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/Support/ELF.h"
20 #include "llvm/Support/ErrorHandling.h"
21 #include "llvm/Support/MachO.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:
73 class PPCAsmBackend : public MCAsmBackend {
74 const Target &TheTarget;
77 PPCAsmBackend(const Target &T, bool isLittle) : MCAsmBackend(), TheTarget(T),
78 IsLittleEndian(isLittle) {}
80 unsigned getNumFixupKinds() const { return PPC::NumTargetFixupKinds; }
82 const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
83 const static MCFixupKindInfo InfosBE[PPC::NumTargetFixupKinds] = {
84 // name offset bits flags
85 { "fixup_ppc_br24", 6, 24, MCFixupKindInfo::FKF_IsPCRel },
86 { "fixup_ppc_brcond14", 16, 14, MCFixupKindInfo::FKF_IsPCRel },
87 { "fixup_ppc_br24abs", 6, 24, 0 },
88 { "fixup_ppc_brcond14abs", 16, 14, 0 },
89 { "fixup_ppc_half16", 0, 16, 0 },
90 { "fixup_ppc_half16ds", 0, 14, 0 },
91 { "fixup_ppc_nofixup", 0, 0, 0 }
93 const static MCFixupKindInfo InfosLE[PPC::NumTargetFixupKinds] = {
94 // name offset bits flags
95 { "fixup_ppc_br24", 2, 24, MCFixupKindInfo::FKF_IsPCRel },
96 { "fixup_ppc_brcond14", 2, 14, MCFixupKindInfo::FKF_IsPCRel },
97 { "fixup_ppc_br24abs", 2, 24, 0 },
98 { "fixup_ppc_brcond14abs", 2, 14, 0 },
99 { "fixup_ppc_half16", 0, 16, 0 },
100 { "fixup_ppc_half16ds", 2, 14, 0 },
101 { "fixup_ppc_nofixup", 0, 0, 0 }
104 if (Kind < FirstTargetFixupKind)
105 return MCAsmBackend::getFixupKindInfo(Kind);
107 assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
109 return (IsLittleEndian? InfosLE : InfosBE)[Kind - FirstTargetFixupKind];
112 void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
113 uint64_t Value, bool IsPCRel) const {
114 Value = adjustFixupValue(Fixup.getKind(), Value);
115 if (!Value) return; // Doesn't change encoding.
117 unsigned Offset = Fixup.getOffset();
118 unsigned NumBytes = getFixupKindNumBytes(Fixup.getKind());
120 // For each byte of the fragment that the fixup touches, mask in the bits
121 // from the fixup value. The Value has been "split up" into the appropriate
123 for (unsigned i = 0; i != NumBytes; ++i) {
124 unsigned Idx = IsLittleEndian ? i : (NumBytes - 1 - i);
125 Data[Offset + i] |= uint8_t((Value >> (Idx * 8)) & 0xff);
129 bool mayNeedRelaxation(const MCInst &Inst) const {
134 bool fixupNeedsRelaxation(const MCFixup &Fixup,
136 const MCRelaxableFragment *DF,
137 const MCAsmLayout &Layout) const {
139 llvm_unreachable("relaxInstruction() unimplemented");
143 void relaxInstruction(const MCInst &Inst, MCInst &Res) const {
145 llvm_unreachable("relaxInstruction() unimplemented");
148 bool writeNopData(uint64_t Count, MCObjectWriter *OW) const {
149 uint64_t NumNops = Count / 4;
150 for (uint64_t i = 0; i != NumNops; ++i)
151 OW->Write32(0x60000000);
154 default: break; // No leftover bytes to write
155 case 1: OW->Write8(0); break;
156 case 2: OW->Write16(0); break;
157 case 3: OW->Write16(0); OW->Write8(0); break;
163 unsigned getPointerSize() const {
164 StringRef Name = TheTarget.getName();
165 if (Name == "ppc64" || Name == "ppc64le") return 8;
166 assert(Name == "ppc32" && "Unknown target name!");
170 bool isLittleEndian() const {
171 return IsLittleEndian;
174 } // end anonymous namespace
177 // FIXME: This should be in a separate file.
179 class DarwinPPCAsmBackend : public PPCAsmBackend {
181 DarwinPPCAsmBackend(const Target &T) : PPCAsmBackend(T, false) { }
183 MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
184 bool is64 = getPointerSize() == 8;
185 return createPPCMachObjectWriter(
188 (is64 ? MachO::CPU_TYPE_POWERPC64 : MachO::CPU_TYPE_POWERPC),
189 MachO::CPU_SUBTYPE_POWERPC_ALL);
193 class ELFPPCAsmBackend : public PPCAsmBackend {
196 ELFPPCAsmBackend(const Target &T, bool IsLittleEndian, uint8_t OSABI) :
197 PPCAsmBackend(T, IsLittleEndian), OSABI(OSABI) { }
200 MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
201 bool is64 = getPointerSize() == 8;
202 return createPPCELFObjectWriter(OS, is64, isLittleEndian(), OSABI);
206 } // end anonymous namespace
208 MCAsmBackend *llvm::createPPCAsmBackend(const Target &T,
209 const MCRegisterInfo &MRI,
210 StringRef TT, StringRef CPU) {
211 if (Triple(TT).isOSDarwin())
212 return new DarwinPPCAsmBackend(T);
214 uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(Triple(TT).getOS());
215 bool IsLittleEndian = Triple(TT).getArch() == Triple::ppc64le;
216 return new ELFPPCAsmBackend(T, IsLittleEndian, OSABI);