#define DEBUG_TYPE "x86-emitter"
#include "X86.h"
#include "X86InstrInfo.h"
+#include "X86FixupKinds.h"
#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
void operator=(const X86MCCodeEmitter &); // DO NOT IMPLEMENT
const TargetMachine &TM;
const TargetInstrInfo &TII;
+ MCContext &Ctx;
+ bool Is64BitMode;
public:
- X86MCCodeEmitter(TargetMachine &tm)
- : TM(tm), TII(*TM.getInstrInfo()) {
+ X86MCCodeEmitter(TargetMachine &tm, MCContext &ctx, bool is64Bit)
+ : TM(tm), TII(*TM.getInstrInfo()), Ctx(ctx) {
+ Is64BitMode = is64Bit;
}
~X86MCCodeEmitter() {}
+
+ unsigned getNumFixupKinds() const {
+ return 4;
+ }
+
+ const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
+ const static MCFixupKindInfo Infos[] = {
+ { "reloc_pcrel_4byte", 0, 4 * 8, MCFixupKindInfo::FKF_IsPCRel },
+ { "reloc_pcrel_1byte", 0, 1 * 8, MCFixupKindInfo::FKF_IsPCRel },
+ { "reloc_riprel_4byte", 0, 4 * 8, MCFixupKindInfo::FKF_IsPCRel },
+ { "reloc_riprel_4byte_movq_load", 0, 4 * 8, MCFixupKindInfo::FKF_IsPCRel }
+ };
+
+ if (Kind < FirstTargetFixupKind)
+ return MCCodeEmitter::getFixupKindInfo(Kind);
+
+ assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
+ "Invalid kind!");
+ return Infos[Kind - FirstTargetFixupKind];
+ }
- void EmitByte(unsigned char C, raw_ostream &OS) const {
+ static unsigned GetX86RegNum(const MCOperand &MO) {
+ return X86RegisterInfo::getX86RegNum(MO.getReg());
+ }
+
+ void EmitByte(unsigned char C, unsigned &CurByte, raw_ostream &OS) const {
OS << (char)C;
+ ++CurByte;
}
- void EncodeInstruction(const MCInst &MI, raw_ostream &OS) const;
+ void EmitConstant(uint64_t Val, unsigned Size, unsigned &CurByte,
+ raw_ostream &OS) const {
+ // Output the constant in little endian byte order.
+ for (unsigned i = 0; i != Size; ++i) {
+ EmitByte(Val & 255, CurByte, OS);
+ Val >>= 8;
+ }
+ }
+
+ void EmitImmediate(const MCOperand &Disp,
+ unsigned ImmSize, MCFixupKind FixupKind,
+ unsigned &CurByte, raw_ostream &OS,
+ SmallVectorImpl<MCFixup> &Fixups,
+ int ImmOffset = 0) const;
+ inline static unsigned char ModRMByte(unsigned Mod, unsigned RegOpcode,
+ unsigned RM) {
+ assert(Mod < 4 && RegOpcode < 8 && RM < 8 && "ModRM Fields out of range!");
+ return RM | (RegOpcode << 3) | (Mod << 6);
+ }
+
+ void EmitRegModRMByte(const MCOperand &ModRMReg, unsigned RegOpcodeFld,
+ unsigned &CurByte, raw_ostream &OS) const {
+ EmitByte(ModRMByte(3, RegOpcodeFld, GetX86RegNum(ModRMReg)), CurByte, OS);
+ }
+
+ void EmitSIBByte(unsigned SS, unsigned Index, unsigned Base,
+ unsigned &CurByte, raw_ostream &OS) const {
+ // SIB byte is in the same format as the ModRMByte.
