1 //===-- MipsAsmBackend.cpp - Mips Asm 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 // This file implements the MipsAsmBackend class.
10 //
11 //===----------------------------------------------------------------------===//
12 //
13
14 #include "MCTargetDesc/MipsAsmBackend.h"
15 #include "MCTargetDesc/MipsABIInfo.h"
16 #include "MCTargetDesc/MipsFixupKinds.h"
17 #include "MCTargetDesc/MipsMCExpr.h"
18 #include "MCTargetDesc/MipsMCTargetDesc.h"
19 #include "llvm/ADT/STLExtras.h"
20 #include "llvm/ADT/StringSwitch.h"
21 #include "llvm/MC/MCAsmBackend.h"
22 #include "llvm/MC/MCAssembler.h"
23 #include "llvm/MC/MCContext.h"
24 #include "llvm/MC/MCDirectives.h"
25 #include "llvm/MC/MCELFObjectWriter.h"
26 #include "llvm/MC/MCFixupKindInfo.h"
27 #include "llvm/MC/MCObjectWriter.h"
28 #include "llvm/MC/MCSubtargetInfo.h"
29 #include "llvm/MC/MCTargetOptions.h"
30 #include "llvm/MC/MCValue.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/Format.h"
33 #include "llvm/Support/MathExtras.h"
34 #include "llvm/Support/raw_ostream.h"
35
36 using namespace llvm;
37
38 // Prepare value for the target space for it
adjustFixupValue(const MCFixup & Fixup,uint64_t Value,MCContext & Ctx)39 static unsigned adjustFixupValue(const MCFixup &Fixup, uint64_t Value,
40 MCContext &Ctx) {
41
42 unsigned Kind = Fixup.getKind();
43
44 // Add/subtract and shift
45 switch (Kind) {
46 default:
47 return 0;
48 case FK_Data_2:
49 case Mips::fixup_Mips_LO16:
50 case Mips::fixup_Mips_GPREL16:
51 case Mips::fixup_Mips_GPOFF_HI:
52 case Mips::fixup_Mips_GPOFF_LO:
53 case Mips::fixup_Mips_GOT_PAGE:
54 case Mips::fixup_Mips_GOT_OFST:
55 case Mips::fixup_Mips_GOT_DISP:
56 case Mips::fixup_Mips_GOT_LO16:
57 case Mips::fixup_Mips_CALL_LO16:
58 case Mips::fixup_MICROMIPS_GPOFF_HI:
59 case Mips::fixup_MICROMIPS_GPOFF_LO:
60 case Mips::fixup_MICROMIPS_LO16:
61 case Mips::fixup_MICROMIPS_GOT_PAGE:
62 case Mips::fixup_MICROMIPS_GOT_OFST:
63 case Mips::fixup_MICROMIPS_GOT_DISP:
64 case Mips::fixup_MIPS_PCLO16:
65 Value &= 0xffff;
66 break;
67 case FK_DTPRel_4:
68 case FK_DTPRel_8:
69 case FK_TPRel_4:
70 case FK_TPRel_8:
71 case FK_GPRel_4:
72 case FK_Data_4:
73 case FK_Data_8:
74 case Mips::fixup_Mips_SUB:
75 case Mips::fixup_MICROMIPS_SUB:
76 break;
77 case Mips::fixup_Mips_PC16:
78 // The displacement is then divided by 4 to give us an 18 bit
79 // address range. Forcing a signed division because Value can be negative.
80 Value = (int64_t)Value / 4;
81 // We now check if Value can be encoded as a 16-bit signed immediate.
82 if (!isInt<16>(Value)) {
83 Ctx.reportError(Fixup.getLoc(), "out of range PC16 fixup");
84 return 0;
85 }
86 break;
87 case Mips::fixup_MIPS_PC19_S2:
88 case Mips::fixup_MICROMIPS_PC19_S2:
89 // Forcing a signed division because Value can be negative.
90 Value = (int64_t)Value / 4;
91 // We now check if Value can be encoded as a 19-bit signed immediate.
92 if (!isInt<19>(Value)) {
93 Ctx.reportError(Fixup.getLoc(), "out of range PC19 fixup");
94 return 0;
95 }
96 break;
97 case Mips::fixup_Mips_26:
98 // So far we are only using this type for jumps.
99 // The displacement is then divided by 4 to give us an 28 bit
100 // address range.
