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clang-p2996/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
Peter Smith e63455d5e0 [MC] Use local MCSubtargetInfo in writeNops 
On some architectures such as Arm and X86 the encoding for a nop may
change depending on the subtarget in operation at the time of
encoding. This change replaces the per module MCSubtargetInfo retained
by the targets AsmBackend in favour of passing through the local
MCSubtargetInfo in operation at the time.

On Arm using the architectural NOP instruction can have a performance
benefit on some implementations.

For Arm I've deleted the copy of the AsmBackend's MCSubtargetInfo to
limit the chances of this causing problems in the future. I've not
done this for other targets such as X86 as there is more frequent use
of the MCSubtargetInfo and it looks to be for stable properties that
we would not expect to vary per function.

This change required threading STI through MCNopsFragment and
MCBoundaryAlignFragment.

I've attempted to take into account the in tree experimental backends.

Differential Revision: https://reviews.llvm.org/D45962
2021-09-07 15:46:19 +01:00

594 lines
24 KiB
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//===-- MipsAsmBackend.cpp - Mips Asm Backend ----------------------------===//
//
// 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 MipsAsmBackend class.
//
//===----------------------------------------------------------------------===//
//
#include "MCTargetDesc/MipsAsmBackend.h"
#include "MCTargetDesc/MipsABIInfo.h"
#include "MCTargetDesc/MipsFixupKinds.h"
#include "MCTargetDesc/MipsMCExpr.h"
#include "MCTargetDesc/MipsMCTargetDesc.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDirectives.h"
#include "llvm/MC/MCELFObjectWriter.h"
#include "llvm/MC/MCFixupKindInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
// Prepare value for the target space for it
static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
MCContext &Ctx) {
unsigned Kind = Fixup.getKind();
// Add/subtract and shift
switch (Kind) {
default:
return 0;
case FK_Data_2:
case Mips::fixup_Mips_LO16:
case Mips::fixup_Mips_GPREL16:
case Mips::fixup_Mips_GPOFF_HI:
case Mips::fixup_Mips_GPOFF_LO:
case Mips::fixup_Mips_GOT_PAGE:
case Mips::fixup_Mips_GOT_OFST:
case Mips::fixup_Mips_GOT_DISP:
case Mips::fixup_Mips_GOT_LO16:
case Mips::fixup_Mips_CALL_LO16:
case Mips::fixup_MICROMIPS_GPOFF_HI:
case Mips::fixup_MICROMIPS_GPOFF_LO:
case Mips::fixup_MICROMIPS_LO16:
case Mips::fixup_MICROMIPS_GOT_PAGE:
case Mips::fixup_MICROMIPS_GOT_OFST:
case Mips::fixup_MICROMIPS_GOT_DISP:
case Mips::fixup_MIPS_PCLO16:
Value &= 0xffff;
break;
case FK_DTPRel_4:
case FK_DTPRel_8:
case FK_TPRel_4:
case FK_TPRel_8:
case FK_GPRel_4:
case FK_Data_4:
case FK_Data_8:
case Mips::fixup_Mips_SUB:
case Mips::fixup_MICROMIPS_SUB:
break;
case Mips::fixup_Mips_PC16:
// The displacement is then divided by 4 to give us an 18 bit
// address range. Forcing a signed division because Value can be negative.
Value = (int64_t)Value / 4;
// We now check if Value can be encoded as a 16-bit signed immediate.
if (!isInt<16>(Value)) {
Ctx.reportError(Fixup.getLoc(), "out of range PC16 fixup");
return 0;
}
break;
case Mips::fixup_MIPS_PC19_S2:
case Mips::fixup_MICROMIPS_PC19_S2:
// Forcing a signed division because Value can be negative.
Value = (int64_t)Value / 4;
// We now check if Value can be encoded as a 19-bit signed immediate.
if (!isInt<19>(Value)) {
Ctx.reportError(Fixup.getLoc(), "out of range PC19 fixup");
return 0;
}
break;
case Mips::fixup_Mips_26:
// So far we are only using this type for jumps.
// The displacement is then divided by 4 to give us an 28 bit
// address range.
