xref: /freebsd/contrib/llvm-project/llvm/lib/TargetParser/ARMTargetParser.cpp (revision 069ac18495ad8fde2748bc94b0f80a50250bb01d)
1 //===-- ARMTargetParser - Parser for ARM target features --------*- 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 // This file implements a target parser to recognise ARM hardware features
10 // such as FPU/CPU/ARCH/extensions and specific support such as HWDIV.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/TargetParser/ARMTargetParser.h"
15 #include "llvm/ADT/StringSwitch.h"
16 #include "llvm/TargetParser/ARMTargetParserCommon.h"
17 #include "llvm/TargetParser/Triple.h"
18 #include <cctype>
19 
20 using namespace llvm;
21 
22 static StringRef getHWDivSynonym(StringRef HWDiv) {
23   return StringSwitch<StringRef>(HWDiv)
24       .Case("thumb,arm", "arm,thumb")
25       .Default(HWDiv);
26 }
27 
28 // Allows partial match, ex. "v7a" matches "armv7a".
29 ARM::ArchKind ARM::parseArch(StringRef Arch) {
30   Arch = getCanonicalArchName(Arch);
31   StringRef Syn = getArchSynonym(Arch);
32   for (const auto &A : ARMArchNames) {
33     if (A.Name.endswith(Syn))
34       return A.ID;
35   }
36   return ArchKind::INVALID;
37 }
38 
39 // Version number (ex. v7 = 7).
40 unsigned ARM::parseArchVersion(StringRef Arch) {
41   Arch = getCanonicalArchName(Arch);
42   switch (parseArch(Arch)) {
43   case ArchKind::ARMV4:
44   case ArchKind::ARMV4T:
45     return 4;
46   case ArchKind::ARMV5T:
47   case ArchKind::ARMV5TE:
48   case ArchKind::IWMMXT:
49   case ArchKind::IWMMXT2:
50   case ArchKind::XSCALE:
51   case ArchKind::ARMV5TEJ:
52     return 5;
53   case ArchKind::ARMV6:
54   case ArchKind::ARMV6K:
55   case ArchKind::ARMV6T2:
56   case ArchKind::ARMV6KZ:
57   case ArchKind::ARMV6M:
58     return 6;
59   case ArchKind::ARMV7A:
60   case ArchKind::ARMV7VE:
61   case ArchKind::ARMV7R:
62   case ArchKind::ARMV7M:
63   case ArchKind::ARMV7S:
64   case ArchKind::ARMV7EM:
65   case ArchKind::ARMV7K:
66     return 7;
67   case ArchKind::ARMV8A:
68   case ArchKind::ARMV8_1A:
69   case ArchKind::ARMV8_2A:
70   case ArchKind::ARMV8_3A:
71   case ArchKind::ARMV8_4A:
72   case ArchKind::ARMV8_5A:
73   case ArchKind::ARMV8_6A:
74   case ArchKind::ARMV8_7A:
75   case ArchKind::ARMV8_8A:
76   case ArchKind::ARMV8_9A:
77   case ArchKind::ARMV8R:
78   case ArchKind::ARMV8MBaseline:
79   case ArchKind::ARMV8MMainline:
80   case ArchKind::ARMV8_1MMainline:
81     return 8;
82   case ArchKind::ARMV9A:
83   case ArchKind::ARMV9_1A:
84   case ArchKind::ARMV9_2A:
85   case ArchKind::ARMV9_3A:
86   case ArchKind::ARMV9_4A:
87     return 9;
88   case ArchKind::INVALID:
89     return 0;
90   }
91   llvm_unreachable("Unhandled architecture");
92 }
93 
94 static ARM::ProfileKind getProfileKind(ARM::ArchKind AK) {
95   switch (AK) {
96   case ARM::ArchKind::ARMV6M:
97   case ARM::ArchKind::ARMV7M:
98   case ARM::ArchKind::ARMV7EM:
99   case ARM::ArchKind::ARMV8MMainline:
100   case ARM::ArchKind::ARMV8MBaseline:
101   case ARM::ArchKind::ARMV8_1MMainline:
102     return ARM::ProfileKind::M;
103   case ARM::ArchKind::ARMV7R:
104   case ARM::ArchKind::ARMV8R:
105     return ARM::ProfileKind::R;
106   case ARM::ArchKind::ARMV7A:
107   case ARM::ArchKind::ARMV7VE:
108   case ARM::ArchKind::ARMV7K:
109   case ARM::ArchKind::ARMV8A:
110   case ARM::ArchKind::ARMV8_1A:
111   case ARM::ArchKind::ARMV8_2A:
112   case ARM::ArchKind::ARMV8_3A:
113   case ARM::ArchKind::ARMV8_4A:
114   case ARM::ArchKind::ARMV8_5A:
115   case ARM::ArchKind::ARMV8_6A:
116   case ARM::ArchKind::ARMV8_7A:
117   case ARM::ArchKind::ARMV8_8A:
118   case ARM::ArchKind::ARMV8_9A:
119   case ARM::ArchKind::ARMV9A:
120   case ARM::ArchKind::ARMV9_1A:
121   case ARM::ArchKind::ARMV9_2A:
122   case ARM::ArchKind::ARMV9_3A:
123   case ARM::ArchKind::ARMV9_4A:
124     return ARM::ProfileKind::A;
125   case ARM::ArchKind::ARMV4:
126   case ARM::ArchKind::ARMV4T:
127   case ARM::ArchKind::ARMV5T:
128   case ARM::ArchKind::ARMV5TE:
129   case ARM::ArchKind::ARMV5TEJ:
130   case ARM::ArchKind::ARMV6:
131   case ARM::ArchKind::ARMV6K:
132   case ARM::ArchKind::ARMV6T2:
133   case ARM::ArchKind::ARMV6KZ:
134   case ARM::ArchKind::ARMV7S:
135   case ARM::ArchKind::IWMMXT:
136   case ARM::ArchKind::IWMMXT2:
137   case ARM::ArchKind::XSCALE:
138   case ARM::ArchKind::INVALID:
139     return ARM::ProfileKind::INVALID;
140   }
141   llvm_unreachable("Unhandled architecture");
142 }
143 
144 // Profile A/R/M
145 ARM::ProfileKind ARM::parseArchProfile(StringRef Arch) {
146   Arch = getCanonicalArchName(Arch);
147   return getProfileKind(parseArch(Arch));
148 }
149 
150 bool ARM::getFPUFeatures(ARM::FPUKind FPUKind,
151                          std::vector<StringRef> &Features) {
152 
153   if (FPUKind >= FK_LAST || FPUKind == FK_INVALID)
154     return false;
155 
156   static const struct FPUFeatureNameInfo {
157     const char *PlusName, *MinusName;
158     FPUVersion MinVersion;
159     FPURestriction MaxRestriction;
160   } FPUFeatureInfoList[] = {
161     // We have to specify the + and - versions of the name in full so
162     // that we can return them as static StringRefs.
163     //
164     // Also, the SubtargetFeatures ending in just "sp" are listed here
165     // under FPURestriction::None, which is the only FPURestriction in
166     // which they would be valid (since FPURestriction::SP doesn't
167     // exist).
168     {"+vfp2", "-vfp2", FPUVersion::VFPV2, FPURestriction::D16},
169     {"+vfp2sp", "-vfp2sp", FPUVersion::VFPV2, FPURestriction::SP_D16},
170     {"+vfp3", "-vfp3", FPUVersion::VFPV3, FPURestriction::None},
171     {"+vfp3d16", "-vfp3d16", FPUVersion::VFPV3, FPURestriction::D16},
172     {"+vfp3d16sp", "-vfp3d16sp", FPUVersion::VFPV3, FPURestriction::SP_D16},
173     {"+vfp3sp", "-vfp3sp", FPUVersion::VFPV3, FPURestriction::None},
