//
//===----------------------------------------------------------------------===//
-#include "MCTargetDesc/ARMMCTargetDesc.h"
+#include "MCTargetDesc/ARMAsmBackend.h"
#include "MCTargetDesc/ARMAddressingModes.h"
+#include "MCTargetDesc/ARMAsmBackendDarwin.h"
+#include "MCTargetDesc/ARMAsmBackendELF.h"
+#include "MCTargetDesc/ARMAsmBackendWinCOFF.h"
#include "MCTargetDesc/ARMBaseInfo.h"
#include "MCTargetDesc/ARMFixupKinds.h"
+#include "MCTargetDesc/ARMMCTargetDesc.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCFixupKindInfo.h"
#include "llvm/MC/MCMachObjectWriter.h"
#include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCValue.h"
-#include "llvm/Object/MachOFormat.h"
+#include "llvm/Support/Debug.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/MachO.h"
+#include "llvm/Support/TargetParser.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
class ARMELFObjectWriter : public MCELFObjectTargetWriter {
public:
ARMELFObjectWriter(uint8_t OSABI)
- : MCELFObjectTargetWriter(/*Is64Bit*/ false, OSABI, ELF::EM_ARM,
- /*HasRelocationAddend*/ false) {}
+ : MCELFObjectTargetWriter(/*Is64Bit*/ false, OSABI, ELF::EM_ARM,
+ /*HasRelocationAddend*/ false) {}
};
+} // end anonymous namespace
-class ARMAsmBackend : public MCAsmBackend {
- const MCSubtargetInfo* STI;
- bool isThumbMode; // Currently emitting Thumb code.
-public:
- ARMAsmBackend(const Target &T, const StringRef TT)
- : MCAsmBackend(), STI(ARM_MC::createARMMCSubtargetInfo(TT, "", "")),
- isThumbMode(TT.startswith("thumb")) {}
-
- ~ARMAsmBackend() {
- delete STI;
- }
-
- unsigned getNumFixupKinds() const { return ARM::NumTargetFixupKinds; }
-
- bool hasNOP() const {
- return (STI->getFeatureBits() & ARM::HasV6T2Ops) != 0;
- }
+const MCFixupKindInfo &ARMAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
+ 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, MCFixupKindInfo::FKF_IsPCRel},
+ {"fixup_t2_ldst_pcrel_12", 0, 32,
+ MCFixupKindInfo::FKF_IsPCRel |
+ MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+ {"fixup_arm_pcrel_10_unscaled", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+ {"fixup_arm_pcrel_10", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+ {"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,
+ MCFixupKindInfo::FKF_IsPCRel |
+ MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+ {"fixup_thumb_adr_pcrel_10", 0, 8,
+ MCFixupKindInfo::FKF_IsPCRel |
+ MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+ {"fixup_arm_adr_pcrel_12", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+ {"fixup_t2_adr_pcrel_12", 0, 32,
+ MCFixupKindInfo::FKF_IsPCRel |
+ 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},
+ };
+ 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, MCFixupKindInfo::FKF_IsPCRel},
+ {"fixup_t2_ldst_pcrel_12", 0, 32,
+ MCFixupKindInfo::FKF_IsPCRel |
+ MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+ {"fixup_arm_pcrel_10_unscaled", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+ {"fixup_arm_pcrel_10", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+ {"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,
+ MCFixupKindInfo::FKF_IsPCRel |
+ MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+ {"fixup_thumb_adr_pcrel_10", 8, 8,
+ MCFixupKindInfo::FKF_IsPCRel |
+ MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
+ {"fixup_arm_adr_pcrel_12", 0, 32, MCFixupKindInfo::FKF_IsPCRel},
+ {"fixup_t2_adr_pcrel_12", 0, 32,
+ MCFixupKindInfo::FKF_IsPCRel |
+ 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},
+ };
+
+ if (Kind < FirstTargetFixupKind)
+ return MCAsmBackend::getFixupKindInfo(Kind);
+
+ assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
+ "Invalid kind!");
+ return (IsLittleEndian ? InfosLE : InfosBE)[Kind - FirstTargetFixupKind];
+}
- const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
