/build/source/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp

Bug Summary

File:	build/source/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
Warning:	line 1072, column 67 The left operand of '-' is a garbage value
Annotated Source Code

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1//===-- ARMAsmBackend.cpp - ARM Assembler Backend -------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//

9#include "MCTargetDesc/ARMAsmBackend.h"
10#include "MCTargetDesc/ARMAddressingModes.h"
11#include "MCTargetDesc/ARMAsmBackendDarwin.h"
12#include "MCTargetDesc/ARMAsmBackendELF.h"
13#include "MCTargetDesc/ARMAsmBackendWinCOFF.h"
14#include "MCTargetDesc/ARMFixupKinds.h"
15#include "MCTargetDesc/ARMMCTargetDesc.h"
16#include "llvm/ADT/StringSwitch.h"
17#include "llvm/BinaryFormat/ELF.h"
18#include "llvm/BinaryFormat/MachO.h"
19#include "llvm/MC/MCAsmBackend.h"
20#include "llvm/MC/MCAsmLayout.h"
21#include "llvm/MC/MCAssembler.h"
22#include "llvm/MC/MCContext.h"
23#include "llvm/MC/MCDirectives.h"
24#include "llvm/MC/MCELFObjectWriter.h"
25#include "llvm/MC/MCExpr.h"
26#include "llvm/MC/MCFixupKindInfo.h"
27#include "llvm/MC/MCObjectWriter.h"
28#include "llvm/MC/MCRegisterInfo.h"
29#include "llvm/MC/MCSectionELF.h"
30#include "llvm/MC/MCSectionMachO.h"
31#include "llvm/MC/MCSubtargetInfo.h"
32#include "llvm/MC/MCValue.h"
33#include "llvm/Support/Debug.h"
34#include "llvm/Support/EndianStream.h"
35#include "llvm/Support/ErrorHandling.h"
36#include "llvm/Support/Format.h"
37#include "llvm/Support/raw_ostream.h"
38using namespace llvm;

40namespace {
41class ARMELFObjectWriter : public MCELFObjectTargetWriter {
42public:
ARMELFObjectWriter(uint8_t OSABI)
    : MCELFObjectTargetWriter(/*Is64Bit*/ false, OSABI, ELF::EM_ARM,
                              /*HasRelocationAddend*/ false) {}
46};
47} // end anonymous namespace

49std::optional<MCFixupKind> ARMAsmBackend::getFixupKind(StringRef Name) const {
return std::nullopt;
51}

53std::optional<MCFixupKind>
54ARMAsmBackendELF::getFixupKind(StringRef Name) const {
unsigned Type = llvm::StringSwitch<unsigned>(Name)
56#define ELF_RELOC(X, Y) .Case(#X, Y)
57#include "llvm/BinaryFormat/ELFRelocs/ARM.def"
58#undef ELF_RELOC
                    .Case("BFD_RELOC_NONE", ELF::R_ARM_NONE)
                    .Case("BFD_RELOC_8", ELF::R_ARM_ABS8)
                    .Case("BFD_RELOC_16", ELF::R_ARM_ABS16)
                    .Case("BFD_RELOC_32", ELF::R_ARM_ABS32)
                    .Default(-1u);
if (Type == -1u)
  return std::nullopt;
return static_cast<MCFixupKind>(FirstLiteralRelocationKind + Type);
67}

69const MCFixupKindInfo &ARMAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
unsigned IsPCRelConstant =
    MCFixupKindInfo::FKF_IsPCRel | MCFixupKindInfo::FKF_Constant;
const static MCFixupKindInfo InfosLE[ARM::NumTargetFixupKinds] = {
    // This table *must* be in the order that the fixup_* kinds are defined in
    // ARMFixupKinds.h.
    //
    // Name                      Offset (bits) Size (bits)     Flags
    {"fixup_arm_ldst_pcrel_12", 0, 32, IsPCRelConstant},
    {"fixup_t2_ldst_pcrel_12", 0, 32,
     IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_pcrel_10_unscaled", 0, 32, IsPCRelConstant},
    {"fixup_arm_pcrel_10", 0, 32, IsPCRelConstant},
    {"fixup_t2_pcrel_10", 0, 32,
     MCFixupKindInfo::FKF_IsPCRel |
         MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_pcrel_9", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_t2_pcrel_9", 0, 32,
     IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_ldst_abs_12", 0, 32, 0},
    {"fixup_thumb_adr_pcrel_10", 0, 8,
     IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_adr_pcrel_12", 0, 32, IsPCRelConstant},
    {"fixup_t2_adr_pcrel_12", 0, 32,
     IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_condbranch", 0, 24, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_uncondbranch", 0, 24, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_t2_condbranch", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_t2_uncondbranch", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_thumb_br", 0, 16, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_uncondbl", 0, 24, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_condbl", 0, 24, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_blx", 0, 24, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_thumb_bl", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_thumb_blx", 0, 32,
     MCFixupKindInfo::FKF_IsPCRel |
         MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_thumb_cb", 0, 16, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_thumb_cp", 0, 8,
     MCFixupKindInfo::FKF_IsPCRel |
         MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_thumb_bcc", 0, 8, MCFixupKindInfo::FKF_IsPCRel},
    // movw / movt: 16-bits immediate but scattered into two chunks 0 - 12, 16
    // - 19.
    {"fixup_arm_movt_hi16", 0, 20, 0},
    {"fixup_arm_movw_lo16", 0, 20, 0},
    {"fixup_t2_movt_hi16", 0, 20, 0},
    {"fixup_t2_movw_lo16", 0, 20, 0},
    {"fixup_arm_mod_imm", 0, 12, 0},
    {"fixup_t2_so_imm", 0, 26, 0},
    {"fixup_bf_branch", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_bf_target", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_bfl_target", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_bfc_target", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_bfcsel_else_target", 0, 32, 0},
    {"fixup_wls", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_le", 0, 32, MCFixupKindInfo::FKF_IsPCRel}};
const static MCFixupKindInfo InfosBE[ARM::NumTargetFixupKinds] = {
    // This table *must* be in the order that the fixup_* kinds are defined in
    // ARMFixupKinds.h.
    //
    // Name                      Offset (bits) Size (bits)     Flags
    {"fixup_arm_ldst_pcrel_12", 0, 32, IsPCRelConstant},
    {"fixup_t2_ldst_pcrel_12", 0, 32,
     IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_pcrel_10_unscaled", 0, 32, IsPCRelConstant},
    {"fixup_arm_pcrel_10", 0, 32, IsPCRelConstant},
    {"fixup_t2_pcrel_10", 0, 32,
     MCFixupKindInfo::FKF_IsPCRel |
         MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_pcrel_9", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_t2_pcrel_9", 0, 32,
     IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_ldst_abs_12", 0, 32, 0},
    {"fixup_thumb_adr_pcrel_10", 8, 8,
     IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_adr_pcrel_12", 0, 32, IsPCRelConstant},
    {"fixup_t2_adr_pcrel_12", 0, 32,
     IsPCRelConstant | MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_condbranch", 8, 24, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_uncondbranch", 8, 24, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_t2_condbranch", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_t2_uncondbranch", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_thumb_br", 0, 16, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_uncondbl", 8, 24, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_condbl", 8, 24, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_blx", 8, 24, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_thumb_bl", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_thumb_blx", 0, 32,
     MCFixupKindInfo::FKF_IsPCRel |
         MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_thumb_cb", 0, 16, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_arm_thumb_cp", 8, 8,
     MCFixupKindInfo::FKF_IsPCRel |
         MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
    {"fixup_arm_thumb_bcc", 8, 8, MCFixupKindInfo::FKF_IsPCRel},
    // movw / movt: 16-bits immediate but scattered into two chunks 0 - 12, 16
    // - 19.
    {"fixup_arm_movt_hi16", 12, 20, 0},
    {"fixup_arm_movw_lo16", 12, 20, 0},
    {"fixup_t2_movt_hi16", 12, 20, 0},
    {"fixup_t2_movw_lo16", 12, 20, 0},
    {"fixup_arm_mod_imm", 20, 12, 0},
    {"fixup_t2_so_imm", 26, 6, 0},
    {"fixup_bf_branch", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_bf_target", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_bfl_target", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_bfc_target", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_bfcsel_else_target", 0, 32, 0},
    {"fixup_wls", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
    {"fixup_le", 0, 32, MCFixupKindInfo::FKF_IsPCRel}};

