diff options
Diffstat (limited to 'lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp')
| -rw-r--r-- | lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp | 1009 |
1 files changed, 491 insertions, 518 deletions
diff --git a/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp b/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp index f1452ab..d8900d4 100644 --- a/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp +++ b/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp @@ -6,168 +6,57 @@ // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// -// -// This file contains the AArch64 implementation of the MCAsmBackend class, -// which is principally concerned with relaxation of the various fixup kinds. -// -//===----------------------------------------------------------------------===// +#include "AArch64.h" +#include "AArch64RegisterInfo.h" #include "MCTargetDesc/AArch64FixupKinds.h" -#include "MCTargetDesc/AArch64MCTargetDesc.h" +#include "llvm/ADT/Triple.h" #include "llvm/MC/MCAsmBackend.h" -#include "llvm/MC/MCELFObjectWriter.h" +#include "llvm/MC/MCDirectives.h" #include "llvm/MC/MCFixupKindInfo.h" #include "llvm/MC/MCObjectWriter.h" -#include "llvm/MC/MCSubtargetInfo.h" -#include "llvm/Support/ELF.h" +#include "llvm/MC/MCSectionMachO.h" +#include "llvm/MC/MCSectionELF.h" #include "llvm/Support/ErrorHandling.h" -#include "llvm/Support/raw_ostream.h" +#include "llvm/Support/MachO.h" using namespace llvm; namespace { -class AArch64AsmBackend : public MCAsmBackend { - const MCSubtargetInfo* STI; -public: - AArch64AsmBackend(const Target &T, const StringRef TT) - : MCAsmBackend(), - STI(AArch64_MC::createAArch64MCSubtargetInfo(TT, "", "")) - {} - - - ~AArch64AsmBackend() { - delete STI; - } - - bool writeNopData(uint64_t Count, MCObjectWriter *OW) const; - - virtual void processFixupValue(const MCAssembler &Asm, - const MCAsmLayout &Layout, - const MCFixup &Fixup, const MCFragment *DF, - const MCValue &Target, uint64_t &Value, - bool &IsResolved); -}; -} // end anonymous namespace - -void AArch64AsmBackend::processFixupValue(const MCAssembler &Asm, - const MCAsmLayout &Layout, - const MCFixup &Fixup, - const MCFragment *DF, - const MCValue &Target, - uint64_t &Value, bool &IsResolved) { - // The ADRP instruction adds some multiple of 0x1000 to the current PC & - // ~0xfff. This means that the required offset to reach a symbol can vary by - // up to one step depending on where the ADRP is in memory. For example: - // - // ADRP x0, there - // there: - // - // If the ADRP occurs at address 0xffc then "there" will be at 0x1000 and - // we'll need that as an offset. At any other address "there" will be in the - // same page as the ADRP and the instruction should encode 0x0. Assuming the - // section isn't 0x1000-aligned, we therefore need to delegate this decision - // to the linker -- a relocation! - if ((uint32_t)Fixup.getKind() == AArch64::fixup_a64_adr_prel_page || - (uint32_t)Fixup.getKind() == AArch64::fixup_a64_adr_prel_got_page || - (uint32_t)Fixup.getKind() == AArch64::fixup_a64_adr_gottprel_page || - (uint32_t)Fixup.getKind() == AArch64::fixup_a64_tlsdesc_adr_page) - IsResolved = false; -} - -static uint64_t adjustFixupValue(unsigned Kind, uint64_t Value); - -namespace { +class AArch64AsmBackend : public MCAsmBackend { + static const unsigned PCRelFlagVal = + MCFixupKindInfo::FKF_IsAlignedDownTo32Bits | MCFixupKindInfo::FKF_IsPCRel; -class ELFAArch64AsmBackend : public AArch64AsmBackend { - uint8_t OSABI; - bool IsLittle; // Big or little endian public: - ELFAArch64AsmBackend(const Target &T, const StringRef TT, - uint8_t _OSABI, bool isLittle) - : AArch64AsmBackend(T, TT), OSABI(_OSABI), IsLittle(isLittle) { } + AArch64AsmBackend(const Target &T) : MCAsmBackend() {} - bool fixupNeedsRelaxation(const MCFixup &Fixup, - uint64_t Value, - const MCRelaxableFragment *DF, - const MCAsmLayout &Layout) const; - - unsigned int getNumFixupKinds() const { + unsigned getNumFixupKinds() const override { return AArch64::NumTargetFixupKinds; } - const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const { + const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override { const static MCFixupKindInfo Infos[AArch64::NumTargetFixupKinds] = { -// This table *must* be in the order that the fixup_* kinds are defined in -// AArch64FixupKinds.h. -// -// Name Offset (bits) Size (bits) Flags -{ "fixup_a64_ld_prel", 0, 32, MCFixupKindInfo::FKF_IsPCRel }, -{ "fixup_a64_adr_prel", 0, 32, MCFixupKindInfo::FKF_IsPCRel }, -{ "fixup_a64_adr_prel_page", 0, 32, MCFixupKindInfo::FKF_IsPCRel }, -{ "fixup_a64_add_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst8_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst16_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst32_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst64_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst128_lo12", 0, 32, 0 }, -{ "fixup_a64_tstbr", 0, 32, MCFixupKindInfo::FKF_IsPCRel }, -{ "fixup_a64_condbr", 0, 32, MCFixupKindInfo::FKF_IsPCRel }, -{ "fixup_a64_uncondbr", 0, 32, MCFixupKindInfo::FKF_IsPCRel }, -{ "fixup_a64_call", 0, 32, MCFixupKindInfo::FKF_IsPCRel }, -{ "fixup_a64_movw_uabs_g0", 0, 32, 0 }, -{ "fixup_a64_movw_uabs_g0_nc", 0, 32, 0 }, -{ "fixup_a64_movw_uabs_g1", 0, 32, 0 }, -{ "fixup_a64_movw_uabs_g1_nc", 0, 32, 0 }, -{ "fixup_a64_movw_uabs_g2", 0, 32, 0 }, -{ "fixup_a64_movw_uabs_g2_nc", 0, 32, 0 }, -{ "fixup_a64_movw_uabs_g3", 0, 32, 0 }, -{ "fixup_a64_movw_sabs_g0", 0, 32, 0 }, -{ "fixup_a64_movw_sabs_g1", 0, 32, 0 }, -{ "fixup_a64_movw_sabs_g2", 0, 32, 0 }, -{ "fixup_a64_adr_prel_got_page", 0, 32, MCFixupKindInfo::FKF_IsPCRel }, -{ "fixup_a64_ld64_got_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_movw_dtprel_g2", 0, 32, 0 }, -{ "fixup_a64_movw_dtprel_g1", 0, 32, 0 }, -{ "fixup_a64_movw_dtprel_g1_nc", 0, 32, 0 }, -{ "fixup_a64_movw_dtprel_g0", 0, 32, 0 }, -{ "fixup_a64_movw_dtprel_g0_nc", 0, 32, 0 }, -{ "fixup_a64_add_dtprel_hi12", 0, 32, 0 }, -{ "fixup_a64_add_dtprel_lo12", 0, 32, 0 }, -{ "fixup_a64_add_dtprel_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_ldst8_dtprel_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst8_dtprel_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_ldst16_dtprel_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst16_dtprel_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_ldst32_dtprel_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst32_dtprel_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_ldst64_dtprel_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst64_dtprel_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_movw_gottprel_g1", 0, 32, 0 }, -{ "fixup_a64_movw_gottprel_g0_nc", 0, 32, 0 }, -{ "fixup_a64_adr_gottprel_page", 0, 32, MCFixupKindInfo::FKF_IsPCRel }, -{ "fixup_a64_ld64_gottprel_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_ld_gottprel_prel19", 0, 32, MCFixupKindInfo::FKF_IsPCRel }, -{ "fixup_a64_movw_tprel_g2", 0, 32, 0 }, -{ "fixup_a64_movw_tprel_g1", 0, 32, 0 }, -{ "fixup_a64_movw_tprel_g1_nc", 0, 32, 0 }, -{ "fixup_a64_movw_tprel_g0", 0, 32, 0 }, -{ "fixup_a64_movw_tprel_g0_nc", 0, 32, 0 }, -{ "fixup_a64_add_tprel_hi12", 0, 32, 0 }, -{ "fixup_a64_add_tprel_lo12", 0, 32, 0 }, -{ "fixup_a64_add_tprel_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_ldst8_tprel_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst8_tprel_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_ldst16_tprel_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst16_tprel_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_ldst32_tprel_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst32_tprel_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_ldst64_tprel_lo12", 0, 32, 0 }, -{ "fixup_a64_ldst64_tprel_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_tlsdesc_adr_page", 0, 32, MCFixupKindInfo::FKF_IsPCRel }, -{ "fixup_a64_tlsdesc_ld64_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_tlsdesc_add_lo12_nc", 0, 32, 0 }, -{ "fixup_a64_tlsdesc_call", 0, 0, 0 } + // This table *must* be in the order that the fixup_* kinds are defined in + // AArch64FixupKinds.h. + // + // Name Offset (bits) Size (bits) Flags + { "fixup_aarch64_pcrel_adr_imm21", 0, 32, PCRelFlagVal }, + { "fixup_aarch64_pcrel_adrp_imm21", 0, 32, PCRelFlagVal }, + { "fixup_aarch64_add_imm12", 10, 12, 0 }, + { "fixup_aarch64_ldst_imm12_scale1", 10, 12, 0 }, + { "fixup_aarch64_ldst_imm12_scale2", 10, 12, 0 }, + { "fixup_aarch64_ldst_imm12_scale4", 10, 12, 0 }, + { "fixup_aarch64_ldst_imm12_scale8", 10, 12, 0 }, + { "fixup_aarch64_ldst_imm12_scale16", 10, 12, 0 }, + { "fixup_aarch64_ldr_pcrel_imm19", 5, 19, PCRelFlagVal }, + { "fixup_aarch64_movw", 5, 16, 0 }, + { "fixup_aarch64_pcrel_branch14", 5, 14, PCRelFlagVal }, + { "fixup_aarch64_pcrel_branch19", 5, 19, PCRelFlagVal }, + { "fixup_aarch64_pcrel_branch26", 0, 26, PCRelFlagVal }, + { "fixup_aarch64_pcrel_call26", 0, 26, PCRelFlagVal }, + { "fixup_aarch64_tlsdesc_call", 0, 0, 0 } }; + if (Kind < FirstTargetFixupKind) return MCAsmBackend::getFixupKindInfo(Kind); @@ -177,417 +66,501 @@ public: } void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize, - uint64_t Value, bool IsPCRel) const { - unsigned NumBytes = getFixupKindInfo(Fixup.getKind()).TargetSize / 8; - Value = adjustFixupValue(Fixup.getKind(), Value); - if (!Value) return; // Doesn't change encoding. - - unsigned Offset = Fixup.getOffset(); - assert(Offset + NumBytes <= DataSize && "Invalid fixup offset!"); - - // For each byte of the fragment that the fixup touches, mask in the bits - // from the fixup value. - for (unsigned i = 0; i != NumBytes; ++i) { - Data[Offset + i] |= uint8_t((Value >> (i * 8)) & 0xff); - } - } + uint64_t Value, bool IsPCRel) const override; - bool mayNeedRelaxation(const MCInst&) const { - return false; - } + bool mayNeedRelaxation(const MCInst &Inst) const override; + bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value, + const MCRelaxableFragment *DF, + const MCAsmLayout &Layout) const override; + void relaxInstruction(const MCInst &Inst, MCInst &Res) const override; + bool writeNopData(uint64_t Count, MCObjectWriter *OW) const override; - void relaxInstruction(const MCInst&, llvm::MCInst&) const { - llvm_unreachable("Cannot relax instructions"); - } + void HandleAssemblerFlag(MCAssemblerFlag Flag) {} - MCObjectWriter *createObjectWriter(raw_ostream &OS) const { - return createAArch64ELFObjectWriter(OS, OSABI, IsLittle); - } + unsigned getPointerSize() const { return 8; } }; } // end anonymous namespace -bool -ELFAArch64AsmBackend::fixupNeedsRelaxation(const MCFixup &Fixup, - uint64_t Value, - const MCRelaxableFragment *DF, - const MCAsmLayout &Layout) const { - // Correct for now. With all instructions 32-bit only very low-level - // considerations could make you select something which may fail. - return false; -} +/// \brief The number of bytes the fixup may change. +static unsigned getFixupKindNumBytes(unsigned Kind) { + switch (Kind) { + default: + assert(0 && "Unknown fixup