+ EmitByte(ModRMByte(SS, Index, Base), CurByte, OS);
+ }
+
+
+ void EmitMemModRMByte(const MCInst &MI, unsigned Op,
+ unsigned RegOpcodeField,
+ uint64_t TSFlags, unsigned &CurByte, raw_ostream &OS,
+ SmallVectorImpl<MCFixup> &Fixups) const;
+
+ void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
+ SmallVectorImpl<MCFixup> &Fixups) const;
+
+ void EmitVEXOpcodePrefix(uint64_t TSFlags, unsigned &CurByte,
+ const MCInst &MI, const TargetInstrDesc &Desc,
+ raw_ostream &OS) const;
+
+ void EmitOpcodePrefix(uint64_t TSFlags, unsigned &CurByte,
+ const MCInst &MI, const TargetInstrDesc &Desc,
+ raw_ostream &OS) const;
};
} // end anonymous namespace
-MCCodeEmitter *llvm::createX86MCCodeEmitter(const Target &,
- TargetMachine &TM) {
- return new X86MCCodeEmitter(TM);
+MCCodeEmitter *llvm::createX86_32MCCodeEmitter(const Target &,
+ TargetMachine &TM,
+ MCContext &Ctx) {
+ return new X86MCCodeEmitter(TM, Ctx, false);
}
+MCCodeEmitter *llvm::createX86_64MCCodeEmitter(const Target &,
+ TargetMachine &TM,
+ MCContext &Ctx) {
+ return new X86MCCodeEmitter(TM, Ctx, true);
+}
+
+
+/// isDisp8 - Return true if this signed displacement fits in a 8-bit
+/// sign-extended field.
+static bool isDisp8(int Value) {
+ return Value == (signed char)Value;
+}
+
+/// getImmFixupKind - Return the appropriate fixup kind to use for an immediate
+/// in an instruction with the specified TSFlags.
+static MCFixupKind getImmFixupKind(uint64_t TSFlags) {
+ unsigned Size = X86II::getSizeOfImm(TSFlags);
+ bool isPCRel = X86II::isImmPCRel(TSFlags);
+
+ switch (Size) {
+ default: assert(0 && "Unknown immediate size");
+ case 1: return isPCRel ? MCFixupKind(X86::reloc_pcrel_1byte) : FK_Data_1;
+ case 4: return isPCRel ? MCFixupKind(X86::reloc_pcrel_4byte) : FK_Data_4;
+ case 2: assert(!isPCRel); return FK_Data_2;
+ case 8: assert(!isPCRel); return FK_Data_8;
+ }
+}
void X86MCCodeEmitter::
-EncodeInstruction(const MCInst &MI, raw_ostream &OS) const {
- unsigned Opcode = MI.getOpcode();
- const TargetInstrDesc &Desc = TII.get(Opcode);
+EmitImmediate(const MCOperand &DispOp, unsigned Size, MCFixupKind FixupKind,
+ unsigned &CurByte, raw_ostream &OS,
+ SmallVectorImpl<MCFixup> &Fixups, int ImmOffset) const {
+ // If this is a simple integer displacement that doesn't require a relocation,
+ // emit it now.
+ if (DispOp.isImm()) {
+ // FIXME: is this right for pc-rel encoding?? Probably need to emit this as
+ // a fixup if so.
+ EmitConstant(DispOp.getImm()+ImmOffset, Size, CurByte, OS);
+ return;
+ }
+
+ // If we have an immoffset, add it to the expression.
+ const MCExpr *Expr = DispOp.getExpr();
+
+ // If the fixup is pc-relative, we need to bias the value to be relative to
+ // the start of the field, not the end of the field.
+ if (FixupKind == MCFixupKind(X86::reloc_pcrel_4byte) ||
+ FixupKind == MCFixupKind(X86::reloc_riprel_4byte) ||
+ FixupKind == MCFixupKind(X86::reloc_riprel_4byte_movq_load))
+ ImmOffset -= 4;
+ if (FixupKind == MCFixupKind(X86::reloc_pcrel_1byte))
+ ImmOffset -= 1;
+ if (ImmOffset)
+ Expr = MCBinaryExpr::CreateAdd(Expr, MCConstantExpr::Create(ImmOffset, Ctx),
+ Ctx);
+
+ // Emit a symbolic constant as a fixup and 4 zeros.