// Fixup kinds from .reloc directive are like R_ARM_NONE. They do not require
// any extra processing.
if (Kind >= FirstLiteralRelocationKind)
  return MCAsmBackend::getFixupKindInfo(FK_NONE);

if (Kind < FirstTargetFixupKind)
  return MCAsmBackend::getFixupKindInfo(Kind);

assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&(static_cast <bool> (unsigned(Kind - FirstTargetFixupKind
) < getNumFixupKinds() && "Invalid kind!") ? void (
0) : __assert_fail ("unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() && \"Invalid kind!\""
, "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp", 190, __extension__
 __PRETTY_FUNCTION__))
       "Invalid kind!")(static_cast <bool> (unsigned(Kind - FirstTargetFixupKind
) < getNumFixupKinds() && "Invalid kind!") ? void (
0) : __assert_fail ("unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() && \"Invalid kind!\""
, "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp", 190, __extension__
 __PRETTY_FUNCTION__));
return (Endian == support::little ? InfosLE
                                  : InfosBE)[Kind - FirstTargetFixupKind];
193}

195void ARMAsmBackend::handleAssemblerFlag(MCAssemblerFlag Flag) {
switch (Flag) {
default:
  break;
case MCAF_Code16:
  setIsThumb(true);
  break;
case MCAF_Code32:
  setIsThumb(false);
  break;
}
206}

208unsigned ARMAsmBackend::getRelaxedOpcode(unsigned Op,
                                       const MCSubtargetInfo &STI) const {
bool HasThumb2 = STI.hasFeature(ARM::FeatureThumb2);
bool HasV8MBaselineOps = STI.hasFeature(ARM::HasV8MBaselineOps);

switch (Op) {
default:
  return Op;
case ARM::tBcc:
  return HasThumb2 ? (unsigned)ARM::t2Bcc : Op;
case ARM::tLDRpci:
  return HasThumb2 ? (unsigned)ARM::t2LDRpci : Op;
case ARM::tADR:
  return HasThumb2 ? (unsigned)ARM::t2ADR : Op;
case ARM::tB:
  return HasV8MBaselineOps ? (unsigned)ARM::t2B : Op;
case ARM::tCBZ:
  return ARM::tHINT;
case ARM::tCBNZ:
  return ARM::tHINT;
}
229}

231bool ARMAsmBackend::mayNeedRelaxation(const MCInst &Inst,
                                    const MCSubtargetInfo &STI) const {
if (getRelaxedOpcode(Inst.getOpcode(), STI) != Inst.getOpcode())
  return true;
return false;
236}

238static const char *checkPCRelOffset(uint64_t Value, int64_t Min, int64_t Max) {
int64_t Offset = int64_t(Value) - 4;
if (Offset < Min || Offset > Max)
  return "out of range pc-relative fixup value";
return nullptr;
243}

245const char *ARMAsmBackend::reasonForFixupRelaxation(const MCFixup &Fixup,
                                                  uint64_t Value) const {
switch (Fixup.getTargetKind()) {
case ARM::fixup_arm_thumb_br: {
  // Relaxing tB to t2B. tB has a signed 12-bit displacement with the
  // low bit being an implied zero. There's an implied +4 offset for the
  // branch, so we adjust the other way here to determine what's
  // encodable.
  //
  // Relax if the value is too big for a (signed) i8.
  int64_t Offset = int64_t(Value) - 4;
  if (Offset > 2046 || Offset < -2048)
    return "out of range pc-relative fixup value";
  break;
}
case ARM::fixup_arm_thumb_bcc: {
  // Relaxing tBcc to t2Bcc. tBcc has a signed 9-bit displacement with the
  // low bit being an implied zero. There's an implied +4 offset for the
  // branch, so we adjust the other way here to determine what's
  // encodable.
  //
  // Relax if the value is too big for a (signed) i8.
  int64_t Offset = int64_t(Value) - 4;
  if (Offset > 254 || Offset < -256)
    return "out of range pc-relative fixup value";
  break;
}
case ARM::fixup_thumb_adr_pcrel_10:
case ARM::fixup_arm_thumb_cp: {
  // If the immediate is negative, greater than 1020, or not a multiple
  // of four, the wide version of the instruction must be used.
  int64_t Offset = int64_t(Value) - 4;
  if (Offset & 3)
    return "misaligned pc-relative fixup value";
  else if (Offset > 1020 || Offset < 0)
    return "out of range pc-relative fixup value";
  break;
}
case ARM::fixup_arm_thumb_cb: {
  // If we have a Thumb CBZ or CBNZ instruction and its target is the next
  // instruction it is actually out of range for the instruction.
  // It will be changed to a NOP.
  int64_t Offset = (Value & ~1);
  if (Offset == 2)
    return "will be converted to nop";
  break;
}
case ARM::fixup_bf_branch:
  return checkPCRelOffset(Value, 0, 30);
case ARM::fixup_bf_target:
  return checkPCRelOffset(Value, -0x10000, +0xfffe);
case ARM::fixup_bfl_target:
  return checkPCRelOffset(Value, -0x40000, +0x3fffe);
case ARM::fixup_bfc_target:
  return checkPCRelOffset(Value, -0x1000, +0xffe);
case ARM::fixup_wls:
  return checkPCRelOffset(Value, 0, +0xffe);
case ARM::fixup_le:
  // The offset field in the LE and LETP instructions is an 11-bit
  // value shifted left by 2 (i.e. 0,2,4,...,4094), and it is
  // interpreted as a negative offset from the value read from pc,
  // i.e. from instruction_address+4.
  //
  // So an LE instruction can in principle address the instruction
  // immediately after itself, or (not very usefully) the address
  // half way through the 4-byte LE.
  return checkPCRelOffset(Value, -0xffe, 0);
case ARM::fixup_bfcsel_else_target: {
  if (Value != 2 && Value != 4)
    return "out of range label-relative fixup value";
  break;
}

default:
  llvm_unreachable("Unexpected fixup kind in reasonForFixupRelaxation()!")::llvm::llvm_unreachable_internal("Unexpected fixup kind in reasonForFixupRelaxation()!"
, "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp", 319);
}
return nullptr;
322}

324bool ARMAsmBackend::fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
                                       const MCRelaxableFragment *DF,
                                       const MCAsmLayout &Layout) const {
return reasonForFixupRelaxation(Fixup, Value);
328}

330void ARMAsmBackend::relaxInstruction(MCInst &Inst,
                                   const MCSubtargetInfo &STI) const {
unsigned RelaxedOp = getRelaxedOpcode(Inst.getOpcode(), STI);

// Return a diagnostic if we get here w/ a bogus instruction.
if (RelaxedOp == Inst.getOpcode()) {
  SmallString<256> Tmp;
  raw_svector_ostream OS(Tmp);
  Inst.dump_pretty(OS);
  OS << "\n";
  report_fatal_error("unexpected instruction to relax: " + OS.str());
}

// If we are changing Thumb CBZ or CBNZ instruction to a NOP, aka tHINT, we
// have to change the operands too.
if ((Inst.getOpcode() == ARM::tCBZ || Inst.getOpcode() == ARM::tCBNZ) &&
    RelaxedOp == ARM::tHINT) {
  MCInst Res;
  Res.setOpcode(RelaxedOp);
  Res.addOperand(MCOperand::createImm(0));
  Res.addOperand(MCOperand::createImm(14));
  Res.addOperand(MCOperand::createReg(0));
  Inst = std::move(Res);
  return;
}

// The rest of instructions we're relaxing have the same operands.
// We just need to update to the proper opcode.
Inst.setOpcode(RelaxedOp);
359}

