1 //===-- PPCAsmBackend.cpp - PPC Assembler Backend -------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "MCTargetDesc/PPCMCTargetDesc.h"
11 #include "MCTargetDesc/PPCFixupKinds.h"
12 #include "llvm/MC/MCAsmBackend.h"
13 #include "llvm/MC/MCELFObjectWriter.h"
14 #include "llvm/MC/MCFixupKindInfo.h"
15 #include "llvm/MC/MCMachObjectWriter.h"
16 #include "llvm/MC/MCObjectWriter.h"
17 #include "llvm/MC/MCSectionMachO.h"
18 #include "llvm/MC/MCValue.h"
19 #include "llvm/Object/MachOFormat.h"
20 #include "llvm/Support/ELF.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/Support/TargetRegistry.h"
25 static uint64_t adjustFixupValue(unsigned Kind, uint64_t Value) {
28 llvm_unreachable("Unknown fixup kind!");
33 case PPC::fixup_ppc_nofixup:
35 case PPC::fixup_ppc_brcond14:
36 case PPC::fixup_ppc_brcond14abs:
37 return Value & 0xfffc;
38 case PPC::fixup_ppc_br24:
39 case PPC::fixup_ppc_br24abs:
40 return Value & 0x3fffffc;
41 case PPC::fixup_ppc_half16:
42 return Value & 0xffff;
43 case PPC::fixup_ppc_half16ds:
44 return Value & 0xfffc;
48 static unsigned getFixupKindNumBytes(unsigned Kind) {
51 llvm_unreachable("Unknown fixup kind!");
55 case PPC::fixup_ppc_half16:
56 case PPC::fixup_ppc_half16ds:
59 case PPC::fixup_ppc_brcond14:
60 case PPC::fixup_ppc_brcond14abs:
61 case PPC::fixup_ppc_br24:
62 case PPC::fixup_ppc_br24abs:
66 case PPC::fixup_ppc_nofixup:
72 class PPCMachObjectWriter : public MCMachObjectTargetWriter {
74 PPCMachObjectWriter(bool Is64Bit, uint32_t CPUType,
76 : MCMachObjectTargetWriter(Is64Bit, CPUType, CPUSubtype) {}
78 void RecordRelocation(MachObjectWriter *Writer,
79 const MCAssembler &Asm, const MCAsmLayout &Layout,
80 const MCFragment *Fragment, const MCFixup &Fixup,
81 MCValue Target, uint64_t &FixedValue) {
82 llvm_unreachable("Relocation emission for MachO/PPC unimplemented!");
86 class PPCAsmBackend : public MCAsmBackend {
87 const Target &TheTarget;
89 PPCAsmBackend(const Target &T) : MCAsmBackend(), TheTarget(T) {}
91 unsigned getNumFixupKinds() const { return PPC::NumTargetFixupKinds; }
93 const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
94 const static MCFixupKindInfo Infos[PPC::NumTargetFixupKinds] = {
95 // name offset bits flags
96 { "fixup_ppc_br24", 6, 24, MCFixupKindInfo::FKF_IsPCRel },
97 { "fixup_ppc_brcond14", 16, 14, MCFixupKindInfo::FKF_IsPCRel },
98 { "fixup_ppc_br24abs", 6, 24, 0 },
99 { "fixup_ppc_brcond14abs", 16, 14, 0 },
100 { "fixup_ppc_half16", 0, 16, 0 },
101 { "fixup_ppc_half16ds", 0, 14, 0 },
102 { "fixup_ppc_nofixup", 0, 0, 0 }
105 if (Kind < FirstTargetFixupKind)
106 return MCAsmBackend::getFixupKindInfo(Kind);
108 assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
110 return Infos[Kind - FirstTargetFixupKind];
113 void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
114 uint64_t Value) const {
115 Value = adjustFixupValue(Fixup.getKind(), Value);
116 if (!Value) return; // Doesn't change encoding.
118 unsigned Offset = Fixup.getOffset();
119 unsigned NumBytes = getFixupKindNumBytes(Fixup.getKind());
121 // For each byte of the fragment that the fixup touches, mask in the bits
122 // from the fixup value. The Value has been "split up" into the appropriate
124 for (unsigned i = 0; i != NumBytes; ++i)
125 Data[Offset + i] |= uint8_t((Value >> ((NumBytes - i - 1)*8)) & 0xff);
128 bool mayNeedRelaxation(const MCInst &Inst) const {
133 bool fixupNeedsRelaxation(const MCFixup &Fixup,
135 const MCRelaxableFragment *DF,
136 const MCAsmLayout &Layout) const {
138 llvm_unreachable("relaxInstruction() unimplemented");
142 void relaxInstruction(const MCInst &Inst, MCInst &Res) const {
144 llvm_unreachable("relaxInstruction() unimplemented");
147 bool writeNopData(uint64_t Count, MCObjectWriter *OW) const {
148 // Can't emit NOP with size not multiple of 32-bits
152 uint64_t NumNops = Count / 4;
153 for (uint64_t i = 0; i != NumNops; ++i)
154 OW->Write32(0x60000000);
159 unsigned getPointerSize() const {
160 StringRef Name = TheTarget.getName();
161 if (Name == "ppc64") return 8;
162 assert(Name == "ppc32" && "Unknown target name!");
166 } // end anonymous namespace
169 // FIXME: This should be in a separate file.
171 class DarwinPPCAsmBackend : public PPCAsmBackend {
173 DarwinPPCAsmBackend(const Target &T) : PPCAsmBackend(T) { }
175 MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
176 bool is64 = getPointerSize() == 8;
177 return createMachObjectWriter(new PPCMachObjectWriter(
179 (is64 ? object::mach::CTM_PowerPC64 :
180 object::mach::CTM_PowerPC),
181 object::mach::CSPPC_ALL),
182 OS, /*IsLittleEndian=*/false);
185 virtual bool doesSectionRequireSymbols(const MCSection &Section) const {
190 class ELFPPCAsmBackend : public PPCAsmBackend {
193 ELFPPCAsmBackend(const Target &T, uint8_t OSABI) :
194 PPCAsmBackend(T), OSABI(OSABI) { }
197 MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
198 bool is64 = getPointerSize() == 8;
199 return createPPCELFObjectWriter(OS, is64, OSABI);
202 virtual bool doesSectionRequireSymbols(const MCSection &Section) const {
207 } // end anonymous namespace
212 MCAsmBackend *llvm::createPPCAsmBackend(const Target &T, StringRef TT, StringRef CPU) {
213 if (Triple(TT).isOSDarwin())
214 return new DarwinPPCAsmBackend(T);
216 uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(Triple(TT).getOS());
217 return new ELFPPCAsmBackend(T, OSABI);