diff options
Diffstat (limited to 'contrib/llvm/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp')
-rw-r--r-- | contrib/llvm/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp b/contrib/llvm/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp new file mode 100644 index 0000000..b6dd595 --- /dev/null +++ b/contrib/llvm/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp @@ -0,0 +1,240 @@ +//===-- PPCAsmBackend.cpp - PPC Assembler Backend -------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "MCTargetDesc/PPCMCTargetDesc.h" +#include "MCTargetDesc/PPCFixupKinds.h" +#include "llvm/MC/MCAsmBackend.h" +#include "llvm/MC/MCAssembler.h" +#include "llvm/MC/MCELFObjectWriter.h" +#include "llvm/MC/MCFixupKindInfo.h" +#include "llvm/MC/MCMachObjectWriter.h" +#include "llvm/MC/MCObjectWriter.h" +#include "llvm/MC/MCSectionMachO.h" +#include "llvm/MC/MCSymbolELF.h" +#include "llvm/MC/MCValue.h" +#include "llvm/Support/ELF.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/MachO.h" +#include "llvm/Support/TargetRegistry.h" +using namespace llvm; + +static uint64_t adjustFixupValue(unsigned Kind, uint64_t Value) { + switch (Kind) { + default: + llvm_unreachable("Unknown fixup kind!"); + case FK_Data_1: + case FK_Data_2: + case FK_Data_4: + case FK_Data_8: + case PPC::fixup_ppc_nofixup: + return Value; + case PPC::fixup_ppc_brcond14: + case PPC::fixup_ppc_brcond14abs: + return Value & 0xfffc; + case PPC::fixup_ppc_br24: + case PPC::fixup_ppc_br24abs: + return Value & 0x3fffffc; + case PPC::fixup_ppc_half16: + return Value & 0xffff; + case PPC::fixup_ppc_half16ds: + return Value & 0xfffc; + } +} + +static unsigned getFixupKindNumBytes(unsigned Kind) { + switch (Kind) { + default: + llvm_unreachable("Unknown fixup kind!"); + case FK_Data_1: + return 1; + case FK_Data_2: + case PPC::fixup_ppc_half16: + case PPC::fixup_ppc_half16ds: + return 2; + case FK_Data_4: + case PPC::fixup_ppc_brcond14: + case PPC::fixup_ppc_brcond14abs: + case PPC::fixup_ppc_br24: + case PPC::fixup_ppc_br24abs: + return 4; + case FK_Data_8: + return 8; + case PPC::fixup_ppc_nofixup: + return 0; + } +} + +namespace { + +class PPCAsmBackend : public MCAsmBackend { + const Target &TheTarget; + bool IsLittleEndian; +public: + PPCAsmBackend(const Target &T, bool isLittle) : MCAsmBackend(), TheTarget(T), + IsLittleEndian(isLittle) {} + + unsigned getNumFixupKinds() const override { + return PPC::NumTargetFixupKinds; + } + + const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override { + const static MCFixupKindInfo InfosBE[PPC::NumTargetFixupKinds] = { + // name offset bits flags + { "fixup_ppc_br24", 6, 24, MCFixupKindInfo::FKF_IsPCRel }, + { "fixup_ppc_brcond14", 16, 14, MCFixupKindInfo::FKF_IsPCRel }, + { "fixup_ppc_br24abs", 6, 24, 0 }, + { "fixup_ppc_brcond14abs", 16, 14, 0 }, + { "fixup_ppc_half16", 0, 16, 0 }, + { "fixup_ppc_half16ds", 0, 14, 0 }, + { "fixup_ppc_nofixup", 0, 0, 0 } + }; + const static MCFixupKindInfo InfosLE[PPC::NumTargetFixupKinds] = { + // name offset bits flags + { "fixup_ppc_br24", 2, 24, MCFixupKindInfo::FKF_IsPCRel }, + { "fixup_ppc_brcond14", 2, 14, MCFixupKindInfo::FKF_IsPCRel }, + { "fixup_ppc_br24abs", 2, 24, 0 }, + { "fixup_ppc_brcond14abs", 2, 14, 0 }, + { "fixup_ppc_half16", 0, 16, 0 }, + { "fixup_ppc_half16ds", 2, 14, 0 }, + { "fixup_ppc_nofixup", 0, 0, 0 } + }; + + if (Kind < FirstTargetFixupKind) + return MCAsmBackend::getFixupKindInfo(Kind); + + assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() && + "Invalid kind!"); + return (IsLittleEndian? InfosLE : InfosBE)[Kind - FirstTargetFixupKind]; + } + + void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize, + uint64_t Value, bool IsPCRel) const override { + Value = adjustFixupValue(Fixup.getKind(), Value); + if (!Value) return; // Doesn't change encoding. + + unsigned Offset = Fixup.getOffset(); + unsigned NumBytes = getFixupKindNumBytes(Fixup.getKind()); + + // For each byte of the fragment that the fixup touches, mask in the bits + // from the fixup value. The Value has been "split up" into the appropriate + // bitfields above. + for (unsigned i = 0; i != NumBytes; ++i) { + unsigned Idx = IsLittleEndian ? i : (NumBytes - 1 - i); + Data[Offset + i] |= uint8_t((Value >> (Idx * 8)) & 0xff); + } + } + + void processFixupValue(const MCAssembler &Asm, const MCAsmLayout &Layout, + const MCFixup &Fixup, const MCFragment *DF, + const MCValue &Target, uint64_t &Value, + bool &IsResolved) override { + switch ((PPC::Fixups)Fixup.getKind()) { + default: break; + case PPC::fixup_ppc_br24: + case PPC::fixup_ppc_br24abs: + // If the target symbol has a local entry point we must not attempt + // to resolve the fixup directly. Emit a relocation and leave + // resolution of the final target address to the linker. + if (const MCSymbolRefExpr *A = Target.getSymA()) { + if (const auto *S = dyn_cast<MCSymbolELF>(&A->getSymbol())) { + // The "other" values are stored in the last 6 bits of the second + // byte. The traditional defines for STO values assume the full byte + // and thus the shift to pack it. + unsigned Other = S->getOther() << 2; + if ((Other & ELF::STO_PPC64_LOCAL_MASK) != 0) + IsResolved = false; + } + } + break; + } + } + + bool mayNeedRelaxation(const MCInst &Inst) const override { + // FIXME. + return false; + } + + bool fixupNeedsRelaxation(const MCFixup &Fixup, + uint64_t Value, + const MCRelaxableFragment *DF, + const MCAsmLayout &Layout) const override { + // FIXME. + llvm_unreachable("relaxInstruction() unimplemented"); + } + + + void relaxInstruction(const MCInst &Inst, MCInst &Res) const override { + // FIXME. + llvm_unreachable("relaxInstruction() unimplemented"); + } + + bool writeNopData(uint64_t Count, MCObjectWriter *OW) const override { + uint64_t NumNops = Count / 4; + for (uint64_t i = 0; i != NumNops; ++i) + OW->write32(0x60000000); + + OW->WriteZeros(Count % 4); + + return true; + } + + unsigned getPointerSize() const { + StringRef Name = TheTarget.getName(); + if (Name == "ppc64" || Name == "ppc64le") return 8; + assert(Name == "ppc32" && "Unknown target name!"); + return 4; + } + + bool isLittleEndian() const { + return IsLittleEndian; + } +}; +} // end anonymous namespace + + +// FIXME: This should be in a separate file. +namespace { + class DarwinPPCAsmBackend : public PPCAsmBackend { + public: + DarwinPPCAsmBackend(const Target &T) : PPCAsmBackend(T, false) { } + + MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override { + bool is64 = getPointerSize() == 8; + return createPPCMachObjectWriter( + OS, + /*Is64Bit=*/is64, + (is64 ? MachO::CPU_TYPE_POWERPC64 : MachO::CPU_TYPE_POWERPC), + MachO::CPU_SUBTYPE_POWERPC_ALL); + } + }; + + class ELFPPCAsmBackend : public PPCAsmBackend { + uint8_t OSABI; + public: + ELFPPCAsmBackend(const Target &T, bool IsLittleEndian, uint8_t OSABI) : + PPCAsmBackend(T, IsLittleEndian), OSABI(OSABI) { } + + MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override { + bool is64 = getPointerSize() == 8; + return createPPCELFObjectWriter(OS, is64, isLittleEndian(), OSABI); + } + }; + +} // end anonymous namespace + +MCAsmBackend *llvm::createPPCAsmBackend(const Target &T, + const MCRegisterInfo &MRI, + const Triple &TT, StringRef CPU) { + if (TT.isOSDarwin()) + return new DarwinPPCAsmBackend(T); + + uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TT.getOS()); + bool IsLittleEndian = TT.getArch() == Triple::ppc64le; + return new ELFPPCAsmBackend(T, IsLittleEndian, OSABI); +} |