361bool ARMAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
                               const MCSubtargetInfo *STI) const {
const uint16_t Thumb1_16bitNopEncoding = 0x46c0; // using MOV r8,r8
const uint16_t Thumb2_16bitNopEncoding = 0xbf00; // NOP
const uint32_t ARMv4_NopEncoding = 0xe1a00000;   // using MOV r0,r0
const uint32_t ARMv6T2_NopEncoding = 0xe320f000; // NOP
if (isThumb()) {
  const uint16_t nopEncoding =
      hasNOP(STI) ? Thumb2_16bitNopEncoding : Thumb1_16bitNopEncoding;
  uint64_t NumNops = Count / 2;
  for (uint64_t i = 0; i != NumNops; ++i)
    support::endian::write(OS, nopEncoding, Endian);
  if (Count & 1)
    OS << '\0';
  return true;
}
// ARM mode
const uint32_t nopEncoding =
    hasNOP(STI) ? ARMv6T2_NopEncoding : ARMv4_NopEncoding;
uint64_t NumNops = Count / 4;
for (uint64_t i = 0; i != NumNops; ++i)
  support::endian::write(OS, nopEncoding, Endian);
// FIXME: should this function return false when unable to write exactly
// 'Count' bytes with NOP encodings?
switch (Count % 4) {
default:
  break; // No leftover bytes to write
case 1:
  OS << '\0';
  break;
case 2:
  OS.write("\0\0", 2);
  break;
case 3:
  OS.write("\0\0\xa0", 3);
  break;
}

return true;
400}

402static uint32_t swapHalfWords(uint32_t Value, bool IsLittleEndian) {
if (IsLittleEndian) {
  // Note that the halfwords are stored high first and low second in thumb;
  // so we need to swap the fixup value here to map properly.
  uint32_t Swapped = (Value & 0xFFFF0000) >> 16;
  Swapped |= (Value & 0x0000FFFF) << 16;
  return Swapped;
} else
  return Value;
411}

413static uint32_t joinHalfWords(uint32_t FirstHalf, uint32_t SecondHalf,
                            bool IsLittleEndian) {
uint32_t Value;

if (IsLittleEndian) {
  Value = (SecondHalf & 0xFFFF) << 16;
  Value |= (FirstHalf & 0xFFFF);
} else {
  Value = (SecondHalf & 0xFFFF);
  Value |= (FirstHalf & 0xFFFF) << 16;
}

return Value;
426}

428unsigned ARMAsmBackend::adjustFixupValue(const MCAssembler &Asm,
                                       const MCFixup &Fixup,
                                       const MCValue &Target, uint64_t Value,
                                       bool IsResolved, MCContext &Ctx,
                                       const MCSubtargetInfo* STI) const {
unsigned Kind = Fixup.getKind();

// MachO tries to make .o files that look vaguely pre-linked, so for MOVW/MOVT
// and .word relocations they put the Thumb bit into the addend if possible.
// Other relocation types don't want this bit though (branches couldn't encode
// it if it *was* present, and no other relocations exist) and it can
// interfere with checking valid expressions.
if (const MCSymbolRefExpr *A = Target.getSymA()) {
  if (A->hasSubsectionsViaSymbols() && Asm.isThumbFunc(&A->getSymbol()) &&
      A->getSymbol().isExternal() &&
      (Kind == FK_Data_4 || Kind == ARM::fixup_arm_movw_lo16 ||
       Kind == ARM::fixup_arm_movt_hi16 || Kind == ARM::fixup_t2_movw_lo16 ||
       Kind == ARM::fixup_t2_movt_hi16))
    Value |= 1;
}

switch (Kind) {
default:
  return 0;
case FK_Data_1:
case FK_Data_2:
case FK_Data_4:
  return Value;
case FK_SecRel_2:
  return Value;
case FK_SecRel_4:
  return Value;
case ARM::fixup_arm_movt_hi16:
  assert(STI != nullptr)(static_cast <bool> (STI != nullptr) ? void (0) : __assert_fail
 ("STI != nullptr", "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp"
, 461, __extension__ __PRETTY_FUNCTION__));
  if (IsResolved || !STI->getTargetTriple().isOSBinFormatELF())
    Value >>= 16;
  [[fallthrough]];
case ARM::fixup_arm_movw_lo16: {
  unsigned Hi4 = (Value & 0xF000) >> 12;
  unsigned Lo12 = Value & 0x0FFF;
  // inst{19-16} = Hi4;
  // inst{11-0} = Lo12;
  Value = (Hi4 << 16) | (Lo12);
  return Value;
}
case ARM::fixup_t2_movt_hi16:
  assert(STI != nullptr)(static_cast <bool> (STI != nullptr) ? void (0) : __assert_fail
 ("STI != nullptr", "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp"
, 474, __extension__ __PRETTY_FUNCTION__));
  if (IsResolved || !STI->getTargetTriple().isOSBinFormatELF())
    Value >>= 16;
  [[fallthrough]];
case ARM::fixup_t2_movw_lo16: {
  unsigned Hi4 = (Value & 0xF000) >> 12;
  unsigned i = (Value & 0x800) >> 11;
  unsigned Mid3 = (Value & 0x700) >> 8;
  unsigned Lo8 = Value & 0x0FF;
  // inst{19-16} = Hi4;
  // inst{26} = i;
  // inst{14-12} = Mid3;
  // inst{7-0} = Lo8;
  Value = (Hi4 << 16) | (i << 26) | (Mid3 << 12) | (Lo8);
  return swapHalfWords(Value, Endian == support::little);
}
case ARM::fixup_arm_ldst_pcrel_12:
  // ARM PC-relative values are offset by 8.
  Value -= 4;
  [[fallthrough]];
case ARM::fixup_t2_ldst_pcrel_12:
  // Offset by 4, adjusted by two due to the half-word ordering of thumb.
  Value -= 4;
  [[fallthrough]];
case ARM::fixup_arm_ldst_abs_12: {
  bool isAdd = true;
  if ((int64_t)Value < 0) {
    Value = -Value;
    isAdd = false;
  }
  if (Value >= 4096) {
    Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value");
    return 0;
  }
  Value |= isAdd << 23;

  // Same addressing mode as fixup_arm_pcrel_10,
  // but with 16-bit halfwords swapped.
  if (Kind == ARM::fixup_t2_ldst_pcrel_12)
    return swapHalfWords(Value, Endian == support::little);

  return Value;
}
case ARM::fixup_arm_adr_pcrel_12: {
  // ARM PC-relative values are offset by 8.
  Value -= 8;
  unsigned opc = 4; // bits {24-21}. Default to add: 0b0100
  if ((int64_t)Value < 0) {
    Value = -Value;
    opc = 2; // 0b0010
  }
  if (ARM_AM::getSOImmVal(Value) == -1) {
    Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value");
    return 0;
  }
  // Encode the immediate and shift the opcode into place.
  return ARM_AM::getSOImmVal(Value) | (opc << 21);
}

case ARM::fixup_t2_adr_pcrel_12: {
  Value -= 4;
  unsigned opc = 0;
  if ((int64_t)Value < 0) {
    Value = -Value;
    opc = 5;
  }

  uint32_t out = (opc << 21);
  out |= (Value & 0x800) << 15;
  out |= (Value & 0x700) << 4;
  out |= (Value & 0x0FF);

  return swapHalfWords(out, Endian == support::little);
}

case ARM::fixup_arm_condbranch:
case ARM::fixup_arm_uncondbranch:
case ARM::fixup_arm_uncondbl:
case ARM::fixup_arm_condbl:
case ARM::fixup_arm_blx:
  // These values don't encode the low two bits since they're always zero.
  // Offset by 8 just as above.
  if (const MCSymbolRefExpr *SRE =
          dyn_cast<MCSymbolRefExpr>(Fixup.getValue()))
    if (SRE->getKind() == MCSymbolRefExpr::VK_TLSCALL)
      return 0;
  return 0xffffff & ((Value - 8) >> 2);
case ARM::fixup_t2_uncondbranch: {
  Value = Value - 4;
  if (!isInt<25>(Value)) {
    Ctx.reportError(Fixup.getLoc(), "Relocation out of range");
    return 0;
  }

  Value >>= 1; // Low bit is not encoded.

  uint32_t out = 0;
  bool I = Value & 0x800000;
  bool J1 = Value & 0x400000;
  bool J2 = Value & 0x200000;
  J1 ^= I;
  J2 ^= I;

  out |= I << 26;                 // S bit
  out |= !J1 << 13;               // J1 bit
  out |= !J2 << 11;               // J2 bit
  out |= (Value & 0x1FF800) << 5; // imm6 field
  out |= (Value & 0x0007FF);      // imm11 field

  return swapHalfWords(out, Endian == support::little);
}
case ARM::fixup_t2_condbranch: {
  Value = Value - 4;
  if (!isInt<21>(Value)) {
    Ctx.reportError(Fixup.getLoc(), "Relocation out of range");
    return 0;
  }

  Value >>= 1; // Low bit is not encoded.