Value >>= 2;
break;
case Mips::fixup_Mips_HI16:
case Mips::fixup_Mips_GOT:
case Mips::fixup_MICROMIPS_GOT16:
case Mips::fixup_Mips_GOT_HI16:
case Mips::fixup_Mips_CALL_HI16:
case Mips::fixup_MICROMIPS_HI16:
case Mips::fixup_MIPS_PCHI16:
// Get the 2nd 16-bits. Also add 1 if bit 15 is 1.
Value = ((Value + 0x8000) >> 16) & 0xffff;
break;
case Mips::fixup_Mips_HIGHER:
case Mips::fixup_MICROMIPS_HIGHER:
// Get the 3rd 16-bits.
Value = ((Value + 0x80008000LL) >> 32) & 0xffff;
break;
case Mips::fixup_Mips_HIGHEST:
case Mips::fixup_MICROMIPS_HIGHEST:
// Get the 4th 16-bits.
Value = ((Value + 0x800080008000LL) >> 48) & 0xffff;
break;
case Mips::fixup_MICROMIPS_26_S1:
Value >>= 1;
break;
case Mips::fixup_MICROMIPS_PC7_S1:
Value -= 4;
// Forcing a signed division because Value can be negative.
Value = (int64_t) Value / 2;
// We now check if Value can be encoded as a 7-bit signed immediate.
if (!isInt<7>(Value)) {
Ctx.reportError(Fixup.getLoc(), "out of range PC7 fixup");
return 0;
}
break;
case Mips::fixup_MICROMIPS_PC10_S1:
Value -= 2;
// Forcing a signed division because Value can be negative.
Value = (int64_t) Value / 2;
// We now check if Value can be encoded as a 10-bit signed immediate.
if (!isInt<10>(Value)) {
Ctx.reportError(Fixup.getLoc(), "out of range PC10 fixup");
return 0;
}
break;
case Mips::fixup_MICROMIPS_PC16_S1:
Value -= 4;
// Forcing a signed division because Value can be negative.
Value = (int64_t)Value / 2;
// We now check if Value can be encoded as a 16-bit signed immediate.
if (!isInt<16>(Value)) {
Ctx.reportError(Fixup.getLoc(), "out of range PC16 fixup");
return 0;
}
break;
case Mips::fixup_MIPS_PC18_S3:
// Forcing a signed division because Value can be negative.
Value = (int64_t)Value / 8;
// We now check if Value can be encoded as a 18-bit signed immediate.
if (!isInt<18>(Value)) {
Ctx.reportError(Fixup.getLoc(), "out of range PC18 fixup");
return 0;
}
break;
case Mips::fixup_MICROMIPS_PC18_S3:
// Check alignment.
if ((Value & 7)) {
Ctx.reportError(Fixup.getLoc(), "out of range PC18 fixup");
}
// Forcing a signed division because Value can be negative.
Value = (int64_t)Value / 8;
// We now check if Value can be encoded as a 18-bit signed immediate.
if (!isInt<18>(Value)) {
Ctx.reportError(Fixup.getLoc(), "out of range PC18 fixup");
return 0;
}
break;
case Mips::fixup_MIPS_PC21_S2:
// Forcing a signed division because Value can be negative.
Value = (int64_t) Value / 4;
// We now check if Value can be encoded as a 21-bit signed immediate.
if (!isInt<21>(Value)) {
Ctx.reportError(Fixup.getLoc(), "out of range PC21 fixup");
return 0;
}
break;
case Mips::fixup_MIPS_PC26_S2:
// Forcing a signed division because Value can be negative.
Value = (int64_t) Value / 4;
// We now check if Value can be encoded as a 26-bit signed immediate.
if (!isInt<26>(Value)) {
Ctx.reportError(Fixup.getLoc(), "out of range PC26 fixup");
return 0;
}
break;
case Mips::fixup_MICROMIPS_PC26_S1:
// Forcing a signed division because Value can be negative.
Value = (int64_t)Value / 2;
// We now check if Value can be encoded as a 26-bit signed immediate.
if (!isInt<26>(Value)) {
Ctx.reportFatalError(Fixup.getLoc(), "out of range PC26 fixup");
return 0;
}
break;
case Mips::fixup_MICROMIPS_PC21_S1:
// Forcing a signed division because Value can be negative.
