-//===-- MipsASMBackend.cpp - ---------===//
+//===-- MipsASMBackend.cpp - Mips Asm Backend ----------------------------===//
//
// The LLVM Compiler Infrastructure
//
#include "llvm/Support/ELF.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
+
using namespace llvm;
+// Prepare value for the target space for it
static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
// Add/subtract and shift
switch (Kind) {
default:
+ return 0;
+ case FK_GPRel_4:
+ case FK_Data_4:
+ case Mips::fixup_Mips_LO16:
break;
case Mips::fixup_Mips_PC16:
// So far we are only using this type for branches.
// address range.
Value >>= 2;
break;
- }
-
- // Mask off value for placement as an operand
- switch (Kind) {
- default:
- break;
- case FK_GPRel_4:
- case FK_Data_4:
- Value &= 0xffffffff;
- break;
- case Mips::fixup_Mips_26:
- Value &= 0x03ffffff;
- break;
- case Mips::fixup_Mips_LO16:
- case Mips::fixup_Mips_PC16:
- Value &= 0x0000ffff;
- break;
case Mips::fixup_Mips_HI16:
- Value >>= 16;
+ case Mips::fixup_Mips_GOT_Local:
+ // Get the higher 16-bits. Also add 1 if bit 15 is 1.
+ Value = (Value >> 16) + ((Value & 0x8000) != 0);
break;
}
}
namespace {
-
-class MipsELFObjectWriter : public MCELFObjectTargetWriter {
-public:
- MipsELFObjectWriter(bool is64Bit, Triple::OSType OSType, uint16_t EMachine,
- bool HasRelocationAddend)
- : MCELFObjectTargetWriter(is64Bit, OSType, EMachine,
- HasRelocationAddend) {}
-};
-
class MipsAsmBackend : public MCAsmBackend {
public:
- MipsAsmBackend(const Target &T) : MCAsmBackend() {}
+ uint8_t OSABI;
+ MipsAsmBackend(const Target &T, uint8_t OSABI_) :
+ MCAsmBackend(), OSABI(OSABI_) {}
/// ApplyFixup - Apply the \arg Value for given \arg Fixup into the provided
/// data fragment, at the offset specified by the fixup and following the
/// fixup kind as appropriate.
- void ApplyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
+ void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
uint64_t Value) const {
- unsigned Kind = (unsigned)Fixup.getKind();
- Value = adjustFixupValue(Kind, Value);
+ MCFixupKind Kind = Fixup.getKind();
+ Value = adjustFixupValue((unsigned)Kind, Value);
if (!Value)
- return; // Doesn't change encoding.
+ return; // Doesn't change encoding.
unsigned Offset = Fixup.getOffset();
- switch (Kind) {
- default:
- llvm_unreachable("Unknown fixup kind!");
- case Mips::fixup_Mips_GOT16: // This will be fixed up at link time
- break;
- case FK_GPRel_4:
- case FK_Data_4:
- case Mips::fixup_Mips_26:
- case Mips::fixup_Mips_LO16:
- case Mips::fixup_Mips_PC16:
- case Mips::fixup_Mips_HI16:
- // For each byte of the fragment that the fixup touches, mask i
- // the fixup value. The Value has been "split up" into the appr
- // bitfields above.
- for (unsigned i = 0; i != 4; ++i) // FIXME - Need to support 2 and 8 bytes
- Data[Offset + i] += uint8_t((Value >> (i * 8)) & 0xff);
- break;
+ // FIXME: The below code will not work across endian models
+ // How many bytes/bits are we fixing up?
+ unsigned NumBytes = ((getFixupKindInfo(Kind).TargetSize-1)/8)+1;
+ uint64_t Mask = ((uint64_t)1 << getFixupKindInfo(Kind).TargetSize) - 1;
+
+ // Grab current value, if any, from bits.
+ uint64_t CurVal = 0;
+ for (unsigned i = 0; i != NumBytes; ++i)
+ CurVal |= ((uint8_t)Data[Offset + i]) << (i * 8);
+
+ CurVal = (CurVal & ~Mask) | ((CurVal + Value) & Mask);
+
+ // Write out the bytes back to the code/data bits.
+ // First the unaffected bits and then the fixup.
+ for (unsigned i = 0; i != NumBytes; ++i) {
+ Data[Offset + i] = uint8_t((CurVal >> (i * 8)) & 0xff);
}
- }
+}
unsigned getNumFixupKinds() const { return Mips::NumTargetFixupKinds; }
const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
const static MCFixupKindInfo Infos[Mips::NumTargetFixupKinds] = {
- // This table *must* be in the order that the fixup_* kinds a
+ // This table *must* be in same the order of fixup_* kinds in
// MipsFixupKinds.h.