101 Value >>= 2;
102 break;
103 case Mips::fixup_Mips_HI16:
104 case Mips::fixup_Mips_GOT:
105 case Mips::fixup_MICROMIPS_GOT16:
106 case Mips::fixup_Mips_GOT_HI16:
107 case Mips::fixup_Mips_CALL_HI16:
108 case Mips::fixup_MICROMIPS_HI16:
109 case Mips::fixup_MIPS_PCHI16:
110 // Get the 2nd 16-bits. Also add 1 if bit 15 is 1.
111 Value = ((Value + 0x8000) >> 16) & 0xffff;
112 break;
113 case Mips::fixup_Mips_HIGHER:
114 case Mips::fixup_MICROMIPS_HIGHER:
115 // Get the 3rd 16-bits.
116 Value = ((Value + 0x80008000LL) >> 32) & 0xffff;
117 break;
118 case Mips::fixup_Mips_HIGHEST:
119 case Mips::fixup_MICROMIPS_HIGHEST:
120 // Get the 4th 16-bits.
121 Value = ((Value + 0x800080008000LL) >> 48) & 0xffff;
122 break;
123 case Mips::fixup_MICROMIPS_26_S1:
124 Value >>= 1;
125 break;
126 case Mips::fixup_MICROMIPS_PC7_S1:
127 Value -= 4;
128 // Forcing a signed division because Value can be negative.
129 Value = (int64_t) Value / 2;
130 // We now check if Value can be encoded as a 7-bit signed immediate.
131 if (!isInt<7>(Value)) {
132 Ctx.reportError(Fixup.getLoc(), "out of range PC7 fixup");
133 return 0;
134 }
135 break;
136 case Mips::fixup_MICROMIPS_PC10_S1:
137 Value -= 2;
138 // Forcing a signed division because Value can be negative.
139 Value = (int64_t) Value / 2;
140 // We now check if Value can be encoded as a 10-bit signed immediate.
141 if (!isInt<10>(Value)) {
142 Ctx.reportError(Fixup.getLoc(), "out of range PC10 fixup");
143 return 0;
144 }
145 break;
146 case Mips::fixup_MICROMIPS_PC16_S1:
147 Value -= 4;
148 // Forcing a signed division because Value can be negative.
149 Value = (int64_t)Value / 2;
150 // We now check if Value can be encoded as a 16-bit signed immediate.
151 if (!isInt<16>(Value)) {
152 Ctx.reportError(Fixup.getLoc(), "out of range PC16 fixup");
153 return 0;
154 }
155 break;
156 case Mips::fixup_MIPS_PC18_S3:
157 // Forcing a signed division because Value can be negative.
158 Value = (int64_t)Value / 8;
159 // We now check if Value can be encoded as a 18-bit signed immediate.
160 if (!isInt<18>(Value)) {
161 Ctx.reportError(Fixup.getLoc(), "out of range PC18 fixup");
162 return 0;
163 }
164 break;
165 case Mips::fixup_MICROMIPS_PC18_S3:
166 // Check alignment.
167 if ((Value & 7)) {
168 Ctx.reportError(Fixup.getLoc(), "out of range PC18 fixup");
169 }
170 // Forcing a signed division because Value can be negative.
171 Value = (int64_t)Value / 8;
172 // We now check if Value can be encoded as a 18-bit signed immediate.
173 if (!isInt<18>(Value)) {
174 Ctx.reportError(Fixup.getLoc(), "out of range PC18 fixup");
175 return 0;
176 }
177 break;
178 case Mips::fixup_MIPS_PC21_S2:
179 // Forcing a signed division because Value can be negative.
180 Value = (int64_t) Value / 4;
181 // We now check if Value can be encoded as a 21-bit signed immediate.
182 if (!isInt<21>(Value)) {
183 Ctx.reportError(Fixup.getLoc(), "out of range PC21 fixup");
184 return 0;
185 }
186 break;
187 case Mips::fixup_MIPS_PC26_S2:
188 // Forcing a signed division because Value can be negative.
189 Value = (int64_t) Value / 4;
190 // We now check if Value can be encoded as a 26-bit signed immediate.
191 if (!isInt<26>(Value)) {
192 Ctx.reportError(Fixup.getLoc(), "out of range PC26 fixup");
193 return 0;
194 }
195 break;
196 case Mips::fixup_MICROMIPS_PC26_S1:
197 // Forcing a signed division because Value can be negative.
198 Value = (int64_t)Value / 2;
199 // We now check if Value can be encoded as a 26-bit signed immediate.
200 if (!isInt<26>(Value)) {
201 Ctx.reportError(Fixup.getLoc(), "out of range PC26 fixup");
202 return 0;
203 }
204 break;
205 case Mips::fixup_MICROMIPS_PC21_S1:
206 // Forcing a signed division because Value can be negative.