Value = (int64_t)Value / 2;
// We now check if Value can be encoded as a 21-bit signed immediate.
if (!isInt<21>(Value)) {
Ctx.reportError(Fixup.getLoc(), "out of range PC21 fixup");
return 0;
}
break;
}
return Value;
}
std::unique_ptr<MCObjectTargetWriter>
MipsAsmBackend::createObjectTargetWriter() const {
return createMipsELFObjectWriter(TheTriple, IsN32);
}
// Little-endian fixup data byte ordering:
// mips32r2: a | b | x | x
// microMIPS: x | x | a | b
static bool needsMMLEByteOrder(unsigned Kind) {
return Kind != Mips::fixup_MICROMIPS_PC10_S1 &&
Kind >= Mips::fixup_MICROMIPS_26_S1 &&
Kind < Mips::LastTargetFixupKind;
}
// Calculate index for microMIPS specific little endian byte order
static unsigned calculateMMLEIndex(unsigned i) {
assert(i <= 3 && "Index out of range!");
return (1 - i / 2) * 2 + i % 2;
}
/// ApplyFixup - Apply the \p Value for given \p Fixup into the provided
/// data fragment, at the offset specified by the fixup and following the
/// fixup kind as appropriate.
void MipsAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
const MCValue &Target,
MutableArrayRef<char> Data, uint64_t Value,
bool IsResolved,
const MCSubtargetInfo *STI) const {
MCFixupKind Kind = Fixup.getKind();
MCContext &Ctx = Asm.getContext();
Value = adjustFixupValue(Fixup, Value, Ctx);
if (!Value)
return; // Doesn't change encoding.
// Where do we start in the object
unsigned Offset = Fixup.getOffset();
// Number of bytes we need to fixup
unsigned NumBytes = (getFixupKindInfo(Kind).TargetSize + 7) / 8;
// Used to point to big endian bytes
unsigned FullSize;
switch ((unsigned)Kind) {
case FK_Data_2:
case Mips::fixup_Mips_16:
case Mips::fixup_MICROMIPS_PC10_S1:
FullSize = 2;
break;
case FK_Data_8:
case Mips::fixup_Mips_64:
FullSize = 8;
break;
case FK_Data_4:
default:
FullSize = 4;
break;
}
// Grab current value, if any, from bits.
uint64_t CurVal = 0;
bool microMipsLEByteOrder = needsMMLEByteOrder((unsigned) Kind);
for (unsigned i = 0; i != NumBytes; ++i) {
unsigned Idx = Endian == support::little
? (microMipsLEByteOrder ? calculateMMLEIndex(i) : i)
: (FullSize - 1 - i);
CurVal |= (uint64_t)((uint8_t)Data[Offset + Idx]) << (i*8);
}
uint64_t Mask = ((uint64_t)(-1) >>
(64 - getFixupKindInfo(Kind).TargetSize));
CurVal |= Value & Mask;
// Write out the fixed up bytes back to the code/data bits.
for (unsigned i = 0; i != NumBytes; ++i) {
unsigned Idx = Endian == support::little
? (microMipsLEByteOrder ? calculateMMLEIndex(i) : i)
: (FullSize - 1 - i);
Data[Offset + Idx] = (uint8_t)((CurVal >> (i*8)) & 0xff);
}
}