//
// name offset bits flags
- { "fixup_Mips_NONE", 0, 0, 0 },
{ "fixup_Mips_16", 0, 16, 0 },
{ "fixup_Mips_32", 0, 32, 0 },
{ "fixup_Mips_REL32", 0, 32, 0 },
{ "fixup_Mips_LO16", 0, 16, 0 },
{ "fixup_Mips_GPREL16", 0, 16, 0 },
{ "fixup_Mips_LITERAL", 0, 16, 0 },
- { "fixup_Mips_GOT16", 0, 16, 0 },
+ { "fixup_Mips_GOT_Global", 0, 16, 0 },
+ { "fixup_Mips_GOT_Local", 0, 16, 0 },
{ "fixup_Mips_PC16", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
{ "fixup_Mips_CALL16", 0, 16, 0 },
{ "fixup_Mips_GPREL32", 0, 32, 0 },
{ "fixup_Mips_GOTTPREL", 0, 16, 0 },
{ "fixup_Mips_TPREL_HI", 0, 16, 0 },
{ "fixup_Mips_TPREL_LO", 0, 16, 0 },
+ { "fixup_Mips_TLSLDM", 0, 16, 0 },
+ { "fixup_Mips_DTPREL_HI", 0, 16, 0 },
+ { "fixup_Mips_DTPREL_LO", 0, 16, 0 },
{ "fixup_Mips_Branch_PCRel", 0, 16, MCFixupKindInfo::FKF_IsPCRel }
};
/// relaxation.
///
/// \param Inst - The instruction to test.
- bool MayNeedRelaxation(const MCInst &Inst) const {
+ bool mayNeedRelaxation(const MCInst &Inst) const {
+ return false;
+ }
+
+ /// fixupNeedsRelaxation - Target specific predicate for whether a given
+ /// fixup requires the associated instruction to be relaxed.
+ bool fixupNeedsRelaxation(const MCFixup &Fixup,
+ uint64_t Value,
+ const MCInstFragment *DF,
+ const MCAsmLayout &Layout) const {
+ // FIXME.
+ assert(0 && "RelaxInstruction() unimplemented");
return false;
}
/// \param Inst - The instruction to relax, which may be the same
/// as the output.
/// \parm Res [output] - On return, the relaxed instruction.
- void RelaxInstruction(const MCInst &Inst, MCInst &Res) const {
+ void relaxInstruction(const MCInst &Inst, MCInst &Res) const {
}
-
+
/// @}
/// WriteNopData - Write an (optimal) nop sequence of Count bytes
/// it should return an error.
///
/// \return - True on success.
- bool WriteNopData(uint64_t Count, MCObjectWriter *OW) const {
+ bool writeNopData(uint64_t Count, MCObjectWriter *OW) const {
return true;
}
};
class MipsEB_AsmBackend : public MipsAsmBackend {
public:
- Triple::OSType OSType;
-
- MipsEB_AsmBackend(const Target &T, Triple::OSType _OSType)
- : MipsAsmBackend(T), OSType(_OSType) {}
+ MipsEB_AsmBackend(const Target &T, uint8_t _OSABI)
+ : MipsAsmBackend(T, _OSABI) {}
MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
- return createELFObjectWriter(createELFObjectTargetWriter(),
- OS, /*IsLittleEndian*/ false);
- }
-
- MCELFObjectTargetWriter *createELFObjectTargetWriter() const {
- return new MipsELFObjectWriter(false, OSType, ELF::EM_MIPS, false);
+ return createMipsELFObjectWriter(OS, /*IsLittleEndian*/ false, OSABI);
}
};
class MipsEL_AsmBackend : public MipsAsmBackend {
public:
- Triple::OSType OSType;
-
- MipsEL_AsmBackend(const Target &T, Triple::OSType _OSType)
- : MipsAsmBackend(T), OSType(_OSType) {}
+ MipsEL_AsmBackend(const Target &T, uint8_t _OSABI)
+ : MipsAsmBackend(T, _OSABI) {}
MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
- return createELFObjectWriter(createELFObjectTargetWriter(),
- OS, /*IsLittleEndian*/ true);
- }
-
- MCELFObjectTargetWriter *createELFObjectTargetWriter() const {
- return new MipsELFObjectWriter(false, OSType, ELF::EM_MIPS, false);
+ return createMipsELFObjectWriter(OS, /*IsLittleEndian*/ true, OSABI);
}
};
} // namespace
-MCAsmBackend *llvm::createMipsAsmBackend(const Target &T, StringRef TT) {
- Triple TheTriple(TT);
+MCAsmBackend *llvm::createMipsBEAsmBackend(const Target &T, StringRef TT) {
+ uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(Triple(TT).getOS());
+ return new MipsEB_AsmBackend(T, OSABI);
+}
- // just return little endian for now
- //
- return new MipsEL_AsmBackend(T, Triple(TT).getOS());
+MCAsmBackend *llvm::createMipsLEAsmBackend(const Target &T, StringRef TT) {
+ uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(Triple(TT).getOS());
+ return new MipsEL_AsmBackend(T, OSABI);
}