xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Sparc/MCTargetDesc/SparcAsmBackend.cpp (revision 9d54812421274e490dc5f0fe4722ab8d35d9b258)
1 //===-- SparcAsmBackend.cpp - Sparc Assembler Backend ---------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "MCTargetDesc/SparcFixupKinds.h"
10 #include "MCTargetDesc/SparcMCTargetDesc.h"
11 #include "llvm/ADT/StringSwitch.h"
12 #include "llvm/MC/MCAsmBackend.h"
13 #include "llvm/MC/MCELFObjectWriter.h"
14 #include "llvm/MC/MCExpr.h"
15 #include "llvm/MC/MCFixupKindInfo.h"
16 #include "llvm/MC/MCObjectWriter.h"
17 #include "llvm/MC/MCSubtargetInfo.h"
18 #include "llvm/MC/MCValue.h"
19 #include "llvm/MC/TargetRegistry.h"
20 #include "llvm/Support/EndianStream.h"
21 
22 using namespace llvm;
23 
24 static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
25   switch (Kind) {
26   default:
27     llvm_unreachable("Unknown fixup kind!");
28   case FK_Data_1:
29   case FK_Data_2:
30   case FK_Data_4:
31   case FK_Data_8:
32     return Value;
33 
34   case Sparc::fixup_sparc_wplt30:
35   case Sparc::fixup_sparc_call30:
36     return (Value >> 2) & 0x3fffffff;
37 
38   case Sparc::fixup_sparc_br22:
39     return (Value >> 2) & 0x3fffff;
40 
41   case Sparc::fixup_sparc_br19:
42     return (Value >> 2) & 0x7ffff;
43 
44   case Sparc::fixup_sparc_br16_2:
45     return (Value >> 2) & 0xc000;
46 
47   case Sparc::fixup_sparc_br16_14:
48     return (Value >> 2) & 0x3fff;
49 
50   case Sparc::fixup_sparc_pc22:
51   case Sparc::fixup_sparc_got22:
52   case Sparc::fixup_sparc_tls_gd_hi22:
53   case Sparc::fixup_sparc_tls_ldm_hi22:
54   case Sparc::fixup_sparc_tls_ie_hi22:
55   case Sparc::fixup_sparc_hi22:
56   case Sparc::fixup_sparc_lm:
57     return (Value >> 10) & 0x3fffff;
58 
59   case Sparc::fixup_sparc_got13:
60   case Sparc::fixup_sparc_13:
61     return Value & 0x1fff;
62 
63   case Sparc::fixup_sparc_pc10:
64   case Sparc::fixup_sparc_got10:
65   case Sparc::fixup_sparc_tls_gd_lo10:
66   case Sparc::fixup_sparc_tls_ldm_lo10:
67   case Sparc::fixup_sparc_tls_ie_lo10:
68   case Sparc::fixup_sparc_lo10:
69     return Value & 0x3ff;
70 
71   case Sparc::fixup_sparc_h44:
72     return (Value >> 22) & 0x3fffff;
73 
74   case Sparc::fixup_sparc_m44:
75     return (Value >> 12) & 0x3ff;
76 
77   case Sparc::fixup_sparc_l44:
78     return Value & 0xfff;
79 
80   case Sparc::fixup_sparc_hh:
81     return (Value >> 42) & 0x3fffff;
82 
83   case Sparc::fixup_sparc_hm:
84     return (Value >> 32) & 0x3ff;
85 
86   case Sparc::fixup_sparc_tls_ldo_hix22:
87   case Sparc::fixup_sparc_tls_le_hix22:
88   case Sparc::fixup_sparc_tls_ldo_lox10:
89   case Sparc::fixup_sparc_tls_le_lox10:
90     assert(Value == 0 && "Sparc TLS relocs expect zero Value");
91     return 0;
92 
93   case Sparc::fixup_sparc_tls_gd_add:
94   case Sparc::fixup_sparc_tls_gd_call:
95   case Sparc::fixup_sparc_tls_ldm_add:
96   case Sparc::fixup_sparc_tls_ldm_call:
97   case Sparc::fixup_sparc_tls_ldo_add:
98   case Sparc::fixup_sparc_tls_ie_ld:
99   case Sparc::fixup_sparc_tls_ie_ldx:
100   case Sparc::fixup_sparc_tls_ie_add:
101     return 0;
102   }
103 }
104 
105 /// getFixupKindNumBytes - The number of bytes the fixup may change.