- const static MCFixupKindInfo Infos[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, MCFixupKindInfo::FKF_IsPCRel },
-{ "fixup_t2_ldst_pcrel_12", 0, 32, MCFixupKindInfo::FKF_IsPCRel |
- MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
-{ "fixup_arm_pcrel_10_unscaled", 0, 32, MCFixupKindInfo::FKF_IsPCRel },
-{ "fixup_arm_pcrel_10", 0, 32, MCFixupKindInfo::FKF_IsPCRel },
-{ "fixup_t2_pcrel_10", 0, 32, MCFixupKindInfo::FKF_IsPCRel |
- MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
-{ "fixup_thumb_adr_pcrel_10",0, 8, MCFixupKindInfo::FKF_IsPCRel |
- MCFixupKindInfo::FKF_IsAlignedDownTo32Bits},
-{ "fixup_arm_adr_pcrel_12", 0, 32, MCFixupKindInfo::FKF_IsPCRel },
-{ "fixup_t2_adr_pcrel_12", 0, 32, MCFixupKindInfo::FKF_IsPCRel |
- 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 },
-{ "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_movt_hi16_pcrel", 0, 20, MCFixupKindInfo::FKF_IsPCRel },
-{ "fixup_arm_movw_lo16_pcrel", 0, 20, MCFixupKindInfo::FKF_IsPCRel },
-{ "fixup_t2_movt_hi16_pcrel", 0, 20, MCFixupKindInfo::FKF_IsPCRel },
-{ "fixup_t2_movw_lo16_pcrel", 0, 20, MCFixupKindInfo::FKF_IsPCRel },
- };
-
- if (Kind < FirstTargetFixupKind)
- return MCAsmBackend::getFixupKindInfo(Kind);
-
- assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
- "Invalid kind!");
- return Infos[Kind - FirstTargetFixupKind];
- }
-
- /// processFixupValue - Target hook to process the literal value of a fixup
- /// if necessary.
- void processFixupValue(const MCAssembler &Asm, const MCAsmLayout &Layout,
- const MCFixup &Fixup, const MCFragment *DF,
- MCValue &Target, uint64_t &Value,
- bool &IsResolved);
-
-
- void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
- uint64_t Value) const;
-
- bool mayNeedRelaxation(const MCInst &Inst) const;
-
- bool fixupNeedsRelaxation(const MCFixup &Fixup,
- uint64_t Value,
- const MCRelaxableFragment *DF,
- const MCAsmLayout &Layout) const;
-
- void relaxInstruction(const MCInst &Inst, MCInst &Res) const;
-
- bool writeNopData(uint64_t Count, MCObjectWriter *OW) const;
-
- void handleAssemblerFlag(MCAssemblerFlag Flag) {
- switch (Flag) {
- default: break;
- case MCAF_Code16:
- setIsThumb(true);
- break;
- case MCAF_Code32:
- setIsThumb(false);
- break;
- }
+void ARMAsmBackend::handleAssemblerFlag(MCAssemblerFlag Flag) {
+ switch (Flag) {
+ default:
+ break;
+ case MCAF_Code16:
+ setIsThumb(true);
+ break;
+ case MCAF_Code32:
+ setIsThumb(false);
+ break;
}
+}
- unsigned getPointerSize() const { return 4; }
- bool isThumb() const { return isThumbMode; }
- void setIsThumb(bool it) { isThumbMode = it; }
-};
-} // end anonymous namespace
+unsigned ARMAsmBackend::getRelaxedOpcode(unsigned Op) const {
+ bool HasThumb2 = STI->getFeatureBits()[ARM::FeatureThumb2];
+ bool HasV8MBaselineOps = STI->getFeatureBits()[ARM::HasV8MBaselineOps];
-static unsigned getRelaxedOpcode(unsigned Op) {
switch (Op) {
- default: return Op;
- case ARM::tBcc: return ARM::t2Bcc;
- case ARM::tLDRpciASM: return ARM::t2LDRpci;
- case ARM::tADR: return ARM::t2ADR;
- case ARM::tB: return ARM::t2B;
+ 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;
}
}
return false;
}
-bool ARMAsmBackend::fixupNeedsRelaxation(const MCFixup &Fixup,
- uint64_t Value,
- const MCRelaxableFragment *DF,
- const MCAsmLayout &Layout) const {
+const char *ARMAsmBackend::reasonForFixupRelaxation(const MCFixup &Fixup,
+ uint64_t Value) const {
switch ((unsigned)Fixup.getKind()) {
case ARM::fixup_arm_thumb_br: {
// Relaxing tB to t2B. tB has a signed 12-bit displacement with the
//
// Relax if the value is too big for a (signed) i8.
int64_t Offset = int64_t(Value) - 4;
- return Offset > 2046 || Offset < -2048;
+ 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
//
// Relax if the value is too big for a (signed) i8.
