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/Support/ARMTargetParser.h"
15 #include "llvm/ADT/StringSwitch.h"
16 #include "llvm/ADT/Triple.h"
17 #include <cctype>
18 
19 using namespace llvm;
20 
21 static StringRef getHWDivSynonym(StringRef HWDiv) {
22   return StringSwitch<StringRef>(HWDiv)
23       .Case("thumb,arm", "arm,thumb")
24       .Default(HWDiv);
25 }
26 
27 // Allows partial match, ex. "v7a" matches "armv7a".
28 ARM::ArchKind ARM::parseArch(StringRef Arch) {
29   Arch = getCanonicalArchName(Arch);
30   StringRef Syn = getArchSynonym(Arch);
31   for (const auto &A : ARCHNames) {
32     if (A.getName().endswith(Syn))
33       return A.ID;
34   }
35   return ArchKind::INVALID;
36 }
37 
38 // Version number (ex. v7 = 7).
39 unsigned ARM::parseArchVersion(StringRef Arch) {
40   Arch = getCanonicalArchName(Arch);
41   switch (parseArch(Arch)) {
42   case ArchKind::ARMV2:
43   case ArchKind::ARMV2A:
44     return 2;
45   case ArchKind::ARMV3:
46   case ArchKind::ARMV3M:
47     return 3;
48   case ArchKind::ARMV4:
49   case ArchKind::ARMV4T:
50     return 4;
51   case ArchKind::ARMV5T:
52   case ArchKind::ARMV5TE:
53   case ArchKind::IWMMXT:
54   case ArchKind::IWMMXT2:
55   case ArchKind::XSCALE:
56   case ArchKind::ARMV5TEJ:
57     return 5;
58   case ArchKind::ARMV6:
59   case ArchKind::ARMV6K:
60   case ArchKind::ARMV6T2:
61   case ArchKind::ARMV6KZ:
62   case ArchKind::ARMV6M:
63     return 6;
64   case ArchKind::ARMV7A:
65   case ArchKind::ARMV7VE:
66   case ArchKind::ARMV7R:
67   case ArchKind::ARMV7M:
68   case ArchKind::ARMV7S:
69   case ArchKind::ARMV7EM:
70   case ArchKind::ARMV7K:
71     return 7;
72   case ArchKind::ARMV8A:
73   case ArchKind::ARMV8_1A:
74   case ArchKind::ARMV8_2A:
75   case ArchKind::ARMV8_3A:
76   case ArchKind::ARMV8_4A:
77   case ArchKind::ARMV8_5A:
78   case ArchKind::ARMV8_6A:
79   case ArchKind::ARMV8_7A:
80   case ArchKind::ARMV8_8A:
81   case ArchKind::ARMV8R:
82   case ArchKind::ARMV8MBaseline:
83   case ArchKind::ARMV8MMainline:
84   case ArchKind::ARMV8_1MMainline:
85     return 8;
86   case ArchKind::ARMV9A:
87   case ArchKind::ARMV9_1A:
88   case ArchKind::ARMV9_2A:
89     return 9;
90   case ArchKind::INVALID:
91     return 0;
92   }
93   llvm_unreachable("Unhandled architecture");
94 }
95 
96 // Profile A/R/M
97 ARM::ProfileKind ARM::parseArchProfile(StringRef Arch) {
98   Arch = getCanonicalArchName(Arch);
99   switch (parseArch(Arch)) {
100   case ArchKind::ARMV6M:
101   case ArchKind::ARMV7M:
102   case ArchKind::ARMV7EM:
103   case ArchKind::ARMV8MMainline:
104   case ArchKind::ARMV8MBaseline:
105   case ArchKind::ARMV8_1MMainline:
106     return ProfileKind::M;
107   case ArchKind::ARMV7R:
108   case ArchKind::ARMV8R:
109     return ProfileKind::R;
110   case ArchKind::ARMV7A:
111   case ArchKind::ARMV7VE:
112   case ArchKind::ARMV7K:
113   case ArchKind::ARMV8A:
114   case ArchKind::ARMV8_1A:
115   case ArchKind::ARMV8_2A:
116   case ArchKind::ARMV8_3A:
117   case ArchKind::ARMV8_4A:
118   case ArchKind::ARMV8_5A:
119   case ArchKind::ARMV8_6A:
120   case ArchKind::ARMV8_7A:
121   case ArchKind::ARMV8_8A:
122   case ArchKind::ARMV9A:
123   case ArchKind::ARMV9_1A:
124   case ArchKind::ARMV9_2A:
125     return ProfileKind::A;
126   case ArchKind::ARMV2:
127   case ArchKind::ARMV2A:
128   case ArchKind::ARMV3:
129   case ArchKind::ARMV3M:
130   case ArchKind::ARMV4:
131   case ArchKind::ARMV4T:
132   case ArchKind::ARMV5T:
133   case ArchKind::ARMV5TE:
134   case ArchKind::ARMV5TEJ:
135   case ArchKind::ARMV6:
136   case ArchKind::ARMV6K:
137   case ArchKind::ARMV6T2:
138   case ArchKind::ARMV6KZ:
139   case ArchKind::ARMV7S:
140   case ArchKind::IWMMXT:
141   case ArchKind::IWMMXT2:
142   case ArchKind::XSCALE:
143   case ArchKind::INVALID:
144     return ProfileKind::INVALID;
145   }
146   llvm_unreachable("Unhandled architecture");
147 }
148 
149 StringRef ARM::getArchSynonym(StringRef Arch) {
150   return StringSwitch<StringRef>(Arch)
151       .Case("v5", "v5t")
152       .Case("v5e", "v5te")
153       .Case("v6j", "v6")
154       .Case("v6hl", "v6k")
155       .Cases("v6m", "v6sm", "v6s-m", "v6-m")
156       .Cases("v6z", "v6zk", "v6kz")
157       .Cases("v7", "v7a", "v7hl", "v7l", "v7-a")
158       .Case("v7r", "v7-r")
159       .Case("v7m", "v7-m")
160       .Case("v7em", "v7e-m")
161       .Cases("v8", "v8a", "v8l", "aarch64", "arm64", "v8-a")
162       .Case("v8.1a", "v8.1-a")
163       .Case("v8.2a", "v8.2-a")
164       .Case("v8.3a", "v8.3-a")
165       .Case("v8.4a", "v8.4-a")
166       .Case("v8.5a", "v8.5-a")
167       .Case("v8.6a", "v8.6-a")
168       .Case("v8.7a", "v8.7-a")
169       .Case("v8.8a", "v8.8-a")
170       .Case("v8r", "v8-r")
171       .Cases("v9", "v9a", "v9-a")
172       .Case("v9.1a", "v9.1-a")
173       .Case("v9.2a", "v9.2-a")
174       .Case("v8m.base", "v8-m.base")
175       .Case("v8m.main", "v8-m.main")
176       .Case("v8.1m.main", "v8.1-m.main")
177       .Default(Arch);
178 }
179 
180 bool ARM::getFPUFeatures(unsigned FPUKind, std::vector<StringRef> &Features) {
181 
182   if (FPUKind >= FK_LAST || FPUKind == FK_INVALID)
183     return false;
184 
185   static const struct FPUFeatureNameInfo {
186     const char *PlusName, *MinusName;
187     FPUVersion MinVersion;
188     FPURestriction MaxRestriction;
189   } FPUFeatureInfoList[] = {
190     // We have to specify the + and - versions of the name in full so
191     // that we can return them as static StringRefs.
192     //
193     // Also, the SubtargetFeatures ending in just "sp" are listed here
194     // under FPURestriction::None, which is the only FPURestriction in
195     // which they would be valid (since FPURestriction::SP doesn't
196     // exist).