  uint64_t out = 0;
  out |= (Value & 0x80000) << 7; // S bit
  out |= (Value & 0x40000) >> 7; // J2 bit
  out |= (Value & 0x20000) >> 4; // J1 bit
  out |= (Value & 0x1F800) << 5; // imm6 field
  out |= (Value & 0x007FF);      // imm11 field

  return swapHalfWords(out, Endian == support::little);
}
case ARM::fixup_arm_thumb_bl: {
  if (!isInt<25>(Value - 4) ||
      (!STI->hasFeature(ARM::FeatureThumb2) &&
       !STI->hasFeature(ARM::HasV8MBaselineOps) &&
       !STI->hasFeature(ARM::HasV6MOps) &&
       !isInt<23>(Value - 4))) {
    Ctx.reportError(Fixup.getLoc(), "Relocation out of range");
    return 0;
  }

  // The value doesn't encode the low bit (always zero) and is offset by
  // four. The 32-bit immediate value is encoded as
  //   imm32 = SignExtend(S:I1:I2:imm10:imm11:0)
  // where I1 = NOT(J1 ^ S) and I2 = NOT(J2 ^ S).
  // The value is encoded into disjoint bit positions in the destination
  // opcode. x = unchanged, I = immediate value bit, S = sign extension bit,
  // J = either J1 or J2 bit
  //
  //   BL:  xxxxxSIIIIIIIIII xxJxJIIIIIIIIIII
  //
  // Note that the halfwords are stored high first, low second; so we need
  // to transpose the fixup value here to map properly.
  uint32_t offset = (Value - 4) >> 1;
  uint32_t signBit = (offset & 0x800000) >> 23;
  uint32_t I1Bit = (offset & 0x400000) >> 22;
  uint32_t J1Bit = (I1Bit ^ 0x1) ^ signBit;
  uint32_t I2Bit = (offset & 0x200000) >> 21;
  uint32_t J2Bit = (I2Bit ^ 0x1) ^ signBit;
  uint32_t imm10Bits = (offset & 0x1FF800) >> 11;
  uint32_t imm11Bits = (offset & 0x000007FF);

  uint32_t FirstHalf = (((uint16_t)signBit << 10) | (uint16_t)imm10Bits);
  uint32_t SecondHalf = (((uint16_t)J1Bit << 13) | ((uint16_t)J2Bit << 11) |
                         (uint16_t)imm11Bits);
  return joinHalfWords(FirstHalf, SecondHalf, Endian == support::little);
}
case ARM::fixup_arm_thumb_blx: {
  // The value doesn't encode the low two bits (always zero) and is offset by
  // four (see fixup_arm_thumb_cp). The 32-bit immediate value is encoded as
  //   imm32 = SignExtend(S:I1:I2:imm10H:imm10L:00)
  // where I1 = NOT(J1 ^ S) and I2 = NOT(J2 ^ S).
  // The value is encoded into disjoint bit positions in the destination
  // opcode. x = unchanged, I = immediate value bit, S = sign extension bit,
  // J = either J1 or J2 bit, 0 = zero.
  //
  //   BLX: xxxxxSIIIIIIIIII xxJxJIIIIIIIIII0
  //
  // Note that the halfwords are stored high first, low second; so we need
  // to transpose the fixup value here to map properly.
  if (Value % 4 != 0) {
    Ctx.reportError(Fixup.getLoc(), "misaligned ARM call destination");
    return 0;
  }

  uint32_t offset = (Value - 4) >> 2;
  if (const MCSymbolRefExpr *SRE =
          dyn_cast<MCSymbolRefExpr>(Fixup.getValue()))
    if (SRE->getKind() == MCSymbolRefExpr::VK_TLSCALL)
      offset = 0;
  uint32_t signBit = (offset & 0x400000) >> 22;
  uint32_t I1Bit = (offset & 0x200000) >> 21;
  uint32_t J1Bit = (I1Bit ^ 0x1) ^ signBit;
  uint32_t I2Bit = (offset & 0x100000) >> 20;
  uint32_t J2Bit = (I2Bit ^ 0x1) ^ signBit;
  uint32_t imm10HBits = (offset & 0xFFC00) >> 10;
  uint32_t imm10LBits = (offset & 0x3FF);

  uint32_t FirstHalf = (((uint16_t)signBit << 10) | (uint16_t)imm10HBits);
  uint32_t SecondHalf = (((uint16_t)J1Bit << 13) | ((uint16_t)J2Bit << 11) |
                         ((uint16_t)imm10LBits) << 1);
  return joinHalfWords(FirstHalf, SecondHalf, Endian == support::little);
}
case ARM::fixup_thumb_adr_pcrel_10:
case ARM::fixup_arm_thumb_cp:
  // On CPUs supporting Thumb2, this will be relaxed to an ldr.w, otherwise we
  // could have an error on our hands.
  assert(STI != nullptr)(static_cast <bool> (STI != nullptr) ? void (0) : __assert_fail
 ("STI != nullptr", "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp"
, 679, __extension__ __PRETTY_FUNCTION__));
  if (!STI->hasFeature(ARM::FeatureThumb2) && IsResolved) {
    const char *FixupDiagnostic = reasonForFixupRelaxation(Fixup, Value);
    if (FixupDiagnostic) {
      Ctx.reportError(Fixup.getLoc(), FixupDiagnostic);
      return 0;
    }
  }
  // Offset by 4, and don't encode the low two bits.
  return ((Value - 4) >> 2) & 0xff;
case ARM::fixup_arm_thumb_cb: {
  // CB instructions can only branch to offsets in [4, 126] in multiples of 2
  // so ensure that the raw value LSB is zero and it lies in [2, 130].
  // An offset of 2 will be relaxed to a NOP.
  if ((int64_t)Value < 2 || Value > 0x82 || Value & 1) {
    Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value");
    return 0;
  }
  // Offset by 4 and don't encode the lower bit, which is always 0.
  // FIXME: diagnose if no Thumb2
  uint32_t Binary = (Value - 4) >> 1;
  return ((Binary & 0x20) << 4) | ((Binary & 0x1f) << 3);
}
case ARM::fixup_arm_thumb_br:
  // Offset by 4 and don't encode the lower bit, which is always 0.
  assert(STI != nullptr)(static_cast <bool> (STI != nullptr) ? void (0) : __assert_fail
 ("STI != nullptr", "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp"
, 704, __extension__ __PRETTY_FUNCTION__));
  if (!STI->hasFeature(ARM::FeatureThumb2) &&
      !STI->hasFeature(ARM::HasV8MBaselineOps)) {
    const char *FixupDiagnostic = reasonForFixupRelaxation(Fixup, Value);
    if (FixupDiagnostic) {
      Ctx.reportError(Fixup.getLoc(), FixupDiagnostic);
      return 0;
    }
  }
  return ((Value - 4) >> 1) & 0x7ff;
case ARM::fixup_arm_thumb_bcc:
  // Offset by 4 and don't encode the lower bit, which is always 0.
  assert(STI != nullptr)(static_cast <bool> (STI != nullptr) ? void (0) : __assert_fail
 ("STI != nullptr", "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp"
, 716, __extension__ __PRETTY_FUNCTION__));
  if (!STI->hasFeature(ARM::FeatureThumb2)) {
    const char *FixupDiagnostic = reasonForFixupRelaxation(Fixup, Value);
    if (FixupDiagnostic) {
      Ctx.reportError(Fixup.getLoc(), FixupDiagnostic);
      return 0;
    }
  }
  return ((Value - 4) >> 1) & 0xff;
case ARM::fixup_arm_pcrel_10_unscaled: {
  Value = Value - 8; // ARM fixups offset by an additional word and don't
                     // need to adjust for the half-word ordering.
  bool isAdd = true;
  if ((int64_t)Value < 0) {
    Value = -Value;
    isAdd = false;
  }
  // The value has the low 4 bits encoded in [3:0] and the high 4 in [11:8].
  if (Value >= 256) {
    Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value");
    return 0;
  }
  Value = (Value & 0xf) | ((Value & 0xf0) << 4);
  return Value | (isAdd << 23);
}
case ARM::fixup_arm_pcrel_10:
  Value = Value - 4; // ARM fixups offset by an additional word and don't
                     // need to adjust for the half-word ordering.
  [[fallthrough]];
case ARM::fixup_t2_pcrel_10: {
  // Offset by 4, adjusted by two due to the half-word ordering of thumb.
  Value = Value - 4;
  bool isAdd = true;
  if ((int64_t)Value < 0) {
    Value = -Value;
    isAdd = false;
  }
  // These values don't encode the low two bits since they're always zero.
  Value >>= 2;
  if (Value >= 256) {
    Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value");
    return 0;
  }
  Value |= isAdd << 23;

