xref: /llvm-project-15.0.7/lld/ELF/Arch/Mips.cpp (revision feefb087)
1 //===- MIPS.cpp -----------------------------------------------------------===//
2 //
3 //                             The LLVM Linker
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "Error.h"
11 #include "InputFiles.h"
12 #include "OutputSections.h"
13 #include "Symbols.h"
14 #include "SyntheticSections.h"
15 #include "Target.h"
16 #include "Thunks.h"
17 #include "llvm/Object/ELF.h"
18 #include "llvm/Support/Endian.h"
19 
20 using namespace llvm;
21 using namespace llvm::object;
22 using namespace llvm::support::endian;
23 using namespace llvm::ELF;
24 using namespace lld;
25 using namespace lld::elf;
26 
27 namespace {
28 template <class ELFT> class MIPS final : public TargetInfo {
29 public:
30   MIPS();
31   RelExpr getRelExpr(uint32_t Type, const SymbolBody &S, const InputFile &File,
32                      const uint8_t *Loc) const override;
33   int64_t getImplicitAddend(const uint8_t *Buf, uint32_t Type) const override;
34   bool isPicRel(uint32_t Type) const override;
35   uint32_t getDynRel(uint32_t Type) const override;
36   void writeGotPlt(uint8_t *Buf, const SymbolBody &S) const override;
37   void writePltHeader(uint8_t *Buf) const override;
38   void writePlt(uint8_t *Buf, uint64_t GotPltEntryAddr, uint64_t PltEntryAddr,
39                 int32_t Index, unsigned RelOff) const override;
40   bool needsThunk(RelExpr Expr, uint32_t RelocType, const InputFile *File,
41                   const SymbolBody &S) const override;
42   void relocateOne(uint8_t *Loc, uint32_t Type, uint64_t Val) const override;
43   bool usesOnlyLowPageBits(uint32_t Type) const override;
44 };
45 } // namespace
46 
47 template <class ELFT> MIPS<ELFT>::MIPS() {
48   GotPltHeaderEntriesNum = 2;
49   DefaultMaxPageSize = 65536;
50   GotEntrySize = sizeof(typename ELFT::uint);
51   GotPltEntrySize = sizeof(typename ELFT::uint);
52   PltEntrySize = 16;
53   PltHeaderSize = 32;
54   CopyRel = R_MIPS_COPY;
55   PltRel = R_MIPS_JUMP_SLOT;
56   NeedsThunks = true;
57   TrapInstr = 0xefefefef;
58 
59   if (ELFT::Is64Bits) {
60     RelativeRel = (R_MIPS_64 << 8) | R_MIPS_REL32;
61     TlsGotRel = R_MIPS_TLS_TPREL64;
62     TlsModuleIndexRel = R_MIPS_TLS_DTPMOD64;
63     TlsOffsetRel = R_MIPS_TLS_DTPREL64;
64   } else {
65     RelativeRel = R_MIPS_REL32;
66     TlsGotRel = R_MIPS_TLS_TPREL32;
67     TlsModuleIndexRel = R_MIPS_TLS_DTPMOD32;
68     TlsOffsetRel = R_MIPS_TLS_DTPREL32;
69   }
70 }
71 
72 template <class ELFT>
73 RelExpr MIPS<ELFT>::getRelExpr(uint32_t Type, const SymbolBody &S,
74                                const InputFile &File,
75                                const uint8_t *Loc) const {
76   // See comment in the calculateMipsRelChain.
77   if (ELFT::Is64Bits || Config->MipsN32Abi)
78     Type &= 0xff;
79   switch (Type) {
80   case R_MIPS_JALR:
81   case R_MICROMIPS_JALR:
82     return R_HINT;
83   case R_MIPS_GPREL16:
84   case R_MIPS_GPREL32:
85   case R_MICROMIPS_GPREL16:
86   case R_MICROMIPS_GPREL7_S2:
87     return R_MIPS_GOTREL;
88   case R_MIPS_26:
89   case R_MICROMIPS_26_S1:
90     return R_PLT;
91   case R_MICROMIPS_PC26_S1:
92     return R_PLT_PC;
93   case R_MIPS_HI16:
94   case R_MIPS_LO16:
95   case R_MIPS_HIGHER:
96   case R_MIPS_HIGHEST:
97   case R_MICROMIPS_HI16:
98   case R_MICROMIPS_LO16:
99   case R_MICROMIPS_HIGHER:
100   case R_MICROMIPS_HIGHEST:
101     // R_MIPS_HI16/R_MIPS_LO16 relocations against _gp_disp calculate
102     // offset between start of function and 'gp' value which by default
103     // equal to the start of .got section. In that case we consider these
104     // relocations as relative.