kind!"); + case AArch64::fixup_aarch64_tlsdesc_call: + return 0; -bool AArch64AsmBackend::writeNopData(uint64_t Count, MCObjectWriter *OW) const { - // Can't emit NOP with size not multiple of 32-bits - if (Count % 4 != 0) - return false; + case FK_Data_1: + return 1; - uint64_t NumNops = Count / 4; - for (uint64_t i = 0; i != NumNops; ++i) - OW->Write32(0xd503201f); + case FK_Data_2: + case AArch64::fixup_aarch64_movw: + return 2; + + case AArch64::fixup_aarch64_pcrel_branch14: + case AArch64::fixup_aarch64_add_imm12: + case AArch64::fixup_aarch64_ldst_imm12_scale1: + case AArch64::fixup_aarch64_ldst_imm12_scale2: + case AArch64::fixup_aarch64_ldst_imm12_scale4: + case AArch64::fixup_aarch64_ldst_imm12_scale8: + case AArch64::fixup_aarch64_ldst_imm12_scale16: + case AArch64::fixup_aarch64_ldr_pcrel_imm19: + case AArch64::fixup_aarch64_pcrel_branch19: + return 3; + + case AArch64::fixup_aarch64_pcrel_adr_imm21: + case AArch64::fixup_aarch64_pcrel_adrp_imm21: + case AArch64::fixup_aarch64_pcrel_branch26: + case AArch64::fixup_aarch64_pcrel_call26: + case FK_Data_4: + return 4; - return true; + case FK_Data_8: + return 8; + } } -static unsigned ADRImmBits(unsigned Value) { +static unsigned AdrImmBits(unsigned Value) { unsigned lo2 = Value & 0x3; - unsigned hi19 = (Value & 0x1fffff) >> 2; - + unsigned hi19 = (Value & 0x1ffffc) >> 2; return (hi19 << 5) | (lo2 << 29); } static uint64_t adjustFixupValue(unsigned Kind, uint64_t Value) { + int64_t SignedValue = static_cast<int64_t>(Value); switch (Kind) { default: - llvm_unreachable("Unknown fixup kind!"); - case FK_Data_2: - assert((int64_t)Value >= -32768 && - (int64_t)Value <= 65536 && - "Out of range ABS16 fixup"); + assert(false && "Unknown fixup kind!"); + case AArch64::fixup_aarch64_pcrel_adr_imm21: + if (SignedValue > 2097151 || SignedValue < -2097152) + report_fatal_error("fixup value out of range"); + return AdrImmBits(Value & 0x1fffffULL); + case AArch64::fixup_aarch64_pcrel_adrp_imm21: + return AdrImmBits((Value & 0x1fffff000ULL) >> 12); + case AArch64::fixup_aarch64_ldr_pcrel_imm19: + case AArch64::fixup_aarch64_pcrel_branch19: + // Signed 21-bit immediate + if (SignedValue > 2097151 || SignedValue < -2097152) + report_fatal_error("fixup value out of range"); + // Low two bits are not encoded. + return (Value >> 2) & 0x7ffff; + case AArch64::fixup_aarch64_add_imm12: + case AArch64::fixup_aarch64_ldst_imm12_scale1: + // Unsigned 12-bit immediate + if (Value >= 0x1000) + report_fatal_error("invalid imm12 fixup value"); return Value; - case FK_Data_4: - assert((int64_t)Value >= -(1LL << 31) && - (int64_t)Value <= (1LL << 32) - 1 && - "Out of range ABS32 fixup"); + case AArch64::fixup_aarch64_ldst_imm12_scale2: + // Unsigned 12-bit immediate which gets multiplied by 2 + if (Value & 1 || Value >= 0x2000) + report_fatal_error("invalid imm12 fixup value"); + return Value >> 1; + case AArch64::fixup_aarch64_ldst_imm12_scale4: + // Unsigned 12-bit immediate which gets multiplied by 4 + if (Value & 3 || Value >= 0x4000) + report_fatal_error("invalid imm12 fixup value"); + return Value >> 2; + case AArch64::fixup_aarch64_ldst_imm12_scale8: + // Unsigned 12-bit immediate which gets multiplied by 8 + if (Value & 7 || Value >= 0x8000) + report_fatal_error("invalid imm12 fixup value"); + return Value >> 3; + case AArch64::fixup_aarch64_ldst_imm12_scale16: + // Unsigned 12-bit immediate which gets multiplied by 16 + if (Value & 15 || Value >= 0x10000) + report_fatal_error("invalid imm12 fixup value"); + return Value >> 4; + case AArch64::fixup_aarch64_movw: + report_fatal_error("no resolvable MOVZ/MOVK fixups supported yet"); return Value; + case AArch64::fixup_aarch64_pcrel_branch14: + // Signed 16-bit immediate + if (SignedValue > 32767 || SignedValue < -32768) + report_fatal_error("fixup value out of range"); + // Low two bits are not encoded (4-byte alignment assumed). + if (Value & 0x3) + report_fatal_error("fixup not sufficiently aligned"); + return (Value >> 2) & 0x3fff; + case AArch64::fixup_aarch64_pcrel_branch26: + case AArch64::fixup_aarch64_pcrel_call26: + // Signed 28-bit immediate + if (SignedValue > 134217727 || SignedValue < -134217728) + report_fatal_error("fixup value out of range"); + // Low two bits are not encoded (4-byte alignment assumed). + if (Value & 0x3) + report_fatal_error("fixup not sufficiently aligned"); + return (Value >> 2) & 0x3ffffff; + case FK_Data_1: + case FK_Data_2: + case FK_Data_4: case FK_Data_8: return Value; + } +} - case AArch64::fixup_a64_ld_gottprel_prel19: - // R_AARCH64_LD_GOTTPREL_PREL19: Set a load-literal immediate to bits 1F - // FFFC of G(TPREL(S+A)) - P; check -2^20 <= X < 2^20. - case AArch64::fixup_a64_ld_prel: - // R_AARCH64_LD_PREL_LO19: Sets a load-literal (immediate) value to bits - // 1F FFFC of S+A-P, checking that -2^20 <= S+A-P < 2^20. - assert((int64_t)Value >= -(1LL << 20) && - (int64_t)Value < (1LL << 20) && "Out of range LDR (lit) fixup"); - return (Value & 0x1ffffc) << 3; - - case AArch64::fixup_a64_adr_prel: - // R_AARCH64_ADR_PREL_LO21: Sets an ADR immediate value to bits 1F FFFF of - // the result of S+A-P, checking that -2^20 <= S+A-P < 2^20. - assert((int64_t)Value >= -(1LL << 20) && - (int64_t)Value < (1LL << 20) && "Out of range ADR fixup"); - return ADRImmBits(Value & 0x1fffff); - - case AArch64::fixup_a64_adr_prel_page: - // R_AARCH64_ADR_PREL_PG_HI21: Sets an ADRP immediate value to bits 1 FFFF - // F000 of the result of the operation, checking that -2^32 <= result < - // 