xref: /freebsd/contrib/llvm-project/clang/lib/Driver/ToolChains/Arch/Mips.cpp (revision 725a9f47324d42037db93c27ceb40d4956872f3e)
1 //===--- Mips.cpp - Tools Implementations -----------------------*- C++ -*-===//
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 "Mips.h"
10 #include "ToolChains/CommonArgs.h"
11 #include "clang/Driver/Driver.h"
12 #include "clang/Driver/DriverDiagnostic.h"
13 #include "clang/Driver/Options.h"
14 #include "llvm/ADT/StringSwitch.h"
15 #include "llvm/Option/ArgList.h"
16 
17 using namespace clang::driver;
18 using namespace clang::driver::tools;
19 using namespace clang;
20 using namespace llvm::opt;
21 
22 // Get CPU and ABI names. They are not independent
23 // so we have to calculate them together.
24 void mips::getMipsCPUAndABI(const ArgList &Args, const llvm::Triple &Triple,
25                             StringRef &CPUName, StringRef &ABIName) {
26   const char *DefMips32CPU = "mips32r2";
27   const char *DefMips64CPU = "mips64r2";
28 
29   // MIPS32r6 is the default for mips(el)?-img-linux-gnu and MIPS64r6 is the
30   // default for mips64(el)?-img-linux-gnu.
31   if (Triple.getVendor() == llvm::Triple::ImaginationTechnologies &&
32       Triple.isGNUEnvironment()) {
33     DefMips32CPU = "mips32r6";
34     DefMips64CPU = "mips64r6";
35   }
36 
37   if (Triple.getSubArch() == llvm::Triple::MipsSubArch_r6) {
38     DefMips32CPU = "mips32r6";
39     DefMips64CPU = "mips64r6";
40   }
41 
42   // MIPS3 is the default for mips64*-unknown-openbsd.
43   if (Triple.isOSOpenBSD())
44     DefMips64CPU = "mips3";
45 
46   // MIPS2 is the default for mips(el)?-unknown-freebsd.
47   // MIPS3 is the default for mips64(el)?-unknown-freebsd.
48   if (Triple.isOSFreeBSD()) {
49     DefMips32CPU = "mips2";
50     DefMips64CPU = "mips3";
51   }
52 
53   if (Arg *A = Args.getLastArg(clang::driver::options::OPT_march_EQ,
54                                options::OPT_mcpu_EQ))
55     CPUName = A->getValue();
56 
57   if (Arg *A = Args.getLastArg(options::OPT_mabi_EQ)) {
58     ABIName = A->getValue();
59     // Convert a GNU style Mips ABI name to the name
60     // accepted by LLVM Mips backend.
61     ABIName = llvm::StringSwitch<llvm::StringRef>(ABIName)
62                   .Case("32", "o32")
63                   .Case("64", "n64")
64                   .Default(ABIName);
65   }
66 
67   // Setup default CPU and ABI names.
68   if (CPUName.empty() && ABIName.empty()) {
69     switch (Triple.getArch()) {
70     default:
71       llvm_unreachable("Unexpected triple arch name");
72     case llvm::Triple::mips:
73     case llvm::Triple::mipsel:
74       CPUName = DefMips32CPU;
75       break;
76     case llvm::Triple::mips64:
77     case llvm::Triple::mips64el:
78       CPUName = DefMips64CPU;
79       break;
80     }
81   }
82 
83   if (ABIName.empty() && (Triple.getEnvironment() == llvm::Triple::GNUABIN32))
84     ABIName = "n32";
85 
86   if (ABIName.empty() &&
87       (Triple.getVendor() == llvm::Triple::MipsTechnologies ||
88        Triple.getVendor() == llvm::Triple::ImaginationTechnologies)) {
89     ABIName = llvm::StringSwitch<const char *>(CPUName)
90                   .Case("mips1", "o32")
91                   .Case("mips2", "o32")
92                   .Case("mips3", "n64")
93                   .Case("mips4", "n64")
94                   .Case("mips5", "n64")
95                   .Case("mips32", "o32")
96                   .Case("mips32r2", "o32")
97                   .Case("mips32r3", "o32")
98                   .Case("mips32r5", "o32")
99                   .Case("mips32r6", "o32")
100                   .Case("mips64", "n64")
101                   .Case("mips64r2", "n64")
102                   .Case("mips64r3", "n64")
103                   .Case("mips64r5", "n64")
104                   .Case("mips64r6", "n64")
105                   .Case("octeon", "n64")
106                   .Case("p5600", "o32")
107                   .Default("");
108   }
109 
110   if (ABIName.empty()) {
111     // Deduce ABI name from the target triple.