207 Value = (int64_t)Value / 2;
208 // We now check if Value can be encoded as a 21-bit signed immediate.
209 if (!isInt<21>(Value)) {
210 Ctx.reportError(Fixup.getLoc(), "out of range PC21 fixup");
211 return 0;
212 }
213 break;
214 }
215
216 return Value;
217 }
218
219 std::unique_ptr<MCObjectTargetWriter>
createObjectTargetWriter() const220 MipsAsmBackend::createObjectTargetWriter() const {
221 return createMipsELFObjectWriter(TheTriple, IsN32);
222 }
223
224 // Little-endian fixup data byte ordering:
225 // mips32r2: a | b | x | x
226 // microMIPS: x | x | a | b
227
needsMMLEByteOrder(unsigned Kind)228 static bool needsMMLEByteOrder(unsigned Kind) {
229 return Kind != Mips::fixup_MICROMIPS_PC10_S1 &&
230 Kind >= Mips::fixup_MICROMIPS_26_S1 &&
231 Kind < Mips::LastTargetFixupKind;
232 }
233
234 // Calculate index for microMIPS specific little endian byte order
calculateMMLEIndex(unsigned i)235 static unsigned calculateMMLEIndex(unsigned i) {
236 assert(i <= 3 && "Index out of range!");
237
238 return (1 - i / 2) * 2 + i % 2;
239 }
240
241 /// ApplyFixup - Apply the \p Value for given \p Fixup into the provided
242 /// data fragment, at the offset specified by the fixup and following the
243 /// fixup kind as appropriate.
applyFixup(const MCAssembler & Asm,const MCFixup & Fixup,const MCValue & Target,MutableArrayRef<char> Data,uint64_t Value,bool IsResolved,const MCSubtargetInfo * STI) const244 void MipsAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
245 const MCValue &Target,
246 MutableArrayRef<char> Data, uint64_t Value,
247 bool IsResolved,
248 const MCSubtargetInfo *STI) const {
249 MCFixupKind Kind = Fixup.getKind();
250 MCContext &Ctx = Asm.getContext();
251 Value = adjustFixupValue(Fixup, Value, Ctx);
252
253 if (!Value)
254 return; // Doesn't change encoding.
255
256 // Where do we start in the object
257 unsigned Offset = Fixup.getOffset();
258 // Number of bytes we need to fixup
259 unsigned NumBytes = (getFixupKindInfo(Kind).TargetSize + 7) / 8;
260 // Used to point to big endian bytes
261 unsigned FullSize;
262
263 switch ((unsigned)Kind) {
264 case FK_Data_2:
265 case Mips::fixup_Mips_16:
266 case Mips::fixup_MICROMIPS_PC10_S1:
267 FullSize = 2;
268 break;
269 case FK_Data_8:
270 case Mips::fixup_Mips_64:
271 FullSize = 8;
272 break;
273 case FK_Data_4:
274 default:
275 FullSize = 4;
276 break;
277 }
278
279 // Grab current value, if any, from bits.
280 uint64_t CurVal = 0;
281
282 bool microMipsLEByteOrder = needsMMLEByteOrder((unsigned) Kind);
283
284 for (unsigned i = 0; i != NumBytes; ++i) {
285 unsigned Idx = Endian == llvm::endianness::little
286 ? (microMipsLEByteOrder ? calculateMMLEIndex(i) : i)
287 : (FullSize - 1 - i);
288 CurVal |= (uint64_t)((uint8_t)Data[Offset + Idx]) << (i*8);
289 }
290
291 uint64_t Mask = ((uint64_t)(-1) >>
292 (64 - getFixupKindInfo(Kind).TargetSize));
293 CurVal |= Value & Mask;
294
295 // Write out the fixed up bytes back to the code/data bits.
