R10: case X86::R11:
case X86::R12: case X86::R13: case X86::R14: case X86::R15:

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@ -18,7 +18,6 @@
#include "X86.h"
#include "X86RegisterInfo.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/Target/TargetRegisterInfo.h"
namespace llvm {
class X86RegisterInfo;
@ -661,9 +660,16 @@ public:
reg == X86::SIL || reg == X86::DIL);
}
static bool isX86_64ExtendedReg(const MachineOperand &MO);
static bool isX86_64ExtendedReg(const MachineOperand &MO) {
if (!MO.isReg()) return false;
return isX86_64ExtendedReg(MO.getReg());
}
static unsigned determineREX(const MachineInstr &MI);
/// isX86_64ExtendedReg - Is the MachineOperand a x86-64 extended (r8 or
/// higher) register? e.g. r8, xmm8, xmm13, etc.
static bool isX86_64ExtendedReg(unsigned RegNo);
/// GetInstSize - Returns the size of the specified MachineInstr.
///
virtual unsigned GetInstSizeInBytes(const MachineInstr *MI) const;

View File

@ -266,6 +266,101 @@ void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op,
EmitDisplacementField(DispForReloc, DispVal, PCAdj, IsPCRel, OS);
}
/// DetermineREXPrefix - Determine if the MCInst has to be encoded with a X86-64
/// REX prefix which specifies 1) 64-bit instructions, 2) non-default operand
/// size, and 3) use of X86-64 extended registers.
static unsigned DetermineREXPrefix(const MCInst &MI, unsigned TSFlags,
const TargetInstrDesc &Desc) {
unsigned REX = 0;
// Pseudo instructions do not need REX prefix byte.
if ((TSFlags & X86II::FormMask) == X86II::Pseudo)
return 0;
if (TSFlags & X86II::REX_W)
REX |= 1 << 3;
if (MI.getNumOperands() == 0) return REX;
unsigned NumOps = MI.getNumOperands();
// FIXME: MCInst should explicitize the two-addrness.
bool isTwoAddr = NumOps > 1 &&
Desc.getOperandConstraint(1, TOI::TIED_TO) != -1;
// If it accesses SPL, BPL, SIL, or DIL, then it requires a 0x40 REX prefix.
unsigned i = isTwoAddr ? 1 : 0;
for (; i != NumOps; ++i) {
const MCOperand &MO = MI.getOperand(i);
if (!MO.isReg()) continue;
unsigned Reg = MO.getReg();
if (!X86InstrInfo::isX86_64NonExtLowByteReg(Reg)) continue;
REX |= 0x40;
break;
}
switch (TSFlags & X86II::FormMask) {
case X86II::MRMInitReg: assert(0 && "FIXME: Remove this!");
case X86II::MRMSrcReg:
if (MI.getOperand(0).isReg() &&
X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0).getReg()))
REX |= 1 << 2;
i = isTwoAddr ? 2 : 1;
for (; i != NumOps; ++i) {
const MCOperand &MO = MI.getOperand(i);
if (MO.isReg() && X86InstrInfo::isX86_64ExtendedReg(MO.getReg()))
REX |= 1 << 0;
}
break;
case X86II::MRMSrcMem: {
if (MI.getOperand(0).isReg() &&
X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0).getReg()))
REX |= 1 << 2;
unsigned Bit = 0;
i = isTwoAddr ? 2 : 1;
for (; i != NumOps; ++i) {
const MCOperand &MO = MI.getOperand(i);
if (MO.isReg()) {
if (X86InstrInfo::isX86_64ExtendedReg(MO.getReg()))
REX |= 1 << Bit;
Bit++;
}
}
break;
}
case X86II::MRM0m: case X86II::MRM1m:
case X86II::MRM2m: case X86II::MRM3m:
case X86II::MRM4m: case X86II::MRM5m:
case X86II::MRM6m: case X86II::MRM7m:
case X86II::MRMDestMem: {
unsigned e = (isTwoAddr ? X86AddrNumOperands+1 : X86AddrNumOperands);
i = isTwoAddr ? 1 : 0;
if (NumOps > e && MI.getOperand(e).isReg() &&
X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(e).getReg()))
REX |= 1 << 2;
unsigned Bit = 0;
for (; i != e; ++i) {
const MCOperand &MO = MI.getOperand(i);
if (MO.isReg()) {
if (X86InstrInfo::isX86_64ExtendedReg(MO.getReg()))
REX |= 1 << Bit;
Bit++;
}
}
break;
}
default:
if (MI.getOperand(0).isReg() &&
X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0).getReg()))
REX |= 1 << 0;
i = isTwoAddr ? 2 : 1;
for (unsigned e = NumOps; i != e; ++i) {
const MCOperand &MO = MI.getOperand(i);
if (MO.isReg() && X86InstrInfo::isX86_64ExtendedReg(MO.getReg()))
REX |= 1 << 2;
}
break;
}
return REX;
}
void X86MCCodeEmitter::
EncodeInstruction(const MCInst &MI, raw_ostream &OS) const {
@ -337,12 +432,11 @@ EncodeInstruction(const MCInst &MI, raw_ostream &OS) const {
}
// Handle REX prefix.
#if 0 // FIXME: Add in, also, can this come before F2 etc to simplify emission?
// FIXME: Can this come before F2 etc to simplify emission?
if (Is64BitMode) {
if (unsigned REX = X86InstrInfo::determineREX(MI))
if (unsigned REX = DetermineREXPrefix(MI, TSFlags, Desc))
EmitByte(0x40 | REX, OS);
}
#endif
// 0x0F escape code must be emitted just before the opcode.
if (Need0FPrefix)