197     {"+vfp2", "-vfp2", FPUVersion::VFPV2, FPURestriction::D16},
198     {"+vfp2sp", "-vfp2sp", FPUVersion::VFPV2, FPURestriction::SP_D16},
199     {"+vfp3", "-vfp3", FPUVersion::VFPV3, FPURestriction::None},
200     {"+vfp3d16", "-vfp3d16", FPUVersion::VFPV3, FPURestriction::D16},
201     {"+vfp3d16sp", "-vfp3d16sp", FPUVersion::VFPV3, FPURestriction::SP_D16},
202     {"+vfp3sp", "-vfp3sp", FPUVersion::VFPV3, FPURestriction::None},
203     {"+fp16", "-fp16", FPUVersion::VFPV3_FP16, FPURestriction::SP_D16},
204     {"+vfp4", "-vfp4", FPUVersion::VFPV4, FPURestriction::None},
205     {"+vfp4d16", "-vfp4d16", FPUVersion::VFPV4, FPURestriction::D16},
206     {"+vfp4d16sp", "-vfp4d16sp", FPUVersion::VFPV4, FPURestriction::SP_D16},
207     {"+vfp4sp", "-vfp4sp", FPUVersion::VFPV4, FPURestriction::None},
208     {"+fp-armv8", "-fp-armv8", FPUVersion::VFPV5, FPURestriction::None},
209     {"+fp-armv8d16", "-fp-armv8d16", FPUVersion::VFPV5, FPURestriction::D16},
210     {"+fp-armv8d16sp", "-fp-armv8d16sp", FPUVersion::VFPV5, FPURestriction::SP_D16},
211     {"+fp-armv8sp", "-fp-armv8sp", FPUVersion::VFPV5, FPURestriction::None},
212     {"+fullfp16", "-fullfp16", FPUVersion::VFPV5_FULLFP16, FPURestriction::SP_D16},
213     {"+fp64", "-fp64", FPUVersion::VFPV2, FPURestriction::D16},
214     {"+d32", "-d32", FPUVersion::VFPV3, FPURestriction::None},
215   };
216 
217   for (const auto &Info: FPUFeatureInfoList) {
218     if (FPUNames[FPUKind].FPUVer >= Info.MinVersion &&
219         FPUNames[FPUKind].Restriction <= Info.MaxRestriction)
220       Features.push_back(Info.PlusName);
221     else
222       Features.push_back(Info.MinusName);
223   }
224 
225   static const struct NeonFeatureNameInfo {
226     const char *PlusName, *MinusName;
227     NeonSupportLevel MinSupportLevel;
228   } NeonFeatureInfoList[] = {
229       {"+neon", "-neon", NeonSupportLevel::Neon},
230       {"+sha2", "-sha2", NeonSupportLevel::Crypto},
231       {"+aes", "-aes", NeonSupportLevel::Crypto},
232   };
233 
234   for (const auto &Info: NeonFeatureInfoList) {
235     if (FPUNames[FPUKind].NeonSupport >= Info.MinSupportLevel)
236       Features.push_back(Info.PlusName);
237     else
238       Features.push_back(Info.MinusName);
239   }
240 
241   return true;
242 }
243 
244 // Little/Big endian
245 ARM::EndianKind ARM::parseArchEndian(StringRef Arch) {
246   if (Arch.startswith("armeb") || Arch.startswith("thumbeb") ||
247       Arch.startswith("aarch64_be"))
248     return EndianKind::BIG;
249 
250   if (Arch.startswith("arm") || Arch.startswith("thumb")) {
251     if (Arch.endswith("eb"))
252       return EndianKind::BIG;
253     else
254       return EndianKind::LITTLE;
255   }
256 
257   if (Arch.startswith("aarch64") || Arch.startswith("aarch64_32"))
258     return EndianKind::LITTLE;
259 
260   return EndianKind::INVALID;
261 }
262 
263 // ARM, Thumb, AArch64
264 ARM::ISAKind ARM::parseArchISA(StringRef Arch) {
265   return StringSwitch<ISAKind>(Arch)
266       .StartsWith("aarch64", ISAKind::AARCH64)
267       .StartsWith("arm64", ISAKind::AARCH64)
268       .StartsWith("thumb", ISAKind::THUMB)
269       .StartsWith("arm", ISAKind::ARM)
270       .Default(ISAKind::INVALID);
271 }
272 
273 unsigned ARM::parseFPU(StringRef FPU) {
274   StringRef Syn = getFPUSynonym(FPU);
275   for (const auto &F : FPUNames) {
276     if (Syn == F.getName())
277       return F.ID;
278   }
279   return FK_INVALID;
280 }
281 
282 ARM::NeonSupportLevel ARM::getFPUNeonSupportLevel(unsigned FPUKind) {
283   if (FPUKind >= FK_LAST)
284     return NeonSupportLevel::None;
285   return FPUNames[FPUKind].NeonSupport;
286 }
287 
288 // MArch is expected to be of the form (arm|thumb)?(eb)?(v.+)?(eb)?, but
289 // (iwmmxt|xscale)(eb)? is also permitted. If the former, return
290 // "v.+", if the latter, return unmodified string, minus 'eb'.
291 // If invalid, return empty string.
292 StringRef ARM::getCanonicalArchName(StringRef Arch) {
293   size_t offset = StringRef::npos;
294   StringRef A = Arch;
295   StringRef Error = "";
296 
297   // Begins with "arm" / "thumb", move past it.