296 for (unsigned i = 0; i != NumBytes; ++i) {
297 unsigned Idx = Endian == llvm::endianness::little
298 ? (microMipsLEByteOrder ? calculateMMLEIndex(i) : i)
299 : (FullSize - 1 - i);
300 Data[Offset + Idx] = (uint8_t)((CurVal >> (i*8)) & 0xff);
301 }
302 }
303
getFixupKind(StringRef Name) const304 std::optional<MCFixupKind> MipsAsmBackend::getFixupKind(StringRef Name) const {
305 unsigned Type = llvm::StringSwitch<unsigned>(Name)
306 .Case("BFD_RELOC_NONE", ELF::R_MIPS_NONE)
307 .Case("BFD_RELOC_16", ELF::R_MIPS_16)
308 .Case("BFD_RELOC_32", ELF::R_MIPS_32)
309 .Case("BFD_RELOC_64", ELF::R_MIPS_64)
310 .Default(-1u);
311 if (Type != -1u)
312 return static_cast<MCFixupKind>(FirstLiteralRelocationKind + Type);
313
314 return StringSwitch<std::optional<MCFixupKind>>(Name)
315 .Case("R_MIPS_NONE", FK_NONE)
316 .Case("R_MIPS_32", FK_Data_4)
317 .Case("R_MIPS_CALL_HI16", (MCFixupKind)Mips::fixup_Mips_CALL_HI16)
318 .Case("R_MIPS_CALL_LO16", (MCFixupKind)Mips::fixup_Mips_CALL_LO16)
319 .Case("R_MIPS_CALL16", (MCFixupKind)Mips::fixup_Mips_CALL16)
320 .Case("R_MIPS_GOT16", (MCFixupKind)Mips::fixup_Mips_GOT)
321 .Case("R_MIPS_GOT_PAGE", (MCFixupKind)Mips::fixup_Mips_GOT_PAGE)
322 .Case("R_MIPS_GOT_OFST", (MCFixupKind)Mips::fixup_Mips_GOT_OFST)
323 .Case("R_MIPS_GOT_DISP", (MCFixupKind)Mips::fixup_Mips_GOT_DISP)
324 .Case("R_MIPS_GOT_HI16", (MCFixupKind)Mips::fixup_Mips_GOT_HI16)
325 .Case("R_MIPS_GOT_LO16", (MCFixupKind)Mips::fixup_Mips_GOT_LO16)
326 .Case("R_MIPS_TLS_GOTTPREL", (MCFixupKind)Mips::fixup_Mips_GOTTPREL)
327 .Case("R_MIPS_TLS_DTPREL_HI16", (MCFixupKind)Mips::fixup_Mips_DTPREL_HI)
328 .Case("R_MIPS_TLS_DTPREL_LO16", (MCFixupKind)Mips::fixup_Mips_DTPREL_LO)
329 .Case("R_MIPS_TLS_GD", (MCFixupKind)Mips::fixup_Mips_TLSGD)
330 .Case("R_MIPS_TLS_LDM", (MCFixupKind)Mips::fixup_Mips_TLSLDM)
331 .Case("R_MIPS_TLS_TPREL_HI16", (MCFixupKind)Mips::fixup_Mips_TPREL_HI)
332 .Case("R_MIPS_TLS_TPREL_LO16", (MCFixupKind)Mips::fixup_Mips_TPREL_LO)
333 .Case("R_MICROMIPS_CALL16", (MCFixupKind)Mips::fixup_MICROMIPS_CALL16)
334 .Case("R_MICROMIPS_GOT_DISP", (MCFixupKind)Mips::fixup_MICROMIPS_GOT_DISP)
335 .Case("R_MICROMIPS_GOT_PAGE", (MCFixupKind)Mips::fixup_MICROMIPS_GOT_PAGE)
336 .Case("R_MICROMIPS_GOT_OFST", (MCFixupKind)Mips::fixup_MICROMIPS_GOT_OFST)
337 .Case("R_MICROMIPS_GOT16", (MCFixupKind)Mips::fixup_MICROMIPS_GOT16)
338 .Case("R_MICROMIPS_TLS_GOTTPREL",
339 (MCFixupKind)Mips::fixup_MICROMIPS_GOTTPREL)
340 .Case("R_MICROMIPS_TLS_DTPREL_HI16",
341 (MCFixupKind)Mips::fixup_MICROMIPS_TLS_DTPREL_HI16)
342 .Case("R_MICROMIPS_TLS_DTPREL_LO16",
343 (MCFixupKind)Mips::fixup_MICROMIPS_TLS_DTPREL_LO16)
344 .Case("R_MICROMIPS_TLS_GD", (MCFixupKind)Mips::fixup_MICROMIPS_TLS_GD)
345 .Case("R_MICROMIPS_TLS_LDM", (MCFixupKind)Mips::fixup_MICROMIPS_TLS_LDM)
346 .Case("R_MICROMIPS_TLS_TPREL_HI16",
347 (MCFixupKind)Mips::fixup_MICROMIPS_TLS_TPREL_HI16)
348 .Case("R_MICROMIPS_TLS_TPREL_LO16",
349 (MCFixupKind)Mips::fixup_MICROMIPS_TLS_TPREL_LO16)
350 .Case("R_MIPS_JALR", (MCFixupKind)Mips::fixup_Mips_JALR)
351 .Case("R_MICROMIPS_JALR", (MCFixupKind)Mips::fixup_MICROMIPS_JALR)
352 .Default(MCAsmBackend::getFixupKind(Name));
353 }
354
355 const MCFixupKindInfo &MipsAsmBackend::
getFixupKindInfo(MCFixupKind Kind) const356 getFixupKindInfo(MCFixupKind Kind) const {
357 const static MCFixupKindInfo LittleEndianInfos[] = {
358 // This table *must* be in same the order of fixup_* kinds in
359 // MipsFixupKinds.h.