int64_t Offset = int64_t(Value) - 4;
- return Offset > 254 || Offset < -256;
+ 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;
- return Offset > 1020 || Offset < 0 || Offset & 3;
+ 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 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;
}
+ default:
+ llvm_unreachable("Unexpected fixup kind in reasonForFixupRelaxation()!");
}
- llvm_unreachable("Unexpected fixup kind in fixupNeedsRelaxation()!");
+ return nullptr;
+}
+
+bool ARMAsmBackend::fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
+ const MCRelaxableFragment *DF,
+ const MCAsmLayout &Layout) const {
+ return reasonForFixupRelaxation(Fixup, Value);
}
-void ARMAsmBackend::relaxInstruction(const MCInst &Inst, MCInst &Res) const {
+void ARMAsmBackend::relaxInstruction(const MCInst &Inst,
+ const MCSubtargetInfo &STI,
+ MCInst &Res) const {
unsigned RelaxedOp = getRelaxedOpcode(Inst.getOpcode());
// Sanity check w/ diagnostic if we get here w/ a bogus instruction.
report_fatal_error("unexpected instruction to relax: " + OS.str());
}
- // The instructions we're relaxing have (so far) the same operands.
+ // 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) {
+ Res.setOpcode(RelaxedOp);
+ Res.addOperand(MCOperand::createImm(0));
+ Res.addOperand(MCOperand::createImm(14));
+ Res.addOperand(MCOperand::createReg(0));
+ return;
+ }
+
+ // The rest of instructions we're relaxing have the same operands.
// We just need to update to the proper opcode.
Res = Inst;
Res.setOpcode(RelaxedOp);
bool ARMAsmBackend::writeNopData(uint64_t Count, MCObjectWriter *OW) 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 ARMv4_NopEncoding = 0xe1a00000; // using MOV r0,r0
const uint32_t ARMv6T2_NopEncoding = 0xe320f000; // NOP
if (isThumb()) {
- const uint16_t nopEncoding = hasNOP() ? Thumb2_16bitNopEncoding
- : Thumb1_16bitNopEncoding;
+ const uint16_t nopEncoding =
+ hasNOP() ? Thumb2_16bitNopEncoding : Thumb1_16bitNopEncoding;
uint64_t NumNops = Count / 2;
for (uint64_t i = 0; i != NumNops; ++i)
- OW->Write16(nopEncoding);
+ OW->write16(nopEncoding);
if (Count & 1)
- OW->Write8(0);
+ OW->write8(0);
return true;
}
// ARM mode
- const uint32_t nopEncoding = hasNOP() ? ARMv6T2_NopEncoding
- : ARMv4_NopEncoding;
+ const uint32_t nopEncoding =
+ hasNOP() ? ARMv6T2_NopEncoding : ARMv4_NopEncoding;
uint64_t NumNops = Count / 4;
for (uint64_t i = 0; i != NumNops; ++i)
- OW->Write32(nopEncoding);
+ OW->write32(nopEncoding);
// 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: OW->Write8(0); break;
- case 2: OW->Write16(0); break;
- case 3: OW->Write16(0); OW->Write8(0xa0); break;
+ default:
+ break; // No leftover bytes to write
+ case 1:
+ OW->write8(0);
+ break;
+ case 2:
+ OW->write16(0);
+ break;
+ case 3:
+ OW->write16(0);
+ OW->write8(0xa0);
+ break;
}
return true;
}
-static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
- MCContext *Ctx = NULL) {
+static 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;
+}
+
+static 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;
+}
+
+unsigned ARMAsmBackend::adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
+ bool IsPCRel, MCContext &Ctx,
+ bool IsLittleEndian,
+ bool IsResolved) const {
unsigned Kind = Fixup.getKind();
switch (Kind) {
default:
- llvm_unreachable("Unknown fixup kind!");
+ Ctx.reportError(Fixup.getLoc(), "bad relocation fixup type");
+ 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:
- Value >>= 16;
- // Fallthrough
- case ARM::fixup_arm_movw_lo16:
- case ARM::fixup_arm_movt_hi16_pcrel:
- case ARM::fixup_arm_movw_lo16_pcrel: {
+ if (!IsPCRel)
+ Value >>= 16;
+ LLVM_FALLTHROUGH;
+ case ARM::fixup_arm_movw_lo16: {
unsigned Hi4 = (Value & 0xF000) >> 12;
unsigned Lo12 = Value & 0x0FFF;
// inst{19-16} = Hi4;
return Value;
}
case ARM::fixup_t2_movt_hi16:
- Value >>= 16;
- // Fallthrough
- case ARM::fixup_t2_movw_lo16:
- case ARM::fixup_t2_movt_hi16_pcrel: //FIXME: Shouldn't this be shifted like
- // the other hi16 fixup?