  // Same addressing mode as fixup_arm_pcrel_10, but with 16-bit halfwords
  // swapped.
  if (Kind == ARM::fixup_t2_pcrel_10)
    return swapHalfWords(Value, Endian == support::little);

  return Value;
}
case ARM::fixup_arm_pcrel_9:
  Value = Value - 4; // ARM fixups offset by an additional word and don't
                     // need to adjust for the half-word ordering.
  [[fallthrough]];
case ARM::fixup_t2_pcrel_9: {
  // Offset by 4, adjusted by two due to the half-word ordering of thumb.
  Value = Value - 4;
  bool isAdd = true;
  if ((int64_t)Value < 0) {
    Value = -Value;
    isAdd = false;
  }
  // These values don't encode the low bit since it's always zero.
  if (Value & 1) {
    Ctx.reportError(Fixup.getLoc(), "invalid value for this fixup");
    return 0;
  }
  Value >>= 1;
  if (Value >= 256) {
    Ctx.reportError(Fixup.getLoc(), "out of range pc-relative fixup value");
    return 0;
  }
  Value |= isAdd << 23;

  // Same addressing mode as fixup_arm_pcrel_9, but with 16-bit halfwords
  // swapped.
  if (Kind == ARM::fixup_t2_pcrel_9)
    return swapHalfWords(Value, Endian == support::little);

  return Value;
}
case ARM::fixup_arm_mod_imm:
  Value = ARM_AM::getSOImmVal(Value);
  if (Value >> 12) {
    Ctx.reportError(Fixup.getLoc(), "out of range immediate fixup value");
    return 0;
  }
  return Value;
case ARM::fixup_t2_so_imm: {
  Value = ARM_AM::getT2SOImmVal(Value);
  if ((int64_t)Value < 0) {
    Ctx.reportError(Fixup.getLoc(), "out of range immediate fixup value");
    return 0;
  }
  // Value will contain a 12-bit value broken up into a 4-bit shift in bits
  // 11:8 and the 8-bit immediate in 0:7. The instruction has the immediate
  // in 0:7. The 4-bit shift is split up into i:imm3 where i is placed at bit
  // 10 of the upper half-word and imm3 is placed at 14:12 of the lower
  // half-word.
  uint64_t EncValue = 0;
  EncValue |= (Value & 0x800) << 15;
  EncValue |= (Value & 0x700) << 4;
  EncValue |= (Value & 0xff);
  return swapHalfWords(EncValue, Endian == support::little);
}
case ARM::fixup_bf_branch: {
  const char *FixupDiagnostic = reasonForFixupRelaxation(Fixup, Value);
  if (FixupDiagnostic) {
    Ctx.reportError(Fixup.getLoc(), FixupDiagnostic);
    return 0;
  }
  uint32_t out = (((Value - 4) >> 1) & 0xf) << 23;
  return swapHalfWords(out, Endian == support::little);
}
case ARM::fixup_bf_target:
case ARM::fixup_bfl_target:
case ARM::fixup_bfc_target: {
  const char *FixupDiagnostic = reasonForFixupRelaxation(Fixup, Value);
  if (FixupDiagnostic) {
    Ctx.reportError(Fixup.getLoc(), FixupDiagnostic);
    return 0;
  }
  uint32_t out = 0;
  uint32_t HighBitMask = (Kind == ARM::fixup_bf_target ? 0xf800 :
                          Kind == ARM::fixup_bfl_target ? 0x3f800 : 0x800);
  out |= (((Value - 4) >> 1) & 0x1) << 11;
  out |= (((Value - 4) >> 1) & 0x7fe);
  out |= (((Value - 4) >> 1) & HighBitMask) << 5;
  return swapHalfWords(out, Endian == support::little);
}
case ARM::fixup_bfcsel_else_target: {
  // If this is a fixup of a branch future's else target then it should be a
  // constant MCExpr representing the distance between the branch targetted
  // and the instruction after that same branch.
  Value = Target.getConstant();

  const char *FixupDiagnostic = reasonForFixupRelaxation(Fixup, Value);
  if (FixupDiagnostic) {
    Ctx.reportError(Fixup.getLoc(), FixupDiagnostic);
    return 0;
  }
  uint32_t out = ((Value >> 2) & 1) << 17;
  return swapHalfWords(out, Endian == support::little);
}
case ARM::fixup_wls:
case ARM::fixup_le: {
  const char *FixupDiagnostic = reasonForFixupRelaxation(Fixup, Value);
  if (FixupDiagnostic) {
    Ctx.reportError(Fixup.getLoc(), FixupDiagnostic);
    return 0;
  }
  uint64_t real_value = Value - 4;
  uint32_t out = 0;
  if (Kind == ARM::fixup_le)
    real_value = -real_value;
  out |= ((real_value >> 1) & 0x1) << 11;
  out |= ((real_value >> 1) & 0x7fe);
  return swapHalfWords(out, Endian == support::little);
}
}
878}

880bool ARMAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
                                        const MCFixup &Fixup,
                                        const MCValue &Target) {
const MCSymbolRefExpr *A = Target.getSymA();
const MCSymbol *Sym = A ? &A->getSymbol() : nullptr;
const unsigned FixupKind = Fixup.getKind();
if (FixupKind >= FirstLiteralRelocationKind)
  return true;
if (FixupKind == ARM::fixup_arm_thumb_bl) {
  assert(Sym && "How did we resolve this?")(static_cast <bool> (Sym && "How did we resolve this?"
) ? void (0) : __assert_fail ("Sym && \"How did we resolve this?\""
, "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp", 889, __extension__
 __PRETTY_FUNCTION__));

  // If the symbol is external the linker will handle it.
  // FIXME: Should we handle it as an optimization?

  // If the symbol is out of range, produce a relocation and hope the
  // linker can handle it. GNU AS produces an error in this case.
  if (Sym->isExternal())
    return true;
}
// Create relocations for unconditional branches to function symbols with
// different execution mode in ELF binaries.
if (Sym && Sym->isELF()) {
  unsigned Type = cast<MCSymbolELF>(Sym)->getType();
  if ((Type == ELF::STT_FUNC || Type == ELF::STT_GNU_IFUNC)) {
    if (Asm.isThumbFunc(Sym) && (FixupKind == ARM::fixup_arm_uncondbranch))
      return true;
    if (!Asm.isThumbFunc(Sym) && (FixupKind == ARM::fixup_arm_thumb_br ||
                                  FixupKind == ARM::fixup_arm_thumb_bl ||
                                  FixupKind == ARM::fixup_t2_condbranch ||
                                  FixupKind == ARM::fixup_t2_uncondbranch))
      return true;
  }
}
// We must always generate a relocation for BL/BLX instructions if we have
// a symbol to reference, as the linker relies on knowing the destination
// symbol's thumb-ness to get interworking right.
if (A && (FixupKind == ARM::fixup_arm_thumb_blx ||
          FixupKind == ARM::fixup_arm_blx ||
          FixupKind == ARM::fixup_arm_uncondbl ||
          FixupKind == ARM::fixup_arm_condbl))
  return true;
return false;
922}

