llvm-for-llvmta/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp

655 lines
26 KiB
C++

//=- AArch64/AArch64MCCodeEmitter.cpp - Convert AArch64 code to machine code-=//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the AArch64MCCodeEmitter class.
//
//===----------------------------------------------------------------------===//
#include "MCTargetDesc/AArch64AddressingModes.h"
#include "MCTargetDesc/AArch64FixupKinds.h"
#include "MCTargetDesc/AArch64MCExpr.h"
#include "Utils/AArch64BaseInfo.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCFixup.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/EndianStream.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
#include <cstdint>
using namespace llvm;
#define DEBUG_TYPE "mccodeemitter"
STATISTIC(MCNumEmitted, "Number of MC instructions emitted.");
STATISTIC(MCNumFixups, "Number of MC fixups created.");
namespace {
class AArch64MCCodeEmitter : public MCCodeEmitter {
MCContext &Ctx;
const MCInstrInfo &MCII;
public:
AArch64MCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx)
: Ctx(ctx), MCII(mcii) {}
AArch64MCCodeEmitter(const AArch64MCCodeEmitter &) = delete;
void operator=(const AArch64MCCodeEmitter &) = delete;
~AArch64MCCodeEmitter() override = default;
// getBinaryCodeForInstr - TableGen'erated function for getting the
// binary encoding for an instruction.
uint64_t getBinaryCodeForInstr(const MCInst &MI,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) 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 MCSubtargetInfo &STI) const;
/// getLdStUImm12OpValue - Return encoding info for 12-bit unsigned immediate
/// attached to a load, store or prfm instruction. If operand requires a
/// relocation, record it and return zero in that part of the encoding.
template <uint32_t FixupKind>
uint32_t getLdStUImm12OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
/// getAdrLabelOpValue - Return encoding info for 21-bit immediate ADR label
/// target.
uint32_t getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
/// getAddSubImmOpValue - Return encoding for the 12-bit immediate value and
/// the 2-bit shift field.
uint32_t getAddSubImmOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
/// getCondBranchTargetOpValue - Return the encoded value for a conditional
/// branch target.
uint32_t getCondBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
/// getLoadLiteralOpValue - Return the encoded value for a load-literal
/// pc-relative address.
uint32_t getLoadLiteralOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
/// getMemExtendOpValue - Return the encoded value for a reg-extend load/store
/// instruction: bit 0 is whether a shift is present, bit 1 is whether the
/// operation is a sign extend (as opposed to a zero extend).
uint32_t getMemExtendOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
/// getTestBranchTargetOpValue - Return the encoded value for a test-bit-and-
/// branch target.
uint32_t getTestBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
/// getBranchTargetOpValue - Return the encoded value for an unconditional
/// branch target.
uint32_t getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
/// getMoveWideImmOpValue - Return the encoded value for the immediate operand
/// of a MOVZ or MOVK instruction.
uint32_t getMoveWideImmOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
/// getVecShifterOpValue - Return the encoded value for the vector shifter.
uint32_t getVecShifterOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
/// getMoveVecShifterOpValue - Return the encoded value for the vector move
/// shifter (MSL).
uint32_t getMoveVecShifterOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
/// getFixedPointScaleOpValue - Return the encoded value for the
// FP-to-fixed-point scale factor.
uint32_t getFixedPointScaleOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
uint32_t getVecShiftR64OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
uint32_t getVecShiftR32OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
uint32_t getVecShiftR16OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
uint32_t getVecShiftR8OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
uint32_t getVecShiftL64OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
uint32_t getVecShiftL32OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
uint32_t getVecShiftL16OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
uint32_t getVecShiftL8OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
uint32_t getImm8OptLsl(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
uint32_t getSVEIncDecImm(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const;
unsigned fixMOVZ(const MCInst &MI, unsigned EncodedValue,
const MCSubtargetInfo &STI) const;
void encodeInstruction(const MCInst &MI, raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const override;
unsigned fixMulHigh(const MCInst &MI, unsigned EncodedValue,
const MCSubtargetInfo &STI) const;
template<int hasRs, int hasRt2> unsigned
fixLoadStoreExclusive(const MCInst &MI, unsigned EncodedValue,
const MCSubtargetInfo &STI) const;
unsigned fixOneOperandFPComparison(const MCInst &MI, unsigned EncodedValue,
const MCSubtargetInfo &STI) const;
private:
FeatureBitset computeAvailableFeatures(const FeatureBitset &FB) const;
void
verifyInstructionPredicates(const MCInst &MI,
const FeatureBitset &AvailableFeatures) const;
};
} // end anonymous namespace
/// getMachineOpValue - Return binary encoding of operand. If the machine
/// operand requires relocation, record the relocation and return zero.