106 static unsigned getFixupKindNumBytes(unsigned Kind) {
107     switch (Kind) {
108   default:
109     return 4;
110   case FK_Data_1:
111     return 1;
112   case FK_Data_2:
113     return 2;
114   case FK_Data_8:
115     return 8;
116   }
117 }
118 
119 namespace {
120   class SparcAsmBackend : public MCAsmBackend {
121   protected:
122     const Target &TheTarget;
123     bool Is64Bit;
124 
125   public:
126     SparcAsmBackend(const Target &T)
127         : MCAsmBackend(StringRef(T.getName()) == "sparcel" ? support::little
128                                                            : support::big),
129           TheTarget(T), Is64Bit(StringRef(TheTarget.getName()) == "sparcv9") {}
130 
131     unsigned getNumFixupKinds() const override {
132       return Sparc::NumTargetFixupKinds;
133     }
134 
135     Optional<MCFixupKind> getFixupKind(StringRef Name) const override {
136       unsigned Type;
137       Type = llvm::StringSwitch<unsigned>(Name)
138 #define ELF_RELOC(X, Y) .Case(#X, Y)
139 #include "llvm/BinaryFormat/ELFRelocs/Sparc.def"
140 #undef ELF_RELOC
141                  .Case("BFD_RELOC_NONE", ELF::R_SPARC_NONE)
142                  .Case("BFD_RELOC_8", ELF::R_SPARC_8)
143                  .Case("BFD_RELOC_16", ELF::R_SPARC_16)
144                  .Case("BFD_RELOC_32", ELF::R_SPARC_32)
145                  .Case("BFD_RELOC_64", ELF::R_SPARC_64)
146                  .Default(-1u);
147       if (Type == -1u)
148         return None;
149       return static_cast<MCFixupKind>(FirstLiteralRelocationKind + Type);
150     }
151 
152     const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override {
153       const static MCFixupKindInfo InfosBE[Sparc::NumTargetFixupKinds] = {
154         // name                    offset bits  flags
155         { "fixup_sparc_call30",     2,     30,  MCFixupKindInfo::FKF_IsPCRel },
156         { "fixup_sparc_br22",      10,     22,  MCFixupKindInfo::FKF_IsPCRel },
157         { "fixup_sparc_br19",      13,     19,  MCFixupKindInfo::FKF_IsPCRel },
158         { "fixup_sparc_br16_2",    10,      2,  MCFixupKindInfo::FKF_IsPCRel },
159         { "fixup_sparc_br16_14",   18,     14,  MCFixupKindInfo::FKF_IsPCRel },
160         { "fixup_sparc_13",        19,     13,  0 },
161         { "fixup_sparc_hi22",      10,     22,  0 },
162         { "fixup_sparc_lo10",      22,     10,  0 },
163         { "fixup_sparc_h44",       10,     22,  0 },
164         { "fixup_sparc_m44",       22,     10,  0 },
165         { "fixup_sparc_l44",       20,     12,  0 },
166         { "fixup_sparc_hh",        10,     22,  0 },
167         { "fixup_sparc_hm",        22,     10,  0 },
168         { "fixup_sparc_lm",        10,     22,  0 },
169         { "fixup_sparc_pc22",      10,     22,  MCFixupKindInfo::FKF_IsPCRel },
170         { "fixup_sparc_pc10",      22,     10,  MCFixupKindInfo::FKF_IsPCRel },
171         { "fixup_sparc_got22",     10,     22,  0 },
172         { "fixup_sparc_got10",     22,     10,  0 },
173         { "fixup_sparc_got13",     19,     13,  0 },
174         { "fixup_sparc_wplt30",     2,     30,  MCFixupKindInfo::FKF_IsPCRel },
175         { "fixup_sparc_tls_gd_hi22",   10, 22,  0 },
176         { "fixup_sparc_tls_gd_lo10",   22, 10,  0 },
177         { "fixup_sparc_tls_gd_add",     0,  0,  0 },
178         { "fixup_sparc_tls_gd_call",    0,  0,  0 },
179         { "fixup_sparc_tls_ldm_hi22",  10, 22,  0 },
