//
//===----------------------------------------------------------------------===//
+#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/MCSubtargetInfo.h"
+#include "llvm/MC/MCDirectives.h"
#include "llvm/MC/MCELFObjectWriter.h"
#include "llvm/MC/MCFixupKindInfo.h"
#include "llvm/MC/MCObjectWriter.h"
-#include "llvm/Support/ELF.h"
+#include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCSectionMachO.h"
+#include "llvm/MC/MCValue.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,
- 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,
- 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 {
public:
- uint8_t OSABI;
- ELFAArch64AsmBackend(const Target &T, const StringRef TT,
- uint8_t _OSABI)
- : AArch64AsmBackend(T, TT), OSABI(_OSABI) { }
-
- bool fixupNeedsRelaxation(const MCFixup &Fixup,
- uint64_t Value,
- const MCRelaxableFragment *DF,
- const MCAsmLayout &Layout) const;
+ AArch64AsmBackend(const Target &T) : MCAsmBackend() {}
- 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);
}
void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
- uint64_t Value) 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);
- }
+ 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:
+ llvm_unreachable("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");
+ 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 {
+ llvm_unreachable("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.
+ OW->WriteZeros(Count % 4);
+
+ // 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
+};
+
+} // namespace CU
+
+// 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;
}
- 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;
+public:
+ DarwinAArch64AsmBackend(const Target &T, const MCRegisterInfo &MRI)
+ : AArch64AsmBackend(T), MRI(MRI) {}
+
+ MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
+ return createAArch64MachObjectWriter(OS, MachO::CPU_TYPE_ARM64,
+ MachO::CPU_SUBTYPE_ARM64_ALL);
}
- 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_pwrite_stream &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;
+}
+
+// Returns whether this fixup is based on an address in the .eh_frame section,
+// and therefore should be byte swapped.
+// FIXME: Should be replaced with something more principled.
+static bool isByteSwappedFixup(const MCExpr *E) {
+ MCValue Val;
+ if (!E->evaluateAsRelocatable(Val, nullptr, nullptr))
+ return false;
+
+ if (!Val.getSymA() || Val.getSymA()->getSymbol().isUndefined())
+ return false;
+
+ const MCSectionELF *SecELF =
+ dyn_cast<MCSectionELF>(&Val.getSymA()->getSymbol().getSection());
+ return SecELF->getSectionName() == ".eh_frame";
}
-MCAsmBackend *
-llvm::createAArch64AsmBackend(const Target &T, StringRef TT, StringRef CPU) {
- Triple TheTriple(TT);
+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) {
+ if (isByteSwappedFixup(Fixup.getValue()))
+ Value = ByteSwap_32(unsigned(Value));
+ }
+ AArch64AsmBackend::applyFixup (Fixup, Data, DataSize, Value, IsPCRel);
+}
+} // namespace
+
+MCAsmBackend *llvm::createAArch64leAsmBackend(const Target &T,
+ const MCRegisterInfo &MRI,
+ const Triple &TheTriple,
+ StringRef CPU) {
+ if (TheTriple.isOSBinFormatMachO())
+ return new DarwinAArch64AsmBackend(T, MRI);
+
+ assert(TheTriple.isOSBinFormatELF() && "Expect either MachO or ELF target");
+ uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TheTriple.getOS());
+ return new ELFAArch64AsmBackend(T, OSABI, /*IsLittleEndian=*/true);
+}
- return new ELFAArch64AsmBackend(T, TT, TheTriple.getOS());
+MCAsmBackend *llvm::createAArch64beAsmBackend(const Target &T,
+ const MCRegisterInfo &MRI,
+ const Triple &TheTriple,
+ StringRef CPU) {
+ assert(TheTriple.isOSBinFormatELF() &&
+ "Big endian is only supported for ELF targets!");
+ uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TheTriple.getOS());
+ return new ELFAArch64AsmBackend(T, OSABI,
+ /*IsLittleEndian=*/false);
}
projects / oota-llvm.git / blobdiff