- case ARM::fixup_t2_movw_lo16_pcrel: {
+ if (!IsPCRel)
+ Value >>= 16;
+ LLVM_FALLTHROUGH;
+ case ARM::fixup_t2_movw_lo16: {
unsigned Hi4 = (Value & 0xF000) >> 12;
unsigned i = (Value & 0x800) >> 11;
unsigned Mid3 = (Value & 0x700) >> 8;
// inst{14-12} = Mid3;
// inst{7-0} = Lo8;
Value = (Hi4 << 16) | (i << 26) | (Mid3 << 12) | (Lo8);
- uint64_t swapped = (Value & 0xFFFF0000) >> 16;
- swapped |= (Value & 0x0000FFFF) << 16;
- return swapped;
+ return swapHalfWords(Value, IsLittleEndian);
}
case ARM::fixup_arm_ldst_pcrel_12:
// ARM PC-relative values are offset by 8.
Value -= 4;
- // FALLTHROUGH
+ LLVM_FALLTHROUGH;
case ARM::fixup_t2_ldst_pcrel_12: {
// Offset by 4, adjusted by two due to the half-word ordering of thumb.
Value -= 4;
Value = -Value;
isAdd = false;
}
- if (Ctx && Value >= 4096)
- Ctx->FatalError(Fixup.getLoc(), "out of range pc-relative fixup value");
+ 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) {
- uint64_t swapped = (Value & 0xFFFF0000) >> 16;
- swapped |= (Value & 0x0000FFFF) << 16;
- return swapped;
- }
+ if (Kind == ARM::fixup_t2_ldst_pcrel_12)
+ return swapHalfWords(Value, IsLittleEndian);
return Value;
}
- case ARM::fixup_thumb_adr_pcrel_10:
- return ((Value - 4) >> 2) & 0xff;
case ARM::fixup_arm_adr_pcrel_12: {
// ARM PC-relative values are offset by 8.
Value -= 8;
Value = -Value;
opc = 2; // 0b0010
}
- if (Ctx && ARM_AM::getSOImmVal(Value) == -1)
- Ctx->FatalError(Fixup.getLoc(), "out of range pc-relative fixup value");
+ 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);
}
out |= (Value & 0x700) << 4;
out |= (Value & 0x0FF);
- uint64_t swapped = (out & 0xFFFF0000) >> 16;
- swapped |= (out & 0x0000FFFF) << 16;
- return swapped;
+ return swapHalfWords(out, IsLittleEndian);
}
case ARM::fixup_arm_condbranch:
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;
Value >>= 1; // Low bit is not encoded.
uint32_t out = 0;
- bool I = Value & 0x800000;
+ 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
+ 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
- uint64_t swapped = (out & 0xFFFF0000) >> 16;
- swapped |= (out & 0x0000FFFF) << 16;
- return swapped;
+ return swapHalfWords(out, IsLittleEndian);
}
case ARM::fixup_t2_condbranch: {
Value = Value - 4;
out |= (Value & 0x1F800) << 5; // imm6 field
out |= (Value & 0x007FF); // imm11 field
- uint32_t swapped = (out & 0xFFFF0000) >> 16;
- swapped |= (out & 0x0000FFFF) << 16;
- return swapped;
+ return swapHalfWords(out, IsLittleEndian);
}
case ARM::fixup_arm_thumb_bl: {
- // 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 Binary = 0;
- uint32_t firstHalf = (((uint16_t)signBit << 10) | (uint16_t)imm10Bits);
- uint32_t secondHalf = (((uint16_t)J1Bit << 13) | ((uint16_t)J2Bit << 11) |
+ // 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);
- Binary |= secondHalf << 16;
- Binary |= firstHalf;
- return Binary;
-
+ return joinHalfWords(FirstHalf, SecondHalf, IsLittleEndian);
}
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.
- uint32_t offset = (Value - 2) >> 2;
- 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 Binary = 0;
- uint32_t firstHalf = (((uint16_t)signBit << 10) | (uint16_t)imm10HBits);
- uint32_t secondHalf = (((uint16_t)J1Bit << 13) | ((uint16_t)J2Bit << 11) |
+ // 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);
- Binary |= secondHalf << 16;
- Binary |= firstHalf;
- return Binary;
+ return joinHalfWords(FirstHalf, SecondHalf, IsLittleEndian);
}
+ case ARM::fixup_thumb_adr_pcrel_10:
case ARM::fixup_arm_thumb_cp:
- // Offset by 4, and don't encode the low two bits. Two bytes of that
- // 'off by 4' is implicitly handled by the half-word ordering of the
- // Thumb encoding, so we only need to adjust by 2 here.