174     {"+fp16", "-fp16", FPUVersion::VFPV3_FP16, FPURestriction::SP_D16},
175     {"+vfp4", "-vfp4", FPUVersion::VFPV4, FPURestriction::None},
176     {"+vfp4d16", "-vfp4d16", FPUVersion::VFPV4, FPURestriction::D16},
177     {"+vfp4d16sp", "-vfp4d16sp", FPUVersion::VFPV4, FPURestriction::SP_D16},
178     {"+vfp4sp", "-vfp4sp", FPUVersion::VFPV4, FPURestriction::None},
179     {"+fp-armv8", "-fp-armv8", FPUVersion::VFPV5, FPURestriction::None},
180     {"+fp-armv8d16", "-fp-armv8d16", FPUVersion::VFPV5, FPURestriction::D16},
181     {"+fp-armv8d16sp", "-fp-armv8d16sp", FPUVersion::VFPV5, FPURestriction::SP_D16},
182     {"+fp-armv8sp", "-fp-armv8sp", FPUVersion::VFPV5, FPURestriction::None},
183     {"+fullfp16", "-fullfp16", FPUVersion::VFPV5_FULLFP16, FPURestriction::SP_D16},
184     {"+fp64", "-fp64", FPUVersion::VFPV2, FPURestriction::D16},
185     {"+d32", "-d32", FPUVersion::VFPV3, FPURestriction::None},
186   };
187 
188   for (const auto &Info: FPUFeatureInfoList) {
189     if (FPUNames[FPUKind].FPUVer >= Info.MinVersion &&
190         FPUNames[FPUKind].Restriction <= Info.MaxRestriction)
191       Features.push_back(Info.PlusName);
192     else
193       Features.push_back(Info.MinusName);
194   }
195 
196   static const struct NeonFeatureNameInfo {
197     const char *PlusName, *MinusName;
198     NeonSupportLevel MinSupportLevel;
199   } NeonFeatureInfoList[] = {
200       {"+neon", "-neon", NeonSupportLevel::Neon},
201       {"+sha2", "-sha2", NeonSupportLevel::Crypto},
202       {"+aes", "-aes", NeonSupportLevel::Crypto},
203   };
204 
205   for (const auto &Info: NeonFeatureInfoList) {
206     if (FPUNames[FPUKind].NeonSupport >= Info.MinSupportLevel)
207       Features.push_back(Info.PlusName);
208     else
209       Features.push_back(Info.MinusName);
210   }
211 
212   return true;
213 }
214 
215 ARM::FPUKind ARM::parseFPU(StringRef FPU) {
216   StringRef Syn = getFPUSynonym(FPU);
217   for (const auto &F : FPUNames) {
218     if (Syn == F.Name)
219       return F.ID;
220   }
221   return FK_INVALID;
222 }
223 
224 ARM::NeonSupportLevel ARM::getFPUNeonSupportLevel(ARM::FPUKind FPUKind) {
225   if (FPUKind >= FK_LAST)
226     return NeonSupportLevel::None;
227   return FPUNames[FPUKind].NeonSupport;
228 }
229 
230 StringRef ARM::getFPUSynonym(StringRef FPU) {
231   return StringSwitch<StringRef>(FPU)
232       .Cases("fpa", "fpe2", "fpe3", "maverick", "invalid") // Unsupported
233       .Case("vfp2", "vfpv2")
234       .Case("vfp3", "vfpv3")
235       .Case("vfp4", "vfpv4")
236       .Case("vfp3-d16", "vfpv3-d16")
237       .Case("vfp4-d16", "vfpv4-d16")
238       .Cases("fp4-sp-d16", "vfpv4-sp-d16", "fpv4-sp-d16")
239       .Cases("fp4-dp-d16", "fpv4-dp-d16", "vfpv4-d16")
240       .Case("fp5-sp-d16", "fpv5-sp-d16")
241       .Cases("fp5-dp-d16", "fpv5-dp-d16", "fpv5-d16")
242       // FIXME: Clang uses it, but it's bogus, since neon defaults to vfpv3.