unsigned
AArch64MCCodeEmitter::getMachineOpValue(const MCInst &MI, const MCOperand &MO,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
if (MO.isReg())
return Ctx.getRegisterInfo()->getEncodingValue(MO.getReg());
assert(MO.isImm() && "did not expect relocated expression");
return static_cast<unsigned>(MO.getImm());
}
template<unsigned FixupKind> uint32_t
AArch64MCCodeEmitter::getLdStUImm12OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
uint32_t ImmVal = 0;
if (MO.isImm())
ImmVal = static_cast<uint32_t>(MO.getImm());
else {
assert(MO.isExpr() && "unable to encode load/store imm operand");
MCFixupKind Kind = MCFixupKind(FixupKind);
Fixups.push_back(MCFixup::create(0, MO.getExpr(), Kind, MI.getLoc()));
++MCNumFixups;
}
return ImmVal;
}
/// getAdrLabelOpValue - Return encoding info for 21-bit immediate ADR label
/// target.
uint32_t
AArch64MCCodeEmitter::getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) 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 target type!");
const MCExpr *Expr = MO.getExpr();
MCFixupKind Kind = MI.getOpcode() == AArch64::ADR
? MCFixupKind(AArch64::fixup_aarch64_pcrel_adr_imm21)
: MCFixupKind(AArch64::fixup_aarch64_pcrel_adrp_imm21);
Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
MCNumFixups += 1;
// All of the information is in the fixup.
return 0;
}
/// getAddSubImmOpValue - Return encoding for the 12-bit immediate value and
/// the 2-bit shift field. The shift field is stored in bits 13-14 of the
/// return value.
uint32_t
AArch64MCCodeEmitter::getAddSubImmOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
// Suboperands are [imm, shifter].
const MCOperand &MO = MI.getOperand(OpIdx);
const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
assert(AArch64_AM::getShiftType(MO1.getImm()) == AArch64_AM::LSL &&
"unexpected shift type for add/sub immediate");
unsigned ShiftVal = AArch64_AM::getShiftValue(MO1.getImm());
assert((ShiftVal == 0 || ShiftVal == 12) &&
"unexpected shift value for add/sub immediate");
if (MO.isImm())
return MO.getImm() | (ShiftVal == 0 ? 0 : (1 << ShiftVal));
assert(MO.isExpr() && "Unable to encode MCOperand!");
const MCExpr *Expr = MO.getExpr();
// Encode the 12 bits of the fixup.
MCFixupKind Kind = MCFixupKind(AArch64::fixup_aarch64_add_imm12);
Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
++MCNumFixups;
// Set the shift bit of the add instruction for relocation types
// R_AARCH64_TLSLE_ADD_TPREL_HI12 and R_AARCH64_TLSLD_ADD_DTPREL_HI12.
if (const AArch64MCExpr *A64E = dyn_cast<AArch64MCExpr>(Expr)) {
AArch64MCExpr::VariantKind RefKind = A64E->getKind();
if (RefKind == AArch64MCExpr::VK_TPREL_HI12 ||
RefKind == AArch64MCExpr::VK_DTPREL_HI12 ||
RefKind == AArch64MCExpr::VK_SECREL_HI12)
ShiftVal = 12;
}
return ShiftVal == 0 ? 0 : (1 << ShiftVal);
}
/// getCondBranchTargetOpValue - Return the encoded value for a conditional
/// branch target.
uint32_t AArch64MCCodeEmitter::getCondBranchTargetOpValue(
const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) 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 target type!");
MCFixupKind Kind = MCFixupKind(AArch64::fixup_aarch64_pcrel_branch19);
Fixups.push_back(MCFixup::create(0, MO.getExpr(), Kind, MI.getLoc()));
++MCNumFixups;
// All of the information is in the fixup.
return 0;
}
/// getLoadLiteralOpValue - Return the encoded value for a load-literal
/// pc-relative address.
uint32_t
AArch64MCCodeEmitter::getLoadLiteralOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) 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 target type!");
MCFixupKind Kind = MCFixupKind(AArch64::fixup_aarch64_ldr_pcrel_imm19);
Fixups.push_back(MCFixup::create(0, MO.getExpr(), Kind, MI.getLoc()));
++MCNumFixups;
// All of the information is in the fixup.
return 0;
}
uint32_t
AArch64MCCodeEmitter::getMemExtendOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
unsigned SignExtend = MI.getOperand(OpIdx).getImm();
unsigned DoShift = MI.getOperand(OpIdx + 1).getImm();
return (SignExtend << 1) | DoShift;
}
uint32_t
AArch64MCCodeEmitter::getMoveWideImmOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
if (MO.isImm())
return MO.getImm();
assert(MO.isExpr() && "Unexpected movz/movk immediate");
Fixups.push_back(MCFixup::create(
0, MO.getExpr(), MCFixupKind(AArch64::fixup_aarch64_movw), MI.getLoc()));
++MCNumFixups;
return 0;
}
/// getTestBranchTargetOpValue - Return the encoded value for a test-bit-and-
/// branch target.