- return ((Value - 2) >> 2) & 0xff;
+ // On CPUs supporting Thumb2, this will be relaxed to an ldr.w, otherwise we
+ // could have an error on our hands.
+ if (!STI->getFeatureBits()[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.
+ if (!STI->getFeatureBits()[ARM::FeatureThumb2] &&
+ !STI->getFeatureBits()[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.
+ if (!STI->getFeatureBits()[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
isAdd = false;
}
// The value has the low 4 bits encoded in [3:0] and the high 4 in [11:8].
- if (Ctx && Value >= 256)
- Ctx->FatalError(Fixup.getLoc(), "out of range pc-relative fixup value");
+ 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.
- // Fall through.
+ LLVM_FALLTHROUGH;
case ARM::fixup_t2_pcrel_10: {
// Offset by 4, adjusted by two due to the half-word ordering of thumb.
Value = Value - 4;
}
// These values don't encode the low two bits since they're always zero.
Value >>= 2;
- if (Ctx && Value >= 256)
- Ctx->FatalError(Fixup.getLoc(), "out of range pc-relative fixup value");
+ 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) {
- uint32_t swapped = (Value & 0xFFFF0000) >> 16;
- swapped |= (Value & 0x0000FFFF) << 16;
- return swapped;
+ if (Kind == ARM::fixup_t2_pcrel_10)
+ return swapHalfWords(Value, IsLittleEndian);
+
+ 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.
+ LLVM_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, IsLittleEndian);
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, IsLittleEndian);
+ }
}
}
const MCAsmLayout &Layout,
const MCFixup &Fixup,
const MCFragment *DF,
- MCValue &Target, uint64_t &Value,
+ const MCValue &Target, uint64_t &Value,
bool &IsResolved) {
const MCSymbolRefExpr *A = Target.getSymA();
- // Some fixups to thumb function symbols need the low bit (thumb bit)
- // twiddled.
- if ((unsigned)Fixup.getKind() != ARM::fixup_arm_ldst_pcrel_12 &&
- (unsigned)Fixup.getKind() != ARM::fixup_t2_ldst_pcrel_12 &&
- (unsigned)Fixup.getKind() != ARM::fixup_arm_adr_pcrel_12 &&
- (unsigned)Fixup.getKind() != ARM::fixup_thumb_adr_pcrel_10 &&
- (unsigned)Fixup.getKind() != ARM::fixup_t2_adr_pcrel_12 &&
- (unsigned)Fixup.getKind() != ARM::fixup_arm_thumb_cp) {
- if (A) {
- const MCSymbol &Sym = A->getSymbol().AliasedSymbol();
- if (Asm.isThumbFunc(&Sym))
+ const MCSymbol *Sym = A ? &A->getSymbol() : nullptr;
+ // MachO (the only user of "Value") 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 ((unsigned)Fixup.getKind() == FK_Data_4 ||
+ (unsigned)Fixup.getKind() == ARM::fixup_arm_movw_lo16 ||
+ (unsigned)Fixup.getKind() == ARM::fixup_arm_movt_hi16 ||
+ (unsigned)Fixup.getKind() == ARM::fixup_t2_movw_lo16 ||
+ (unsigned)Fixup.getKind() == ARM::fixup_t2_movt_hi16) {
+ if (Sym) {
+ if (Asm.isThumbFunc(Sym))
Value |= 1;
}
}
+ if (IsResolved && (unsigned)Fixup.getKind() == ARM::fixup_arm_thumb_bl) {
+ assert(Sym && "How did we resolve this?");
+
+ // 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() || Value >= 0x400004)
+ IsResolved = false;
+ // When an ARM function is called from a Thumb function, produce a
+ // relocation so the linker will use the correct branch instruction for ELF
+ // binaries.
+ if (Sym->isELF()) {
+ unsigned Type = dyn_cast<MCSymbolELF>(Sym)->getType();
+ if ((Type == ELF::STT_FUNC || Type == ELF::STT_GNU_IFUNC) &&
+ !Asm.isThumbFunc(Sym))
+ IsResolved = false;
+ }
+ }
// 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 && ((unsigned)Fixup.getKind() == ARM::fixup_arm_thumb_blx ||
- (unsigned)Fixup.getKind() == ARM::fixup_arm_thumb_bl ||
(unsigned)Fixup.getKind() == ARM::fixup_arm_blx ||
(unsigned)Fixup.getKind() == ARM::fixup_arm_uncondbl ||
(unsigned)Fixup.getKind() == ARM::fixup_arm_condbl))
IsResolved = false;
-
- // Try to get the encoded value for the fixup as-if we're mapping it into
- // the instruction. This allows adjustFixupValue() to issue a diagnostic
- // if the value aren't invalid.