243       .Case("neon-vfpv3", "neon")
244       .Default(FPU);
245 }
246 
247 StringRef ARM::getFPUName(ARM::FPUKind FPUKind) {
248   if (FPUKind >= FK_LAST)
249     return StringRef();
250   return FPUNames[FPUKind].Name;
251 }
252 
253 ARM::FPUVersion ARM::getFPUVersion(ARM::FPUKind FPUKind) {
254   if (FPUKind >= FK_LAST)
255     return FPUVersion::NONE;
256   return FPUNames[FPUKind].FPUVer;
257 }
258 
259 ARM::FPURestriction ARM::getFPURestriction(ARM::FPUKind FPUKind) {
260   if (FPUKind >= FK_LAST)
261     return FPURestriction::None;
262   return FPUNames[FPUKind].Restriction;
263 }
264 
265 ARM::FPUKind ARM::getDefaultFPU(StringRef CPU, ARM::ArchKind AK) {
266   if (CPU == "generic")
267     return ARM::ARMArchNames[static_cast<unsigned>(AK)].DefaultFPU;
268 
269   return StringSwitch<ARM::FPUKind>(CPU)
270 #define ARM_CPU_NAME(NAME, ID, DEFAULT_FPU, IS_DEFAULT, DEFAULT_EXT)           \
271   .Case(NAME, DEFAULT_FPU)
272 #include "llvm/TargetParser/ARMTargetParser.def"
273       .Default(ARM::FK_INVALID);
274 }
275 
276 uint64_t ARM::getDefaultExtensions(StringRef CPU, ARM::ArchKind AK) {
277   if (CPU == "generic")
278     return ARM::ARMArchNames[static_cast<unsigned>(AK)].ArchBaseExtensions;
279 
280   return StringSwitch<uint64_t>(CPU)
281 #define ARM_CPU_NAME(NAME, ID, DEFAULT_FPU, IS_DEFAULT, DEFAULT_EXT)           \
282   .Case(NAME,                                                                  \
283         ARMArchNames[static_cast<unsigned>(ArchKind::ID)].ArchBaseExtensions | \
284             DEFAULT_EXT)
285 #include "llvm/TargetParser/ARMTargetParser.def"
286   .Default(ARM::AEK_INVALID);
287 }
288 
289 bool ARM::getHWDivFeatures(uint64_t HWDivKind,
290                            std::vector<StringRef> &Features) {
291 
292   if (HWDivKind == AEK_INVALID)
293     return false;
294 
295   if (HWDivKind & AEK_HWDIVARM)
296     Features.push_back("+hwdiv-arm");
297   else
298     Features.push_back("-hwdiv-arm");
299 
300   if (HWDivKind & AEK_HWDIVTHUMB)
301     Features.push_back("+hwdiv");
302   else
303     Features.push_back("-hwdiv");
304 
305   return true;
306 }
307 
308 bool ARM::getExtensionFeatures(uint64_t Extensions,
309                                std::vector<StringRef> &Features) {
310 
311   if (Extensions == AEK_INVALID)
312     return false;
313 
314   for (const auto &AE : ARCHExtNames) {
315     if ((Extensions & AE.ID) == AE.ID && !AE.Feature.empty())
316       Features.push_back(AE.Feature);
317     else if (!AE.NegFeature.empty())
318       Features.push_back(AE.NegFeature);
319   }
320 
321   return getHWDivFeatures(Extensions, Features);
322 }
323 
324 StringRef ARM::getArchName(ARM::ArchKind AK) {
325   return ARMArchNames[static_cast<unsigned>(AK)].Name;
326 }
327 
328 StringRef ARM::getCPUAttr(ARM::ArchKind AK) {
329   return ARMArchNames[static_cast<unsigned>(AK)].CPUAttr;
330 }
331 
332 StringRef ARM::getSubArch(ARM::ArchKind AK) {
333   return ARMArchNames[static_cast<unsigned>(AK)].getSubArch();
334 }
335 
336 unsigned ARM::getArchAttr(ARM::ArchKind AK) {
337   return ARMArchNames[static_cast<unsigned>(AK)].ArchAttr;
338 }
339 
340 StringRef ARM::getArchExtName(uint64_t ArchExtKind) {
341   for (const auto &AE : ARCHExtNames) {
342     if (ArchExtKind == AE.ID)
343       return AE.Name;
344   }
345   return StringRef();
346 }
347 
348 static bool stripNegationPrefix(StringRef &Name) {
349   if (Name.startswith("no")) {
350     Name = Name.substr(2);
351     return true;
352   }
353   return false;
354 }
355 
356 StringRef ARM::getArchExtFeature(StringRef ArchExt) {
357   bool Negated = stripNegationPrefix(ArchExt);
358   for (const auto &AE : ARCHExtNames) {
359     if (!AE.Feature.empty() && ArchExt == AE.Name)
360       return StringRef(Negated ? AE.NegFeature : AE.Feature);
361   }
362 
363   return StringRef();
364 }
365 
366 static ARM::FPUKind findDoublePrecisionFPU(ARM::FPUKind InputFPUKind) {
367   const ARM::FPUName &InputFPU = ARM::FPUNames[InputFPUKind];
368 
369   // If the input FPU already supports double-precision, then there
370   // isn't any different FPU we can return here.
371   //
372   // The current available FPURestriction values are None (no
373   // restriction), D16 (only 16 d-regs) and SP_D16 (16 d-regs
374   // and single precision only); there's no value representing
375   // SP restriction without D16. So this test just means 'is it
376   // SP only?'.