uint32_t AArch64MCCodeEmitter::getTestBranchTargetOpValue(
const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) 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 ADR target type!");
MCFixupKind Kind = MCFixupKind(AArch64::fixup_aarch64_pcrel_branch14);
Fixups.push_back(MCFixup::create(0, MO.getExpr(), Kind, MI.getLoc()));
++MCNumFixups;
// All of the information is in the fixup.
return 0;
}
/// getBranchTargetOpValue - Return the encoded value for an unconditional
/// branch target.
uint32_t
AArch64MCCodeEmitter::getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) 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 ADR target type!");
MCFixupKind Kind = MI.getOpcode() == AArch64::BL
? MCFixupKind(AArch64::fixup_aarch64_pcrel_call26)
: MCFixupKind(AArch64::fixup_aarch64_pcrel_branch26);
Fixups.push_back(MCFixup::create(0, MO.getExpr(), Kind, MI.getLoc()));
++MCNumFixups;
// All of the information is in the fixup.
return 0;
}
/// getVecShifterOpValue - Return the encoded value for the vector shifter:
///
/// 00 -> 0
/// 01 -> 8
/// 10 -> 16
/// 11 -> 24
uint32_t
AArch64MCCodeEmitter::getVecShifterOpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
assert(MO.isImm() && "Expected an immediate value for the shift amount!");
switch (MO.getImm()) {
default:
break;
case 0:
return 0;
case 8:
return 1;
case 16:
return 2;
case 24:
return 3;
}
llvm_unreachable("Invalid value for vector shift amount!");
}
/// getFixedPointScaleOpValue - Return the encoded value for the
// FP-to-fixed-point scale factor.
uint32_t AArch64MCCodeEmitter::getFixedPointScaleOpValue(
const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
assert(MO.isImm() && "Expected an immediate value for the scale amount!");
return 64 - MO.getImm();
}
uint32_t
AArch64MCCodeEmitter::getVecShiftR64OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
assert(MO.isImm() && "Expected an immediate value for the scale amount!");
return 64 - MO.getImm();
}
uint32_t
AArch64MCCodeEmitter::getVecShiftR32OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
assert(MO.isImm() && "Expected an immediate value for the scale amount!");
return 32 - MO.getImm();
}
uint32_t
AArch64MCCodeEmitter::getVecShiftR16OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
assert(MO.isImm() && "Expected an immediate value for the scale amount!");
return 16 - MO.getImm();
}
uint32_t
AArch64MCCodeEmitter::getVecShiftR8OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
assert(MO.isImm() && "Expected an immediate value for the scale amount!");
return 8 - MO.getImm();
}
uint32_t
AArch64MCCodeEmitter::getVecShiftL64OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
assert(MO.isImm() && "Expected an immediate value for the scale amount!");
return MO.getImm() - 64;
}
uint32_t
AArch64MCCodeEmitter::getVecShiftL32OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
assert(MO.isImm() && "Expected an immediate value for the scale amount!");
return MO.getImm() - 32;
}
uint32_t
AArch64MCCodeEmitter::getVecShiftL16OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
assert(MO.isImm() && "Expected an immediate value for the scale amount!");
return MO.getImm() - 16;
}
uint32_t
AArch64MCCodeEmitter::getVecShiftL8OpValue(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
assert(MO.isImm() && "Expected an immediate value for the scale amount!");
return MO.getImm() - 8;
}
uint32_t
AArch64MCCodeEmitter::getImm8OptLsl(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
// Test shift
auto ShiftOpnd = MI.getOperand(OpIdx + 1).getImm();
assert(AArch64_AM::getShiftType(ShiftOpnd) == AArch64_AM::LSL &&
"Unexpected shift type for imm8_opt_lsl immediate.");
unsigned ShiftVal = AArch64_AM::getShiftValue(ShiftOpnd);
assert((ShiftVal == 0 || ShiftVal == 8) &&
"Unexpected shift value for imm8_opt_lsl immediate.");
// Test immediate
auto Immediate = MI.getOperand(OpIdx).getImm();
return (Immediate & 0xff) | (ShiftVal == 0 ? 0 : (1 << ShiftVal));
}
uint32_t
AArch64MCCodeEmitter::getSVEIncDecImm(const MCInst &MI, unsigned OpIdx,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
assert(MO.isImm() && "Expected an immediate value!");
// Normalize 1-16 range to 0-15.