+ Fixups.push_back(MCFixup::Create(CurByte, Expr, FixupKind));
+ EmitConstant(0, Size, CurByte, OS);
+}
+
+
+void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op,
+ unsigned RegOpcodeField,
+ uint64_t TSFlags, unsigned &CurByte,
+ raw_ostream &OS,
+ SmallVectorImpl<MCFixup> &Fixups) const{
+ const MCOperand &Disp = MI.getOperand(Op+3);
+ const MCOperand &Base = MI.getOperand(Op);
+ const MCOperand &Scale = MI.getOperand(Op+1);
+ const MCOperand &IndexReg = MI.getOperand(Op+2);
+ unsigned BaseReg = Base.getReg();
+
+ // Handle %rip relative addressing.
+ if (BaseReg == X86::RIP) { // [disp32+RIP] in X86-64 mode
+ assert(Is64BitMode && "Rip-relative addressing requires 64-bit mode");
+ assert(IndexReg.getReg() == 0 && "Invalid rip-relative address");
+ EmitByte(ModRMByte(0, RegOpcodeField, 5), CurByte, OS);
+
+ unsigned FixupKind = X86::reloc_riprel_4byte;
+
+ // movq loads are handled with a special relocation form which allows the
+ // linker to eliminate some loads for GOT references which end up in the
+ // same linkage unit.
+ if (MI.getOpcode() == X86::MOV64rm ||
+ MI.getOpcode() == X86::MOV64rm_TC)
+ FixupKind = X86::reloc_riprel_4byte_movq_load;
+
+ // rip-relative addressing is actually relative to the *next* instruction.
+ // Since an immediate can follow the mod/rm byte for an instruction, this
+ // means that we need to bias the immediate field of the instruction with
+ // the size of the immediate field. If we have this case, add it into the
+ // expression to emit.
+ int ImmSize = X86II::hasImm(TSFlags) ? X86II::getSizeOfImm(TSFlags) : 0;
+
+ EmitImmediate(Disp, 4, MCFixupKind(FixupKind),
+ CurByte, OS, Fixups, -ImmSize);
+ return;
+ }
+
+ unsigned BaseRegNo = BaseReg ? GetX86RegNum(Base) : -1U;
+
+ // Determine whether a SIB byte is needed.
+ // If no BaseReg, issue a RIP relative instruction only if the MCE can
+ // resolve addresses on-the-fly, otherwise use SIB (Intel Manual 2A, table
+ // 2-7) and absolute references.
+
+ if (// The SIB byte must be used if there is an index register.
+ IndexReg.getReg() == 0 &&
+ // The SIB byte must be used if the base is ESP/RSP/R12, all of which
+ // encode to an R/M value of 4, which indicates that a SIB byte is
+ // present.
+ BaseRegNo != N86::ESP &&
+ // If there is no base register and we're in 64-bit mode, we need a SIB
+ // byte to emit an addr that is just 'disp32' (the non-RIP relative form).
+ (!Is64BitMode || BaseReg != 0)) {
+
+ if (BaseReg == 0) { // [disp32] in X86-32 mode
+ EmitByte(ModRMByte(0, RegOpcodeField, 5), CurByte, OS);
+ EmitImmediate(Disp, 4, FK_Data_4, CurByte, OS, Fixups);
+ return;
+ }
+
+ // If the base is not EBP/ESP and there is no displacement, use simple
+ // indirect register encoding, this handles addresses like [EAX]. The
+ // encoding for [EBP] with no displacement means [disp32] so we handle it
+ // by emitting a displacement of 0 below.
+ if (Disp.isImm() && Disp.getImm() == 0 && BaseRegNo != N86::EBP) {
+ EmitByte(ModRMByte(0, RegOpcodeField, BaseRegNo), CurByte, OS);
+ return;
+ }
+
+ // Otherwise, if the displacement fits in a byte, encode as [REG+disp8].
