]>
git.proxmox.com Git - rustc.git/blob - src/llvm/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp
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/MCAssembler.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
);