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/MCAssembler.h"
13 #include "llvm/MC/MCAsmBackend.h"
14 #include "llvm/MC/MCELF.h"
15 #include "llvm/MC/MCELFObjectWriter.h"
16 #include "llvm/MC/MCFixupKindInfo.h"
17 #include "llvm/MC/MCMachObjectWriter.h"
18 #include "llvm/MC/MCObjectWriter.h"
19 #include "llvm/MC/MCSectionMachO.h"
20 #include "llvm/MC/MCValue.h"
21 #include "llvm/Support/ELF.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/Support/MachO.h"
24 #include "llvm/Support/TargetRegistry.h"
27 static uint64_t adjustFixupValue(unsigned Kind, uint64_t Value) {
30 llvm_unreachable("Unknown fixup kind!");
35 case PPC::fixup_ppc_nofixup:
37 case PPC::fixup_ppc_brcond14:
38 case PPC::fixup_ppc_brcond14abs:
39 return Value & 0xfffc;
40 case PPC::fixup_ppc_br24:
41 case PPC::fixup_ppc_br24abs:
42 return Value & 0x3fffffc;
43 case PPC::fixup_ppc_half16:
44 return Value & 0xffff;
45 case PPC::fixup_ppc_half16ds:
46 return Value & 0xfffc;
50 static unsigned getFixupKindNumBytes(unsigned Kind) {
53 llvm_unreachable("Unknown fixup kind!");
57 case PPC::fixup_ppc_half16:
58 case PPC::fixup_ppc_half16ds:
61 case PPC::fixup_ppc_brcond14:
62 case PPC::fixup_ppc_brcond14abs:
63 case PPC::fixup_ppc_br24:
64 case PPC::fixup_ppc_br24abs:
68 case PPC::fixup_ppc_nofixup:
75 class PPCAsmBackend : public MCAsmBackend {
76 const Target &TheTarget;
79 PPCAsmBackend(const Target &T, bool isLittle) : MCAsmBackend(), TheTarget(T),
80 IsLittleEndian(isLittle) {}
82 unsigned getNumFixupKinds() const override {
83 return PPC::NumTargetFixupKinds;
86 const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override {
87 const static MCFixupKindInfo InfosBE[PPC::NumTargetFixupKinds] = {
88 // name offset bits flags
89 { "fixup_ppc_br24", 6, 24, MCFixupKindInfo::FKF_IsPCRel },
90 { "fixup_ppc_brcond14", 16, 14, MCFixupKindInfo::FKF_IsPCRel },
91 { "fixup_ppc_br24abs", 6, 24, 0 },
92 { "fixup_ppc_brcond14abs", 16, 14, 0 },
93 { "fixup_ppc_half16", 0, 16, 0 },
94 { "fixup_ppc_half16ds", 0, 14, 0 },
95 { "fixup_ppc_nofixup", 0, 0, 0 }
97 const static MCFixupKindInfo InfosLE[PPC::NumTargetFixupKinds] = {
98 // name offset bits flags
99 { "fixup_ppc_br24", 2, 24, MCFixupKindInfo::FKF_IsPCRel },
100 { "fixup_ppc_brcond14", 2, 14, MCFixupKindInfo::FKF_IsPCRel },
101 { "fixup_ppc_br24abs", 2, 24, 0 },
102 { "fixup_ppc_brcond14abs", 2, 14, 0 },
103 { "fixup_ppc_half16", 0, 16, 0 },
104 { "fixup_ppc_half16ds", 2, 14, 0 },
105 { "fixup_ppc_nofixup", 0, 0, 0 }
108 if (Kind < FirstTargetFixupKind)
109 return MCAsmBackend::getFixupKindInfo(Kind);
111 assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
113 return (IsLittleEndian? InfosLE : InfosBE)[Kind - FirstTargetFixupKind];
116 void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
117 uint64_t Value, bool IsPCRel) const override {
118 Value = adjustFixupValue(Fixup.getKind(), Value);
119 if (!Value) return; // Doesn't change encoding.