105     if (&S == ElfSym::MipsGpDisp)
106       return R_MIPS_GOT_GP_PC;
107     if (&S == ElfSym::MipsLocalGp)
108       return R_MIPS_GOT_GP;
109     LLVM_FALLTHROUGH;
110   case R_MIPS_32:
111   case R_MIPS_64:
112   case R_MIPS_GOT_OFST:
113   case R_MIPS_SUB:
114   case R_MIPS_TLS_DTPREL_HI16:
115   case R_MIPS_TLS_DTPREL_LO16:
116   case R_MIPS_TLS_DTPREL32:
117   case R_MIPS_TLS_DTPREL64:
118   case R_MIPS_TLS_TPREL_HI16:
119   case R_MIPS_TLS_TPREL_LO16:
120   case R_MIPS_TLS_TPREL32:
121   case R_MIPS_TLS_TPREL64:
122   case R_MICROMIPS_GOT_OFST:
123   case R_MICROMIPS_SUB:
124   case R_MICROMIPS_TLS_DTPREL_HI16:
125   case R_MICROMIPS_TLS_DTPREL_LO16:
126   case R_MICROMIPS_TLS_TPREL_HI16:
127   case R_MICROMIPS_TLS_TPREL_LO16:
128     return R_ABS;
129   case R_MIPS_PC32:
130   case R_MIPS_PC16:
131   case R_MIPS_PC19_S2:
132   case R_MIPS_PC21_S2:
133   case R_MIPS_PC26_S2:
134   case R_MIPS_PCHI16:
135   case R_MIPS_PCLO16:
136   case R_MICROMIPS_PC7_S1:
137   case R_MICROMIPS_PC10_S1:
138   case R_MICROMIPS_PC16_S1:
139   case R_MICROMIPS_PC18_S3:
140   case R_MICROMIPS_PC19_S2:
141   case R_MICROMIPS_PC23_S2:
142   case R_MICROMIPS_PC21_S1:
143     return R_PC;
144   case R_MIPS_GOT16:
145   case R_MICROMIPS_GOT16:
146     if (S.isLocal())
147       return R_MIPS_GOT_LOCAL_PAGE;
148     LLVM_FALLTHROUGH;
149   case R_MIPS_CALL16:
150   case R_MIPS_GOT_DISP:
151   case R_MIPS_TLS_GOTTPREL:
152   case R_MICROMIPS_CALL16:
153   case R_MICROMIPS_GOT_DISP:
154   case R_MICROMIPS_TLS_GOTTPREL:
155     return R_MIPS_GOT_OFF;
156   case R_MIPS_CALL_HI16:
157   case R_MIPS_CALL_LO16:
158   case R_MIPS_GOT_HI16:
159   case R_MIPS_GOT_LO16:
160   case R_MICROMIPS_CALL_HI16:
161   case R_MICROMIPS_CALL_LO16:
162   case R_MICROMIPS_GOT_HI16:
163   case R_MICROMIPS_GOT_LO16:
164     return R_MIPS_GOT_OFF32;
165   case R_MIPS_GOT_PAGE:
166   case R_MICROMIPS_GOT_PAGE:
167     return R_MIPS_GOT_LOCAL_PAGE;
168   case R_MIPS_TLS_GD:
169   case R_MICROMIPS_TLS_GD:
170     return R_MIPS_TLSGD;
171   case R_MIPS_TLS_LDM:
172   case R_MICROMIPS_TLS_LDM:
173     return R_MIPS_TLSLD;
174   case R_MIPS_NONE:
175     return R_NONE;
176   default:
177     error("do not know how to handle relocation '" + toString(Type) + "' (" +
178           Twine(Type) + ")");
179     return R_HINT;
180   }
181 }
182 
183 template <class ELFT> bool MIPS<ELFT>::isPicRel(uint32_t Type) const {
184   return Type == R_MIPS_32 || Type == R_MIPS_64;
185 }
186 
187 template <class ELFT> uint32_t MIPS<ELFT>::getDynRel(uint32_t Type) const {
188   return RelativeRel;
189 }
190 
191 template <class ELFT>
192 void MIPS<ELFT>::writeGotPlt(uint8_t *Buf, const SymbolBody &) const {
193   write32<ELFT::TargetEndianness>(Buf, InX::Plt->getVA());
194 }
195 
196 template <endianness E> static uint32_t readShuffle(const uint8_t *Loc) {
197   // The major opcode of a microMIPS instruction needs to appear
198   // in the first 16-bit word (lowest address) for efficient hardware
199   // decode so that it knows if the instruction is 16-bit or 32-bit
200   // as early as possible. To do so, little-endian binaries keep 16-bit
201   // words in a big-endian order. That is why we have to swap these
202   // words to get a correct value.