+ if (Disp.isImm() && isDisp8(Disp.getImm())) {
+ EmitByte(ModRMByte(1, RegOpcodeField, BaseRegNo), CurByte, OS);
+ EmitImmediate(Disp, 1, FK_Data_1, CurByte, OS, Fixups);
+ return;
+ }
+
+ // Otherwise, emit the most general non-SIB encoding: [REG+disp32]
+ EmitByte(ModRMByte(2, RegOpcodeField, BaseRegNo), CurByte, OS);
+ EmitImmediate(Disp, 4, FK_Data_4, CurByte, OS, Fixups);
+ return;
+ }
+
+ // We need a SIB byte, so start by outputting the ModR/M byte first
+ assert(IndexReg.getReg() != X86::ESP &&
+ IndexReg.getReg() != X86::RSP && "Cannot use ESP as index reg!");
+
+ bool ForceDisp32 = false;
+ bool ForceDisp8 = false;
+ if (BaseReg == 0) {
+ // If there is no base register, we emit the special case SIB byte with
+ // MOD=0, BASE=5, to JUST get the index, scale, and displacement.
+ EmitByte(ModRMByte(0, RegOpcodeField, 4), CurByte, OS);
+ ForceDisp32 = true;
+ } else if (!Disp.isImm()) {
+ // Emit the normal disp32 encoding.
+ EmitByte(ModRMByte(2, RegOpcodeField, 4), CurByte, OS);
+ ForceDisp32 = true;
+ } else if (Disp.getImm() == 0 &&
+ // Base reg can't be anything that ends up with '5' as the base
+ // reg, it is the magic [*] nomenclature that indicates no base.
+ BaseRegNo != N86::EBP) {
+ // Emit no displacement ModR/M byte
+ EmitByte(ModRMByte(0, RegOpcodeField, 4), CurByte, OS);
+ } else if (isDisp8(Disp.getImm())) {
+ // Emit the disp8 encoding.
+ EmitByte(ModRMByte(1, RegOpcodeField, 4), CurByte, OS);
+ ForceDisp8 = true; // Make sure to force 8 bit disp if Base=EBP
+ } else {
+ // Emit the normal disp32 encoding.
+ EmitByte(ModRMByte(2, RegOpcodeField, 4), CurByte, OS);
+ }
+
+ // Calculate what the SS field value should be...
+ static const unsigned SSTable[] = { ~0, 0, 1, ~0, 2, ~0, ~0, ~0, 3 };
+ unsigned SS = SSTable[Scale.getImm()];
+
+ if (BaseReg == 0) {
+ // Handle the SIB byte for the case where there is no base, see Intel
+ // Manual 2A, table 2-7. The displacement has already been output.
+ unsigned IndexRegNo;
+ if (IndexReg.getReg())
+ IndexRegNo = GetX86RegNum(IndexReg);
+ else // Examples: [ESP+1*<noreg>+4] or [scaled idx]+disp32 (MOD=0,BASE=5)
+ IndexRegNo = 4;
+ EmitSIBByte(SS, IndexRegNo, 5, CurByte, OS);
+ } else {
+ unsigned IndexRegNo;
+ if (IndexReg.getReg())
+ IndexRegNo = GetX86RegNum(IndexReg);
+ else
+ IndexRegNo = 4; // For example [ESP+1*<noreg>+4]
+ EmitSIBByte(SS, IndexRegNo, GetX86RegNum(Base), CurByte, OS);
+ }
+
+ // Do we need to output a displacement?
+ if (ForceDisp8)
+ EmitImmediate(Disp, 1, FK_Data_1, CurByte, OS, Fixups);
+ else if (ForceDisp32 || Disp.getImm() != 0)
+ EmitImmediate(Disp, 4, FK_Data_4, CurByte, OS, Fixups);
+}
+
+/// EmitVEXOpcodePrefix - AVX instructions are encoded using a opcode prefix
+/// called VEX.
+void X86MCCodeEmitter::EmitVEXOpcodePrefix(uint64_t TSFlags, unsigned &CurByte,
+ const MCInst &MI, const TargetInstrDesc &Desc,
+ raw_ostream &OS) const {
+
+ // Pseudo instructions never have a VEX prefix.