924/// getFixupKindNumBytes - The number of bytes the fixup may change.
925static unsigned getFixupKindNumBytes(unsigned Kind) {
switch (Kind) {
default:
  llvm_unreachable("Unknown fixup kind!")::llvm::llvm_unreachable_internal("Unknown fixup kind!", "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp"
, 928);

case FK_Data_1:
case ARM::fixup_arm_thumb_bcc:
case ARM::fixup_arm_thumb_cp:
case ARM::fixup_thumb_adr_pcrel_10:
  return 1;

case FK_Data_2:
case ARM::fixup_arm_thumb_br:
case ARM::fixup_arm_thumb_cb:
case ARM::fixup_arm_mod_imm:
  return 2;

case ARM::fixup_arm_pcrel_10_unscaled:
case ARM::fixup_arm_ldst_pcrel_12:
case ARM::fixup_arm_pcrel_10:
case ARM::fixup_arm_pcrel_9:
case ARM::fixup_arm_ldst_abs_12:
case ARM::fixup_arm_adr_pcrel_12:
case ARM::fixup_arm_uncondbl:
case ARM::fixup_arm_condbl:
case ARM::fixup_arm_blx:
case ARM::fixup_arm_condbranch:
case ARM::fixup_arm_uncondbranch:
  return 3;

case FK_Data_4:
case ARM::fixup_t2_ldst_pcrel_12:
case ARM::fixup_t2_condbranch:
case ARM::fixup_t2_uncondbranch:
case ARM::fixup_t2_pcrel_10:
case ARM::fixup_t2_pcrel_9:
case ARM::fixup_t2_adr_pcrel_12:
case ARM::fixup_arm_thumb_bl:
case ARM::fixup_arm_thumb_blx:
case ARM::fixup_arm_movt_hi16:
case ARM::fixup_arm_movw_lo16:
case ARM::fixup_t2_movt_hi16:
case ARM::fixup_t2_movw_lo16:
case ARM::fixup_t2_so_imm:
case ARM::fixup_bf_branch:
case ARM::fixup_bf_target:
case ARM::fixup_bfl_target:
case ARM::fixup_bfc_target:
case ARM::fixup_bfcsel_else_target:
case ARM::fixup_wls:
case ARM::fixup_le:
  return 4;

case FK_SecRel_2:
  return 2;
case FK_SecRel_4:
  return 4;
}
983}

985/// getFixupKindContainerSizeBytes - The number of bytes of the
986/// container involved in big endian.
987static unsigned getFixupKindContainerSizeBytes(unsigned Kind) {
switch (Kind) {
default:
  llvm_unreachable("Unknown fixup kind!")::llvm::llvm_unreachable_internal("Unknown fixup kind!", "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp"
, 990);

case FK_Data_1:
  return 1;
case FK_Data_2:
  return 2;
case FK_Data_4:
  return 4;

case ARM::fixup_arm_thumb_bcc:
case ARM::fixup_arm_thumb_cp:
case ARM::fixup_thumb_adr_pcrel_10:
case ARM::fixup_arm_thumb_br:
case ARM::fixup_arm_thumb_cb:
  // Instruction size is 2 bytes.
  return 2;

case ARM::fixup_arm_pcrel_10_unscaled:
case ARM::fixup_arm_ldst_pcrel_12:
case ARM::fixup_arm_pcrel_10:
case ARM::fixup_arm_pcrel_9:
case ARM::fixup_arm_adr_pcrel_12:
case ARM::fixup_arm_uncondbl:
case ARM::fixup_arm_condbl:
case ARM::fixup_arm_blx:
case ARM::fixup_arm_condbranch:
case ARM::fixup_arm_uncondbranch:
case ARM::fixup_t2_ldst_pcrel_12:
case ARM::fixup_t2_condbranch:
case ARM::fixup_t2_uncondbranch:
case ARM::fixup_t2_pcrel_10:
case ARM::fixup_t2_pcrel_9:
case ARM::fixup_t2_adr_pcrel_12:
case ARM::fixup_arm_thumb_bl:
case ARM::fixup_arm_thumb_blx:
case ARM::fixup_arm_movt_hi16:
case ARM::fixup_arm_movw_lo16:
case ARM::fixup_t2_movt_hi16:
case ARM::fixup_t2_movw_lo16:
case ARM::fixup_arm_mod_imm:
case ARM::fixup_t2_so_imm:
case ARM::fixup_bf_branch:
case ARM::fixup_bf_target:
case ARM::fixup_bfl_target:
case ARM::fixup_bfc_target:
case ARM::fixup_bfcsel_else_target:
case ARM::fixup_wls:
case ARM::fixup_le:
  // Instruction size is 4 bytes.
  return 4;
}
1041}

1043void ARMAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
                             const MCValue &Target,
                             MutableArrayRef<char> Data, uint64_t Value,
                             bool IsResolved,
                             const MCSubtargetInfo* STI) const {
unsigned Kind = Fixup.getKind();
if (Kind >= FirstLiteralRelocationKind)
1
Assuming 'Kind' is < FirstLiteralRelocationKind→
2
←
Taking false branch→
  return;
MCContext &Ctx = Asm.getContext();
Value = adjustFixupValue(Asm, Fixup, Target, Value, IsResolved, Ctx, STI);
if (!Value)
3
←
Assuming 'Value' is not equal to 0→
4
←
Taking false branch→
  return; // Doesn't change encoding.
const unsigned NumBytes = getFixupKindNumBytes(Kind);

unsigned Offset = Fixup.getOffset();
assert(Offset + NumBytes <= Data.size() && "Invalid fixup offset!")(static_cast <bool> (Offset + NumBytes <= Data.size(
) && "Invalid fixup offset!") ? void (0) : __assert_fail
 ("Offset + NumBytes <= Data.size() && \"Invalid fixup offset!\""
, "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp", 1058,
 __extension__ __PRETTY_FUNCTION__));
5
←
Assuming the condition is true→
6
←
'?' condition is true→

// Used to point to big endian bytes.
unsigned FullSizeBytes;
7
←
'FullSizeBytes' declared without an initial value→
if (Endian == support::big) {
8
←
Assuming field 'Endian' is not equal to big→
9
←
Taking false branch→
  FullSizeBytes = getFixupKindContainerSizeBytes(Kind);
  assert((Offset + FullSizeBytes) <= Data.size() && "Invalid fixup size!")(static_cast <bool> ((Offset + FullSizeBytes) <= Data
.size() && "Invalid fixup size!") ? void (0) : __assert_fail
 ("(Offset + FullSizeBytes) <= Data.size() && \"Invalid fixup size!\""
, "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp", 1064,
 __extension__ __PRETTY_FUNCTION__));
  assert(NumBytes <= FullSizeBytes && "Invalid fixup size!")(static_cast <bool> (NumBytes <= FullSizeBytes &&
 "Invalid fixup size!") ? void (0) : __assert_fail ("NumBytes <= FullSizeBytes && \"Invalid fixup size!\""
, "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp", 1065,
 __extension__ __PRETTY_FUNCTION__));
}

// For each byte of the fragment that the fixup touches, mask in the bits from
// the fixup value. The Value has been "split up" into the appropriate
// bitfields above.
for (unsigned i = 0; i != NumBytes; ++i) {
  unsigned Idx = Endian == support::little ? i : (FullSizeBytes - 1 - i);
10
←
Loop condition is true.  Entering loop body→
11
←
Assuming field 'Endian' is not equal to little→
12
←
'?' condition is false→
13
←
The left operand of '-' is a garbage value
  Data[Offset + Idx] |= uint8_t((Value >> (i * 8)) & 0xff);
}
1075}

1077namespace CU {

1079/// Compact unwind encoding values.
1080enum CompactUnwindEncodings {
UNWIND_ARM_MODE_MASK                         = 0x0F000000,
UNWIND_ARM_MODE_FRAME                        = 0x01000000,
UNWIND_ARM_MODE_FRAME_D                      = 0x02000000,
UNWIND_ARM_MODE_DWARF                        = 0x04000000,

UNWIND_ARM_FRAME_STACK_ADJUST_MASK           = 0x00C00000,

UNWIND_ARM_FRAME_FIRST_PUSH_R4               = 0x00000001,
UNWIND_ARM_FRAME_FIRST_PUSH_R5               = 0x00000002,
UNWIND_ARM_FRAME_FIRST_PUSH_R6               = 0x00000004,

UNWIND_ARM_FRAME_SECOND_PUSH_R8              = 0x00000008,
UNWIND_ARM_FRAME_SECOND_PUSH_R9              = 0x00000010,
UNWIND_ARM_FRAME_SECOND_PUSH_R10             = 0x00000020,
UNWIND_ARM_FRAME_SECOND_PUSH_R11             = 0x00000040,
UNWIND_ARM_FRAME_SECOND_PUSH_R12             = 0x00000080,

UNWIND_ARM_FRAME_D_REG_COUNT_MASK            = 0x00000F00,

UNWIND_ARM_DWARF_SECTION_OFFSET              = 0x00FFFFFF
1101};