203   uint32_t V = read32<E>(Loc);
204   if (E == support::little)
205     return (V << 16) | (V >> 16);
206   return V;
207 }
208 
209 template <endianness E>
210 static void writeRelocation(uint8_t *Loc, uint64_t V, uint8_t BitsSize,
211                             uint8_t Shift) {
212   uint32_t Instr = read32<E>(Loc);
213   uint32_t Mask = 0xffffffff >> (32 - BitsSize);
214   uint32_t Data = (Instr & ~Mask) | ((V >> Shift) & Mask);
215   write32<E>(Loc, Data);
216 }
217 
218 template <endianness E>
219 static void writeMicroRelocation32(uint8_t *Loc, uint64_t V, uint8_t BitsSize,
220                                    uint8_t Shift) {
221   // See comments in readShuffle for purpose of this code.
222   uint16_t *Words = (uint16_t *)Loc;
223   if (E == support::little)
224     std::swap(Words[0], Words[1]);
225 
226   writeRelocation<E>(Loc, V, BitsSize, Shift);
227 
228   if (E == support::little)
229     std::swap(Words[0], Words[1]);
230 }
231 
232 template <endianness E>
233 static void writeMicroRelocation16(uint8_t *Loc, uint64_t V, uint8_t BitsSize,
234                                    uint8_t Shift) {
235   uint16_t Instr = read16<E>(Loc);
236   uint16_t Mask = 0xffff >> (16 - BitsSize);
237   uint16_t Data = (Instr & ~Mask) | ((V >> Shift) & Mask);
238   write16<E>(Loc, Data);
239 }
240 
241 static bool isMicroMips() { return Config->MipsEFlags & EF_MIPS_MICROMIPS; }
242 
243 template <class ELFT> void MIPS<ELFT>::writePltHeader(uint8_t *Buf) const {
244   const endianness E = ELFT::TargetEndianness;
245   if (isMicroMips()) {
246     uint64_t GotPlt = In<ELFT>::GotPlt->getVA();
247     uint64_t Plt = In<ELFT>::Plt->getVA();
248     // Overwrite trap instructions written by Writer::writeTrapInstr.
249     memset(Buf, 0, PltHeaderSize);
250 
251     write16<E>(Buf, isMipsR6() ? 0x7860 : 0x7980);  // addiupc v1, (GOTPLT) - .