112     ABIName = Triple.isMIPS32() ? "o32" : "n64";
113   }
114 
115   if (CPUName.empty()) {
116     // Deduce CPU name from ABI name.
117     CPUName = llvm::StringSwitch<const char *>(ABIName)
118                   .Case("o32", DefMips32CPU)
119                   .Cases("n32", "n64", DefMips64CPU)
120                   .Default("");
121   }
122 
123   // FIXME: Warn on inconsistent use of -march and -mabi.
124 }
125 
126 std::string mips::getMipsABILibSuffix(const ArgList &Args,
127                                       const llvm::Triple &Triple) {
128   StringRef CPUName, ABIName;
129   tools::mips::getMipsCPUAndABI(Args, Triple, CPUName, ABIName);
130   return llvm::StringSwitch<std::string>(ABIName)
131       .Case("o32", "")
132       .Case("n32", "32")
133       .Case("n64", "64");
134 }
135 
136 // Convert ABI name to the GNU tools acceptable variant.
137 StringRef mips::getGnuCompatibleMipsABIName(StringRef ABI) {
138   return llvm::StringSwitch<llvm::StringRef>(ABI)
139       .Case("o32", "32")
140       .Case("n64", "64")
141       .Default(ABI);
142 }
143 
144 // Select the MIPS float ABI as determined by -msoft-float, -mhard-float,
145 // and -mfloat-abi=.
146 mips::FloatABI mips::getMipsFloatABI(const Driver &D, const ArgList &Args,
147                                      const llvm::Triple &Triple) {
148   mips::FloatABI ABI = mips::FloatABI::Invalid;
149   if (Arg *A =
150           Args.getLastArg(options::OPT_msoft_float, options::OPT_mhard_float,
151                           options::OPT_mfloat_abi_EQ)) {
152     if (A->getOption().matches(options::OPT_msoft_float))
153       ABI = mips::FloatABI::Soft;
154     else if (A->getOption().matches(options::OPT_mhard_float))
155       ABI = mips::FloatABI::Hard;
156     else {
157       ABI = llvm::StringSwitch<mips::FloatABI>(A->getValue())
158                 .Case("soft", mips::FloatABI::Soft)
159                 .Case("hard", mips::FloatABI::Hard)
160                 .Default(mips::FloatABI::Invalid);
161       if (ABI == mips::FloatABI::Invalid && !StringRef(A->getValue()).empty()) {
162         D.Diag(clang::diag::err_drv_invalid_mfloat_abi) << A->getAsString(Args);
163         ABI = mips::FloatABI::Hard;
164       }
165     }
166   }
167 
168   // If unspecified, choose the default based on the platform.
169   if (ABI == mips::FloatABI::Invalid) {
170     if (Triple.isOSFreeBSD()) {
171       // For FreeBSD, assume "soft" on all flavors of MIPS.
172       ABI = mips::FloatABI::Soft;
173     } else {
174       // Assume "hard", because it's a default value used by gcc.
175       // When we start to recognize specific target MIPS processors,
176       // we will be able to select the default more correctly.