- (void)adjustFixupValue(Fixup, Value, &Asm.getContext());
}
/// getFixupKindNumBytes - The number of bytes the fixup may change.
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_adr_pcrel_12:
case ARM::fixup_arm_uncondbl:
case ARM::fixup_arm_condbl:
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_arm_movt_hi16_pcrel:
- case ARM::fixup_arm_movw_lo16_pcrel:
case ARM::fixup_t2_movt_hi16:
case ARM::fixup_t2_movw_lo16:
- case ARM::fixup_t2_movt_hi16_pcrel:
- case ARM::fixup_t2_movw_lo16_pcrel:
+ case ARM::fixup_t2_so_imm:
+ return 4;
+
+ case FK_SecRel_2:
+ return 2;
+ case FK_SecRel_4:
+ return 4;
+ }
+}
+
+/// getFixupKindContainerSizeBytes - The number of bytes of the
+/// container involved in big endian.
+static unsigned getFixupKindContainerSizeBytes(unsigned Kind) {
+ switch (Kind) {
+ default:
+ llvm_unreachable("Unknown fixup kind!");
+
+ 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_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_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:
+ // Instruction size is 4 bytes.
return 4;
}
}
void ARMAsmBackend::applyFixup(const MCFixup &Fixup, char *Data,
- unsigned DataSize, uint64_t Value) const {
+ unsigned DataSize, uint64_t Value, bool IsPCRel,
+ MCContext &Ctx) const {
unsigned NumBytes = getFixupKindNumBytes(Fixup.getKind());
- Value = adjustFixupValue(Fixup, Value);
- if (!Value) return; // Doesn't change encoding.
+ Value = adjustFixupValue(Fixup, Value, IsPCRel, Ctx, IsLittleEndian, true);
+ if (!Value)
+ return; // Doesn't change encoding.
unsigned Offset = Fixup.getOffset();
assert(Offset + NumBytes <= DataSize && "Invalid fixup offset!");
+ // Used to point to big endian bytes.
+ unsigned FullSizeBytes;
+ if (!IsLittleEndian) {
+ FullSizeBytes = getFixupKindContainerSizeBytes(Fixup.getKind());
+ assert((Offset + FullSizeBytes) <= DataSize && "Invalid fixup size!");
+ assert(NumBytes <= FullSizeBytes && "Invalid fixup size!");
+ }
+
// 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)
- Data[Offset + i] |= uint8_t((Value >> (i * 8)) & 0xff);
+ for (unsigned i = 0; i != NumBytes; ++i) {
+ unsigned Idx = IsLittleEndian ? i : (FullSizeBytes - 1 - i);
+ Data[Offset + Idx] |= uint8_t((Value >> (i * 8)) & 0xff);
+ }
}
-namespace {
+namespace CU {
-// FIXME: This should be in a separate file.
-// ELF is an ELF of course...
-class ELFARMAsmBackend : public ARMAsmBackend {
-public:
- uint8_t OSABI;
- ELFARMAsmBackend(const Target &T, const StringRef TT,
- uint8_t _OSABI)
- : ARMAsmBackend(T, TT), OSABI(_OSABI) { }
+/// \brief Compact unwind encoding values.
+enum CompactUnwindEncodings {
+ UNWIND_ARM_MODE_MASK = 0x0F000000,
+ UNWIND_ARM_MODE_FRAME = 0x01000000,
+ UNWIND_ARM_MODE_FRAME_D = 0x02000000,
+ UNWIND_ARM_MODE_DWARF = 0x04000000,
- MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
- return createARMELFObjectWriter(OS, OSABI);
- }
+ 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
};
-// FIXME: This should be in a separate file.
-class DarwinARMAsmBackend : public ARMAsmBackend {
-public:
- const object::mach::CPUSubtypeARM Subtype;
- DarwinARMAsmBackend(const Target &T, const StringRef TT,
- object::mach::CPUSubtypeARM st)
- : ARMAsmBackend(T, TT), Subtype(st) {
- HasDataInCodeSupport = true;
+} // end CU namespace
+
+/// Generate compact unwind encoding for the function based on the CFI
+/// instructions. If the CFI instructions describe a frame that cannot be
+/// encoded in compact unwind, the method returns UNWIND_ARM_MODE_DWARF which
+/// tells the runtime to fallback and unwind using dwarf.
