llvm-6502/lib/Target/ARM/ARMMCCodeEmitter.cpp
2010-11-19 00:27:09 +00:00

772 lines
26 KiB
C++

//===-- ARM/ARMMCCodeEmitter.cpp - Convert ARM code to machine code -------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the ARMMCCodeEmitter class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "mccodeemitter"
#include "ARM.h"
#include "ARMAddressingModes.h"
#include "ARMFixupKinds.h"
#include "ARMInstrInfo.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
STATISTIC(MCNumEmitted, "Number of MC instructions emitted.");
STATISTIC(MCNumCPRelocations, "Number of constant pool relocations created.");
namespace {
class ARMMCCodeEmitter : public MCCodeEmitter {
ARMMCCodeEmitter(const ARMMCCodeEmitter &); // DO NOT IMPLEMENT
void operator=(const ARMMCCodeEmitter &); // DO NOT IMPLEMENT
const TargetMachine &TM;
const TargetInstrInfo &TII;
MCContext &Ctx;
public:
ARMMCCodeEmitter(TargetMachine &tm, MCContext &ctx)
: TM(tm), TII(*TM.getInstrInfo()), Ctx(ctx) {
}
~ARMMCCodeEmitter() {}
unsigned getNumFixupKinds() const { return ARM::NumTargetFixupKinds; }
const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
const static MCFixupKindInfo Infos[] = {
// name offset bits flags
{ "fixup_arm_pcrel_12", 2, 12, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_arm_vfp_pcrel_12", 3, 8, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_arm_branch", 1, 24, MCFixupKindInfo::FKF_IsPCRel },
};
if (Kind < FirstTargetFixupKind)
return MCCodeEmitter::getFixupKindInfo(Kind);
assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
"Invalid kind!");
return Infos[Kind - FirstTargetFixupKind];
}
unsigned getMachineSoImmOpValue(unsigned SoImm) const;
// getBinaryCodeForInstr - TableGen'erated function for getting the
// binary encoding for an instruction.
unsigned getBinaryCodeForInstr(const MCInst &MI,
SmallVectorImpl<MCFixup> &Fixups) const;
/// getMachineOpValue - Return binary encoding of operand. If the machine
/// operand requires relocation, record the relocation and return zero.
unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO,
SmallVectorImpl<MCFixup> &Fixups) const;
/// getMovtImmOpValue - Return the encoding for the movw/movt pair
uint32_t getMovtImmOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const;
bool EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx,
unsigned &Reg, unsigned &Imm,
SmallVectorImpl<MCFixup> &Fixups) const;
/// getBranchTargetOpValue - Return encoding info for 24-bit immediate
/// branch target.
uint32_t getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const;
/// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12'
/// operand.
uint32_t getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const;
/// getLdStSORegOpValue - Return encoding info for 'reg +/- reg shop imm'
/// operand as needed by load/store instructions.
uint32_t getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const;
/// getLdStmModeOpValue - Return encoding for load/store multiple mode.
uint32_t getLdStmModeOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
ARM_AM::AMSubMode Mode = (ARM_AM::AMSubMode)MI.getOperand(OpIdx).getImm();
switch (Mode) {
default: assert(0 && "Unknown addressing sub-mode!");
case ARM_AM::da: return 0;
case ARM_AM::ia: return 1;
case ARM_AM::db: return 2;
case ARM_AM::ib: return 3;
}
}
/// getShiftOp - Return the shift opcode (bit[6:5]) of the immediate value.
///
unsigned getShiftOp(ARM_AM::ShiftOpc ShOpc) const {
switch (ShOpc) {
default: llvm_unreachable("Unknown shift opc!");
case ARM_AM::no_shift:
case ARM_AM::lsl: return 0;
case ARM_AM::lsr: return 1;
case ARM_AM::asr: return 2;
case ARM_AM::ror:
case ARM_AM::rrx: return 3;
}
return 0;
}
/// getAddrMode2OpValue - Return encoding for addrmode2 operands.
uint32_t getAddrMode2OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const;
/// getAddrMode2OffsetOpValue - Return encoding for am2offset operands.
uint32_t getAddrMode2OffsetOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const;
/// getAddrMode3OffsetOpValue - Return encoding for am3offset operands.
uint32_t getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const;
/// getAddrMode3OpValue - Return encoding for addrmode3 operands.