177       ABI = mips::FloatABI::Hard;
178     }
179   }
180 
181   assert(ABI != mips::FloatABI::Invalid && "must select an ABI");
182   return ABI;
183 }
184 
185 void mips::getMIPSTargetFeatures(const Driver &D, const llvm::Triple &Triple,
186                                  const ArgList &Args,
187                                  std::vector<StringRef> &Features) {
188   StringRef CPUName;
189   StringRef ABIName;
190   getMipsCPUAndABI(Args, Triple, CPUName, ABIName);
191   ABIName = getGnuCompatibleMipsABIName(ABIName);
192 
193   // Historically, PIC code for MIPS was associated with -mabicalls, a.k.a
194   // SVR4 abicalls. Static code does not use SVR4 calling sequences. An ABI
195   // extension was developed by Richard Sandiford & Code Sourcery to support
196   // static code calling PIC code (CPIC). For O32 and N32 this means we have
197   // several combinations of PIC/static and abicalls. Pure static, static
198   // with the CPIC extension, and pure PIC code.
199 
200   // At final link time, O32 and N32 with CPIC will have another section
201   // added to the binary which contains the stub functions to perform
202   // any fixups required for PIC code.
203 
204   // For N64, the situation is more regular: code can either be static
205   // (non-abicalls) or PIC (abicalls). GCC has traditionally picked PIC code
206   // code for N64. Since Clang has already built the relocation model portion
207   // of the commandline, we pick add +noabicalls feature in the N64 static
208   // case.
209 
210   // The is another case to be accounted for: -msym32, which enforces that all
211   // symbols have 32 bits in size. In this case, N64 can in theory use CPIC
212   // but it is unsupported.
213 
214   // The combinations for N64 are:
215   // a) Static without abicalls and 64bit symbols.
216   // b) Static with abicalls and 32bit symbols.
217   // c) PIC with abicalls and 64bit symbols.
218 
219   // For case (a) we need to add +noabicalls for N64.
220 
221   bool IsN64 = ABIName == "64";
222   bool IsPIC = false;
223   bool NonPIC = false;
224   bool HasNaN2008Opt = false;
225 
226   Arg *LastPICArg = Args.getLastArg(options::OPT_fPIC, options::OPT_fno_PIC,
227                                     options::OPT_fpic, options::OPT_fno_pic,
228                                     options::OPT_fPIE, options::OPT_fno_PIE,
229                                     options::OPT_fpie, options::OPT_fno_pie);
230   if (LastPICArg) {
231     Option O = LastPICArg->getOption();
232     NonPIC =
233         (O.matches(options::OPT_fno_PIC) || O.matches(options::OPT_fno_pic) ||
234          O.matches(options::OPT_fno_PIE) || O.matches(options::OPT_fno_pie));
235     IsPIC =
236         (O.matches(options::OPT_fPIC) || O.matches(options::OPT_fpic) ||
237          O.matches(options::OPT_fPIE) || O.matches(options::OPT_fpie));
238   }
239 
240   bool UseAbiCalls = false;
241 
242   Arg *ABICallsArg =
243       Args.getLastArg(options::OPT_mabicalls, options::OPT_mno_abicalls);
244   UseAbiCalls =
245       !ABICallsArg || ABICallsArg->getOption().matches(options::OPT_mabicalls);
246 
247   if (IsN64 && NonPIC && (!ABICallsArg || UseAbiCalls)) {
248     D.Diag(diag::warn_drv_unsupported_pic_with_mabicalls)
249         << LastPICArg->getAsString(Args) << (!ABICallsArg ? 0 : 1);
250   }
251 
252   if (ABICallsArg && !UseAbiCalls && IsPIC) {
253     D.Diag(diag::err_drv_unsupported_noabicalls_pic);
254   }
255 
256   if (!UseAbiCalls)
257     Features.push_back("+noabicalls");
258   else
259     Features.push_back("-noabicalls");
260 
261   if (Arg *A = Args.getLastArg(options::OPT_mlong_calls,
262                                options::OPT_mno_long_calls)) {
263     if (A->getOption().matches(options::OPT_mno_long_calls))
264       Features.push_back("-long-calls");
265     else if (!UseAbiCalls)
266       Features.push_back("+long-calls");
267     else
268       D.Diag(diag::warn_drv_unsupported_longcalls) << (ABICallsArg ? 0 : 1);
269   }
270 
271   if (Arg *A = Args.getLastArg(options::OPT_mxgot, options::OPT_mno_xgot)) {
272     if (A->getOption().matches(options::OPT_mxgot))
273       Features.push_back("+xgot");
274     else
275       Features.push_back("-xgot");
276   }
277 
278   mips::FloatABI FloatABI = mips::getMipsFloatABI(D, Args, Triple);
279   if (FloatABI == mips::FloatABI::Soft) {
280     // FIXME: Note, this is a hack. We need to pass the selected float
281     // mode to the MipsTargetInfoBase to define appropriate macros there.