180         { "fixup_sparc_tls_ldm_lo10",  22, 10,  0 },
181         { "fixup_sparc_tls_ldm_add",    0,  0,  0 },
182         { "fixup_sparc_tls_ldm_call",   0,  0,  0 },
183         { "fixup_sparc_tls_ldo_hix22", 10, 22,  0 },
184         { "fixup_sparc_tls_ldo_lox10", 22, 10,  0 },
185         { "fixup_sparc_tls_ldo_add",    0,  0,  0 },
186         { "fixup_sparc_tls_ie_hi22",   10, 22,  0 },
187         { "fixup_sparc_tls_ie_lo10",   22, 10,  0 },
188         { "fixup_sparc_tls_ie_ld",      0,  0,  0 },
189         { "fixup_sparc_tls_ie_ldx",     0,  0,  0 },
190         { "fixup_sparc_tls_ie_add",     0,  0,  0 },
191         { "fixup_sparc_tls_le_hix22",   0,  0,  0 },
192         { "fixup_sparc_tls_le_lox10",   0,  0,  0 }
193       };
194 
195       const static MCFixupKindInfo InfosLE[Sparc::NumTargetFixupKinds] = {
196         // name                    offset bits  flags
197         { "fixup_sparc_call30",     0,     30,  MCFixupKindInfo::FKF_IsPCRel },
198         { "fixup_sparc_br22",       0,     22,  MCFixupKindInfo::FKF_IsPCRel },
199         { "fixup_sparc_br19",       0,     19,  MCFixupKindInfo::FKF_IsPCRel },
200         { "fixup_sparc_br16_2",    20,      2,  MCFixupKindInfo::FKF_IsPCRel },
201         { "fixup_sparc_br16_14",    0,     14,  MCFixupKindInfo::FKF_IsPCRel },
202         { "fixup_sparc_13",         0,     13,  0 },
203         { "fixup_sparc_hi22",       0,     22,  0 },
204         { "fixup_sparc_lo10",       0,     10,  0 },
205         { "fixup_sparc_h44",        0,     22,  0 },
206         { "fixup_sparc_m44",        0,     10,  0 },
207         { "fixup_sparc_l44",        0,     12,  0 },
208         { "fixup_sparc_hh",         0,     22,  0 },
209         { "fixup_sparc_hm",         0,     10,  0 },
210         { "fixup_sparc_lm",         0,     22,  0 },
211         { "fixup_sparc_pc22",       0,     22,  MCFixupKindInfo::FKF_IsPCRel },
212         { "fixup_sparc_pc10",       0,     10,  MCFixupKindInfo::FKF_IsPCRel },
213         { "fixup_sparc_got22",      0,     22,  0 },
214         { "fixup_sparc_got10",      0,     10,  0 },
215         { "fixup_sparc_got13",      0,     13,  0 },
216         { "fixup_sparc_wplt30",      0,     30,  MCFixupKindInfo::FKF_IsPCRel },
217         { "fixup_sparc_tls_gd_hi22",    0, 22,  0 },
218         { "fixup_sparc_tls_gd_lo10",    0, 10,  0 },
219         { "fixup_sparc_tls_gd_add",     0,  0,  0 },
220         { "fixup_sparc_tls_gd_call",    0,  0,  0 },
221         { "fixup_sparc_tls_ldm_hi22",   0, 22,  0 },
222         { "fixup_sparc_tls_ldm_lo10",   0, 10,  0 },
223         { "fixup_sparc_tls_ldm_add",    0,  0,  0 },
224         { "fixup_sparc_tls_ldm_call",   0,  0,  0 },
225         { "fixup_sparc_tls_ldo_hix22",  0, 22,  0 },
226         { "fixup_sparc_tls_ldo_lox10",  0, 10,  0 },
227         { "fixup_sparc_tls_ldo_add",    0,  0,  0 },
228         { "fixup_sparc_tls_ie_hi22",    0, 22,  0 },
229         { "fixup_sparc_tls_ie_lo10",    0, 10,  0 },
230         { "fixup_sparc_tls_ie_ld",      0,  0,  0 },
231         { "fixup_sparc_tls_ie_ldx",     0,  0,  0 },
232         { "fixup_sparc_tls_ie_add",     0,  0,  0 },
233         { "fixup_sparc_tls_le_hix22",   0,  0,  0 },
234         { "fixup_sparc_tls_le_lox10",   0,  0,  0 }
235       };
236 
237       // Fixup kinds from .reloc directive are like R_SPARC_NONE. They do
238       // not require any extra processing.