uint32_t getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const;
/// getAddrMode5OpValue - Return encoding info for 'reg +/- imm8' operand.
uint32_t getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const;
/// getCCOutOpValue - Return encoding of the 's' bit.
unsigned getCCOutOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const {
// The operand is either reg0 or CPSR. The 's' bit is encoded as '0' or
// '1' respectively.
return MI.getOperand(Op).getReg() == ARM::CPSR;
}
/// getSOImmOpValue - Return an encoded 12-bit shifted-immediate value.
unsigned getSOImmOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const {
unsigned SoImm = MI.getOperand(Op).getImm();
int SoImmVal = ARM_AM::getSOImmVal(SoImm);
assert(SoImmVal != -1 && "Not a valid so_imm value!");
// Encode rotate_imm.
unsigned Binary = (ARM_AM::getSOImmValRot((unsigned)SoImmVal) >> 1)
<< ARMII::SoRotImmShift;
// Encode immed_8.
Binary |= ARM_AM::getSOImmValImm((unsigned)SoImmVal);
return Binary;
}
/// getT2SOImmOpValue - Return an encoded 12-bit shifted-immediate value.
unsigned getT2SOImmOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const {
unsigned SoImm = MI.getOperand(Op).getImm();
unsigned Encoded = ARM_AM::getT2SOImmVal(SoImm);
assert(Encoded != ~0U && "Not a Thumb2 so_imm value?");
return Encoded;
}
/// getSORegOpValue - Return an encoded so_reg shifted register value.
unsigned getSORegOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getT2SORegOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getRotImmOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const {
switch (MI.getOperand(Op).getImm()) {
default: assert (0 && "Not a valid rot_imm value!");
case 0: return 0;
case 8: return 1;
case 16: return 2;
case 24: return 3;
}
}
unsigned getImmMinusOneOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const {
return MI.getOperand(Op).getImm() - 1;
}
unsigned getNEONVcvtImm32OpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const {
return 64 - MI.getOperand(Op).getImm();
}
unsigned getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getRegisterListOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const;
unsigned NEONThumb2DataIPostEncoder(const MCInst &MI,
unsigned EncodedValue) const;
unsigned NEONThumb2LoadStorePostEncoder(const MCInst &MI,
unsigned EncodedValue) const;
unsigned NEONThumb2DupPostEncoder(const MCInst &MI,
unsigned EncodedValue) const;
void EmitByte(unsigned char C, raw_ostream &OS) const {
OS << (char)C;
}
void EmitConstant(uint64_t Val, unsigned Size, raw_ostream &OS) const {
// Output the constant in little endian byte order.
for (unsigned i = 0; i != Size; ++i) {
EmitByte(Val & 255, OS);
Val >>= 8;
}
}
void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups) const;
};
} // end anonymous namespace
MCCodeEmitter *llvm::createARMMCCodeEmitter(const Target &, TargetMachine &TM,
MCContext &Ctx) {
return new ARMMCCodeEmitter(TM, Ctx);
}
/// NEONThumb2DataIPostEncoder - Post-process encoded NEON data-processing
/// instructions, and rewrite them to their Thumb2 form if we are currently in
/// Thumb2 mode.
unsigned ARMMCCodeEmitter::NEONThumb2DataIPostEncoder(const MCInst &MI,
unsigned EncodedValue) const {
const ARMSubtarget &Subtarget = TM.getSubtarget<ARMSubtarget>();
if (Subtarget.isThumb2()) {
// NEON Thumb2 data-processsing encodings are very simple: bit 24 is moved
// to bit 12 of the high half-word (i.e. bit 28), and bits 27-24 are
// set to 1111.
unsigned Bit24 = EncodedValue & 0x01000000;
unsigned Bit28 = Bit24 << 4;
EncodedValue &= 0xEFFFFFFF;
EncodedValue |= Bit28;
EncodedValue |= 0x0F000000;
}
return EncodedValue;
}
/// NEONThumb2LoadStorePostEncoder - Post-process encoded NEON load/store
/// instructions, and rewrite them to their Thumb2 form if we are currently in
/// Thumb2 mode.