2^32. - assert((int64_t)Value >= -(1LL << 32) && - (int64_t)Value < (1LL << 32) && "Out of range ADRP fixup"); - return ADRImmBits((Value & 0x1fffff000ULL) >> 12); - - case AArch64::fixup_a64_add_dtprel_hi12: - // R_AARCH64_TLSLD_ADD_DTPREL_LO12: Set an ADD immediate field to bits - // FF F000 of DTPREL(S+A), check 0 <= X < 2^24. - case AArch64::fixup_a64_add_tprel_hi12: - // R_AARCH64_TLSLD_ADD_TPREL_LO12: Set an ADD immediate field to bits - // FF F000 of TPREL(S+A), check 0 <= X < 2^24. - assert((int64_t)Value >= 0 && - (int64_t)Value < (1LL << 24) && "Out of range ADD fixup"); - return (Value & 0xfff000) >> 2; - - case AArch64::fixup_a64_add_dtprel_lo12: - // R_AARCH64_TLSLD_ADD_DTPREL_LO12: Set an ADD immediate field to bits - // FFF of DTPREL(S+A), check 0 <= X < 2^12. - case AArch64::fixup_a64_add_tprel_lo12: - // R_AARCH64_TLSLD_ADD_TPREL_LO12: Set an ADD immediate field to bits - // FFF of TPREL(S+A), check 0 <= X < 2^12. - assert((int64_t)Value >= 0 && - (int64_t)Value < (1LL << 12) && "Out of range ADD fixup"); - // ... fallthrough to no-checking versions ... - case AArch64::fixup_a64_add_dtprel_lo12_nc: - // R_AARCH64_TLSLD_ADD_DTPREL_LO12_NC: Set an ADD immediate field to bits - // FFF of DTPREL(S+A) with no overflow check. - case AArch64::fixup_a64_add_tprel_lo12_nc: - // R_AARCH64_TLSLD_ADD_TPREL_LO12_NC: Set an ADD immediate field to bits - // FFF of TPREL(S+A) with no overflow check. - case AArch64::fixup_a64_tlsdesc_add_lo12_nc: - // R_AARCH64_TLSDESC_ADD_LO12_NC: Set an ADD immediate field to bits - // FFF of G(TLSDESC(S+A)), with no overflow check. - case AArch64::fixup_a64_add_lo12: - // R_AARCH64_ADD_ABS_LO12_NC: Sets an ADD immediate value to bits FFF of - // S+A, with no overflow check. - return (Value & 0xfff) << 10; - - case AArch64::fixup_a64_ldst8_dtprel_lo12: - // R_AARCH64_TLSLD_LDST8_DTPREL_LO12: Set an LD/ST offset field to bits FFF - // of DTPREL(S+A), check 0 <= X < 2^12. - case AArch64::fixup_a64_ldst8_tprel_lo12: - // R_AARCH64_TLSLE_LDST8_TPREL_LO12: Set an LD/ST offset field to bits FFF - // of DTPREL(S+A), check 0 <= X < 2^12. - assert((int64_t) Value >= 0 && - (int64_t) Value < (1LL << 12) && "Out of range LD/ST fixup"); - // ... fallthrough to no-checking versions ... - case AArch64::fixup_a64_ldst8_dtprel_lo12_nc: - // R_AARCH64_TLSLD_LDST8_DTPREL_LO12: Set an LD/ST offset field to bits FFF - // of DTPREL(S+A), with no overflow check. - case AArch64::fixup_a64_ldst8_tprel_lo12_nc: - // R_AARCH64_TLSLD_LDST8_TPREL_LO12: Set an LD/ST offset field to bits FFF - // of TPREL(S+A), with no overflow check. - case AArch64::fixup_a64_ldst8_lo12: - // R_AARCH64_LDST8_ABS_LO12_NC: Sets an LD/ST immediate value to bits FFF - // of S+A, with no overflow check. - return (Value & 0xfff) << 10; - - case AArch64::fixup_a64_ldst16_dtprel_lo12: - // R_AARCH64_TLSLD_LDST16_DTPREL_LO12: Set an LD/ST offset field to bits FFE - // of DTPREL(S+A), check 0 <= X < 2^12. - case AArch64::fixup_a64_ldst16_tprel_lo12: - // R_AARCH64_TLSLE_LDST16_TPREL_LO12: Set an LD/ST offset field to bits FFE - // of DTPREL(S+A), check 0 <= X < 2^12. - assert((int64_t) Value >= 0 && - (int64_t) Value < (1LL << 12) && "Out of range LD/ST fixup"); - // ... fallthrough to no-checking versions ... - case AArch64::fixup_a64_ldst16_dtprel_lo12_nc: - // R_AARCH64_TLSLD_LDST16_DTPREL_LO12: Set an LD/ST offset field to bits FFE - // of DTPREL(S+A), with no overflow check. - case AArch64::fixup_a64_ldst16_tprel_lo12_nc: - // R_AARCH64_TLSLD_LDST16_TPREL_LO12: Set an LD/ST offset field to bits FFE - // of TPREL(S+A), with no overflow check. - case AArch64::fixup_a64_ldst16_lo12: - // R_AARCH64_LDST16_ABS_LO12_NC: Sets an LD/ST immediate value to bits FFE - // of S+A, with no overflow check. - return (Value & 0xffe) << 9; - - case AArch64::fixup_a64_ldst32_dtprel_lo12: - // R_AARCH64_TLSLD_LDST32_DTPREL_LO12: Set an LD/ST offset field to bits FFC - // of DTPREL(S+A), check 0 <= X < 2^12. - case AArch64::fixup_a64_ldst32_tprel_lo12: - // R_AARCH64_TLSLE_LDST32_TPREL_LO12: Set an LD/ST offset field to bits FFC - // of DTPREL(S+A), check 0 <= X < 2^12. - assert((int64_t) Value >= 0 && - (int64_t) Value < (1LL << 12) && "Out of range LD/ST fixup"); - // ... fallthrough to no-checking versions ... - case AArch64::fixup_a64_ldst32_dtprel_lo12_nc: - // R_AARCH64_TLSLD_LDST32_DTPREL_LO12: Set an LD/ST offset field to bits FFC - // of DTPREL(S+A), with no overflow check. - case AArch64::fixup_a64_ldst32_tprel_lo12_nc: - // R_AARCH64_TLSLD_LDST32_TPREL_LO12: Set an LD/ST offset field to bits FFC - // of TPREL(S+A), with no overflow check. - case AArch64::fixup_a64_ldst32_lo12: - // R_AARCH64_LDST32_ABS_LO12_NC: Sets an LD/ST immediate value to bits FFC - // of S+A, with no overflow check. - return (Value & 0xffc) << 8; - - case AArch64::fixup_a64_ldst64_dtprel_lo12: - // R_AARCH64_TLSLD_LDST64_DTPREL_LO12: Set an LD/ST offset field to bits FF8 - // of DTPREL(S+A), check 0 <= X < 2^12. - case AArch64::fixup_a64_ldst64_tprel_lo12: - // R_AARCH64_TLSLE_LDST64_TPREL_LO12: Set an LD/ST offset field to bits FF8 - // of DTPREL(S+A), check 0 <= X < 2^12. - assert((int64_t) Value >= 0 && - (int64_t) Value < (1LL << 12) && "Out of range LD/ST fixup"); - // ... fallthrough to no-checking versions ... - case AArch64::fixup_a64_ldst64_dtprel_lo12_nc: - // R_AARCH64_TLSLD_LDST64_DTPREL_LO12: Set an LD/ST offset field to bits FF8 - // of DTPREL(S+A), with no overflow check. - case AArch64::fixup_a64_ldst64_tprel_lo12_nc: - // R_AARCH64_TLSLD_LDST64_TPREL_LO12: Set an LD/ST offset field to bits FF8 - // of TPREL(S+A), with no overflow check. - case AArch64::fixup_a64_ldst64_lo12: - // R_AARCH64_LDST64_ABS_LO12_NC: Sets an LD/ST immediate value to bits FF8 - // of S+A, with no overflow check. - return (Value & 0xff8) << 7; - - case AArch64::fixup_a64_ldst128_lo12: - // R_AARCH64_LDST128_ABS_LO12_NC: Sets an LD/ST immediate value to bits FF0 - // of S+A, with no overflow check. - return (Value & 0xff0) << 6; - - case AArch64::fixup_a64_movw_uabs_g0: - // R_AARCH64_MOVW_UABS_G0: Sets a MOVZ immediate field to bits FFFF of S+A - // with a check that S+A < 2^16 - assert(Value <= 0xffff && "Out of range move wide fixup"); - return (Value & 0xffff) << 5; - - case AArch64::fixup_a64_movw_dtprel_g0_nc: - // R_AARCH64_TLSLD_MOVW_DTPREL_G0_NC: Sets a MOVK immediate field to bits - // FFFF of DTPREL(S+A) with no overflow check. - case AArch64::fixup_a64_movw_gottprel_g0_nc: - // R_AARCH64_TLSIE_MOVW_GOTTPREL_G0_NC: Sets a MOVK immediate field to bits - // FFFF of G(TPREL(S+A)) - GOT with no overflow check. - case AArch64::fixup_a64_movw_tprel_g0_nc: - // R_AARCH64_TLSLE_MOVW_TPREL_G0_NC: Sets a MOVK immediate field to bits - // FFFF of TPREL(S+A) with no overflow check. - case AArch64::fixup_a64_movw_uabs_g0_nc: - // R_AARCH64_MOVW_UABS_G0_NC: Sets a MOVK immediate field to bits FFFF of - // S+A with no overflow check. - return (Value & 0xffff) << 5; - - case AArch64::fixup_a64_movw_uabs_g1: - // R_AARCH64_MOVW_UABS_G1: Sets a MOVZ immediate field to bits FFFF0000 of - // S+A with a check that S+A < 2^32 - assert(Value <= 0xffffffffull && "Out of range move wide fixup"); - return ((Value >> 16) & 0xffff) << 5; - - case AArch64::fixup_a64_movw_dtprel_g1_nc: - // R_AARCH64_TLSLD_MOVW_DTPREL_G1_NC: Set a MOVK immediate field - // to bits FFFF0000 of DTPREL(S+A), with no overflow check. - case AArch64::fixup_a64_movw_tprel_g1_nc: - // R_AARCH64_TLSLD_MOVW_TPREL_G1_NC: Set a MOVK immediate field - // to bits FFFF0000 of TPREL(S+A), with no overflow check. - case AArch64::fixup_a64_movw_uabs_g1_nc: - // R_AARCH64_MOVW_UABS_G1_NC: Sets a MOVK immediate field to bits - // FFFF0000 of S+A with no overflow check. - return ((Value >> 16) & 0xffff) << 5; - - case AArch64::fixup_a64_movw_uabs_g2: - // R_AARCH64_MOVW_UABS_G2: Sets a MOVZ immediate field to bits FFFF 0000 - // 0000 of S+A with a check that S+A < 2^48 - assert(Value <= 0xffffffffffffull && "Out of range move wide fixup"); - return ((Value >> 32) & 0xffff) << 5; - - case AArch64::fixup_a64_movw_uabs_g2_nc: - // R_AARCH64_MOVW_UABS_G2: Sets a MOVK immediate field to bits FFFF 0000 - // 0000 of S+A with no overflow check. - return ((Value >> 32) & 0xffff) << 5; - - case AArch64::fixup_a64_movw_uabs_g3: - // R_AARCH64_MOVW_UABS_G3: Sets a MOVZ immediate field to bits FFFF 0000 - // 0000 0000 of S+A (no overflow check needed) - return ((Value >> 48) & 0xffff) << 5; - - case AArch64::fixup_a64_movw_dtprel_g0: - // R_AARCH64_TLSLD_MOVW_DTPREL_G0: Set a MOV[NZ] immediate field - // to bits FFFF of DTPREL(S+A). - case AArch64::fixup_a64_movw_tprel_g0: - // R_AARCH64_TLSLE_MOVW_TPREL_G0: Set a MOV[NZ] immediate field to - // bits FFFF of TPREL(S+A). - case AArch64::fixup_a64_movw_sabs_g0: { - // R_AARCH64_MOVW_SABS_G0: Sets MOV[NZ] immediate field using bits FFFF of - // S+A (see notes below); check -2^16 <= S+A < 2^16. (notes say that we - // should convert between MOVN and MOVZ to achieve our goals). - int64_t Signed = Value; - assert(Signed >= -(1LL << 16) && Signed < (1LL << 16) - && "Out of range move wide fixup"); - if (Signed >= 0) { - Value = (Value & 0xffff) << 5; - // Bit 30 converts the MOVN encoding into a MOVZ - Value |= 1 << 30; - } else { - // MCCodeEmitter should have encoded a MOVN, which is fine. - Value = (~Value & 0xffff) << 5; - } - return Value; +void AArch64AsmBackend::applyFixup(const MCFixup &Fixup, char *Data, + unsigned DataSize, uint64_t Value, + bool IsPCRel) const { + unsigned NumBytes = getFixupKindNumBytes(Fixup.getKind()); + if (!Value) + return; // Doesn't change encoding. + MCFixupKindInfo Info = getFixupKindInfo(Fixup.getKind()); + // Apply any target-specific value adjustments. + Value = adjustFixupValue(Fixup.getKind(), Value); + + // Shift the value into position. + Value <<= Info.TargetOffset; + + unsigned Offset = Fixup.getOffset(); + assert(Offset + NumBytes <= DataSize && "Invalid fixup offset!"); + + // For each byte of the fragment that the fixup touches, mask in the + // bits from the fixup value. + for (unsigned i = 0; i != NumBytes; ++i) + Data[Offset + i] |= uint8_t((Value >> (i * 8)) & 0xff); +} + +bool AArch64AsmBackend::mayNeedRelaxation(const MCInst &Inst) const { + return false; +} + +bool AArch64AsmBackend::fixupNeedsRelaxation(const MCFixup &Fixup, + uint64_t Value, + const MCRelaxableFragment *DF, + const MCAsmLayout &Layout) const { + // FIXME: This isn't correct for AArch64. Just moving the "generic" logic + // into the targets for now. + // + // Relax if the value is too big for a (signed) i8. + return int64_t(Value) != int64_t(int8_t(Value)); +} + +void AArch64AsmBackend::relaxInstruction(const MCInst &Inst, + MCInst &Res) const { + assert(false && "AArch64AsmBackend::relaxInstruction() unimplemented"); +} + +bool AArch64AsmBackend::writeNopData(uint64_t Count, MCObjectWriter *OW) const { + // 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. + if ((Count & 3) != 0) { + for (uint64_t i = 0, e = (Count & 3); i != e; ++i) + OW->Write8(0); } - case