+ if ((TSFlags & X86II::FormMask) == X86II::Pseudo)
+ return;
+
+ // VEX_R: opcode externsion equivalent to REX.R in
+ // 1's complement (inverted) form
+ //
+ // 1: Same as REX_R=0 (must be 1 in 32-bit mode)
+ // 0: Same as REX_R=1 (64 bit mode only)
+ //
+ unsigned char VEX_R = 0x1;
+
+ // VEX_B:
+ //
+ // 1: Same as REX_B=0 (ignored in 32-bit mode)
+ // 0: Same as REX_B=1 (64 bit mode only)
+ //
+ unsigned char VEX_B = 0x1;
+
+ // VEX_W: opcode specific (use like REX.W, or used for
+ // opcode extension, or ignored, depending on the opcode byte)
+ unsigned char VEX_W = 0;
+
+ // VEX_5M (VEX m-mmmmm field):
+ //
+ // 0b00000: Reserved for future use
+ // 0b00001: implied 0F leading opcode
+ // 0b00010: implied 0F 38 leading opcode bytes
+ // 0b00011: implied 0F 3A leading opcode bytes
+ // 0b00100-0b11111: Reserved for future use
+ //
+ unsigned char VEX_5M = 0x1;
+
+ // VEX_4V (VEX vvvv field): a register specifier
+ // (in 1's complement form) or 1111 if unused.
+ unsigned char VEX_4V = 0xf;
+
+ // VEX_L (Vector Length):
+ //
+ // 0: scalar or 128-bit vector
+ // 1: 256-bit vector
+ //
+ unsigned char VEX_L = 0;
+
+ // VEX_PP: opcode extension providing equivalent
+ // functionality of a SIMD prefix
+ //
+ // 0b00: None
+ // 0b01: 66 (not handled yet)
+ // 0b10: F3
+ // 0b11: F2
+ //
+ unsigned char VEX_PP = 0;
+
+ switch (TSFlags & X86II::Op0Mask) {
+ default: assert(0 && "Invalid prefix!");
+ case 0: break; // No prefix!
+ case X86II::T8: // 0F 38
+ VEX_5M = 0x2;
+ break;
+ case X86II::TA: // 0F 3A
+ VEX_5M = 0x3;
+ break;
+ case X86II::TF: // F2 0F 38
+ VEX_PP = 0x3;
+ VEX_5M = 0x2;
+ break;
+ case X86II::XS: // F3 0F
+ VEX_PP = 0x2;
+ break;
+ case X86II::XD: // F2 0F
+ VEX_PP = 0x3;
+ break;
+ }
+
+ unsigned NumOps = MI.getNumOperands();
+ unsigned i = 0;
+ unsigned SrcReg = 0, SrcRegNum = 0;
+
+ 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()))
+ VEX_R = 0x0;
+
+ // On regular x86, both XMM0-XMM7 and XMM8-XMM15 are encoded in the
+ // range 0-7 and the difference between the 2 groups is given by the
+ // REX prefix. In the VEX prefix, registers are seen sequencially
+ // from 0-15 and encoded in 1's complement form, example:
+ //
+ // ModRM field => XMM9 => 1
+ // VEX.VVVV => XMM9 => ~9
+ //
+ // See table 4-35 of Intel AVX Programming Reference for details.
+ SrcReg = MI.getOperand(1).getReg();
+ SrcRegNum = GetX86RegNum(MI.getOperand(1));
+ if (SrcReg >= X86::XMM8 && SrcReg <= X86::XMM15)
+ SrcRegNum += 8;
+
+ // The registers represented through VEX_VVVV should
+ // be encoded in 1's complement form.
+ if ((TSFlags >> 32) & X86II::VEX_4V)
+ VEX_4V = (~SrcRegNum) & 0xf;
+
+ i = 2; // Skip the VEX.VVVV operand.