unsigned ARMMCCodeEmitter::NEONThumb2LoadStorePostEncoder(const MCInst &MI,
unsigned EncodedValue) const {
const ARMSubtarget &Subtarget = TM.getSubtarget<ARMSubtarget>();
if (Subtarget.isThumb2()) {
EncodedValue &= 0xF0FFFFFF;
EncodedValue |= 0x09000000;
}
return EncodedValue;
}
/// NEONThumb2DupPostEncoder - Post-process encoded NEON vdup
/// instructions, and rewrite them to their Thumb2 form if we are currently in
/// Thumb2 mode.
unsigned ARMMCCodeEmitter::NEONThumb2DupPostEncoder(const MCInst &MI,
unsigned EncodedValue) const {
const ARMSubtarget &Subtarget = TM.getSubtarget<ARMSubtarget>();
if (Subtarget.isThumb2()) {
EncodedValue &= 0x00FFFFFF;
EncodedValue |= 0xEE000000;
}
return EncodedValue;
}
/// getMachineOpValue - Return binary encoding of operand. If the machine
/// operand requires relocation, record the relocation and return zero.
unsigned ARMMCCodeEmitter::
getMachineOpValue(const MCInst &MI, const MCOperand &MO,
SmallVectorImpl<MCFixup> &Fixups) const {
if (MO.isReg()) {
unsigned Reg = MO.getReg();
unsigned RegNo = getARMRegisterNumbering(Reg);
// Q registers are encodes as 2x their register number.
switch (Reg) {
default:
return RegNo;
case ARM::Q0: case ARM::Q1: case ARM::Q2: case ARM::Q3:
case ARM::Q4: case ARM::Q5: case ARM::Q6: case ARM::Q7:
case ARM::Q8: case ARM::Q9: case ARM::Q10: case ARM::Q11:
case ARM::Q12: case ARM::Q13: case ARM::Q14: case ARM::Q15:
return 2 * RegNo;
}
} else if (MO.isImm()) {
return static_cast<unsigned>(MO.getImm());
} else if (MO.isFPImm()) {
return static_cast<unsigned>(APFloat(MO.getFPImm())
.bitcastToAPInt().getHiBits(32).getLimitedValue());
}
llvm_unreachable("Unable to encode MCOperand!");
return 0;
}
/// getAddrModeImmOpValue - Return encoding info for 'reg +/- imm' operand.
bool ARMMCCodeEmitter::
EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx, unsigned &Reg,
unsigned &Imm, SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(OpIdx);
const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
Reg = getARMRegisterNumbering(MO.getReg());
int32_t SImm = MO1.getImm();
bool isAdd = true;
// Special value for #-0
if (SImm == INT32_MIN)
SImm = 0;
// Immediate is always encoded as positive. The 'U' bit controls add vs sub.
if (SImm < 0) {
SImm = -SImm;
isAdd = false;
}
Imm = SImm;
return isAdd;
}
/// getBranchTargetOpValue - Return encoding info for 24-bit immediate
/// branch target.
uint32_t ARMMCCodeEmitter::
getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(OpIdx);
// If the destination is an immediate, we have nothing to do.
if (MO.isImm()) return MO.getImm();
assert (MO.isExpr() && "Unexpected branch target type!");
const MCExpr *Expr = MO.getExpr();
MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_branch);
Fixups.push_back(MCFixup::Create(0, Expr, Kind));
// All of the information is in the fixup.
return 0;
}
/// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12' operand.
uint32_t ARMMCCodeEmitter::
getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
// {17-13} = reg
// {12} = (U)nsigned (add == '1', sub == '0')
// {11-0} = imm12
unsigned Reg, Imm12;
bool isAdd = true;
// If The first operand isn't a register, we have a label reference.
const MCOperand &MO = MI.getOperand(OpIdx);
if (!MO.isReg()) {
Reg = getARMRegisterNumbering(ARM::PC); // Rn is PC.