AArch64::fixup_a64_movw_dtprel_g1: - // R_AARCH64_TLSLD_MOVW_DTPREL_G1: Set a MOV[NZ] immediate field - // to bits FFFF0000 of DTPREL(S+A). - case AArch64::fixup_a64_movw_gottprel_g1: - // R_AARCH64_TLSIE_MOVW_GOTTPREL_G1: Set a MOV[NZ] immediate field - // to bits FFFF0000 of G(TPREL(S+A)) - GOT. - case AArch64::fixup_a64_movw_tprel_g1: - // R_AARCH64_TLSLE_MOVW_TPREL_G1: Set a MOV[NZ] immediate field to - // bits FFFF0000 of TPREL(S+A). - case AArch64::fixup_a64_movw_sabs_g1: { - // R_AARCH64_MOVW_SABS_G1: Sets MOV[NZ] immediate field using bits FFFF 0000 - // of S+A (see notes below); check -2^32 <= S+A < 2^32. (notes say that we - // should convert between MOVN and MOVZ to achieve our goals). - int64_t Signed = Value; - assert(Signed >= -(1LL << 32) && Signed < (1LL << 32) - && "Out of range move wide fixup"); - if (Signed >= 0) { - Value = ((Value >> 16) & 0xffff) << 5; - // Bit 30 converts the MOVN encoding into a MOVZ - Value |= 1 << 30; - } else { - Value = ((~Value >> 16) & 0xffff) << 5; - } - return Value; + // We are properly aligned, so write NOPs as requested. + Count /= 4; + for (uint64_t i = 0; i != Count; ++i) + OW->Write32(0xd503201f); + return true; +} + +namespace { + +namespace CU { + +/// \brief Compact unwind encoding values. +enum CompactUnwindEncodings { + /// \brief A "frameless" leaf function, where no non-volatile registers are + /// saved. The return remains in LR throughout the function. + UNWIND_AArch64_MODE_FRAMELESS = 0x02000000, + + /// \brief No compact unwind encoding available. Instead the low 23-bits of + /// the compact unwind encoding is the offset of the DWARF FDE in the + /// __eh_frame section. This mode is never used in object files. It is only + /// generated by the linker in final linked images, which have only DWARF info + /// for a function. + UNWIND_AArch64_MODE_DWARF = 0x03000000, + + /// \brief This is a standard arm64 prologue where FP/LR are immediately + /// pushed on the stack, then SP is copied to FP. If there are any + /// non-volatile register saved, they are copied into the stack fame in pairs + /// in a contiguous ranger right below the saved FP/LR pair. Any subset of the + /// five X pairs and four D pairs can be saved, but the memory layout must be + /// in register number order. + UNWIND_AArch64_MODE_FRAME = 0x04000000, + + /// \brief Frame register pair encodings. + UNWIND_AArch64_FRAME_X19_X20_PAIR = 0x00000001, + UNWIND_AArch64_FRAME_X21_X22_PAIR = 0x00000002, + UNWIND_AArch64_FRAME_X23_X24_PAIR = 0x00000004, + UNWIND_AArch64_FRAME_X25_X26_PAIR = 0x00000008, + UNWIND_AArch64_FRAME_X27_X28_PAIR = 0x00000010, + UNWIND_AArch64_FRAME_D8_D9_PAIR = 0x00000100, + UNWIND_AArch64_FRAME_D10_D11_PAIR = 0x00000200, + UNWIND_AArch64_FRAME_D12_D13_PAIR = 0x00000400, + UNWIND_AArch64_FRAME_D14_D15_PAIR = 0x00000800 +}; + +} // end CU namespace + +// FIXME: This should be in a separate file. +class DarwinAArch64AsmBackend : public AArch64AsmBackend { + const MCRegisterInfo &MRI; + + /// \brief Encode compact unwind stack adjustment for frameless functions. + /// See UNWIND_AArch64_FRAMELESS_STACK_SIZE_MASK in compact_unwind_encoding.h. + /// The stack size always needs to be 16 byte aligned. + uint32_t encodeStackAdjustment(uint32_t StackSize) const { + return (StackSize / 16) << 12; + } + +public: + DarwinAArch64AsmBackend(const Target &T, const MCRegisterInfo &MRI) + : AArch64AsmBackend(T), MRI(MRI) {} + + MCObjectWriter *createObjectWriter(raw_ostream &OS) const override { + return createAArch64MachObjectWriter(OS, MachO::CPU_TYPE_ARM64, + MachO::CPU_SUBTYPE_ARM64_ALL); + } + + bool doesSectionRequireSymbols(const MCSection &Section) const override { + // Any section for which the linker breaks things into atoms needs to + // preserve symbols, including assembler local symbols, to identify + // those atoms. These sections are: + // Sections of type: + // + // S_CSTRING_LITERALS (e.g. __cstring) + // S_LITERAL_POINTERS (e.g. objc selector pointers) + // S_16BYTE_LITERALS, S_8BYTE_LITERALS, S_4BYTE_LITERALS + // + // Sections named: + // + // __TEXT,__eh_frame + // __TEXT,__ustring + // __DATA,__cfstring + // __DATA,__objc_classrefs + // __DATA,__objc_catlist + // + // FIXME: It would be better if the compiler used actual linker local + // symbols for each of these sections rather than preserving what + // are ostensibly assembler local symbols. + const MCSectionMachO &SMO = static_cast<const MCSectionMachO &>(Section); + return (SMO.getType() == MachO::S_CSTRING_LITERALS || + SMO.getType() == MachO::S_4BYTE_LITERALS || + SMO.getType() == MachO::S_8BYTE_LITERALS || + SMO.getType() == MachO::S_16BYTE_LITERALS || + SMO.getType() == MachO::S_LITERAL_POINTERS || + (SMO.getSegmentName() == "__TEXT" && + (SMO.getSectionName() == "__eh_frame" || + SMO.getSectionName() == "__ustring")) || + (SMO.getSegmentName() == "__DATA" && + (SMO.getSectionName() == "__cfstring" || + SMO.getSectionName() == "__objc_classrefs" || + SMO.getSectionName() == "__objc_catlist"))); } - case AArch64::fixup_a64_movw_dtprel_g2: - // R_AARCH64_TLSLD_MOVW_DTPREL_G2: Set a MOV[NZ] immediate field - // to bits FFFF 0000 0000 of DTPREL(S+A). - case AArch64::fixup_a64_movw_tprel_g2: - // R_AARCH64_TLSLE_MOVW_TPREL_G2: Set a MOV[NZ] immediate field to - // bits FFFF 0000 0000 of TPREL(S+A). - case AArch64::fixup_a64_movw_sabs_g2: { - // R_AARCH64_MOVW_SABS_G2: Sets MOV[NZ] immediate field using bits FFFF 0000 - // 0000 of S+A (see notes below); check -2^48 <= S+A < 2^48. (notes say that - // we