+uint32_t ARMAsmBackendDarwin::generateCompactUnwindEncoding(
+ ArrayRef<MCCFIInstruction> Instrs) const {
+ DEBUG_WITH_TYPE("compact-unwind", llvm::dbgs() << "generateCU()\n");
+ // 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.
+ int 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 (size_t i = 0, e = Instrs.size(); i != e; ++i) {
+ int Reg;
+ const MCCFIInstruction &Inst = Instrs[i];
+ 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",
+ llvm::dbgs() << ".cfi_offset on unknown register="
+ << Inst.getRegister() << "\n");
+ 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",
+ llvm::dbgs()
+ << "CFI directive not compatiable with comact "
+ "unwind encoding, opcode=" << Inst.getOperation()
+ << "\n");
+ return CU::UNWIND_ARM_MODE_DWARF;
+ break;
}
+ }
+
+ // If no frame set up, return no unwind info.
+ if ((CFARegister == ARM::SP) && (CFARegisterOffset == 0))
+ return 0;
- MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
- return createARMMachObjectWriter(OS, /*Is64Bit=*/false,
- object::mach::CTM_ARM,
- Subtype);
+ // Verify standard frame (lr/r7) was used.
+ if (CFARegister != ARM::R7) {
+ DEBUG_WITH_TYPE("compact-unwind", llvm::dbgs() << "frame register is "
+ << CFARegister
+ << " instead of r7\n");
+ return CU::UNWIND_ARM_MODE_DWARF;
+ }
+ int StackAdjust = CFARegisterOffset - 8;
+ if (RegOffsets.lookup(ARM::LR) != (-4 - StackAdjust)) {
+ DEBUG_WITH_TYPE("compact-unwind",
+ llvm::dbgs()
+ << "LR not saved as standard frame, StackAdjust="
+ << StackAdjust
+ << ", CFARegisterOffset=" << CFARegisterOffset
+ << ", lr save at offset=" << RegOffsets[14] << "\n");
+ return CU::UNWIND_ARM_MODE_DWARF;
+ }
+ if (RegOffsets.lookup(ARM::R7) != (-8 - StackAdjust)) {
+ DEBUG_WITH_TYPE("compact-unwind",
+ llvm::dbgs() << "r7 not saved as standard frame\n");
+ 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()
+ << ".cfi_def_cfa stack adjust ("
+ << StackAdjust << ") out of range\n");
+ return CU::UNWIND_ARM_MODE_DWARF;
}
- virtual bool doesSectionRequireSymbols(const MCSection &Section) const {
- return false;
+ // 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",
+ llvm::dbgs() << MRI.getName(CSReg.Reg) << " saved at "
+ << RegOffset << " but only supported at "
+ << CurOffset << "\n");
+ return CU::UNWIND_ARM_MODE_DWARF;
+ }
+ CompactUnwindEncoding |= CSReg.Encoding;
+ CurOffset -= 4;
}
-};
-} // end anonymous namespace
+ // 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",
+ llvm::dbgs() << "unsupported number of D registers saved ("
+ << FloatRegCount << ")\n");
+ return CU::UNWIND_ARM_MODE_DWARF;
+ }
-MCAsmBackend *llvm::createARMAsmBackend(const Target &T, StringRef TT, StringRef CPU) {
- Triple TheTriple(TT);
+ // 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",
+ llvm::dbgs() << FloatRegCount << " D-regs saved, but "
+ << MRI.getName(FPRCSRegs[Idx])
+ << " not saved\n");
+ return CU::UNWIND_ARM_MODE_DWARF;
+ } else if (Offset->second != CurOffset - 8) {
+ DEBUG_WITH_TYPE("compact-unwind",
+ llvm::dbgs() << FloatRegCount << " D-regs saved, but "
+ << MRI.getName(FPRCSRegs[Idx])
+ << " saved at " << Offset->second
+ << ", expected at " << CurOffset - 8
+ << "\n");
+ return CU::UNWIND_ARM_MODE_DWARF;
+ }
+ CurOffset -= 8;
+ }
- if (TheTriple.isOSDarwin()) {
- object::mach::CPUSubtypeARM CS =
- StringSwitch<object::mach::CPUSubtypeARM>(TheTriple.getArchName())