Imm12 = 0;
assert(MO.isExpr() && "Unexpected machine operand type!");
const MCExpr *Expr = MO.getExpr();
MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_pcrel_12);
Fixups.push_back(MCFixup::Create(0, Expr, Kind));
++MCNumCPRelocations;
} else
isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm12, Fixups);
uint32_t Binary = Imm12 & 0xfff;
// Immediate is always encoded as positive. The 'U' bit controls add vs sub.
if (isAdd)
Binary |= (1 << 12);
Binary |= (Reg << 13);
return Binary;
}
uint32_t ARMMCCodeEmitter::
getMovtImmOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
// {20-16} = imm{15-12}
// {11-0} = imm{11-0}
const MCOperand &MO = MI.getOperand(OpIdx);
if (MO.isImm()) {
return static_cast<unsigned>(MO.getImm());
} else if (const MCSymbolRefExpr *Expr =
dyn_cast<MCSymbolRefExpr>(MO.getExpr())) {
MCFixupKind Kind;
switch (Expr->getKind()) {
case MCSymbolRefExpr::VK_ARM_HI16:
Kind = MCFixupKind(ARM::fixup_arm_movt_hi16);
break;
case MCSymbolRefExpr::VK_ARM_LO16:
Kind = MCFixupKind(ARM::fixup_arm_movw_lo16);
break;
default: assert(0 && "Unsupported ARMFixup"); break;
}
Fixups.push_back(MCFixup::Create(0, Expr, Kind));
return 0;
};
llvm_unreachable("Unsupported MCExpr type in MCOperand!");
return 0;
}
uint32_t ARMMCCodeEmitter::
getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(OpIdx);
const MCOperand &MO1 = MI.getOperand(OpIdx+1);
const MCOperand &MO2 = MI.getOperand(OpIdx+2);
unsigned Rn = getARMRegisterNumbering(MO.getReg());
unsigned Rm = getARMRegisterNumbering(MO1.getReg());
unsigned ShImm = ARM_AM::getAM2Offset(MO2.getImm());
bool isAdd = ARM_AM::getAM2Op(MO2.getImm()) == ARM_AM::add;
ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(MO2.getImm());
unsigned SBits = getShiftOp(ShOp);
// {16-13} = Rn
// {12} = isAdd
// {11-0} = shifter
// {3-0} = Rm
// {4} = 0
// {6-5} = type
// {11-7} = imm
uint32_t Binary = Rm;
Binary |= Rn << 13;
Binary |= SBits << 5;
Binary |= ShImm << 7;
if (isAdd)
Binary |= 1 << 12;
return Binary;
}
uint32_t ARMMCCodeEmitter::
getAddrMode2OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
// {17-14} Rn
// {13} 1 == imm12, 0 == Rm
// {12} isAdd
// {11-0} imm12/Rm
const MCOperand &MO = MI.getOperand(OpIdx);
unsigned Rn = getARMRegisterNumbering(MO.getReg());
uint32_t Binary = getAddrMode2OffsetOpValue(MI, OpIdx + 1, Fixups);
Binary |= Rn << 14;
return Binary;
}
uint32_t ARMMCCodeEmitter::
getAddrMode2OffsetOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
// {13} 1 == imm12, 0 == Rm
// {12} isAdd
// {11-0} imm12/Rm
const MCOperand &MO = MI.getOperand(OpIdx);
const MCOperand &MO1 = MI.getOperand(OpIdx+1);
unsigned Imm = MO1.getImm();
bool isAdd = ARM_AM::getAM2Op(Imm) == ARM_AM::add;
bool isReg = MO.getReg() != 0;
uint32_t Binary = ARM_AM::getAM2Offset(Imm);
// if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm12
if (isReg) {
ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(Imm);
Binary <<= 7; // Shift amount is bits [11:7]
Binary |= getShiftOp(ShOp) << 5; // Shift type is bits [6:5]
Binary |= getARMRegisterNumbering(MO.getReg()); // Rm is bits [3:0]
}
return Binary | (isAdd << 12) | (isReg << 13);
}
uint32_t ARMMCCodeEmitter::
getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
// {9} 1 == imm8, 0 == Rm
// {8} isAdd
// {7-4} imm7_4/zero
// {3-0} imm3_0/Rm
const MCOperand &MO = MI.getOperand(OpIdx);
const MCOperand &MO1 = MI.getOperand(OpIdx+1);
unsigned Imm = MO1.getImm();
bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
bool isImm = MO.getReg() == 0;
uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
// if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
if (!isImm)
Imm8 = getARMRegisterNumbering(MO.getReg());
return Imm8 | (isAdd << 8) | (isImm << 9);
}
uint32_t ARMMCCodeEmitter::
getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
// {13} 1 == imm8, 0 == Rm
// {12-9} Rn
// {8} isAdd
// {7-4} imm7_4/zero
// {3-0} imm3_0/Rm
const MCOperand &MO = MI.getOperand(OpIdx);
const MCOperand &MO1 = MI.getOperand(OpIdx+1);
const MCOperand &MO2 = MI.getOperand(OpIdx+2);
unsigned Rn = getARMRegisterNumbering(MO.getReg());
unsigned Imm = MO2.getImm();
bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
bool isImm = MO1.getReg() == 0;
uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
// if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
if (!isImm)
Imm8 = getARMRegisterNumbering(MO1.getReg());
return (Rn << 9) | Imm8 | (isAdd << 8) | (isImm << 13);
}
/// getAddrMode5OpValue - Return encoding info for 'reg +/- imm12' operand.