360 //
361 // name offset bits flags
362 { "fixup_Mips_16", 0, 16, 0 },
363 { "fixup_Mips_32", 0, 32, 0 },
364 { "fixup_Mips_REL32", 0, 32, 0 },
365 { "fixup_Mips_26", 0, 26, 0 },
366 { "fixup_Mips_HI16", 0, 16, 0 },
367 { "fixup_Mips_LO16", 0, 16, 0 },
368 { "fixup_Mips_GPREL16", 0, 16, 0 },
369 { "fixup_Mips_LITERAL", 0, 16, 0 },
370 { "fixup_Mips_GOT", 0, 16, 0 },
371 { "fixup_Mips_PC16", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
372 { "fixup_Mips_CALL16", 0, 16, 0 },
373 { "fixup_Mips_GPREL32", 0, 32, 0 },
374 { "fixup_Mips_SHIFT5", 6, 5, 0 },
375 { "fixup_Mips_SHIFT6", 6, 5, 0 },
376 { "fixup_Mips_64", 0, 64, 0 },
377 { "fixup_Mips_TLSGD", 0, 16, 0 },
378 { "fixup_Mips_GOTTPREL", 0, 16, 0 },
379 { "fixup_Mips_TPREL_HI", 0, 16, 0 },
380 { "fixup_Mips_TPREL_LO", 0, 16, 0 },
381 { "fixup_Mips_TLSLDM", 0, 16, 0 },
382 { "fixup_Mips_DTPREL_HI", 0, 16, 0 },
383 { "fixup_Mips_DTPREL_LO", 0, 16, 0 },
384 { "fixup_Mips_Branch_PCRel", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
385 { "fixup_Mips_GPOFF_HI", 0, 16, 0 },
386 { "fixup_MICROMIPS_GPOFF_HI",0, 16, 0 },
387 { "fixup_Mips_GPOFF_LO", 0, 16, 0 },
388 { "fixup_MICROMIPS_GPOFF_LO",0, 16, 0 },
389 { "fixup_Mips_GOT_PAGE", 0, 16, 0 },
390 { "fixup_Mips_GOT_OFST", 0, 16, 0 },
391 { "fixup_Mips_GOT_DISP", 0, 16, 0 },
392 { "fixup_Mips_HIGHER", 0, 16, 0 },
393 { "fixup_MICROMIPS_HIGHER", 0, 16, 0 },
394 { "fixup_Mips_HIGHEST", 0, 16, 0 },
395 { "fixup_MICROMIPS_HIGHEST", 0, 16, 0 },
396 { "fixup_Mips_GOT_HI16", 0, 16, 0 },
397 { "fixup_Mips_GOT_LO16", 0, 16, 0 },
398 { "fixup_Mips_CALL_HI16", 0, 16, 0 },
399 { "fixup_Mips_CALL_LO16", 0, 16, 0 },
400 { "fixup_Mips_PC18_S3", 0, 18, MCFixupKindInfo::FKF_IsPCRel },
401 { "fixup_MIPS_PC19_S2", 0, 19, MCFixupKindInfo::FKF_IsPCRel },
402 { "fixup_MIPS_PC21_S2", 0, 21, MCFixupKindInfo::FKF_IsPCRel },
403 { "fixup_MIPS_PC26_S2", 0, 26, MCFixupKindInfo::FKF_IsPCRel },
404 { "fixup_MIPS_PCHI16", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
405 { "fixup_MIPS_PCLO16", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
406 { "fixup_MICROMIPS_26_S1", 0, 26, 0 },
407 { "fixup_MICROMIPS_HI16", 0, 16, 0 },
408 { "fixup_MICROMIPS_LO16", 0, 16, 0 },
409 { "fixup_MICROMIPS_GOT16", 0, 16, 0 },
410 { "fixup_MICROMIPS_PC7_S1", 0, 7, MCFixupKindInfo::FKF_IsPCRel },
411 { "fixup_MICROMIPS_PC10_S1", 0, 10, MCFixupKindInfo::FKF_IsPCRel },
412 { "fixup_MICROMIPS_PC16_S1", 0, 16, MCFixupKindInfo::FKF_IsPCRel },
413 { "fixup_MICROMIPS_PC26_S1", 0, 26, MCFixupKindInfo::FKF_IsPCRel },
414 { "fixup_MICROMIPS_PC19_S2", 0, 19, MCFixupKindInfo::FKF_IsPCRel },