282     // Now it is the only method.
283     Features.push_back("+soft-float");
284   }
285 
286   if (Arg *A = Args.getLastArg(options::OPT_mnan_EQ)) {
287     StringRef Val = StringRef(A->getValue());
288     if (Val == "2008") {
289       if (mips::getIEEE754Standard(CPUName) & mips::Std2008) {
290         Features.push_back("+nan2008");
291         HasNaN2008Opt = true;
292       } else {
293         Features.push_back("-nan2008");
294         D.Diag(diag::warn_target_unsupported_nan2008) << CPUName;
295       }
296     } else if (Val == "legacy") {
297       if (mips::getIEEE754Standard(CPUName) & mips::Legacy)
298         Features.push_back("-nan2008");
299       else {
300         Features.push_back("+nan2008");
301         D.Diag(diag::warn_target_unsupported_nanlegacy) << CPUName;
302       }
303     } else
304       D.Diag(diag::err_drv_unsupported_option_argument)
305           << A->getSpelling() << Val;
306   }
307 
308   if (Arg *A = Args.getLastArg(options::OPT_mabs_EQ)) {
309     StringRef Val = StringRef(A->getValue());
310     if (Val == "2008") {
311       if (mips::getIEEE754Standard(CPUName) & mips::Std2008) {
312         Features.push_back("+abs2008");
313       } else {
314         Features.push_back("-abs2008");
315         D.Diag(diag::warn_target_unsupported_abs2008) << CPUName;
316       }
317     } else if (Val == "legacy") {
318       if (mips::getIEEE754Standard(CPUName) & mips::Legacy) {
319         Features.push_back("-abs2008");
320       } else {
321         Features.push_back("+abs2008");
322         D.Diag(diag::warn_target_unsupported_abslegacy) << CPUName;
323       }
324     } else {
325       D.Diag(diag::err_drv_unsupported_option_argument)
326           << A->getSpelling() << Val;
327     }
328   } else if (HasNaN2008Opt) {
329     Features.push_back("+abs2008");
330   }
331 
332   AddTargetFeature(Args, Features, options::OPT_msingle_float,
333                    options::OPT_mdouble_float, "single-float");
334   AddTargetFeature(Args, Features, options::OPT_mips16, options::OPT_mno_mips16,
335                    "mips16");
336   AddTargetFeature(Args, Features, options::OPT_mmicromips,
337                    options::OPT_mno_micromips, "micromips");
338   AddTargetFeature(Args, Features, options::OPT_mdsp, options::OPT_mno_dsp,
339                    "dsp");
340   AddTargetFeature(Args, Features, options::OPT_mdspr2, options::OPT_mno_dspr2,
341                    "dspr2");
342   AddTargetFeature(Args, Features, options::OPT_mmsa, options::OPT_mno_msa,
343                    "msa");
344 
345   // Add the last -mfp32/-mfpxx/-mfp64, if none are given and the ABI is O32
346   // pass -mfpxx, or if none are given and fp64a is default, pass fp64 and
347   // nooddspreg.