Optional<MCFixupKind> MipsAsmBackend::getFixupKind(StringRef Name) const {
return StringSwitch<Optional<MCFixupKind>>(Name)
.Case("R_MIPS_NONE", FK_NONE)
.Case("R_MIPS_32", FK_Data_4)
.Case("R_MIPS_CALL_HI16", (MCFixupKind)Mips::fixup_Mips_CALL_HI16)
.Case("R_MIPS_CALL_LO16", (MCFixupKind)Mips::fixup_Mips_CALL_LO16)
.Case("R_MIPS_CALL16", (MCFixupKind)Mips::fixup_Mips_CALL16)
.Case("R_MIPS_GOT16", (MCFixupKind)Mips::fixup_Mips_GOT)
.Case("R_MIPS_GOT_PAGE", (MCFixupKind)Mips::fixup_Mips_GOT_PAGE)
.Case("R_MIPS_GOT_OFST", (MCFixupKind)Mips::fixup_Mips_GOT_OFST)
.Case("R_MIPS_GOT_DISP", (MCFixupKind)Mips::fixup_Mips_GOT_DISP)
.Case("R_MIPS_GOT_HI16", (MCFixupKind)Mips::fixup_Mips_GOT_HI16)
.Case("R_MIPS_GOT_LO16", (MCFixupKind)Mips::fixup_Mips_GOT_LO16)
.Case("R_MIPS_TLS_GOTTPREL", (MCFixupKind)Mips::fixup_Mips_GOTTPREL)
.Case("R_MIPS_TLS_DTPREL_HI16", (MCFixupKind)Mips::fixup_Mips_DTPREL_HI)
.Case("R_MIPS_TLS_DTPREL_LO16", (MCFixupKind)Mips::fixup_Mips_DTPREL_LO)
.Case("R_MIPS_TLS_GD", (MCFixupKind)Mips::fixup_Mips_TLSGD)
.Case("R_MIPS_TLS_LDM", (MCFixupKind)Mips::fixup_Mips_TLSLDM)
.Case("R_MIPS_TLS_TPREL_HI16", (MCFixupKind)Mips::fixup_Mips_TPREL_HI)
.Case("R_MIPS_TLS_TPREL_LO16", (MCFixupKind)Mips::fixup_Mips_TPREL_LO)
.Case("R_MICROMIPS_CALL16", (MCFixupKind)Mips::fixup_MICROMIPS_CALL16)
.Case("R_MICROMIPS_GOT_DISP", (MCFixupKind)Mips::fixup_MICROMIPS_GOT_DISP)
.Case("R_MICROMIPS_GOT_PAGE", (MCFixupKind)Mips::fixup_MICROMIPS_GOT_PAGE)
.Case("R_MICROMIPS_GOT_OFST", (MCFixupKind)Mips::fixup_MICROMIPS_GOT_OFST)
.Case("R_MICROMIPS_GOT16", (MCFixupKind)Mips::fixup_MICROMIPS_GOT16)
.Case("R_MICROMIPS_TLS_GOTTPREL",
(MCFixupKind)Mips::fixup_MICROMIPS_GOTTPREL)
.Case("R_MICROMIPS_TLS_DTPREL_HI16",
(MCFixupKind)Mips::fixup_MICROMIPS_TLS_DTPREL_HI16)
.Case("R_MICROMIPS_TLS_DTPREL_LO16",
(MCFixupKind)Mips::fixup_MICROMIPS_TLS_DTPREL_LO16)
.Case("R_MICROMIPS_TLS_GD", (MCFixupKind)Mips::fixup_MICROMIPS_TLS_GD)
.Case("R_MICROMIPS_TLS_LDM", (MCFixupKind)Mips::fixup_MICROMIPS_TLS_LDM)
.Case("R_MICROMIPS_TLS_TPREL_HI16",
(MCFixupKind)Mips::fixup_MICROMIPS_TLS_TPREL_HI16)
.Case("R_MICROMIPS_TLS_TPREL_LO16",
(MCFixupKind)Mips::fixup_MICROMIPS_TLS_TPREL_LO16)
.Case("R_MIPS_JALR", (MCFixupKind)Mips::fixup_Mips_JALR)
.Case("R_MICROMIPS_JALR", (MCFixupKind)Mips::fixup_MICROMIPS_JALR)
.Default(MCAsmBackend::getFixupKind(Name));
}
const MCFixupKindInfo &MipsAsmBackend::
getFixupKindInfo(MCFixupKind Kind) const {
const static MCFixupKindInfo LittleEndianInfos[] = {
// This table *must* be in same the order of fixup_* kinds in
// MipsFixupKinds.h.