return MO.getImm() - 1;
}
/// getMoveVecShifterOpValue - Return the encoded value for the vector move
/// shifter (MSL).
uint32_t AArch64MCCodeEmitter::getMoveVecShifterOpValue(
const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
const MCOperand &MO = MI.getOperand(OpIdx);
assert(MO.isImm() &&
"Expected an immediate value for the move shift amount!");
unsigned ShiftVal = AArch64_AM::getShiftValue(MO.getImm());
assert((ShiftVal == 8 || ShiftVal == 16) && "Invalid shift amount!");
return ShiftVal == 8 ? 0 : 1;
}
unsigned AArch64MCCodeEmitter::fixMOVZ(const MCInst &MI, unsigned EncodedValue,
const MCSubtargetInfo &STI) const {
// If one of the signed fixup kinds is applied to a MOVZ instruction, the
// eventual result could be either a MOVZ or a MOVN. It's the MCCodeEmitter's
// job to ensure that any bits possibly affected by this are 0. This means we
// must zero out bit 30 (essentially emitting a MOVN).
MCOperand UImm16MO = MI.getOperand(1);
// Nothing to do if there's no fixup.
if (UImm16MO.isImm())
return EncodedValue;
const MCExpr *E = UImm16MO.getExpr();
if (const AArch64MCExpr *A64E = dyn_cast<AArch64MCExpr>(E)) {
switch (A64E->getKind()) {
case AArch64MCExpr::VK_DTPREL_G2:
case AArch64MCExpr::VK_DTPREL_G1:
case AArch64MCExpr::VK_DTPREL_G0:
case AArch64MCExpr::VK_GOTTPREL_G1:
case AArch64MCExpr::VK_TPREL_G2:
case AArch64MCExpr::VK_TPREL_G1:
case AArch64MCExpr::VK_TPREL_G0:
return EncodedValue & ~(1u << 30);
default:
// Nothing to do for an unsigned fixup.
return EncodedValue;
}
}
return EncodedValue;
}
void AArch64MCCodeEmitter::encodeInstruction(const MCInst &MI, raw_ostream &OS,
SmallVectorImpl<MCFixup> &Fixups,
const MCSubtargetInfo &STI) const {
verifyInstructionPredicates(MI,
computeAvailableFeatures(STI.getFeatureBits()));
if (MI.getOpcode() == AArch64::TLSDESCCALL) {
// This is a directive which applies an R_AARCH64_TLSDESC_CALL to the
// following (BLR) instruction. It doesn't emit any code itself so it
// doesn't go through the normal TableGenerated channels.
MCFixupKind Fixup = MCFixupKind(AArch64::fixup_aarch64_tlsdesc_call);
Fixups.push_back(MCFixup::create(0, MI.getOperand(0).getExpr(), Fixup));
return;
}
if (MI.getOpcode() == AArch64::CompilerBarrier ||
MI.getOpcode() == AArch64::SPACE) {
// CompilerBarrier just prevents the compiler from reordering accesses, and
// SPACE just increases basic block size, in both cases no actual code.
return;
}
uint64_t Binary = getBinaryCodeForInstr(MI, Fixups, STI);
support::endian::write<uint32_t>(OS, Binary, support::little);
++MCNumEmitted; // Keep track of the # of mi's emitted.
}
unsigned
AArch64MCCodeEmitter::fixMulHigh(const MCInst &MI,
unsigned EncodedValue,
const MCSubtargetInfo &STI) const {
// The Ra field of SMULH and UMULH is unused: it should be assembled as 31
// (i.e. all bits 1) but is ignored by the processor.
EncodedValue |= 0x1f << 10;
return EncodedValue;
}
template<int hasRs, int hasRt2> unsigned
AArch64MCCodeEmitter::fixLoadStoreExclusive(const MCInst &MI,
unsigned EncodedValue,
const MCSubtargetInfo &STI) const {
if (!hasRs) EncodedValue |= 0x001F0000;
if (!hasRt2) EncodedValue |= 0x00007C00;
return EncodedValue;
}
unsigned AArch64MCCodeEmitter::fixOneOperandFPComparison(
const MCInst &MI, unsigned EncodedValue, const MCSubtargetInfo &STI) const {
// The Rm field of FCMP and friends is unused - it should be assembled
// as 0, but is ignored by the processor.
EncodedValue &= ~(0x1f << 16);
return EncodedValue;
}
#define ENABLE_INSTR_PREDICATE_VERIFIER
#include "AArch64GenMCCodeEmitter.inc"
MCCodeEmitter *llvm::createAArch64MCCodeEmitter(const MCInstrInfo &MCII,
const MCRegisterInfo &MRI,
MCContext &Ctx) {
return new AArch64MCCodeEmitter(MCII, Ctx);
}