377   if (InputFPU.Restriction != ARM::FPURestriction::SP_D16)
378     return ARM::FK_INVALID;
379 
380   // Otherwise, look for an FPU entry with all the same fields, except
381   // that SP_D16 has been replaced with just D16, representing adding
382   // double precision and not changing anything else.
383   for (const ARM::FPUName &CandidateFPU : ARM::FPUNames) {
384     if (CandidateFPU.FPUVer == InputFPU.FPUVer &&
385         CandidateFPU.NeonSupport == InputFPU.NeonSupport &&
386         CandidateFPU.Restriction == ARM::FPURestriction::D16) {
387       return CandidateFPU.ID;
388     }
389   }
390 
391   // nothing found
392   return ARM::FK_INVALID;
393 }
394 
395 bool ARM::appendArchExtFeatures(StringRef CPU, ARM::ArchKind AK,
396                                 StringRef ArchExt,
397                                 std::vector<StringRef> &Features,
398                                 ARM::FPUKind &ArgFPUKind) {
399 
400   size_t StartingNumFeatures = Features.size();
401   const bool Negated = stripNegationPrefix(ArchExt);
402   uint64_t ID = parseArchExt(ArchExt);
403 
404   if (ID == AEK_INVALID)
405     return false;
406 
407   for (const auto &AE : ARCHExtNames) {
408     if (Negated) {
409       if ((AE.ID & ID) == ID && !AE.NegFeature.empty())
410         Features.push_back(AE.NegFeature);
411     } else {
412       if ((AE.ID & ID) == AE.ID && !AE.Feature.empty())
413         Features.push_back(AE.Feature);
414     }
415   }
416 
417   if (CPU == "")
418     CPU = "generic";
419 
420   if (ArchExt == "fp" || ArchExt == "fp.dp") {
421     ARM::FPUKind FPUKind;
422     if (ArchExt == "fp.dp") {
423       if (Negated) {
424         Features.push_back("-fp64");
425         return true;
426       }
427       FPUKind = findDoublePrecisionFPU(getDefaultFPU(CPU, AK));
428     } else if (Negated) {
429       FPUKind = ARM::FK_NONE;
430     } else {
431       FPUKind = getDefaultFPU(CPU, AK);
432     }
433     ArgFPUKind = FPUKind;
434     return ARM::getFPUFeatures(FPUKind, Features);
435   }
436   return StartingNumFeatures != Features.size();
437 }
438 
439 ARM::ArchKind ARM::convertV9toV8(ARM::ArchKind AK) {
440   if (getProfileKind(AK) != ProfileKind::A)
441     return ARM::ArchKind::INVALID;
442   if (AK < ARM::ArchKind::ARMV9A || AK > ARM::ArchKind::ARMV9_3A)
443     return ARM::ArchKind::INVALID;
444   unsigned AK_v8 = static_cast<unsigned>(ARM::ArchKind::ARMV8_5A);
445   AK_v8 += static_cast<unsigned>(AK) -
446            static_cast<unsigned>(ARM::ArchKind::ARMV9A);
447   return static_cast<ARM::ArchKind>(AK_v8);
448 }
449 
450 StringRef ARM::getDefaultCPU(StringRef Arch) {
451   ArchKind AK = parseArch(Arch);
452   if (AK == ArchKind::INVALID)
453     return StringRef();
454 
455   // Look for multiple AKs to find the default for pair AK+Name.