should convert between MOVN and MOVZ to achieve our goals). - int64_t Signed = Value; - assert(Signed >= -(1LL << 48) && Signed < (1LL << 48) - && "Out of range move wide fixup"); - if (Signed >= 0) { - Value = ((Value >> 32) & 0xffff) << 5; - // Bit 30 converts the MOVN encoding into a MOVZ - Value |= 1 << 30; - } else { - Value = ((~Value >> 32) & 0xffff) << 5; + /// \brief Generate the compact unwind encoding from the CFI directives. + uint32_t generateCompactUnwindEncoding( + ArrayRef<MCCFIInstruction> Instrs) const override { + if (Instrs.empty()) + return CU::UNWIND_AArch64_MODE_FRAMELESS; + + bool HasFP = false; + unsigned StackSize = 0; + + uint32_t CompactUnwindEncoding = 0; + for (size_t i = 0, e = Instrs.size(); i != e; ++i) { + const MCCFIInstruction &Inst = Instrs[i]; + + switch (Inst.getOperation()) { + default: + // Cannot handle this directive: bail out. + return CU::UNWIND_AArch64_MODE_DWARF; + case MCCFIInstruction::OpDefCfa: { + // Defines a frame pointer. + assert(getXRegFromWReg(MRI.getLLVMRegNum(Inst.getRegister(), true)) == + AArch64::FP && + "Invalid frame pointer!"); + assert(i + 2 < e && "Insufficient CFI instructions to define a frame!"); + + const MCCFIInstruction &LRPush = Instrs[++i]; + assert(LRPush.getOperation() == MCCFIInstruction::OpOffset && + "Link register not pushed!"); + const MCCFIInstruction &FPPush = Instrs[++i]; + assert(FPPush.getOperation() == MCCFIInstruction::OpOffset && + "Frame pointer not pushed!"); + + unsigned LRReg = MRI.getLLVMRegNum(LRPush.getRegister(), true); + unsigned FPReg = MRI.getLLVMRegNum(FPPush.getRegister(), true); + + LRReg = getXRegFromWReg(LRReg); + FPReg = getXRegFromWReg(FPReg); + + assert(LRReg == AArch64::LR && FPReg == AArch64::FP && + "Pushing invalid registers for frame!"); + + // Indicate that the function has a frame. + CompactUnwindEncoding |= CU::UNWIND_AArch64_MODE_FRAME; + HasFP = true; + break; + } + case MCCFIInstruction::OpDefCfaOffset: { + assert(StackSize == 0 && "We already have the CFA offset!"); + StackSize = std::abs(Inst.getOffset()); + break; + } + case MCCFIInstruction::OpOffset: { + // Registers are saved in pairs. We expect there to be two consecutive + // `.cfi_offset' instructions with the appropriate registers specified. + unsigned Reg1 = MRI.getLLVMRegNum(Inst.getRegister(), true); + if (i + 1 == e) + return CU::UNWIND_AArch64_MODE_DWARF; + + const MCCFIInstruction &Inst2 = Instrs[++i]; + if (Inst2.getOperation() != MCCFIInstruction::OpOffset) + return CU::UNWIND_AArch64_MODE_DWARF; + unsigned Reg2 = MRI.getLLVMRegNum(Inst2.getRegister(), true); + + // N.B. The encodings must be in register number order, and the X + // registers before the D registers. + + // X19/X20 pair = 0x00000001, + // X21/X22 pair = 0x00000002, + // X23/X24 pair = 0x00000004, + // X25/X26 pair = 0x00000008, + // X27/X28 pair = 0x00000010 + Reg1 = getXRegFromWReg(Reg1); + Reg2 = getXRegFromWReg(Reg2); + + if (Reg1 == AArch64::X19 && Reg2 == AArch64::X20 && + (CompactUnwindEncoding & 0xF1E) == 0) + CompactUnwindEncoding |= CU::UNWIND_AArch64_FRAME_X19_X20_PAIR; + else if (Reg1 == AArch64::X21 && Reg2 == AArch64::X22 && + (CompactUnwindEncoding & 0xF1C) == 0) + CompactUnwindEncoding |= CU::UNWIND_AArch64_FRAME_X21_X22_PAIR; + else if (Reg1 == AArch64::X23 && Reg2 == AArch64::X24 && + (CompactUnwindEncoding & 0xF18) == 0) + CompactUnwindEncoding |= CU::UNWIND_AArch64_FRAME_X23_X24_PAIR; + else if (Reg1 == AArch64::X25 && Reg2 == AArch64::X26 && + (CompactUnwindEncoding & 0xF10) == 0) + CompactUnwindEncoding |= CU::UNWIND_AArch64_FRAME_X25_X26_PAIR; + else if (Reg1 == AArch64::X27 && Reg2 == AArch64::X28 && + (CompactUnwindEncoding & 0xF00) == 0) + CompactUnwindEncoding |= CU::UNWIND_AArch64_FRAME_X27_X28_PAIR; + else { + Reg1 = getDRegFromBReg(Reg1); + Reg2 = getDRegFromBReg(Reg2); + + // D8/D9 pair = 0x00000100, + // D10/D11 pair = 0x00000200, + // D12/D13 pair = 0x00000400, + // D14/D15 pair = 0x00000800 + if (Reg1 == AArch64::D8 && Reg2 == AArch64::D9 && + (CompactUnwindEncoding & 0xE00) == 0) + CompactUnwindEncoding |= CU::UNWIND_AArch64_FRAME_D8_D9_PAIR; + else if (Reg1 == AArch64::D10 && Reg2 == AArch64::D11 && + (CompactUnwindEncoding & 0xC00) == 0) + CompactUnwindEncoding |= CU::UNWIND_AArch64_FRAME_D10_D11_PAIR; + else if (Reg1 == AArch64::D12 && Reg2 == AArch64::D13 && + (CompactUnwindEncoding & 0x800) == 0) + CompactUnwindEncoding |= CU::UNWIND_AArch64_FRAME_D12_D13_PAIR; + else if (Reg1 == AArch64::D14 && Reg2 == AArch64::D15) + CompactUnwindEncoding |= CU::UNWIND_AArch64_FRAME_D14_D15_PAIR; + else + // A pair was pushed which we cannot handle. + return CU::UNWIND_AArch64_MODE_DWARF; + } + + break; + } + } } - return Value; + + if (!HasFP) { + // With compact unwind info we can only represent stack adjustments of up + // to 65520 bytes. + if (StackSize > 65520) + return CU::UNWIND_AArch64_MODE_DWARF; + + CompactUnwindEncoding |= CU::UNWIND_AArch64_MODE_FRAMELESS; + CompactUnwindEncoding |= encodeStackAdjustment(StackSize); + } + + return CompactUnwindEncoding; } +}; - case AArch64::fixup_a64_tstbr: - // R_AARCH64_TSTBR14: Sets the immediate field of a TBZ/TBNZ instruction to - // bits FFFC of S+A-P, checking -2^15 <= S+A-P < 2^15. - assert((int64_t)Value >= -(1LL << 15) && - (int64_t)Value < (1LL << 15) && "Out of range TBZ/TBNZ fixup"); - return (Value & 0xfffc) << (5 - 2); - - case AArch64::fixup_a64_condbr: - // R_AARCH64_CONDBR19: Sets the immediate field of a conditional branch - // instruction to bits 1FFFFC of