348   if (Arg *A = Args.getLastArg(options::OPT_mfp32, options::OPT_mfpxx,
349                                options::OPT_mfp64)) {
350     if (A->getOption().matches(options::OPT_mfp32))
351       Features.push_back("-fp64");
352     else if (A->getOption().matches(options::OPT_mfpxx)) {
353       Features.push_back("+fpxx");
354       Features.push_back("+nooddspreg");
355     } else
356       Features.push_back("+fp64");
357   } else if (mips::shouldUseFPXX(Args, Triple, CPUName, ABIName, FloatABI)) {
358     Features.push_back("+fpxx");
359     Features.push_back("+nooddspreg");
360   } else if (mips::isFP64ADefault(Triple, CPUName)) {
361     Features.push_back("+fp64");
362     Features.push_back("+nooddspreg");
363   }
364 
365   AddTargetFeature(Args, Features, options::OPT_mno_odd_spreg,
366                    options::OPT_modd_spreg, "nooddspreg");
367   AddTargetFeature(Args, Features, options::OPT_mno_madd4, options::OPT_mmadd4,
368                    "nomadd4");
369   AddTargetFeature(Args, Features, options::OPT_mmt, options::OPT_mno_mt, "mt");
370   AddTargetFeature(Args, Features, options::OPT_mcrc, options::OPT_mno_crc,
371                    "crc");
372   AddTargetFeature(Args, Features, options::OPT_mvirt, options::OPT_mno_virt,
373                    "virt");
374   AddTargetFeature(Args, Features, options::OPT_mginv, options::OPT_mno_ginv,
375                    "ginv");
376 
377   if (Arg *A = Args.getLastArg(options::OPT_mindirect_jump_EQ)) {
378     StringRef Val = StringRef(A->getValue());
379     if (Val == "hazard") {
380       Arg *B =
381           Args.getLastArg(options::OPT_mmicromips, options::OPT_mno_micromips);
382       Arg *C = Args.getLastArg(options::OPT_mips16, options::OPT_mno_mips16);
383 
384       if (B && B->getOption().matches(options::OPT_mmicromips))
385         D.Diag(diag::err_drv_unsupported_indirect_jump_opt)
386             << "hazard" << "micromips";
387       else if (C && C->getOption().matches(options::OPT_mips16))
388         D.Diag(diag::err_drv_unsupported_indirect_jump_opt)
389             << "hazard" << "mips16";
390       else if (mips::supportsIndirectJumpHazardBarrier(CPUName))
391         Features.push_back("+use-indirect-jump-hazard");
392       else
393         D.Diag(diag::err_drv_unsupported_indirect_jump_opt)
394             << "hazard" << CPUName;
395     } else
396       D.Diag(diag::err_drv_unknown_indirect_jump_opt) << Val;
397   }
398 }
399 
400 mips::IEEE754Standard mips::getIEEE754Standard(StringRef &CPU) {
401   // Strictly speaking, mips32r2 and mips64r2 do not conform to the
402   // IEEE754-2008 standard. Support for this standard was first introduced
403   // in Release 3. However, other compilers have traditionally allowed it
404   // for Release 2 so we should do the same.
405   return (IEEE754Standard)llvm::StringSwitch<int>(CPU)
406       .Case("mips1", Legacy)
407       .Case("mips2", Legacy)
408       .Case("mips3", Legacy)
409       .Case("mips4", Legacy)
410       .Case("mips5", Legacy)
411       .Case("mips32", Legacy)
412       .Case("mips32r2", Legacy | Std2008)
413       .Case("mips32r3", Legacy | Std2008)
414       .Case("mips32r5", Legacy | Std2008)
415       .Case("mips32r6", Std2008)
416       .Case("mips64", Legacy)
417       .Case("mips64r2", Legacy | Std2008)
418       .Case("mips64r3", Legacy | Std2008)
419       .Case("mips64r5", Legacy | Std2008)
420       .Case("mips64r6", Std2008)
421       .Default(Std2008);
422 }
423 
424 bool mips::hasCompactBranches(StringRef &CPU) {
425   // mips32r6 and mips64r6 have compact branches.