252     write16<E>(Buf + 4, 0xff23);    // lw      $25, 0($3)
253     write16<E>(Buf + 8, 0x0535);    // subu16  $2,  $2, $3
254     write16<E>(Buf + 10, 0x2525);   // srl16   $2,  $2, 2
255     write16<E>(Buf + 12, 0x3302);   // addiu   $24, $2, -2
256     write16<E>(Buf + 14, 0xfffe);
257     write16<E>(Buf + 16, 0x0dff);   // move    $15, $31
258     if (isMipsR6()) {
259       write16<E>(Buf + 18, 0x0f83); // move    $28, $3
260       write16<E>(Buf + 20, 0x472b); // jalrc   $25
261       write16<E>(Buf + 22, 0x0c00); // nop
262       relocateOne(Buf, R_MICROMIPS_PC19_S2, GotPlt - Plt);
263     } else {
264       write16<E>(Buf + 18, 0x45f9); // jalrc   $25
265       write16<E>(Buf + 20, 0x0f83); // move    $28, $3
266       write16<E>(Buf + 22, 0x0c00); // nop
267       relocateOne(Buf, R_MICROMIPS_PC23_S2, GotPlt - Plt);
268     }
269     return;
270   }
271 
272   if (Config->MipsN32Abi) {
273     write32<E>(Buf, 0x3c0e0000);      // lui   $14, %hi(&GOTPLT[0])
274     write32<E>(Buf + 4, 0x8dd90000);  // lw    $25, %lo(&GOTPLT[0])($14)
275     write32<E>(Buf + 8, 0x25ce0000);  // addiu $14, $14, %lo(&GOTPLT[0])
276     write32<E>(Buf + 12, 0x030ec023); // subu  $24, $24, $14
277   } else {
278     write32<E>(Buf, 0x3c1c0000);      // lui   $28, %hi(&GOTPLT[0])
279     write32<E>(Buf + 4, 0x8f990000);  // lw    $25, %lo(&GOTPLT[0])($28)
280     write32<E>(Buf + 8, 0x279c0000);  // addiu $28, $28, %lo(&GOTPLT[0])
281     write32<E>(Buf + 12, 0x031cc023); // subu  $24, $24, $28
282   }
283 
284   write32<E>(Buf + 16, 0x03e07825); // move  $15, $31
285   write32<E>(Buf + 20, 0x0018c082); // srl   $24, $24, 2
286   write32<E>(Buf + 24, 0x0320f809); // jalr  $25
287   write32<E>(Buf + 28, 0x2718fffe); // subu  $24, $24, 2
288 
289   uint64_t GotPlt = InX::GotPlt->getVA();
290   writeRelocation<E>(Buf, GotPlt + 0x8000, 16, 16);
291   writeRelocation<E>(Buf + 4, GotPlt, 16, 0);
292   writeRelocation<E>(Buf + 8, GotPlt, 16, 0);
293 }
294 
295 template <class ELFT>
296 void MIPS<ELFT>::writePlt(uint8_t *Buf, uint64_t GotPltEntryAddr,
297                           uint64_t PltEntryAddr, int32_t Index,
298                           unsigned RelOff) const {
299   const endianness E = ELFT::TargetEndianness;
300   if (isMicroMips()) {
301     // Overwrite trap instructions written by Writer::writeTrapInstr.
302     memset(Buf, 0, PltEntrySize);
303 
304     if (isMipsR6()) {
305       write16<E>(Buf, 0x7840);      // addiupc $2, (GOTPLT) - .
306       write16<E>(Buf + 4, 0xff22);  // lw $25, 0($2)
307       write16<E>(Buf + 8, 0x0f02);  // move $24, $2
308       write16<E>(Buf + 10, 0x4723); // jrc $25 / jr16 $25
309       relocateOne(Buf, R_MICROMIPS_PC19_S2, GotPltEntryAddr - PltEntryAddr);
310     } else {
311       write16<E>(Buf, 0x7900);      // addiupc $2, (GOTPLT) - .
312       write16<E>(Buf + 4, 0xff22);  // lw $25, 0($2)
313       write16<E>(Buf + 8, 0x4599);  // jrc $25 / jr16 $25
314       write16<E>(Buf + 10, 0x0f02); // move $24, $2
315       relocateOne(Buf, R_MICROMIPS_PC23_S2, GotPltEntryAddr - PltEntryAddr);
316     }
317     return;
318   }
319 
320   write32<E>(Buf, 0x3c0f0000);     // lui   $15, %hi(.got.plt entry)
321   write32<E>(Buf + 4, 0x8df90000); // l[wd] $25, %lo(.got.plt entry)($15)
322   write32<E>(Buf + 8, isMipsR6() ? 0x03200009 : 0x03200008);  // jr  $25
323   write32<E>(Buf + 12, 0x25f80000); // addiu $24, $15, %lo(.got.plt entry)
324   writeRelocation<E>(Buf, GotPltEntryAddr + 0x8000, 16, 16);
325   writeRelocation<E>(Buf + 4, GotPltEntryAddr, 16, 0);
326   writeRelocation<E>(Buf + 12, GotPltEntryAddr, 16, 0);
327 }
328 
329 template <class ELFT>
330 bool MIPS<ELFT>::needsThunk(RelExpr Expr, uint32_t Type, const InputFile *File,
331                             const SymbolBody &S) const {
332   // Any MIPS PIC code function is invoked with its address in register $t9.