//
// name offset bits flags
{ "fixup_Mips_16", 0, 16, 0 },
{ "fixup_Mips_32", 0, 32, 0 },
{ "fixup_Mips_REL32", 0, 32, 0 },
{ "fixup_Mips_26", 0, 26, 0 },
{ "fixup_Mips_HI16", 0, 16, 0 },
{ "fixup_Mips_LO16", 0, 16, 0 },
{ "fixup_Mips_GPREL16", 0, 16, 0 },
{ "fixup_Mips_LITERAL", 0, 16, 0 },
{ "fixup_Mips_GOT", 0, 16, 0 },
{ "fixup_Mips_PC16", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_Mips_CALL16", 0, 16, 0 },
{ "fixup_Mips_GPREL32", 0, 32, 0 },
{ "fixup_Mips_SHIFT5", 6, 5, 0 },
{ "fixup_Mips_SHIFT6", 6, 5, 0 },
{ "fixup_Mips_64", 0, 64, 0 },
{ "fixup_Mips_TLSGD", 0, 16, 0 },
{ "fixup_Mips_GOTTPREL", 0, 16, 0 },
{ "fixup_Mips_TPREL_HI", 0, 16, 0 },
{ "fixup_Mips_TPREL_LO", 0, 16, 0 },
{ "fixup_Mips_TLSLDM", 0, 16, 0 },
{ "fixup_Mips_DTPREL_HI", 0, 16, 0 },
{ "fixup_Mips_DTPREL_LO", 0, 16, 0 },
{ "fixup_Mips_Branch_PCRel", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_Mips_GPOFF_HI", 0, 16, 0 },
{ "fixup_MICROMIPS_GPOFF_HI",0, 16, 0 },
{ "fixup_Mips_GPOFF_LO", 0, 16, 0 },
{ "fixup_MICROMIPS_GPOFF_LO",0, 16, 0 },
{ "fixup_Mips_GOT_PAGE", 0, 16, 0 },
{ "fixup_Mips_GOT_OFST", 0, 16, 0 },
{ "fixup_Mips_GOT_DISP", 0, 16, 0 },
{ "fixup_Mips_HIGHER", 0, 16, 0 },
{ "fixup_MICROMIPS_HIGHER", 0, 16, 0 },
{ "fixup_Mips_HIGHEST", 0, 16, 0 },
{ "fixup_MICROMIPS_HIGHEST", 0, 16, 0 },
{ "fixup_Mips_GOT_HI16", 0, 16, 0 },
{ "fixup_Mips_GOT_LO16", 0, 16, 0 },
{ "fixup_Mips_CALL_HI16", 0, 16, 0 },
{ "fixup_Mips_CALL_LO16", 0, 16, 0 },
{ "fixup_Mips_PC18_S3", 0, 18, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MIPS_PC19_S2", 0, 19, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MIPS_PC21_S2", 0, 21, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MIPS_PC26_S2", 0, 26, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MIPS_PCHI16", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MIPS_PCLO16", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_26_S1", 0, 26, 0 },
{ "fixup_MICROMIPS_HI16", 0, 16, 0 },
{ "fixup_MICROMIPS_LO16", 0, 16, 0 },
{ "fixup_MICROMIPS_GOT16", 0, 16, 0 },
{ "fixup_MICROMIPS_PC7_S1", 0, 7, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_PC10_S1", 0, 10, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_PC16_S1", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_PC26_S1", 0, 26, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_PC19_S2", 0, 19, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_PC18_S3", 0, 18, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_PC21_S1", 0, 21, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_CALL16", 0, 16, 0 },
{ "fixup_MICROMIPS_GOT_DISP", 0, 16, 0 },
{ "fixup_MICROMIPS_GOT_PAGE", 0, 16, 0 },
{ "fixup_MICROMIPS_GOT_OFST", 0, 16, 0 },
{ "fixup_MICROMIPS_TLS_GD", 0, 16, 0 },
{ "fixup_MICROMIPS_TLS_LDM", 0, 16, 0 },
{ "fixup_MICROMIPS_TLS_DTPREL_HI16", 0, 16, 0 },
{ "fixup_MICROMIPS_TLS_DTPREL_LO16", 0, 16, 0 },
{ "fixup_MICROMIPS_GOTTPREL", 0, 16, 0 },
{ "fixup_MICROMIPS_TLS_TPREL_HI16", 0, 16, 0 },
{ "fixup_MICROMIPS_TLS_TPREL_LO16", 0, 16, 0 },
{ "fixup_Mips_SUB", 0, 64, 0 },
{ "fixup_MICROMIPS_SUB", 0, 64, 0 },
{ "fixup_Mips_JALR", 0, 32, 0 },
{ "fixup_MICROMIPS_JALR", 0, 32, 0 }
};
static_assert(array_lengthof(LittleEndianInfos) == Mips::NumTargetFixupKinds,
"Not all MIPS little endian fixup kinds added!");
const static MCFixupKindInfo BigEndianInfos[] = {
// This table *must* be in same the order of fixup_* kinds in
// MipsFixupKinds.h.