+ for (; i != NumOps; ++i) {
+ const MCOperand &MO = MI.getOperand(i);
+ if (MO.isReg() && X86InstrInfo::isX86_64ExtendedReg(MO.getReg()))
+ VEX_B = 0x0;
+ }
+ break;
+ default:
+ assert(0 && "Not implemented!");
+ }
+
+ // VEX opcode prefix can have 2 or 3 bytes
+ //
+ // 3 bytes:
+ // +-----+ +--------------+ +-------------------+
+ // | C4h | | RXB | m-mmmm | | W | vvvv | L | pp |
+ // +-----+ +--------------+ +-------------------+
+ // 2 bytes:
+ // +-----+ +-------------------+
+ // | C5h | | R | vvvv | L | pp |
+ // +-----+ +-------------------+
+ //
+ // Note: VEX.X isn't used so far
+ //
+ unsigned char LastByte = VEX_PP | (VEX_L << 2) | (VEX_4V << 3);
+
+ if (VEX_B /* & VEX_X */) { // 2 byte VEX prefix
+ EmitByte(0xC5, CurByte, OS);
+ EmitByte(LastByte | (VEX_R << 7), CurByte, OS);
+ return;
+ }
+
+ // 3 byte VEX prefix
+ EmitByte(0xC4, CurByte, OS);
+ EmitByte(VEX_R << 7 | 1 << 6 /* VEX_X = 1 */ | VEX_5M, CurByte, OS);
+ EmitByte(LastByte | (VEX_W << 7), CurByte, 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, uint64_t TSFlags,
+ const TargetInstrDesc &Desc) {
+ // Pseudo instructions never have a rex byte.
+ if ((TSFlags & X86II::FormMask) == X86II::Pseudo)
+ return 0;
+
+ unsigned REX = 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;
+ // FIXME: The caller of DetermineREXPrefix slaps this prefix onto anything
+ // that returns non-zero.
+ 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;
+}
+
+/// EmitOpcodePrefix - Emit all instruction prefixes prior to the opcode.
+void X86MCCodeEmitter::EmitOpcodePrefix(uint64_t TSFlags, unsigned &CurByte,
+ const MCInst &MI, const TargetInstrDesc &Desc,
+ raw_ostream &OS) const {
+
// Emit the lock opcode prefix as needed.
- if (Desc.TSFlags & X86II::LOCK)
- EmitByte(0xF0, OS);
+ if (TSFlags & X86II::LOCK)
+ EmitByte(0xF0, CurByte, OS);
// Emit segment override opcode prefix as needed.
- switch (Desc.TSFlags & X86II::SegOvrMask) {
+ switch (TSFlags & X86II::SegOvrMask) {
default: assert(0 && "Invalid segment!");
case 0: break; // No segment override!
case X86II::FS:
- EmitByte(0x64, OS);
+ EmitByte(0x64, CurByte, OS);
break;
case X86II::GS:
- EmitByte(0x65, OS);
+ EmitByte(0x65, CurByte, OS);
+ break;
+ }
+
+ // Emit the repeat opcode prefix as needed.
+ if ((TSFlags & X86II::Op0Mask) == X86II::REP)
+ EmitByte(0xF3, CurByte, OS);
+
+ // Emit the operand size opcode prefix as needed.
+ if (TSFlags & X86II::OpSize)
+ EmitByte(0x66, CurByte, OS);
+
+ // Emit the address size opcode prefix as needed.
+ if (TSFlags & X86II::AdSize)
+ EmitByte(0x67, CurByte, OS);
+
+ bool Need0FPrefix = false;
+ switch (TSFlags & X86II::Op0Mask) {
+ default: assert(0 && "Invalid prefix!");
+ case 0: break; // No prefix!
+ case X86II::REP: break; // already handled.
+ case X86II::TB: // Two-byte opcode prefix
+ case X86II::T8: // 0F 38
+ case X86II::TA: // 0F 3A
+ Need0FPrefix = true;
+ break;
+ case X86II::TF: // F2 0F 38
+ EmitByte(0xF2, CurByte, OS);
+ Need0FPrefix = true;
+ break;
+ case X86II::XS: // F3 0F
+ EmitByte(0xF3, CurByte, OS);
+ Need0FPrefix = true;
+ break;
+ case X86II::XD: // F2 0F
+ EmitByte(0xF2, CurByte, OS);
+ Need0FPrefix = true;
+ break;
+ case X86II::D8: EmitByte(0xD8, CurByte, OS); break;
+ case X86II::D9: EmitByte(0xD9, CurByte, OS); break;
+ case X86II::DA: EmitByte(0xDA, CurByte, OS); break;
+ case X86II::DB: EmitByte(0xDB, CurByte, OS); break;
+ case X86II::DC: EmitByte(0xDC, CurByte, OS); break;
+ case X86II::DD: EmitByte(0xDD, CurByte, OS); break;
+ case X86II::DE: EmitByte(0xDE, CurByte, OS); break;
+ case X86II::DF: EmitByte(0xDF, CurByte, OS); break;
+ }
+
+ // Handle REX prefix.