333   // So if we have a branch instruction from non-PIC code to the PIC one
334   // we cannot make the jump directly and need to create a small stubs
335   // to save the target function address.
336   // See page 3-38 ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
337   if (Type != R_MIPS_26 && Type != R_MICROMIPS_26_S1 &&
338       Type != R_MICROMIPS_PC26_S1)
339     return false;
340   auto *F = dyn_cast_or_null<ELFFileBase<ELFT>>(File);
341   if (!F)
342     return false;
343   // If current file has PIC code, LA25 stub is not required.
344   if (F->getObj().getHeader()->e_flags & EF_MIPS_PIC)
345     return false;
346   auto *D = dyn_cast<DefinedRegular>(&S);
347   // LA25 is required if target file has PIC code
348   // or target symbol is a PIC symbol.
349   return D && D->isMipsPIC<ELFT>();
350 }
351 
352 template <class ELFT>
353 int64_t MIPS<ELFT>::getImplicitAddend(const uint8_t *Buf, uint32_t Type) const {
354   const endianness E = ELFT::TargetEndianness;
355   switch (Type) {
356   default:
357     return 0;
358   case R_MIPS_32:
359   case R_MIPS_GPREL32:
360   case R_MIPS_TLS_DTPREL32:
361   case R_MIPS_TLS_TPREL32:
362     return SignExtend64<32>(read32<E>(Buf));
363   case R_MIPS_26:
364     // FIXME (simon): If the relocation target symbol is not a PLT entry
365     // we should use another expression for calculation:
366     // ((A << 2) | (P & 0xf0000000)) >> 2
367     return SignExtend64<28>(read32<E>(Buf) << 2);
368   case R_MIPS_GOT16:
369   case R_MIPS_HI16:
370   case R_MIPS_PCHI16:
371     return SignExtend64<16>(read32<E>(Buf)) << 16;
372   case R_MIPS_GPREL16:
373   case R_MIPS_LO16:
374   case R_MIPS_PCLO16:
375   case R_MIPS_TLS_DTPREL_HI16:
376   case R_MIPS_TLS_DTPREL_LO16:
377   case R_MIPS_TLS_TPREL_HI16:
378   case R_MIPS_TLS_TPREL_LO16:
379     return SignExtend64<16>(read32<E>(Buf));
380   case R_MICROMIPS_GOT16:
381   case R_MICROMIPS_HI16:
382     return SignExtend64<16>(readShuffle<E>(Buf)) << 16;
383   case R_MICROMIPS_GPREL16:
384   case R_MICROMIPS_LO16:
385   case R_MICROMIPS_TLS_DTPREL_HI16:
386   case R_MICROMIPS_TLS_DTPREL_LO16:
387   case R_MICROMIPS_TLS_TPREL_HI16:
388   case R_MICROMIPS_TLS_TPREL_LO16:
389     return SignExtend64<16>(readShuffle<E>(Buf));
390   case R_MICROMIPS_GPREL7_S2:
391     return SignExtend64<9>(readShuffle<E>(Buf) << 2);
392   case R_MIPS_PC16:
393     return SignExtend64<18>(read32<E>(Buf) << 2);
394   case R_MIPS_PC19_S2:
395     return SignExtend64<21>(read32<E>(Buf) << 2);
396   case R_MIPS_PC21_S2:
397     return SignExtend64<23>(read32<E>(Buf) << 2);
398   case R_MIPS_PC26_S2:
399     return SignExtend64<28>(read32<E>(Buf) << 2);
400   case R_MIPS_PC32:
401     return SignExtend64<32>(read32<E>(Buf));
402   case R_MICROMIPS_26_S1:
403     return SignExtend64<27>(readShuffle<E>(Buf) << 1);
404   case R_MICROMIPS_PC7_S1:
405     return SignExtend64<8>(read16<E>(Buf) << 1);
406   case R_MICROMIPS_PC10_S1:
407     return SignExtend64<11>(read16<E>(Buf) << 1);
408   case R_MICROMIPS_PC16_S1:
409     return SignExtend64<17>(readShuffle<E>(Buf) << 1);
410   case R_MICROMIPS_PC18_S3:
411     return SignExtend64<21>(readShuffle<E>(Buf) << 3);
412   case R_MICROMIPS_PC19_S2:
413     return SignExtend64<21>(readShuffle<E>(Buf) << 2);
414   case R_MICROMIPS_PC21_S1:
415     return SignExtend64<22>(readShuffle<E>(Buf) << 1);
416   case R_MICROMIPS_PC23_S2:
417     return SignExtend64<25>(readShuffle<E>(Buf) << 2);
418   case R_MICROMIPS_PC26_S1:
419     return SignExtend64<27>(readShuffle<E>(Buf) << 1);
420   }
421 }
422 
423 static std::pair<uint32_t, uint64_t>
424 calculateMipsRelChain(uint8_t *Loc, uint32_t Type, uint64_t Val) {
425   // MIPS N64 ABI packs multiple relocations into the single relocation
426   // record. In general, all up to three relocations can have arbitrary
427   // types. In fact, Clang and GCC uses only a few combinations. For now,
428   // we support two of them. That is allow to pass at least all LLVM
429   // test suite cases.
430   // <any relocation> / R_MIPS_SUB / R_MIPS_HI16 | R_MIPS_LO16
431   // <any relocation> / R_MIPS_64 / R_MIPS_NONE
432   // The first relocation is a 'real' relocation which is calculated
433   // using the corresponding symbol's value. The second and the third
434   // relocations used to modify result of the first one: extend it to
435   // 64-bit, extract high or low part etc. For details, see part 2.9 Relocation
436   // at the https://dmz-portal.mips.com/mw/images/8/82/007-4658-001.pdf
437   uint32_t Type2 = (Type >> 8) & 0xff;
438   uint32_t Type3 = (Type >> 16) & 0xff;
439   if (Type2 == R_MIPS_NONE && Type3 == R_MIPS_NONE)
440     return std::make_pair(Type, Val);
441   if (Type2 == R_MIPS_64 && Type3 == R_MIPS_NONE)
442     return std::make_pair(Type2, Val);
443   if (Type2 == R_MIPS_SUB && (Type3 == R_MIPS_HI16 || Type3 == R_MIPS_LO16))
444     return std::make_pair(Type3, -Val);
445   if (Type2 == R_MICROMIPS_SUB &&
446       (Type3 == R_MICROMIPS_HI16 || Type3 == R_MICROMIPS_LO16))
447     return std::make_pair(Type3, -Val);
448   error(getErrorLocation(Loc) + "unsupported relocations combination " +
449         Twine(Type));
450   return std::make_pair(Type & 0xff, Val);
451 }
452 
453 template <class ELFT>
454 void MIPS<ELFT>::relocateOne(uint8_t *Loc, uint32_t Type, uint64_t Val) const {
455   const endianness E = ELFT::TargetEndianness;
456   // Thread pointer and DRP offsets from the start of TLS data area.
457   // https://www.linux-mips.org/wiki/NPTL
458   if (Type == R_MIPS_TLS_DTPREL_HI16 || Type == R_MIPS_TLS_DTPREL_LO16 ||
459       Type == R_MIPS_TLS_DTPREL32 || Type == R_MIPS_TLS_DTPREL64 ||
460       Type == R_MICROMIPS_TLS_DTPREL_HI16 ||
461       Type == R_MICROMIPS_TLS_DTPREL_LO16)
462     Val -= 0x8000;
463   else if (Type == R_MIPS_TLS_TPREL_HI16 || Type == R_MIPS_TLS_TPREL_LO16 ||
464            Type == R_MIPS_TLS_TPREL32 || Type == R_MIPS_TLS_TPREL64 ||
465            Type == R_MICROMIPS_TLS_TPREL_HI16 ||
466            Type == R_MICROMIPS_TLS_TPREL_LO16)
467     Val -= 0x7000;
468   if (ELFT::Is64Bits || Config->MipsN32Abi)
469     std::tie(Type, Val) = calculateMipsRelChain(Loc, Type, Val);
470   switch (Type) {
471   case R_MIPS_32:
472   case R_MIPS_GPREL32:
473   case R_MIPS_TLS_DTPREL32:
474   case R_MIPS_TLS_TPREL32:
475     write32<E>(Loc, Val);
476     break;
477   case R_MIPS_64:
478   case R_MIPS_TLS_DTPREL64:
479   case R_MIPS_TLS_TPREL64:
480     write64<E>(Loc, Val);
481     break;
482   case R_MIPS_26:
483     writeRelocation<E>(Loc, Val, 26, 2);
484     break;
485   case R_MIPS_GOT16:
486     // The R_MIPS_GOT16 relocation's value in "relocatable" linking mode
487     // is updated addend (not a GOT index). In that case write high 16 bits
488     // to store a correct addend value.