S+A-P, checking -2^20 <= S+A-P < 2^20. - assert((int64_t)Value >= -(1LL << 20) && - (int64_t)Value < (1LL << 20) && "Out of range B.cond fixup"); - return (Value & 0x1ffffc) << (5 - 2); - - case AArch64::fixup_a64_uncondbr: - // R_AARCH64_JUMP26 same as below (except to a linker, possibly). - case AArch64::fixup_a64_call: - // R_AARCH64_CALL26: Sets a CALL immediate field to bits FFFFFFC of S+A-P, - // checking that -2^27 <= S+A-P < 2^27. - assert((int64_t)Value >= -(1LL << 27) && - (int64_t)Value < (1LL << 27) && "Out of range branch fixup"); - return (Value & 0xffffffc) >> 2; - - case AArch64::fixup_a64_adr_gottprel_page: - // R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: Set an ADRP immediate field to bits - // 1FFFFF000 of Page(G(TPREL(S+A))) - Page(P); check -2^32 <= X < 2^32. - case AArch64::fixup_a64_tlsdesc_adr_page: - // R_AARCH64_TLSDESC_ADR_PAGE: Set an ADRP immediate field to bits 1FFFFF000 - // of Page(G(TLSDESC(S+A))) - Page(P); check -2^32 <= X < 2^32. - case AArch64::fixup_a64_adr_prel_got_page: - // R_AARCH64_ADR_GOT_PAGE: Sets the immediate value of an ADRP to bits - // 1FFFFF000 of the operation, checking that -2^32 < Page(G(S))-Page(GOT) < - // 2^32. - assert((int64_t)Value >= -(1LL << 32) && - (int64_t)Value < (1LL << 32) && "Out of range ADRP fixup"); - return ADRImmBits((Value & 0x1fffff000ULL) >> 12); - - case AArch64::fixup_a64_ld64_gottprel_lo12_nc: - // R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: Set an LD offset field to bits FF8 - // of X, with no overflow check. Check that X & 7 == 0. - case AArch64::fixup_a64_tlsdesc_ld64_lo12_nc: - // R_AARCH64_TLSDESC_LD64_LO12_NC: Set an LD offset field to bits FF8 of - // G(TLSDESC(S+A)), with no overflow check. Check that X & 7 == 0. - case AArch64::fixup_a64_ld64_got_lo12_nc: - // R_AARCH64_LD64_GOT_LO12_NC: Sets the LD/ST immediate field to bits FF8 of - // G(S) with no overflow check. Check X & 7 == 0 - assert(((int64_t)Value & 7) == 0 && "Misaligned fixup"); - return (Value & 0xff8) << 7; - - case AArch64::fixup_a64_tlsdesc_call: - // R_AARCH64_TLSDESC_CALL: For relaxation only. - return 0; +} // end anonymous namespace + +namespace { + +class ELFAArch64AsmBackend : public AArch64AsmBackend { +public: + uint8_t OSABI; + bool IsLittleEndian; + + ELFAArch64AsmBackend(const Target &T, uint8_t OSABI, bool IsLittleEndian) + : AArch64AsmBackend(T), OSABI(OSABI), IsLittleEndian(IsLittleEndian) {} + + MCObjectWriter *createObjectWriter(raw_ostream &OS) const override { + return createAArch64ELFObjectWriter(OS, OSABI, IsLittleEndian); } + + void processFixupValue(const MCAssembler &Asm, const MCAsmLayout &Layout, + const MCFixup &Fixup, const MCFragment *DF, + const MCValue &Target, uint64_t &Value, + bool &IsResolved) override; + + void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize, + uint64_t Value, bool IsPCRel) const override; +}; + +void ELFAArch64AsmBackend::processFixupValue( + const MCAssembler &Asm, const MCAsmLayout &Layout, const MCFixup &Fixup, + const MCFragment *DF, const MCValue &Target, uint64_t &Value, + bool &IsResolved) { + // The ADRP instruction adds some multiple of 0x1000 to the current PC & + // ~0xfff. This means that the required offset to reach a symbol can vary by + // up to one step depending on where the ADRP is in memory. For example: + // + // ADRP x0, there + // there: + // + // If the ADRP occurs at address 0xffc then "there" will be at 0x1000 and + // we'll need that as an offset. At any other address "there" will be in the + // same page as the ADRP and the instruction should encode 0x0. Assuming the + // section isn't 0x1000-aligned, we therefore need to delegate this decision + // to the linker -- a relocation! + if ((uint32_t)Fixup.getKind() == AArch64::fixup_aarch64_pcrel_adrp_imm21) + IsResolved = false; +} + +void ELFAArch64AsmBackend::applyFixup(const MCFixup &Fixup, char *Data, + unsigned DataSize, uint64_t Value, + bool IsPCRel) const { + // store fixups in .eh_frame section in big endian order + if (!IsLittleEndian && Fixup.getKind() == FK_Data_4) { + const MCSection *Sec = Fixup.getValue()->FindAssociatedSection(); + const MCSectionELF *SecELF = static_cast<const MCSectionELF *>(Sec); + if (SecELF->getSectionName() == ".eh_frame") + Value = ByteSwap_32(unsigned(Value)); + } + AArch64AsmBackend::applyFixup (Fixup, Data, DataSize, Value, IsPCRel); +} } -MCAsmBackend * -llvm::createAArch64leAsmBackend(const Target &T, const MCRegisterInfo &MRI, - StringRef TT, StringRef CPU) { +MCAsmBackend *llvm::createAArch64leAsmBackend(const Target &T, + const MCRegisterInfo &MRI, + StringRef TT, StringRef CPU) { Triple TheTriple(TT); - return new ELFAArch64AsmBackend(T, TT, TheTriple.getOS(), /*isLittle*/ true); + + if (TheTriple.isOSDarwin()) + return new DarwinAArch64AsmBackend(T, MRI); + + assert(TheTriple.isOSBinFormatELF() && "Expect either MachO or ELF target"); + return new ELFAArch64AsmBackend(T, TheTriple.getOS(), /*IsLittleEndian=*/true); } -MCAsmBackend * -llvm::createAArch64beAsmBackend(const Target &T, const MCRegisterInfo &MRI, - StringRef TT, StringRef CPU) { +MCAsmBackend *llvm::createAArch64beAsmBackend(const Target &T, + const MCRegisterInfo &MRI, + StringRef TT, StringRef CPU) { Triple TheTriple(TT); - return new ELFAArch64AsmBackend(T, TT, TheTriple.getOS(), /*isLittle*/ false); + + assert(TheTriple.isOSBinFormatELF() && + "Big endian is only supported for ELF targets!"); + return new ELFAArch64AsmBackend(T, TheTriple.getOS(), + /*IsLittleEndian=*/false); } |