+ // FIXME: Can this come before F2 etc to simplify emission?
+ if (Is64BitMode) {
+ if (unsigned REX = DetermineREXPrefix(MI, TSFlags, Desc))
+ EmitByte(0x40 | REX, CurByte, OS);
+ }
+
+ // 0x0F escape code must be emitted just before the opcode.
+ if (Need0FPrefix)
+ EmitByte(0x0F, CurByte, OS);
+
+ // FIXME: Pull this up into previous switch if REX can be moved earlier.
+ switch (TSFlags & X86II::Op0Mask) {
+ case X86II::TF: // F2 0F 38
+ case X86II::T8: // 0F 38
+ EmitByte(0x38, CurByte, OS);
+ break;
+ case X86II::TA: // 0F 3A
+ EmitByte(0x3A, CurByte, OS);
break;
}
+}
+
+void X86MCCodeEmitter::
+EncodeInstruction(const MCInst &MI, raw_ostream &OS,
+ SmallVectorImpl<MCFixup> &Fixups) const {
+ unsigned Opcode = MI.getOpcode();
+ const TargetInstrDesc &Desc = TII.get(Opcode);
+ uint64_t TSFlags = Desc.TSFlags;
+
+ // Keep track of the current byte being emitted.
+ unsigned CurByte = 0;
+ // Is this instruction encoded in AVX form?
+ bool IsAVXForm = false;
+ if ((TSFlags >> 32) & X86II::VEX_4V)
+ IsAVXForm = true;
+
+ // FIXME: We should emit the prefixes in exactly the same order as GAS does,
+ // in order to provide diffability.
+
+ if (!IsAVXForm)
+ EmitOpcodePrefix(TSFlags, CurByte, MI, Desc, OS);
+ else
+ EmitVEXOpcodePrefix(TSFlags, CurByte, MI, Desc, OS);
+ // If this is a two-address instruction, skip one of the register operands.
+ unsigned NumOps = Desc.getNumOperands();
+ unsigned CurOp = 0;
+ if (NumOps > 1 && Desc.getOperandConstraint(1, TOI::TIED_TO) != -1)
+ ++CurOp;
+ else if (NumOps > 2 && Desc.getOperandConstraint(NumOps-1, TOI::TIED_TO)== 0)
+ // Skip the last source operand that is tied_to the dest reg. e.g. LXADD32
+ --NumOps;
+
+ unsigned char BaseOpcode = X86II::getBaseOpcodeFor(TSFlags);
+ unsigned SrcRegNum = 0;
+ switch (TSFlags & X86II::FormMask) {
+ case X86II::MRMInitReg:
+ assert(0 && "FIXME: Remove this form when the JIT moves to MCCodeEmitter!");
+ default: errs() << "FORM: " << (TSFlags & X86II::FormMask) << "\n";
+ assert(0 && "Unknown FormMask value in X86MCCodeEmitter!");
+ case X86II::Pseudo: return; // Pseudo instructions encode to nothing.