415 { "fixup_MICROMIPS_PC18_S3", 0, 18, MCFixupKindInfo::FKF_IsPCRel },
416 { "fixup_MICROMIPS_PC21_S1", 0, 21, MCFixupKindInfo::FKF_IsPCRel },
417 { "fixup_MICROMIPS_CALL16", 0, 16, 0 },
418 { "fixup_MICROMIPS_GOT_DISP", 0, 16, 0 },
419 { "fixup_MICROMIPS_GOT_PAGE", 0, 16, 0 },
420 { "fixup_MICROMIPS_GOT_OFST", 0, 16, 0 },
421 { "fixup_MICROMIPS_TLS_GD", 0, 16, 0 },
422 { "fixup_MICROMIPS_TLS_LDM", 0, 16, 0 },
423 { "fixup_MICROMIPS_TLS_DTPREL_HI16", 0, 16, 0 },
424 { "fixup_MICROMIPS_TLS_DTPREL_LO16", 0, 16, 0 },
425 { "fixup_MICROMIPS_GOTTPREL", 0, 16, 0 },
426 { "fixup_MICROMIPS_TLS_TPREL_HI16", 0, 16, 0 },
427 { "fixup_MICROMIPS_TLS_TPREL_LO16", 0, 16, 0 },
428 { "fixup_Mips_SUB", 0, 64, 0 },
429 { "fixup_MICROMIPS_SUB", 0, 64, 0 },
430 { "fixup_Mips_JALR", 0, 32, 0 },
431 { "fixup_MICROMIPS_JALR", 0, 32, 0 }
432 };
433 static_assert(std::size(LittleEndianInfos) == Mips::NumTargetFixupKinds,
434 "Not all MIPS little endian fixup kinds added!");
435
436 const static MCFixupKindInfo BigEndianInfos[] = {
437 // This table *must* be in same the order of fixup_* kinds in
438 // MipsFixupKinds.h.
439 //
440 // name offset bits flags
441 { "fixup_Mips_16", 16, 16, 0 },
442 { "fixup_Mips_32", 0, 32, 0 },
443 { "fixup_Mips_REL32", 0, 32, 0 },
444 { "fixup_Mips_26", 6, 26, 0 },
445 { "fixup_Mips_HI16", 16, 16, 0 },
446 { "fixup_Mips_LO16", 16, 16, 0 },
447 { "fixup_Mips_GPREL16", 16, 16, 0 },
448 { "fixup_Mips_LITERAL", 16, 16, 0 },
449 { "fixup_Mips_GOT", 16, 16, 0 },
450 { "fixup_Mips_PC16", 16, 16, MCFixupKindInfo::FKF_IsPCRel },
451 { "fixup_Mips_CALL16", 16, 16, 0 },
452 { "fixup_Mips_GPREL32", 0, 32, 0 },
453 { "fixup_Mips_SHIFT5", 21, 5, 0 },
454 { "fixup_Mips_SHIFT6", 21, 5, 0 },
455 { "fixup_Mips_64", 0, 64, 0 },
456 { "fixup_Mips_TLSGD", 16, 16, 0 },
457 { "fixup_Mips_GOTTPREL", 16, 16, 0 },
458 { "fixup_Mips_TPREL_HI", 16, 16, 0 },
459 { "fixup_Mips_TPREL_LO", 16, 16, 0 },
460 { "fixup_Mips_TLSLDM", 16, 16, 0 },
461 { "fixup_Mips_DTPREL_HI", 16, 16, 0 },
462 { "fixup_Mips_DTPREL_LO", 16, 16, 0 },
463 { "fixup_Mips_Branch_PCRel",16, 16, MCFixupKindInfo::FKF_IsPCRel },
464 { "fixup_Mips_GPOFF_HI", 16, 16, 0 },
465 { "fixup_MICROMIPS_GPOFF_HI", 16, 16, 0 },
466 { "fixup_Mips_GPOFF_LO", 16, 16, 0 },
467 { "fixup_MICROMIPS_GPOFF_LO", 16, 16, 0 },
468 { "fixup_Mips_GOT_PAGE", 16, 16, 0 },
469 { "fixup_Mips_GOT_OFST", 16, 16, 0 },
470 { "fixup_Mips_GOT_DISP", 16, 16, 0 },
471 { "fixup_Mips_HIGHER", 16, 16, 0 },
472 { "fixup_MICROMIPS_HIGHER", 16, 16, 0 },
473 { "fixup_Mips_HIGHEST", 16, 16, 0 },
474 { "fixup_MICROMIPS_HIGHEST",16, 16, 0 },
475 { "fixup_Mips_GOT_HI16", 16, 16, 0 },
476 { "fixup_Mips_GOT_LO16", 16, 16, 0 },