uint32_t ARMMCCodeEmitter::
getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
// {12-9} = reg
// {8} = (U)nsigned (add == '1', sub == '0')
// {7-0} = imm8
unsigned Reg, Imm8;
// If The first operand isn't a register, we have a label reference.
const MCOperand &MO = MI.getOperand(OpIdx);
if (!MO.isReg()) {
Reg = getARMRegisterNumbering(ARM::PC); // Rn is PC.
Imm8 = 0;
assert(MO.isExpr() && "Unexpected machine operand type!");
const MCExpr *Expr = MO.getExpr();
MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_vfp_pcrel_12);
Fixups.push_back(MCFixup::Create(0, Expr, Kind));
++MCNumCPRelocations;
} else
EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups);
uint32_t Binary = ARM_AM::getAM5Offset(Imm8);
// Immediate is always encoded as positive. The 'U' bit controls add vs sub.
if (ARM_AM::getAM5Op(Imm8) == ARM_AM::add)
Binary |= (1 << 8);
Binary |= (Reg << 9);
return Binary;
}
unsigned ARMMCCodeEmitter::
getSORegOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
// Sub-operands are [reg, reg, imm]. The first register is Rm, the reg to be
// shifted. The second is either Rs, the amount to shift by, or reg0 in which
// case the imm contains the amount to shift by.
//
// {3-0} = Rm.
// {4} = 1 if reg shift, 0 if imm shift
// {6-5} = type
// If reg shift:
// {11-8} = Rs
// {7} = 0
// else (imm shift)
// {11-7} = imm
const MCOperand &MO = MI.getOperand(OpIdx);
const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
const MCOperand &MO2 = MI.getOperand(OpIdx + 2);
ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO2.getImm());
// Encode Rm.
unsigned Binary = getARMRegisterNumbering(MO.getReg());
// Encode the shift opcode.
unsigned SBits = 0;
unsigned Rs = MO1.getReg();
if (Rs) {
// Set shift operand (bit[7:4]).
// LSL - 0001
// LSR - 0011
// ASR - 0101
// ROR - 0111
// RRX - 0110 and bit[11:8] clear.
switch (SOpc) {
default: llvm_unreachable("Unknown shift opc!");
case ARM_AM::lsl: SBits = 0x1; break;
case ARM_AM::lsr: SBits = 0x3; break;
case ARM_AM::asr: SBits = 0x5; break;
case ARM_AM::ror: SBits = 0x7; break;
case ARM_AM::rrx: SBits = 0x6; break;
}
} else {
// Set shift operand (bit[6:4]).
// LSL - 000
// LSR - 010
// ASR - 100
// ROR - 110
switch (SOpc) {
default: llvm_unreachable("Unknown shift opc!");
case ARM_AM::lsl: SBits = 0x0; break;
case ARM_AM::lsr: SBits = 0x2; break;
case ARM_AM::asr: SBits = 0x4; break;
case ARM_AM::ror: SBits = 0x6; break;
}
}
Binary |= SBits << 4;
if (SOpc == ARM_AM::rrx)
return Binary;
// Encode the shift operation Rs or shift_imm (except rrx).
if (Rs) {
// Encode Rs bit[11:8].
assert(ARM_AM::getSORegOffset(MO2.getImm()) == 0);
return Binary | (getARMRegisterNumbering(Rs) << ARMII::RegRsShift);
}
// Encode shift_imm bit[11:7].
return Binary | ARM_AM::getSORegOffset(MO2.getImm()) << 7;
}
unsigned ARMMCCodeEmitter::
getT2SORegOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups) const {
// Sub-operands are [reg, imm]. The first register is Rm, the reg to be
// shifted. The second is the amount to shift by.