426   return llvm::StringSwitch<bool>(CPU)
427       .Case("mips32r6", true)
428       .Case("mips64r6", true)
429       .Default(false);
430 }
431 
432 bool mips::hasMipsAbiArg(const ArgList &Args, const char *Value) {
433   Arg *A = Args.getLastArg(options::OPT_mabi_EQ);
434   return A && (A->getValue() == StringRef(Value));
435 }
436 
437 bool mips::isUCLibc(const ArgList &Args) {
438   Arg *A = Args.getLastArg(options::OPT_m_libc_Group);
439   return A && A->getOption().matches(options::OPT_muclibc);
440 }
441 
442 bool mips::isNaN2008(const Driver &D, const ArgList &Args,
443                      const llvm::Triple &Triple) {
444   if (Arg *NaNArg = Args.getLastArg(options::OPT_mnan_EQ))
445     return llvm::StringSwitch<bool>(NaNArg->getValue())
446         .Case("2008", true)
447         .Case("legacy", false)
448         .Default(false);
449 
450   // NaN2008 is the default for MIPS32r6/MIPS64r6.
451   return llvm::StringSwitch<bool>(getCPUName(D, Args, Triple))
452       .Cases("mips32r6", "mips64r6", true)
453       .Default(false);
454 }
455 
456 bool mips::isFP64ADefault(const llvm::Triple &Triple, StringRef CPUName) {
457   if (!Triple.isAndroid())
458     return false;
459 
460   // Android MIPS32R6 defaults to FP64A.
461   return llvm::StringSwitch<bool>(CPUName)
462       .Case("mips32r6", true)
463       .Default(false);
464 }
465 
466 bool mips::isFPXXDefault(const llvm::Triple &Triple, StringRef CPUName,
467                          StringRef ABIName, mips::FloatABI FloatABI) {
468   if (ABIName != "32")
469     return false;
470 
471   // FPXX shouldn't be used if either -msoft-float or -mfloat-abi=soft is
472   // present.
473   if (FloatABI == mips::FloatABI::Soft)
474     return false;
475 
476   return llvm::StringSwitch<bool>(CPUName)
477       .Cases("mips2", "mips3", "mips4", "mips5", true)
478       .Cases("mips32", "mips32r2", "mips32r3", "mips32r5", true)
479       .Cases("mips64", "mips64r2", "mips64r3", "mips64r5", true)
480       .Default(false);
481 }
482 
483 bool mips::shouldUseFPXX(const ArgList &Args, const llvm::Triple &Triple,
484                          StringRef CPUName, StringRef ABIName,
485                          mips::FloatABI FloatABI) {
486   bool UseFPXX = isFPXXDefault(Triple, CPUName, ABIName, FloatABI);
487 
488   // FPXX shouldn't be used if -msingle-float is present.
489   if (Arg *A = Args.getLastArg(options::OPT_msingle_float,
490                                options::OPT_mdouble_float))
491     if (A->getOption().matches(options::OPT_msingle_float))
492       UseFPXX = false;
493 
494   return UseFPXX;
495 }
496 
497 bool mips::supportsIndirectJumpHazardBarrier(StringRef &CPU) {
498   // Supporting the hazard barrier method of dealing with indirect
499   // jumps requires MIPSR2 support.
500   return llvm::StringSwitch<bool>(CPU)
501       .Case("mips32r2", true)
502       .Case("mips32r3", true)
503       .Case("mips32r5", true)
504       .Case("mips32r6", true)
505       .Case("mips64r2", true)
506       .Case("mips64r3", true)
507       .Case("mips64r5", true)
508       .Case("mips64r6", true)
509       .Case("octeon", true)
510       .Case("p5600", true)
511       .Default(false);
512 }
513