477 { "fixup_Mips_CALL_HI16", 16, 16, 0 },
478 { "fixup_Mips_CALL_LO16", 16, 16, 0 },
479 { "fixup_Mips_PC18_S3", 14, 18, MCFixupKindInfo::FKF_IsPCRel },
480 { "fixup_MIPS_PC19_S2", 13, 19, MCFixupKindInfo::FKF_IsPCRel },
481 { "fixup_MIPS_PC21_S2", 11, 21, MCFixupKindInfo::FKF_IsPCRel },
482 { "fixup_MIPS_PC26_S2", 6, 26, MCFixupKindInfo::FKF_IsPCRel },
483 { "fixup_MIPS_PCHI16", 16, 16, MCFixupKindInfo::FKF_IsPCRel },
484 { "fixup_MIPS_PCLO16", 16, 16, MCFixupKindInfo::FKF_IsPCRel },
485 { "fixup_MICROMIPS_26_S1", 6, 26, 0 },
486 { "fixup_MICROMIPS_HI16", 16, 16, 0 },
487 { "fixup_MICROMIPS_LO16", 16, 16, 0 },
488 { "fixup_MICROMIPS_GOT16", 16, 16, 0 },
489 { "fixup_MICROMIPS_PC7_S1", 9, 7, MCFixupKindInfo::FKF_IsPCRel },
490 { "fixup_MICROMIPS_PC10_S1", 6, 10, MCFixupKindInfo::FKF_IsPCRel },
491 { "fixup_MICROMIPS_PC16_S1",16, 16, MCFixupKindInfo::FKF_IsPCRel },
492 { "fixup_MICROMIPS_PC26_S1", 6, 26, MCFixupKindInfo::FKF_IsPCRel },
493 { "fixup_MICROMIPS_PC19_S2",13, 19, MCFixupKindInfo::FKF_IsPCRel },
494 { "fixup_MICROMIPS_PC18_S3",14, 18, MCFixupKindInfo::FKF_IsPCRel },
495 { "fixup_MICROMIPS_PC21_S1",11, 21, MCFixupKindInfo::FKF_IsPCRel },
496 { "fixup_MICROMIPS_CALL16", 16, 16, 0 },
497 { "fixup_MICROMIPS_GOT_DISP", 16, 16, 0 },
498 { "fixup_MICROMIPS_GOT_PAGE", 16, 16, 0 },
499 { "fixup_MICROMIPS_GOT_OFST", 16, 16, 0 },
500 { "fixup_MICROMIPS_TLS_GD", 16, 16, 0 },
501 { "fixup_MICROMIPS_TLS_LDM", 16, 16, 0 },
502 { "fixup_MICROMIPS_TLS_DTPREL_HI16", 16, 16, 0 },
503 { "fixup_MICROMIPS_TLS_DTPREL_LO16", 16, 16, 0 },
504 { "fixup_MICROMIPS_GOTTPREL", 16, 16, 0 },
505 { "fixup_MICROMIPS_TLS_TPREL_HI16", 16, 16, 0 },
506 { "fixup_MICROMIPS_TLS_TPREL_LO16", 16, 16, 0 },
507 { "fixup_Mips_SUB", 0, 64, 0 },
508 { "fixup_MICROMIPS_SUB", 0, 64, 0 },
509 { "fixup_Mips_JALR", 0, 32, 0 },
510 { "fixup_MICROMIPS_JALR", 0, 32, 0 }
511 };
512 static_assert(std::size(BigEndianInfos) == Mips::NumTargetFixupKinds,
513 "Not all MIPS big endian fixup kinds added!");
514
515 if (Kind >= FirstLiteralRelocationKind)
516 return MCAsmBackend::getFixupKindInfo(FK_NONE);
517 if (Kind < FirstTargetFixupKind)
518 return MCAsmBackend::getFixupKindInfo(Kind);
519
520 assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
521 "Invalid kind!");
522
523 if (Endian == llvm::endianness::little)
524 return LittleEndianInfos[Kind - FirstTargetFixupKind];
525 return BigEndianInfos[Kind - FirstTargetFixupKind];
526 }
527
528 /// WriteNopData - Write an (optimal) nop sequence of Count bytes
529 /// to the given output. If the target cannot generate such a sequence,
530 /// it should return an error.