//
// name offset bits flags
{ "fixup_Mips_16", 16, 16, 0 },
{ "fixup_Mips_32", 0, 32, 0 },
{ "fixup_Mips_REL32", 0, 32, 0 },
{ "fixup_Mips_26", 6, 26, 0 },
{ "fixup_Mips_HI16", 16, 16, 0 },
{ "fixup_Mips_LO16", 16, 16, 0 },
{ "fixup_Mips_GPREL16", 16, 16, 0 },
{ "fixup_Mips_LITERAL", 16, 16, 0 },
{ "fixup_Mips_GOT", 16, 16, 0 },
{ "fixup_Mips_PC16", 16, 16, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_Mips_CALL16", 16, 16, 0 },
{ "fixup_Mips_GPREL32", 0, 32, 0 },
{ "fixup_Mips_SHIFT5", 21, 5, 0 },
{ "fixup_Mips_SHIFT6", 21, 5, 0 },
{ "fixup_Mips_64", 0, 64, 0 },
{ "fixup_Mips_TLSGD", 16, 16, 0 },
{ "fixup_Mips_GOTTPREL", 16, 16, 0 },
{ "fixup_Mips_TPREL_HI", 16, 16, 0 },
{ "fixup_Mips_TPREL_LO", 16, 16, 0 },
{ "fixup_Mips_TLSLDM", 16, 16, 0 },
{ "fixup_Mips_DTPREL_HI", 16, 16, 0 },
{ "fixup_Mips_DTPREL_LO", 16, 16, 0 },
{ "fixup_Mips_Branch_PCRel",16, 16, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_Mips_GPOFF_HI", 16, 16, 0 },
{ "fixup_MICROMIPS_GPOFF_HI", 16, 16, 0 },
{ "fixup_Mips_GPOFF_LO", 16, 16, 0 },
{ "fixup_MICROMIPS_GPOFF_LO", 16, 16, 0 },
{ "fixup_Mips_GOT_PAGE", 16, 16, 0 },
{ "fixup_Mips_GOT_OFST", 16, 16, 0 },
{ "fixup_Mips_GOT_DISP", 16, 16, 0 },
{ "fixup_Mips_HIGHER", 16, 16, 0 },
{ "fixup_MICROMIPS_HIGHER", 16, 16, 0 },
{ "fixup_Mips_HIGHEST", 16, 16, 0 },
{ "fixup_MICROMIPS_HIGHEST",16, 16, 0 },
{ "fixup_Mips_GOT_HI16", 16, 16, 0 },
{ "fixup_Mips_GOT_LO16", 16, 16, 0 },
{ "fixup_Mips_CALL_HI16", 16, 16, 0 },
{ "fixup_Mips_CALL_LO16", 16, 16, 0 },
{ "fixup_Mips_PC18_S3", 14, 18, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MIPS_PC19_S2", 13, 19, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MIPS_PC21_S2", 11, 21, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MIPS_PC26_S2", 6, 26, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MIPS_PCHI16", 16, 16, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MIPS_PCLO16", 16, 16, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_26_S1", 6, 26, 0 },
{ "fixup_MICROMIPS_HI16", 16, 16, 0 },
{ "fixup_MICROMIPS_LO16", 16, 16, 0 },
{ "fixup_MICROMIPS_GOT16", 16, 16, 0 },
{ "fixup_MICROMIPS_PC7_S1", 9, 7, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_PC10_S1", 6, 10, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_PC16_S1",16, 16, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_PC26_S1", 6, 26, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_PC19_S2",13, 19, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_PC18_S3",14, 18, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_PC21_S1",11, 21, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_MICROMIPS_CALL16", 16, 16, 0 },
{ "fixup_MICROMIPS_GOT_DISP", 16, 16, 0 },
{ "fixup_MICROMIPS_GOT_PAGE", 16, 16, 0 },
{ "fixup_MICROMIPS_GOT_OFST", 16, 16, 0 },
{ "fixup_MICROMIPS_TLS_GD", 16, 16, 0 },
{ "fixup_MICROMIPS_TLS_LDM", 16, 16, 0 },
{ "fixup_MICROMIPS_TLS_DTPREL_HI16", 16, 16, 0 },
{ "fixup_MICROMIPS_TLS_DTPREL_LO16", 16, 16, 0 },
{ "fixup_MICROMIPS_GOTTPREL", 16, 16, 0 },
{ "fixup_MICROMIPS_TLS_TPREL_HI16", 16, 16, 0 },
{ "fixup_MICROMIPS_TLS_TPREL_LO16", 16, 16, 0 },
{ "fixup_Mips_SUB", 0, 64, 0 },
{ "fixup_MICROMIPS_SUB", 0, 64, 0 },
{ "fixup_Mips_JALR", 0, 32, 0 },
{ "fixup_MICROMIPS_JALR", 0, 32, 0 }
};
static_assert(array_lengthof(BigEndianInfos) == Mips::NumTargetFixupKinds,
"Not all MIPS big endian fixup kinds added!");
if (Kind < FirstTargetFixupKind)
return MCAsmBackend::getFixupKindInfo(Kind);
assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
"Invalid kind!");
if (Endian == support::little)
return LittleEndianInfos[Kind - FirstTargetFixupKind];
return BigEndianInfos[Kind - FirstTargetFixupKind];
}
/// WriteNopData - Write an (optimal) nop sequence of Count bytes
/// to the given output. If the target cannot generate such a sequence,
/// it should return an error.