1103} // end CU namespace

1105/// Generate compact unwind encoding for the function based on the CFI
1106/// instructions. If the CFI instructions describe a frame that cannot be
1107/// encoded in compact unwind, the method returns UNWIND_ARM_MODE_DWARF which
1108/// tells the runtime to fallback and unwind using dwarf.
1109uint32_t ARMAsmBackendDarwin::generateCompactUnwindEncoding(
  ArrayRef<MCCFIInstruction> Instrs) const {
DEBUG_WITH_TYPE("compact-unwind", llvm::dbgs() << "generateCU()\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "generateCU()\n";
 } } while (false);
// Only armv7k uses CFI based unwinding.
if (Subtype != MachO::CPU_SUBTYPE_ARM_V7K)
  return 0;
// No .cfi directives means no frame.
if (Instrs.empty())
  return 0;
// Start off assuming CFA is at SP+0.
unsigned CFARegister = ARM::SP;
int CFARegisterOffset = 0;
// Mark savable registers as initially unsaved
DenseMap<unsigned, int> RegOffsets;
int FloatRegCount = 0;
// Process each .cfi directive and build up compact unwind info.
for (const MCCFIInstruction &Inst : Instrs) {
  unsigned Reg;
  switch (Inst.getOperation()) {
  case MCCFIInstruction::OpDefCfa: // DW_CFA_def_cfa
    CFARegisterOffset = Inst.getOffset();
    CFARegister = *MRI.getLLVMRegNum(Inst.getRegister(), true);
    break;
  case MCCFIInstruction::OpDefCfaOffset: // DW_CFA_def_cfa_offset
    CFARegisterOffset = Inst.getOffset();
    break;
  case MCCFIInstruction::OpDefCfaRegister: // DW_CFA_def_cfa_register
    CFARegister = *MRI.getLLVMRegNum(Inst.getRegister(), true);
    break;
  case MCCFIInstruction::OpOffset: // DW_CFA_offset
    Reg = *MRI.getLLVMRegNum(Inst.getRegister(), true);
    if (ARMMCRegisterClasses[ARM::GPRRegClassID].contains(Reg))
      RegOffsets[Reg] = Inst.getOffset();
    else if (ARMMCRegisterClasses[ARM::DPRRegClassID].contains(Reg)) {
      RegOffsets[Reg] = Inst.getOffset();
      ++FloatRegCount;
    } else {
      DEBUG_WITH_TYPE("compact-unwind",do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << ".cfi_offset on unknown register="
 << Inst.getRegister() << "\n"; } } while (false)
                      llvm::dbgs() << ".cfi_offset on unknown register="do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << ".cfi_offset on unknown register="
 << Inst.getRegister() << "\n"; } } while (false)
                                   << Inst.getRegister() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << ".cfi_offset on unknown register="
 << Inst.getRegister() << "\n"; } } while (false);
      return CU::UNWIND_ARM_MODE_DWARF;
    }
    break;
  case MCCFIInstruction::OpRelOffset: // DW_CFA_advance_loc
    // Ignore
    break;
  default:
    // Directive not convertable to compact unwind, bail out.
    DEBUG_WITH_TYPE("compact-unwind",do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "CFI directive not compatible with compact "
 "unwind encoding, opcode=" << Inst.getOperation() <<
 "\n"; } } while (false)
                    llvm::dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "CFI directive not compatible with compact "
 "unwind encoding, opcode=" << Inst.getOperation() <<
 "\n"; } } while (false)
                        << "CFI directive not compatible with compact "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "CFI directive not compatible with compact "
 "unwind encoding, opcode=" << Inst.getOperation() <<
 "\n"; } } while (false)
                           "unwind encoding, opcode=" << Inst.getOperation()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "CFI directive not compatible with compact "
 "unwind encoding, opcode=" << Inst.getOperation() <<
 "\n"; } } while (false)
                        << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "CFI directive not compatible with compact "
 "unwind encoding, opcode=" << Inst.getOperation() <<
 "\n"; } } while (false);
    return CU::UNWIND_ARM_MODE_DWARF;
    break;
  }
}

// If no frame set up, return no unwind info.
if ((CFARegister == ARM::SP) && (CFARegisterOffset == 0))
  return 0;

// Verify standard frame (lr/r7) was used.
if (CFARegister != ARM::R7) {
  DEBUG_WITH_TYPE("compact-unwind", llvm::dbgs() << "frame register is "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "frame register is "
 << CFARegister << " instead of r7\n"; } } while (
false)
                                                 << CFARegisterdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "frame register is "
 << CFARegister << " instead of r7\n"; } } while (
false)
                                                 << " instead of r7\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "frame register is "
 << CFARegister << " instead of r7\n"; } } while (
false);
  return CU::UNWIND_ARM_MODE_DWARF;
}
int StackAdjust = CFARegisterOffset - 8;
if (RegOffsets.lookup(ARM::LR) != (-4 - StackAdjust)) {
  DEBUG_WITH_TYPE("compact-unwind",do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "LR not saved as standard frame, StackAdjust="
 << StackAdjust << ", CFARegisterOffset=" <<
 CFARegisterOffset << ", lr save at offset=" << RegOffsets
[14] << "\n"; } } while (false)
                  llvm::dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "LR not saved as standard frame, StackAdjust="
 << StackAdjust << ", CFARegisterOffset=" <<
 CFARegisterOffset << ", lr save at offset=" << RegOffsets
[14] << "\n"; } } while (false)
                      << "LR not saved as standard frame, StackAdjust="do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "LR not saved as standard frame, StackAdjust="
 << StackAdjust << ", CFARegisterOffset=" <<
 CFARegisterOffset << ", lr save at offset=" << RegOffsets
[14] << "\n"; } } while (false)
                      << StackAdjustdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "LR not saved as standard frame, StackAdjust="
 << StackAdjust << ", CFARegisterOffset=" <<
 CFARegisterOffset << ", lr save at offset=" << RegOffsets
[14] << "\n"; } } while (false)
                      << ", CFARegisterOffset=" << CFARegisterOffsetdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "LR not saved as standard frame, StackAdjust="
 << StackAdjust << ", CFARegisterOffset=" <<
 CFARegisterOffset << ", lr save at offset=" << RegOffsets
[14] << "\n"; } } while (false)
                      << ", lr save at offset=" << RegOffsets[14] << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "LR not saved as standard frame, StackAdjust="
 << StackAdjust << ", CFARegisterOffset=" <<
 CFARegisterOffset << ", lr save at offset=" << RegOffsets
[14] << "\n"; } } while (false);
  return CU::UNWIND_ARM_MODE_DWARF;
}
if (RegOffsets.lookup(ARM::R7) != (-8 - StackAdjust)) {
  DEBUG_WITH_TYPE("compact-unwind",do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "r7 not saved as standard frame\n"
; } } while (false)
                  llvm::dbgs() << "r7 not saved as standard frame\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "r7 not saved as standard frame\n"
; } } while (false);
  return CU::UNWIND_ARM_MODE_DWARF;
}
uint32_t CompactUnwindEncoding = CU::UNWIND_ARM_MODE_FRAME;

// If var-args are used, there may be a stack adjust required.
switch (StackAdjust) {
case 0:
  break;
case 4:
  CompactUnwindEncoding |= 0x00400000;
  break;
case 8:
  CompactUnwindEncoding |= 0x00800000;
  break;
case 12:
  CompactUnwindEncoding |= 0x00C00000;
  break;
default:
  DEBUG_WITH_TYPE("compact-unwind", llvm::dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << ".cfi_def_cfa stack adjust ("
 << StackAdjust << ") out of range\n"; } } while (
false)
                                        << ".cfi_def_cfa stack adjust ("do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << ".cfi_def_cfa stack adjust ("
 << StackAdjust << ") out of range\n"; } } while (
false)
                                        << StackAdjust << ") out of range\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << ".cfi_def_cfa stack adjust ("
 << StackAdjust << ") out of range\n"; } } while (
false);
  return CU::UNWIND_ARM_MODE_DWARF;
}