531 ///
532 /// \return - True on success.
writeNopData(raw_ostream & OS,uint64_t Count,const MCSubtargetInfo * STI) const533 bool MipsAsmBackend::writeNopData(raw_ostream &OS, uint64_t Count,
534 const MCSubtargetInfo *STI) const {
535 // Check for a less than instruction size number of bytes
536 // FIXME: 16 bit instructions are not handled yet here.
537 // We shouldn't be using a hard coded number for instruction size.
538
539 // If the count is not 4-byte aligned, we must be writing data into the text
540 // section (otherwise we have unaligned instructions, and thus have far
541 // bigger problems), so just write zeros instead.
542 OS.write_zeros(Count);
543 return true;
544 }
545
shouldForceRelocation(const MCAssembler & Asm,const MCFixup & Fixup,const MCValue & Target,const MCSubtargetInfo * STI)546 bool MipsAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
547 const MCFixup &Fixup,
548 const MCValue &Target,
549 const MCSubtargetInfo *STI) {
550 if (Fixup.getKind() >= FirstLiteralRelocationKind)
551 return true;
552 const unsigned FixupKind = Fixup.getKind();
553 switch (FixupKind) {
554 default:
555 return false;
556 // All these relocations require special processing
557 // at linking time. Delegate this work to a linker.
558 case Mips::fixup_Mips_CALL_HI16:
559 case Mips::fixup_Mips_CALL_LO16:
560 case Mips::fixup_Mips_CALL16:
561 case Mips::fixup_Mips_GOT:
562 case Mips::fixup_Mips_GOT_PAGE:
563 case Mips::fixup_Mips_GOT_OFST:
564 case Mips::fixup_Mips_GOT_DISP:
565 case Mips::fixup_Mips_GOT_HI16:
566 case Mips::fixup_Mips_GOT_LO16:
567 case Mips::fixup_Mips_GOTTPREL:
568 case Mips::fixup_Mips_DTPREL_HI:
569 case Mips::fixup_Mips_DTPREL_LO:
570 case Mips::fixup_Mips_TLSGD:
571 case Mips::fixup_Mips_TLSLDM:
572 case Mips::fixup_Mips_TPREL_HI:
573 case Mips::fixup_Mips_TPREL_LO:
574 case Mips::fixup_Mips_JALR:
575 case Mips::fixup_MICROMIPS_CALL16:
576 case Mips::fixup_MICROMIPS_GOT_DISP:
577 case Mips::fixup_MICROMIPS_GOT_PAGE:
578 case Mips::fixup_MICROMIPS_GOT_OFST:
579 case Mips::fixup_MICROMIPS_GOT16:
580 case Mips::fixup_MICROMIPS_GOTTPREL:
581 case Mips::fixup_MICROMIPS_TLS_DTPREL_HI16:
582 case Mips::fixup_MICROMIPS_TLS_DTPREL_LO16:
583 case Mips::fixup_MICROMIPS_TLS_GD:
584 case Mips::fixup_MICROMIPS_TLS_LDM:
585 case Mips::fixup_MICROMIPS_TLS_TPREL_HI16:
586 case Mips::fixup_MICROMIPS_TLS_TPREL_LO16:
587 case Mips::fixup_MICROMIPS_JALR:
588 return true;
589 }
590 }
591
isMicroMips(const MCSymbol * Sym) const592 bool MipsAsmBackend::isMicroMips(const MCSymbol *Sym) const {
593 if (const auto *ElfSym = dyn_cast<const MCSymbolELF>(Sym)) {
594 if (ElfSym->getOther() & ELF::STO_MIPS_MICROMIPS)
595 return true;
596 }
597 return false;
598 }
599
createMipsAsmBackend(const Target & T,const MCSubtargetInfo & STI,const MCRegisterInfo & MRI,const MCTargetOptions & Options)600 MCAsmBackend *llvm::createMipsAsmBackend(const Target &T,
601 const MCSubtargetInfo &STI,
602 const MCRegisterInfo &MRI,
603 const MCTargetOptions &Options) {
604 MipsABIInfo ABI = MipsABIInfo::computeTargetABI(STI.getTargetTriple(),
605 STI.getCPU(), Options);
606 return new MipsAsmBackend(T, MRI, STI.getTargetTriple(), STI.getCPU(),
607 ABI.IsN32());
608 }
609