///
/// \return - True on success.
bool MipsAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
const MCSubtargetInfo *STI) const {
// Check for a less than instruction size number of bytes
// FIXME: 16 bit instructions are not handled yet here.
// We shouldn't be using a hard coded number for instruction size.
// If the count is not 4-byte aligned, we must be writing data into the text
// section (otherwise we have unaligned instructions, and thus have far
// bigger problems), so just write zeros instead.
OS.write_zeros(Count);
return true;
}
bool MipsAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
const MCFixup &Fixup,
const MCValue &Target) {
const unsigned FixupKind = Fixup.getKind();
switch (FixupKind) {
default:
return false;
// All these relocations require special processing
// at linking time. Delegate this work to a linker.
case Mips::fixup_Mips_CALL_HI16:
case Mips::fixup_Mips_CALL_LO16:
case Mips::fixup_Mips_CALL16:
case Mips::fixup_Mips_GOT:
case Mips::fixup_Mips_GOT_PAGE:
case Mips::fixup_Mips_GOT_OFST:
case Mips::fixup_Mips_GOT_DISP:
case Mips::fixup_Mips_GOT_HI16:
case Mips::fixup_Mips_GOT_LO16:
case Mips::fixup_Mips_GOTTPREL:
case Mips::fixup_Mips_DTPREL_HI:
case Mips::fixup_Mips_DTPREL_LO:
case Mips::fixup_Mips_TLSGD:
case Mips::fixup_Mips_TLSLDM:
case Mips::fixup_Mips_TPREL_HI:
case Mips::fixup_Mips_TPREL_LO:
case Mips::fixup_Mips_JALR:
case Mips::fixup_MICROMIPS_CALL16:
case Mips::fixup_MICROMIPS_GOT_DISP:
case Mips::fixup_MICROMIPS_GOT_PAGE:
case Mips::fixup_MICROMIPS_GOT_OFST:
case Mips::fixup_MICROMIPS_GOT16:
case Mips::fixup_MICROMIPS_GOTTPREL:
case Mips::fixup_MICROMIPS_TLS_DTPREL_HI16:
case Mips::fixup_MICROMIPS_TLS_DTPREL_LO16:
case Mips::fixup_MICROMIPS_TLS_GD:
case Mips::fixup_MICROMIPS_TLS_LDM:
case Mips::fixup_MICROMIPS_TLS_TPREL_HI16:
case Mips::fixup_MICROMIPS_TLS_TPREL_LO16:
case Mips::fixup_MICROMIPS_JALR:
return true;
}
}
bool MipsAsmBackend::isMicroMips(const MCSymbol *Sym) const {
if (const auto *ElfSym = dyn_cast<const MCSymbolELF>(Sym)) {
if (ElfSym->getOther() & ELF::STO_MIPS_MICROMIPS)
return true;
}
return false;
}
MCAsmBackend *llvm::createMipsAsmBackend(const Target &T,
const MCSubtargetInfo &STI,
const MCRegisterInfo &MRI,
const MCTargetOptions &Options) {
MipsABIInfo ABI = MipsABIInfo::computeTargetABI(STI.getTargetTriple(),
STI.getCPU(), Options);
return new MipsAsmBackend(T, MRI, STI.getTargetTriple(), STI.getCPU(),
ABI.IsN32());
}
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