239       if (Kind >= FirstLiteralRelocationKind)
240         return MCAsmBackend::getFixupKindInfo(FK_NONE);
241 
242       if (Kind < FirstTargetFixupKind)
243         return MCAsmBackend::getFixupKindInfo(Kind);
244 
245       assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
246              "Invalid kind!");
247       if (Endian == support::little)
248         return InfosLE[Kind - FirstTargetFixupKind];
249 
250       return InfosBE[Kind - FirstTargetFixupKind];
251     }
252 
253     bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
254                                const MCValue &Target) override {
255       if (Fixup.getKind() >= FirstLiteralRelocationKind)
256         return true;
257       switch ((Sparc::Fixups)Fixup.getKind()) {
258       default:
259         return false;
260       case Sparc::fixup_sparc_wplt30:
261         if (Target.getSymA()->getSymbol().isTemporary())
262           return false;
263         LLVM_FALLTHROUGH;
264       case Sparc::fixup_sparc_tls_gd_hi22:
265       case Sparc::fixup_sparc_tls_gd_lo10:
266       case Sparc::fixup_sparc_tls_gd_add:
267       case Sparc::fixup_sparc_tls_gd_call:
268       case Sparc::fixup_sparc_tls_ldm_hi22:
269       case Sparc::fixup_sparc_tls_ldm_lo10:
270       case Sparc::fixup_sparc_tls_ldm_add:
271       case Sparc::fixup_sparc_tls_ldm_call:
272       case Sparc::fixup_sparc_tls_ldo_hix22:
273       case Sparc::fixup_sparc_tls_ldo_lox10:
274       case Sparc::fixup_sparc_tls_ldo_add:
275       case Sparc::fixup_sparc_tls_ie_hi22:
276       case Sparc::fixup_sparc_tls_ie_lo10:
277       case Sparc::fixup_sparc_tls_ie_ld:
278       case Sparc::fixup_sparc_tls_ie_ldx:
279       case Sparc::fixup_sparc_tls_ie_add:
280       case Sparc::fixup_sparc_tls_le_hix22:
281       case Sparc::fixup_sparc_tls_le_lox10:
282         return true;
283       }
284     }
285 
286     /// fixupNeedsRelaxation - Target specific predicate for whether a given
287     /// fixup requires the associated instruction to be relaxed.
288     bool fixupNeedsRelaxation(const MCFixup &Fixup,
289                               uint64_t Value,
290                               const MCRelaxableFragment *DF,
291                               const MCAsmLayout &Layout) const override {
292       // FIXME.
293       llvm_unreachable("fixupNeedsRelaxation() unimplemented");
294       return false;
295     }
296     void relaxInstruction(MCInst &Inst,
297                           const MCSubtargetInfo &STI) const override {
298       // FIXME.
299       llvm_unreachable("relaxInstruction() unimplemented");
300     }
301 
302     bool writeNopData(raw_ostream &OS, uint64_t Count,
303                       const MCSubtargetInfo *STI) const override {
304       // Cannot emit NOP with size not multiple of 32 bits.
305       if (Count % 4 != 0)
306         return false;
307 
308       uint64_t NumNops = Count / 4;
309       for (uint64_t i = 0; i != NumNops; ++i)
310         support::endian::write<uint32_t>(OS, 0x01000000, Endian);
311 
312       return true;
313     }
314   };
315 
316   class ELFSparcAsmBackend : public SparcAsmBackend {
317     Triple::OSType OSType;
318   public:
319     ELFSparcAsmBackend(const Target &T, Triple::OSType OSType) :
320       SparcAsmBackend(T), OSType(OSType) { }
321 
322     void applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
323                     const MCValue &Target, MutableArrayRef<char> Data,
324                     uint64_t Value, bool IsResolved,
325                     const MCSubtargetInfo *STI) const override {
326 
327       if (Fixup.getKind() >= FirstLiteralRelocationKind)
328         return;
329       Value = adjustFixupValue(Fixup.getKind(), Value);
330       if (!Value) return;           // Doesn't change encoding.
331 
332       unsigned NumBytes = getFixupKindNumBytes(Fixup.getKind());
333       unsigned Offset = Fixup.getOffset();
334       // For each byte of the fragment that the fixup touches, mask in the bits
335       // from the fixup value. The Value has been "split up" into the
336       // appropriate bitfields above.
337       for (unsigned i = 0; i != NumBytes; ++i) {
338         unsigned Idx = Endian == support::little ? i : (NumBytes - 1) - i;
339         Data[Offset + Idx] |= uint8_t((Value >> (i * 8)) & 0xff);
340       }
341     }
342 
343     std::unique_ptr<MCObjectTargetWriter>
344     createObjectTargetWriter() const override {
345       uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(OSType);
346       return createSparcELFObjectWriter(Is64Bit, OSABI);
347     }
348   };
349 
350 } // end anonymous namespace
351 
352 MCAsmBackend *llvm::createSparcAsmBackend(const Target &T,
353                                           const MCSubtargetInfo &STI,
354                                           const MCRegisterInfo &MRI,
355                                           const MCTargetOptions &Options) {
356   return new ELFSparcAsmBackend(T, STI.getTargetTriple().getOS());
357 }
358