//
// {3-0} = Rm.
// {4} = 0
// {6-5} = type
// {11-7} = imm
const MCOperand &MO = MI.getOperand(OpIdx);
const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO1.getImm());
// Encode Rm.
unsigned Binary = getARMRegisterNumbering(MO.getReg());
// Encode the shift opcode.
unsigned SBits = 0;
// Set shift operand (bit[6:4]).
// LSL - 000
// LSR - 010
// ASR - 100
// ROR - 110
switch (SOpc) {
default: llvm_unreachable("Unknown shift opc!");
case ARM_AM::lsl: SBits = 0x0; break;
case ARM_AM::lsr: SBits = 0x2; break;
case ARM_AM::asr: SBits = 0x4; break;
case ARM_AM::ror: SBits = 0x6; break;
}
Binary |= SBits << 4;
if (SOpc == ARM_AM::rrx)
return Binary;
// Encode shift_imm bit[11:7].
return Binary | ARM_AM::getSORegOffset(MO1.getImm()) << 7;
}
unsigned ARMMCCodeEmitter::
getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const {
// 10 bits. lower 5 bits are are the lsb of the mask, high five bits are the
// msb of the mask.
const MCOperand &MO = MI.getOperand(Op);
uint32_t v = ~MO.getImm();
uint32_t lsb = CountTrailingZeros_32(v);
uint32_t msb = (32 - CountLeadingZeros_32 (v)) - 1;
assert (v != 0 && lsb < 32 && msb < 32 && "Illegal bitfield mask!");
return lsb | (msb << 5);
}
unsigned ARMMCCodeEmitter::
getRegisterListOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const {
// VLDM/VSTM:
// {12-8} = Vd
// {7-0} = Number of registers
//
// LDM/STM:
// {15-0} = Bitfield of GPRs.
unsigned Reg = MI.getOperand(Op).getReg();
bool SPRRegs = ARM::SPRRegClass.contains(Reg);
bool DPRRegs = ARM::DPRRegClass.contains(Reg);
unsigned Binary = 0;
if (SPRRegs || DPRRegs) {
// VLDM/VSTM
unsigned RegNo = getARMRegisterNumbering(Reg);
unsigned NumRegs = (MI.getNumOperands() - Op) & 0xff;
Binary |= (RegNo & 0x1f) << 8;
if (SPRRegs)
Binary |= NumRegs;
else
Binary |= NumRegs * 2;
} else {
for (unsigned I = Op, E = MI.getNumOperands(); I < E; ++I) {
unsigned RegNo = getARMRegisterNumbering(MI.getOperand(I).getReg());
Binary |= 1 << RegNo;
}
}
return Binary;
}
unsigned ARMMCCodeEmitter::
getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &Reg = MI.getOperand(Op);
const MCOperand &Imm = MI.getOperand(Op + 1);
unsigned RegNo = getARMRegisterNumbering(Reg.getReg());
unsigned Align = 0;
switch (Imm.getImm()) {
default: break;
case 2:
case 4:
case 8: Align = 0x01; break;
case 16: Align = 0x02; break;
case 32: Align = 0x03; break;
}
return RegNo | (Align << 4);
}
unsigned ARMMCCodeEmitter::
getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
SmallVectorImpl<MCFixup> &Fixups) const {
const MCOperand &MO = MI.getOperand(Op);
if (MO.getReg() == 0) return 0x0D;
return MO.getReg();
}
void ARMMCCodeEmitter::
EncodeInstruction(const MCInst &MI, raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups) const {
// Pseudo instructions don't get encoded.
const TargetInstrDesc &Desc = TII.get(MI.getOpcode());
uint64_t TSFlags = Desc.TSFlags;
if ((TSFlags & ARMII::FormMask) == ARMII::Pseudo)
return;
int Size;
// Basic size info comes from the TSFlags field.
switch ((TSFlags & ARMII::SizeMask) >> ARMII::SizeShift) {
default: llvm_unreachable("Unexpected instruction size!");
case ARMII::Size2Bytes: Size = 2; break;
case ARMII::Size4Bytes: Size = 4; break;
}
EmitConstant(getBinaryCodeForInstr(MI, Fixups), Size, OS);
++MCNumEmitted; // Keep track of the # of mi's emitted.
}
#include "ARMGenMCCodeEmitter.inc"