489     if (Config->Relocatable) {
490       writeRelocation<E>(Loc, Val + 0x8000, 16, 16);
491     } else {
492       checkInt<16>(Loc, Val, Type);
493       writeRelocation<E>(Loc, Val, 16, 0);
494     }
495     break;
496   case R_MICROMIPS_GOT16:
497     if (Config->Relocatable) {
498       writeMicroRelocation32<E>(Loc, Val + 0x8000, 16, 16);
499     } else {
500       checkInt<16>(Loc, Val, Type);
501       writeMicroRelocation32<E>(Loc, Val, 16, 0);
502     }
503     break;
504   case R_MIPS_GOT_DISP:
505   case R_MIPS_GOT_PAGE:
506   case R_MIPS_GPREL16:
507   case R_MIPS_TLS_GD:
508   case R_MIPS_TLS_LDM:
509     checkInt<16>(Loc, Val, Type);
510     LLVM_FALLTHROUGH;
511   case R_MIPS_CALL16:
512   case R_MIPS_CALL_LO16:
513   case R_MIPS_GOT_LO16:
514   case R_MIPS_GOT_OFST:
515   case R_MIPS_LO16:
516   case R_MIPS_PCLO16:
517   case R_MIPS_TLS_DTPREL_LO16:
518   case R_MIPS_TLS_GOTTPREL:
519   case R_MIPS_TLS_TPREL_LO16:
520     writeRelocation<E>(Loc, Val, 16, 0);
521     break;
522   case R_MICROMIPS_GOT_DISP:
523   case R_MICROMIPS_GOT_PAGE:
524   case R_MICROMIPS_GPREL16:
525   case R_MICROMIPS_TLS_GD:
526   case R_MICROMIPS_TLS_LDM:
527     checkInt<16>(Loc, Val, Type);
528     writeMicroRelocation32<E>(Loc, Val, 16, 0);
529     break;
530   case R_MICROMIPS_CALL16:
531   case R_MICROMIPS_CALL_LO16:
532   case R_MICROMIPS_GOT_OFST:
533   case R_MICROMIPS_LO16:
534   case R_MICROMIPS_TLS_DTPREL_LO16:
535   case R_MICROMIPS_TLS_GOTTPREL:
536   case R_MICROMIPS_TLS_TPREL_LO16:
537     writeMicroRelocation32<E>(Loc, Val, 16, 0);
538     break;
539   case R_MICROMIPS_GPREL7_S2:
540     checkInt<7>(Loc, Val, Type);
541     writeMicroRelocation32<E>(Loc, Val, 7, 2);
542     break;
543   case R_MIPS_CALL_HI16:
544   case R_MIPS_GOT_HI16:
545   case R_MIPS_HI16:
546   case R_MIPS_PCHI16:
547   case R_MIPS_TLS_DTPREL_HI16:
548   case R_MIPS_TLS_TPREL_HI16:
549     writeRelocation<E>(Loc, Val + 0x8000, 16, 16);
550     break;
551   case R_MICROMIPS_CALL_HI16:
552   case R_MICROMIPS_GOT_HI16:
553   case R_MICROMIPS_HI16:
554   case R_MICROMIPS_TLS_DTPREL_HI16:
555   case R_MICROMIPS_TLS_TPREL_HI16:
556     writeMicroRelocation32<E>(Loc, Val + 0x8000, 16, 16);
557     break;
558   case R_MIPS_HIGHER:
559     writeRelocation<E>(Loc, Val + 0x80008000, 16, 32);
560     break;
561   case R_MIPS_HIGHEST:
562     writeRelocation<E>(Loc, Val + 0x800080008000, 16, 48);
563     break;
564   case R_MICROMIPS_HIGHER:
565     writeMicroRelocation32<E>(Loc, Val + 0x80008000, 16, 32);
566     break;
567   case R_MICROMIPS_HIGHEST:
568     writeMicroRelocation32<E>(Loc, Val + 0x800080008000, 16, 48);
569     break;
570   case R_MIPS_JALR:
571   case R_MICROMIPS_JALR:
572     // Ignore this optimization relocation for now
573     break;
574   case R_MIPS_PC16:
575     checkAlignment<4>(Loc, Val, Type);
576     checkInt<18>(Loc, Val, Type);
577     writeRelocation<E>(Loc, Val, 16, 2);
578     break;
579   case R_MIPS_PC19_S2:
580     checkAlignment<4>(Loc, Val, Type);
581     checkInt<21>(Loc, Val, Type);
582     writeRelocation<E>(Loc, Val, 19, 2);
583     break;
584   case R_MIPS_PC21_S2:
585     checkAlignment<4>(Loc, Val, Type);
586     checkInt<23>(Loc, Val, Type);
587     writeRelocation<E>(Loc, Val, 21, 2);
588     break;
589   case R_MIPS_PC26_S2:
590     checkAlignment<4>(Loc, Val, Type);
591     checkInt<28>(Loc, Val, Type);
592     writeRelocation<E>(Loc, Val, 26, 2);
593     break;
594   case R_MIPS_PC32:
595     writeRelocation<E>(Loc, Val, 32, 0);
596     break;
597   case R_MICROMIPS_26_S1:
598   case R_MICROMIPS_PC26_S1:
599     checkInt<27>(Loc, Val, Type);
600     writeMicroRelocation32<E>(Loc, Val, 26, 1);
601     break;
602   case R_MICROMIPS_PC7_S1:
603     checkInt<8>(Loc, Val, Type);
604     writeMicroRelocation16<E>(Loc, Val, 7, 1);
605     break;
606   case R_MICROMIPS_PC10_S1:
607     checkInt<11>(Loc, Val, Type);
608     writeMicroRelocation16<E>(Loc, Val, 10, 1);
609     break;
610   case R_MICROMIPS_PC16_S1:
611     checkInt<17>(Loc, Val, Type);
612     writeMicroRelocation32<E>(Loc, Val, 16, 1);
613     break;
614   case R_MICROMIPS_PC18_S3:
615     checkInt<21>(Loc, Val, Type);
616     writeMicroRelocation32<E>(Loc, Val, 18, 3);
617     break;
618   case R_MICROMIPS_PC19_S2:
619     checkInt<21>(Loc, Val, Type);
620     writeMicroRelocation32<E>(Loc, Val, 19, 2);
621     break;
622   case R_MICROMIPS_PC21_S1:
623     checkInt<22>(Loc, Val, Type);
624     writeMicroRelocation32<E>(Loc, Val, 21, 1);
625     break;
626   case R_MICROMIPS_PC23_S2:
627     checkInt<25>(Loc, Val, Type);
628     writeMicroRelocation32<E>(Loc, Val, 23, 2);
629     break;
630   default:
631     error(getErrorLocation(Loc) + "unrecognized reloc " + Twine(Type));
632   }
633 }
634 
635 template <class ELFT>
636 bool MIPS<ELFT>::usesOnlyLowPageBits(uint32_t Type) const {
637   return Type == R_MIPS_LO16 || Type == R_MIPS_GOT_OFST ||
638          Type == R_MICROMIPS_LO16 || Type == R_MICROMIPS_GOT_OFST;
639 }
640 
641 template <class ELFT> TargetInfo *elf::getMipsTargetInfo() {
642   static MIPS<ELFT> Target;
643   return &Target;
644 }
645 
646 template TargetInfo *elf::getMipsTargetInfo<ELF32LE>();
647 template TargetInfo *elf::getMipsTargetInfo<ELF32BE>();
648 template TargetInfo *elf::getMipsTargetInfo<ELF64LE>();
649 template TargetInfo *elf::getMipsTargetInfo<ELF64BE>();
650