- .Cases("armv4t", "thumbv4t", object::mach::CSARM_V4T)
- .Cases("armv5e", "thumbv5e",object::mach::CSARM_V5TEJ)
- .Cases("armv6", "thumbv6", object::mach::CSARM_V6)
- .Cases("armv6m", "thumbv6m", object::mach::CSARM_V6M)
- .Cases("armv7em", "thumbv7em", object::mach::CSARM_V7EM)
- .Cases("armv7f", "thumbv7f", object::mach::CSARM_V7F)
- .Cases("armv7k", "thumbv7k", object::mach::CSARM_V7K)
- .Cases("armv7m", "thumbv7m", object::mach::CSARM_V7M)
- .Cases("armv7s", "thumbv7s", object::mach::CSARM_V7S)
- .Default(object::mach::CSARM_V7);
+ return CompactUnwindEncoding | ((FloatRegCount - 1) << 8);
+}
- return new DarwinARMAsmBackend(T, TT, CS);
+static MachO::CPUSubTypeARM getMachOSubTypeFromArch(StringRef Arch) {
+ unsigned AK = ARM::parseArch(Arch);
+ switch (AK) {
+ default:
+ return MachO::CPU_SUBTYPE_ARM_V7;
+ case ARM::AK_ARMV4T:
+ return MachO::CPU_SUBTYPE_ARM_V4T;
+ case ARM::AK_ARMV5T:
+ case ARM::AK_ARMV5TE:
+ case ARM::AK_ARMV5TEJ:
+ return MachO::CPU_SUBTYPE_ARM_V5;
+ case ARM::AK_ARMV6:
+ case ARM::AK_ARMV6K:
+ return MachO::CPU_SUBTYPE_ARM_V6;
+ case ARM::AK_ARMV7A:
+ return MachO::CPU_SUBTYPE_ARM_V7;
+ case ARM::AK_ARMV7S:
+ return MachO::CPU_SUBTYPE_ARM_V7S;
+ case ARM::AK_ARMV7K:
+ return MachO::CPU_SUBTYPE_ARM_V7K;
+ case ARM::AK_ARMV6M:
+ return MachO::CPU_SUBTYPE_ARM_V6M;
+ case ARM::AK_ARMV7M:
+ return MachO::CPU_SUBTYPE_ARM_V7M;
+ case ARM::AK_ARMV7EM:
+ return MachO::CPU_SUBTYPE_ARM_V7EM;
}
+}
- if (TheTriple.isOSWindows())
- assert(0 && "Windows not supported on ARM");
+MCAsmBackend *llvm::createARMAsmBackend(const Target &T,
+ const MCRegisterInfo &MRI,
+ const Triple &TheTriple, StringRef CPU,
+ const MCTargetOptions &Options,
+ bool isLittle) {
+ switch (TheTriple.getObjectFormat()) {
+ default:
+ llvm_unreachable("unsupported object format");
+ case Triple::MachO: {
+ MachO::CPUSubTypeARM CS = getMachOSubTypeFromArch(TheTriple.getArchName());
+ return new ARMAsmBackendDarwin(T, TheTriple, MRI, CS);
+ }
+ case Triple::COFF:
+ assert(TheTriple.isOSWindows() && "non-Windows ARM COFF is not supported");
+ return new ARMAsmBackendWinCOFF(T, TheTriple);
+ case Triple::ELF:
+ assert(TheTriple.isOSBinFormatELF() && "using ELF for non-ELF target");
+ uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TheTriple.getOS());
+ return new ARMAsmBackendELF(T, TheTriple, OSABI, isLittle);
+ }
+}
+
+MCAsmBackend *llvm::createARMLEAsmBackend(const Target &T,
+ const MCRegisterInfo &MRI,
+ const Triple &TT, StringRef CPU,
+ const MCTargetOptions &Options) {
+ return createARMAsmBackend(T, MRI, TT, CPU, Options, true);
+}
+
+MCAsmBackend *llvm::createARMBEAsmBackend(const Target &T,
+ const MCRegisterInfo &MRI,
+ const Triple &TT, StringRef CPU,
+ const MCTargetOptions &Options) {
+ return createARMAsmBackend(T, MRI, TT, CPU, Options, false);
+}
+
+MCAsmBackend *llvm::createThumbLEAsmBackend(const Target &T,
+ const MCRegisterInfo &MRI,
+ const Triple &TT, StringRef CPU,
+ const MCTargetOptions &Options) {
+ return createARMAsmBackend(T, MRI, TT, CPU, Options, true);
+}
- uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(Triple(TT).getOS());
- return new ELFARMAsmBackend(T, TT, OSABI);
+MCAsmBackend *llvm::createThumbBEAsmBackend(const Target &T,
+ const MCRegisterInfo &MRI,
+ const Triple &TT, StringRef CPU,
+ const MCTargetOptions &Options) {
+ return createARMAsmBackend(T, MRI, TT, CPU, Options, false);
}