121 unsigned Offset = Fixup.getOffset();
122 unsigned NumBytes = getFixupKindNumBytes(Fixup.getKind());
124 // For each byte of the fragment that the fixup touches, mask in the bits
125 // from the fixup value. The Value has been "split up" into the appropriate
127 for (unsigned i = 0; i != NumBytes; ++i) {
128 unsigned Idx = IsLittleEndian ? i : (NumBytes - 1 - i);
129 Data[Offset + i] |= uint8_t((Value >> (Idx * 8)) & 0xff);
133 void processFixupValue(const MCAssembler &Asm, const MCAsmLayout &Layout,
134 const MCFixup &Fixup, const MCFragment *DF,
135 const MCValue &Target, uint64_t &Value,
136 bool &IsResolved) override {
137 switch ((PPC::Fixups)Fixup.getKind()) {
139 case PPC::fixup_ppc_br24:
140 case PPC::fixup_ppc_br24abs:
141 // If the target symbol has a local entry point we must not attempt
142 // to resolve the fixup directly. Emit a relocation and leave
143 // resolution of the final target address to the linker.
144 if (const MCSymbolRefExpr *A = Target.getSymA()) {
145 const MCSymbolData &Data = Asm.getSymbolData(A->getSymbol());
146 // The "other" values are stored in the last 6 bits of the second byte.
147 // The traditional defines for STO values assume the full byte and thus
148 // the shift to pack it.
149 unsigned Other = MCELF::getOther(Data) << 2;
150 if ((Other & ELF::STO_PPC64_LOCAL_MASK) != 0)
157 bool mayNeedRelaxation(const MCInst &Inst) const override {
162 bool fixupNeedsRelaxation(const MCFixup &Fixup,
164 const MCRelaxableFragment *DF,
165 const MCAsmLayout &Layout) const override {
167 llvm_unreachable("relaxInstruction() unimplemented");
171 void relaxInstruction(const MCInst &Inst, MCInst &Res) const override {
173 llvm_unreachable("relaxInstruction() unimplemented");
176 bool writeNopData(uint64_t Count, MCObjectWriter *OW) const override {
177 uint64_t NumNops = Count / 4;
178 for (uint64_t i = 0; i != NumNops; ++i)
179 OW->Write32(0x60000000);
182 default: break; // No leftover bytes to write
183 case 1: OW->Write8(0); break;
184 case 2: OW->Write16(0); break;
185 case 3: OW->Write16(0); OW->Write8(0); break;
191 unsigned getPointerSize() const {
192 StringRef Name = TheTarget.getName();
193 if (Name == "ppc64" || Name == "ppc64le") return 8;
194 assert(Name == "ppc32" && "Unknown target name!");
198 bool isLittleEndian() const {
199 return IsLittleEndian;
202 } // end anonymous namespace
205 // FIXME: This should be in a separate file.
207 class DarwinPPCAsmBackend : public PPCAsmBackend {
209 DarwinPPCAsmBackend(const Target &T) : PPCAsmBackend(T, false) { }
211 MCObjectWriter *createObjectWriter(raw_ostream &OS) const override {
212 bool is64 = getPointerSize() == 8;
213 return createPPCMachObjectWriter(
216 (is64 ? MachO::CPU_TYPE_POWERPC64 : MachO::CPU_TYPE_POWERPC),
217 MachO::CPU_SUBTYPE_POWERPC_ALL);
221 class ELFPPCAsmBackend : public PPCAsmBackend {
224 ELFPPCAsmBackend(const Target &T, bool IsLittleEndian, uint8_t OSABI) :
225 PPCAsmBackend(T, IsLittleEndian), OSABI(OSABI) { }
228 MCObjectWriter *createObjectWriter(raw_ostream &OS) const override {
229 bool is64 = getPointerSize() == 8;
230 return createPPCELFObjectWriter(OS, is64, isLittleEndian(), OSABI);
234 } // end anonymous namespace
236 MCAsmBackend *llvm::createPPCAsmBackend(const Target &T,
237 const MCRegisterInfo &MRI,
238 StringRef TT, StringRef CPU) {
239 if (Triple(TT).isOSDarwin())
240 return new DarwinPPCAsmBackend(T);
242 uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(Triple(TT).getOS());
243 bool IsLittleEndian = Triple(TT).getArch() == Triple::ppc64le;
244 return new ELFPPCAsmBackend(T, IsLittleEndian, OSABI);