+ case X86II::RawFrm:
+ EmitByte(BaseOpcode, CurByte, OS);
+ break;
+
+ case X86II::AddRegFrm:
+ EmitByte(BaseOpcode + GetX86RegNum(MI.getOperand(CurOp++)), CurByte, OS);
+ break;
+
+ case X86II::MRMDestReg:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitRegModRMByte(MI.getOperand(CurOp),
+ GetX86RegNum(MI.getOperand(CurOp+1)), CurByte, OS);
+ CurOp += 2;
+ break;
+
+ case X86II::MRMDestMem:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitMemModRMByte(MI, CurOp,
+ GetX86RegNum(MI.getOperand(CurOp + X86AddrNumOperands)),
+ TSFlags, CurByte, OS, Fixups);
+ CurOp += X86AddrNumOperands + 1;
+ break;
+
+ case X86II::MRMSrcReg:
+ EmitByte(BaseOpcode, CurByte, OS);
+ SrcRegNum = CurOp + 1;
+
+ if (IsAVXForm) // Skip 1st src (which is encoded in VEX_VVVV)
+ SrcRegNum++;
+
+ EmitRegModRMByte(MI.getOperand(SrcRegNum),
+ GetX86RegNum(MI.getOperand(CurOp)), CurByte, OS);
+ CurOp = SrcRegNum + 1;
+ break;
+
+ case X86II::MRMSrcMem: {
+ EmitByte(BaseOpcode, CurByte, OS);
+
+ // FIXME: Maybe lea should have its own form? This is a horrible hack.
+ int AddrOperands;
+ if (Opcode == X86::LEA64r || Opcode == X86::LEA64_32r ||
+ Opcode == X86::LEA16r || Opcode == X86::LEA32r)
+ AddrOperands = X86AddrNumOperands - 1; // No segment register
+ else
+ AddrOperands = X86AddrNumOperands;
+
+ EmitMemModRMByte(MI, CurOp+1, GetX86RegNum(MI.getOperand(CurOp)),
+ TSFlags, CurByte, OS, Fixups);
+ CurOp += AddrOperands + 1;
+ break;
+ }
+
+ case X86II::MRM0r: case X86II::MRM1r:
+ case X86II::MRM2r: case X86II::MRM3r:
+ case X86II::MRM4r: case X86II::MRM5r:
+ case X86II::MRM6r: case X86II::MRM7r:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitRegModRMByte(MI.getOperand(CurOp++),
+ (TSFlags & X86II::FormMask)-X86II::MRM0r,
+ CurByte, OS);
+ 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:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitMemModRMByte(MI, CurOp, (TSFlags & X86II::FormMask)-X86II::MRM0m,
+ TSFlags, CurByte, OS, Fixups);
+ CurOp += X86AddrNumOperands;
+ break;
+ case X86II::MRM_C1:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitByte(0xC1, CurByte, OS);
+ break;
+ case X86II::MRM_C2:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitByte(0xC2, CurByte, OS);
+ break;
+ case X86II::MRM_C3:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitByte(0xC3, CurByte, OS);
+ break;
+ case X86II::MRM_C4:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitByte(0xC4, CurByte, OS);
+ break;
+ case X86II::MRM_C8:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitByte(0xC8, CurByte, OS);
+ break;
+ case X86II::MRM_C9:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitByte(0xC9, CurByte, OS);
+ break;
+ case X86II::MRM_E8:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitByte(0xE8, CurByte, OS);
+ break;
+ case X86II::MRM_F0:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitByte(0xF0, CurByte, OS);
+ break;
+ case X86II::MRM_F8:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitByte(0xF8, CurByte, OS);
+ break;
+ case X86II::MRM_F9:
+ EmitByte(BaseOpcode, CurByte, OS);
+ EmitByte(0xF9, CurByte, OS);
+ break;
+ }
+
+ // If there is a remaining operand, it must be a trailing immediate. Emit it
+ // according to the right size for the instruction.
+ if (CurOp != NumOps)
+ EmitImmediate(MI.getOperand(CurOp++),
+ X86II::getSizeOfImm(TSFlags), getImmFixupKind(TSFlags),
+ CurByte, OS, Fixups);
+
+#ifndef NDEBUG
+ // FIXME: Verify.
+ if (/*!Desc.isVariadic() &&*/ CurOp != NumOps) {
+ errs() << "Cannot encode all operands of: ";
+ MI.dump();
+ errs() << '\n';
+ abort();
+ }
+#endif
}
projects / oota-llvm.git / blobdiff