456   for (const auto &CPU : CPUNames) {
457     if (CPU.ArchID == AK && CPU.Default)
458       return CPU.Name;
459   }
460 
461   // If we can't find a default then target the architecture instead
462   return "generic";
463 }
464 
465 uint64_t ARM::parseHWDiv(StringRef HWDiv) {
466   StringRef Syn = getHWDivSynonym(HWDiv);
467   for (const auto &D : HWDivNames) {
468     if (Syn == D.Name)
469       return D.ID;
470   }
471   return AEK_INVALID;
472 }
473 
474 uint64_t ARM::parseArchExt(StringRef ArchExt) {
475   for (const auto &A : ARCHExtNames) {
476     if (ArchExt == A.Name)
477       return A.ID;
478   }
479   return AEK_INVALID;
480 }
481 
482 ARM::ArchKind ARM::parseCPUArch(StringRef CPU) {
483   for (const auto &C : CPUNames) {
484     if (CPU == C.Name)
485       return C.ArchID;
486   }
487   return ArchKind::INVALID;
488 }
489 
490 void ARM::fillValidCPUArchList(SmallVectorImpl<StringRef> &Values) {
491   for (const auto &Arch : CPUNames) {
492     if (Arch.ArchID != ArchKind::INVALID)
493       Values.push_back(Arch.Name);
494   }
495 }
496 
497 StringRef ARM::computeDefaultTargetABI(const Triple &TT, StringRef CPU) {
498   StringRef ArchName =
499       CPU.empty() ? TT.getArchName() : getArchName(parseCPUArch(CPU));
500 
501   if (TT.isOSBinFormatMachO()) {
502     if (TT.getEnvironment() == Triple::EABI ||
503         TT.getOS() == Triple::UnknownOS ||
504         parseArchProfile(ArchName) == ProfileKind::M)
505       return "aapcs";
506     if (TT.isWatchABI())
507       return "aapcs16";
508     return "apcs-gnu";
509   } else if (TT.isOSWindows())
510     // FIXME: this is invalid for WindowsCE.
511     return "aapcs";
512 
513   // Select the default based on the platform.
514   switch (TT.getEnvironment()) {
515   case Triple::Android:
516   case Triple::GNUEABI:
517   case Triple::GNUEABIHF:
518   case Triple::MuslEABI:
519   case Triple::MuslEABIHF:
520     return "aapcs-linux";
521   case Triple::EABIHF:
522   case Triple::EABI:
523     return "aapcs";
524   default:
525     if (TT.isOSNetBSD())
526       return "apcs-gnu";
527     if (TT.isOSFreeBSD() || TT.isOSOpenBSD() || TT.isOHOSFamily())
528       return "aapcs-linux";
529     return "aapcs";
530   }
531 }
532 
533 StringRef ARM::getARMCPUForArch(const llvm::Triple &Triple, StringRef MArch) {
534   if (MArch.empty())
535     MArch = Triple.getArchName();
536   MArch = llvm::ARM::getCanonicalArchName(MArch);
537 
538   // Some defaults are forced.
539   switch (Triple.getOS()) {
540   case llvm::Triple::FreeBSD:
541   case llvm::Triple::NetBSD:
542   case llvm::Triple::OpenBSD:
543     if (!MArch.empty() && MArch == "v6")
544       return "arm1176jzf-s";
545     if (!MArch.empty() && MArch == "v7")
546       return "cortex-a8";
547     break;
548   case llvm::Triple::Win32:
549     // FIXME: this is invalid for WindowsCE
550     if (llvm::ARM::parseArchVersion(MArch) <= 7)
551       return "cortex-a9";
552     break;
553   case llvm::Triple::IOS:
554   case llvm::Triple::MacOSX:
555   case llvm::Triple::TvOS:
556   case llvm::Triple::WatchOS:
557   case llvm::Triple::DriverKit:
558     if (MArch == "v7k")
559       return "cortex-a7";
560     break;
561   default:
562     break;
563   }
564 
565   if (MArch.empty())
566     return StringRef();
567 
568   StringRef CPU = llvm::ARM::getDefaultCPU(MArch);
569   if (!CPU.empty() && !CPU.equals("invalid"))
570     return CPU;
571 
572   // If no specific architecture version is requested, return the minimum CPU
573   // required by the OS and environment.
574   switch (Triple.getOS()) {
575   case llvm::Triple::NetBSD:
576     switch (Triple.getEnvironment()) {
577     case llvm::Triple::EABI:
578     case llvm::Triple::EABIHF:
579     case llvm::Triple::GNUEABI:
580     case llvm::Triple::GNUEABIHF:
581       return "arm926ej-s";
582     default:
583       return "strongarm";
584     }
585   case llvm::Triple::NaCl:
586   case llvm::Triple::OpenBSD:
587     return "cortex-a8";
588   default:
589     switch (Triple.getEnvironment()) {
590     case llvm::Triple::EABIHF:
591     case llvm::Triple::GNUEABIHF:
592     case llvm::Triple::MuslEABIHF:
593       return "arm1176jzf-s";
594     default:
595       return "arm7tdmi";
596     }
597   }
598 
599   llvm_unreachable("invalid arch name");
600 }
601