// If r6 is saved, it must be right below r7.
static struct {
  unsigned Reg;
  unsigned Encoding;
} GPRCSRegs[] = {{ARM::R6, CU::UNWIND_ARM_FRAME_FIRST_PUSH_R6},
                 {ARM::R5, CU::UNWIND_ARM_FRAME_FIRST_PUSH_R5},
                 {ARM::R4, CU::UNWIND_ARM_FRAME_FIRST_PUSH_R4},
                 {ARM::R12, CU::UNWIND_ARM_FRAME_SECOND_PUSH_R12},
                 {ARM::R11, CU::UNWIND_ARM_FRAME_SECOND_PUSH_R11},
                 {ARM::R10, CU::UNWIND_ARM_FRAME_SECOND_PUSH_R10},
                 {ARM::R9, CU::UNWIND_ARM_FRAME_SECOND_PUSH_R9},
                 {ARM::R8, CU::UNWIND_ARM_FRAME_SECOND_PUSH_R8}};

int CurOffset = -8 - StackAdjust;
for (auto CSReg : GPRCSRegs) {
  auto Offset = RegOffsets.find(CSReg.Reg);
  if (Offset == RegOffsets.end())
    continue;

  int RegOffset = Offset->second;
  if (RegOffset != CurOffset - 4) {
    DEBUG_WITH_TYPE("compact-unwind",do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << MRI.getName(CSReg
.Reg) << " saved at " << RegOffset << " but only supported at "
 << CurOffset << "\n"; } } while (false)
                    llvm::dbgs() << MRI.getName(CSReg.Reg) << " saved at "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << MRI.getName(CSReg
.Reg) << " saved at " << RegOffset << " but only supported at "
 << CurOffset << "\n"; } } while (false)
                                 << RegOffset << " but only supported at "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << MRI.getName(CSReg
.Reg) << " saved at " << RegOffset << " but only supported at "
 << CurOffset << "\n"; } } while (false)
                                 << CurOffset << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << MRI.getName(CSReg
.Reg) << " saved at " << RegOffset << " but only supported at "
 << CurOffset << "\n"; } } while (false);
    return CU::UNWIND_ARM_MODE_DWARF;
  }
  CompactUnwindEncoding |= CSReg.Encoding;
  CurOffset -= 4;
}

// If no floats saved, we are done.
if (FloatRegCount == 0)
  return CompactUnwindEncoding;

// Switch mode to include D register saving.
CompactUnwindEncoding &= ~CU::UNWIND_ARM_MODE_MASK;
CompactUnwindEncoding |= CU::UNWIND_ARM_MODE_FRAME_D;

// FIXME: supporting more than 4 saved D-registers compactly would be trivial,
// but needs coordination with the linker and libunwind.
if (FloatRegCount > 4) {
  DEBUG_WITH_TYPE("compact-unwind",do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "unsupported number of D registers saved ("
 << FloatRegCount << ")\n"; } } while (false)
                  llvm::dbgs() << "unsupported number of D registers saved ("do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "unsupported number of D registers saved ("
 << FloatRegCount << ")\n"; } } while (false)
                               << FloatRegCount << ")\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << "unsupported number of D registers saved ("
 << FloatRegCount << ")\n"; } } while (false);
    return CU::UNWIND_ARM_MODE_DWARF;
}

// Floating point registers must either be saved sequentially, or we defer to
// DWARF. No gaps allowed here so check that each saved d-register is
// precisely where it should be.
static unsigned FPRCSRegs[] = { ARM::D8, ARM::D10, ARM::D12, ARM::D14 };
for (int Idx = FloatRegCount - 1; Idx >= 0; --Idx) {
  auto Offset = RegOffsets.find(FPRCSRegs[Idx]);
  if (Offset == RegOffsets.end()) {
    DEBUG_WITH_TYPE("compact-unwind",do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << FloatRegCount <<
 " D-regs saved, but " << MRI.getName(FPRCSRegs[Idx]) <<
 " not saved\n"; } } while (false)
                    llvm::dbgs() << FloatRegCount << " D-regs saved, but "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << FloatRegCount <<
 " D-regs saved, but " << MRI.getName(FPRCSRegs[Idx]) <<
 " not saved\n"; } } while (false)
                                 << MRI.getName(FPRCSRegs[Idx])do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << FloatRegCount <<
 " D-regs saved, but " << MRI.getName(FPRCSRegs[Idx]) <<
 " not saved\n"; } } while (false)
                                 << " not saved\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << FloatRegCount <<
 " D-regs saved, but " << MRI.getName(FPRCSRegs[Idx]) <<
 " not saved\n"; } } while (false);
    return CU::UNWIND_ARM_MODE_DWARF;
  } else if (Offset->second != CurOffset - 8) {
    DEBUG_WITH_TYPE("compact-unwind",do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << FloatRegCount <<
 " D-regs saved, but " << MRI.getName(FPRCSRegs[Idx]) <<
 " saved at " << Offset->second << ", expected at "
 << CurOffset - 8 << "\n"; } } while (false)
                    llvm::dbgs() << FloatRegCount << " D-regs saved, but "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << FloatRegCount <<
 " D-regs saved, but " << MRI.getName(FPRCSRegs[Idx]) <<
 " saved at " << Offset->second << ", expected at "
 << CurOffset - 8 << "\n"; } } while (false)
                                 << MRI.getName(FPRCSRegs[Idx])do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << FloatRegCount <<
 " D-regs saved, but " << MRI.getName(FPRCSRegs[Idx]) <<
 " saved at " << Offset->second << ", expected at "
 << CurOffset - 8 << "\n"; } } while (false)
                                 << " saved at " << Offset->seconddo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << FloatRegCount <<
 " D-regs saved, but " << MRI.getName(FPRCSRegs[Idx]) <<
 " saved at " << Offset->second << ", expected at "
 << CurOffset - 8 << "\n"; } } while (false)
                                 << ", expected at " << CurOffset - 8do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << FloatRegCount <<
 " D-regs saved, but " << MRI.getName(FPRCSRegs[Idx]) <<
 " saved at " << Offset->second << ", expected at "
 << CurOffset - 8 << "\n"; } } while (false)
                                 << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("compact-unwind")) { llvm::dbgs() << FloatRegCount <<
 " D-regs saved, but " << MRI.getName(FPRCSRegs[Idx]) <<
 " saved at " << Offset->second << ", expected at "
 << CurOffset - 8 << "\n"; } } while (false);
    return CU::UNWIND_ARM_MODE_DWARF;
  }
  CurOffset -= 8;
}

return CompactUnwindEncoding | ((FloatRegCount - 1) << 8);
1288}

1290static MCAsmBackend *createARMAsmBackend(const Target &T,
                                       const MCSubtargetInfo &STI,
                                       const MCRegisterInfo &MRI,
                                       const MCTargetOptions &Options,
                                       support::endianness Endian) {
const Triple &TheTriple = STI.getTargetTriple();
switch (TheTriple.getObjectFormat()) {
default:
  llvm_unreachable("unsupported object format")::llvm::llvm_unreachable_internal("unsupported object format"
, "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp", 1298);
case Triple::MachO:
  return new ARMAsmBackendDarwin(T, STI, MRI);
case Triple::COFF:
  assert(TheTriple.isOSWindows() && "non-Windows ARM COFF is not supported")(static_cast <bool> (TheTriple.isOSWindows() &&
 "non-Windows ARM COFF is not supported") ? void (0) : __assert_fail
 ("TheTriple.isOSWindows() && \"non-Windows ARM COFF is not supported\""
, "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp", 1302,
 __extension__ __PRETTY_FUNCTION__));
  return new ARMAsmBackendWinCOFF(T, STI.getTargetTriple().isThumb());
case Triple::ELF:
  assert(TheTriple.isOSBinFormatELF() && "using ELF for non-ELF target")(static_cast <bool> (TheTriple.isOSBinFormatELF() &&
 "using ELF for non-ELF target") ? void (0) : __assert_fail (
"TheTriple.isOSBinFormatELF() && \"using ELF for non-ELF target\""
, "llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp", 1305,
 __extension__ __PRETTY_FUNCTION__));
  uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TheTriple.getOS());
  return new ARMAsmBackendELF(T, STI.getTargetTriple().isThumb(), OSABI,
                              Endian);
}
1310}

1312MCAsmBackend *llvm::createARMLEAsmBackend(const Target &T,
                                        const MCSubtargetInfo &STI,
                                        const MCRegisterInfo &MRI,
                                        const MCTargetOptions &Options) {
return createARMAsmBackend(T, STI, MRI, Options, support::little);
1317}

1319MCAsmBackend *llvm::createARMBEAsmBackend(const Target &T,
                                        const MCSubtargetInfo &STI,
                                        const MCRegisterInfo &MRI,
                                        const MCTargetOptions &Options) {
return createARMAsmBackend(T, STI, MRI, Options, support::big);
1324}