298   if (A.startswith("arm64_32"))
299     offset = 8;
300   else if (A.startswith("arm64e"))
301     offset = 6;
302   else if (A.startswith("arm64"))
303     offset = 5;
304   else if (A.startswith("aarch64_32"))
305     offset = 10;
306   else if (A.startswith("arm"))
307     offset = 3;
308   else if (A.startswith("thumb"))
309     offset = 5;
310   else if (A.startswith("aarch64")) {
311     offset = 7;
312     // AArch64 uses "_be", not "eb" suffix.
313     if (A.contains("eb"))
314       return Error;
315     if (A.substr(offset, 3) == "_be")
316       offset += 3;
317   }
318 
319   // Ex. "armebv7", move past the "eb".
320   if (offset != StringRef::npos && A.substr(offset, 2) == "eb")
321     offset += 2;
322   // Or, if it ends with eb ("armv7eb"), chop it off.
323   else if (A.endswith("eb"))
324     A = A.substr(0, A.size() - 2);
325   // Trim the head
326   if (offset != StringRef::npos)
327     A = A.substr(offset);
328 
329   // Empty string means offset reached the end, which means it's valid.
330   if (A.empty())
331     return Arch;
332 
333   // Only match non-marketing names
334   if (offset != StringRef::npos) {
335     // Must start with 'vN'.
336     if (A.size() >= 2 && (A[0] != 'v' || !std::isdigit(A[1])))
337       return Error;
338     // Can't have an extra 'eb'.
339     if (A.contains("eb"))
340       return Error;
341   }
342 
343   // Arch will either be a 'v' name (v7a) or a marketing name (xscale).
344   return A;
345 }
346 
347 StringRef ARM::getFPUSynonym(StringRef FPU) {
348   return StringSwitch<StringRef>(FPU)
349       .Cases("fpa", "fpe2", "fpe3", "maverick", "invalid") // Unsupported
350       .Case("vfp2", "vfpv2")
351       .Case("vfp3", "vfpv3")
352       .Case("vfp4", "vfpv4")
353       .Case("vfp3-d16", "vfpv3-d16")
354       .Case("vfp4-d16", "vfpv4-d16")
355       .Cases("fp4-sp-d16", "vfpv4-sp-d16", "fpv4-sp-d16")
356       .Cases("fp4-dp-d16", "fpv4-dp-d16", "vfpv4-d16")
357       .Case("fp5-sp-d16", "fpv5-sp-d16")
358       .Cases("fp5-dp-d16", "fpv5-dp-d16", "fpv5-d16")
359       // FIXME: Clang uses it, but it's bogus, since neon defaults to vfpv3.
360       .Case("neon-vfpv3", "neon")
361       .Default(FPU);
362 }
363 
364 StringRef ARM::getFPUName(unsigned FPUKind) {
365   if (FPUKind >= FK_LAST)
366     return StringRef();
367   return FPUNames[FPUKind].getName();
368 }
369 
370 ARM::FPUVersion ARM::getFPUVersion(unsigned FPUKind) {
371   if (FPUKind >= FK_LAST)
372     return FPUVersion::NONE;
373   return FPUNames[FPUKind].FPUVer;
374 }
375 
376 ARM::FPURestriction ARM::getFPURestriction(unsigned FPUKind) {
377   if (FPUKind >= FK_LAST)
378     return FPURestriction::None;
379   return FPUNames[FPUKind].Restriction;
380 }
381 
382 unsigned ARM::getDefaultFPU(StringRef CPU, ARM::ArchKind AK) {
383   if (CPU == "generic")
384     return ARM::ARCHNames[static_cast<unsigned>(AK)].DefaultFPU;
385 
386   return StringSwitch<unsigned>(CPU)
387 #define ARM_CPU_NAME(NAME, ID, DEFAULT_FPU, IS_DEFAULT, DEFAULT_EXT)           \
388   .Case(NAME, DEFAULT_FPU)
389 #include "llvm/Support/ARMTargetParser.def"
390    .Default(ARM::FK_INVALID);
391 }
392 
393 uint64_t ARM::getDefaultExtensions(StringRef CPU, ARM::ArchKind AK) {
394   if (CPU == "generic")
395     return ARM::ARCHNames[static_cast<unsigned>(AK)].ArchBaseExtensions;
396 
397   return StringSwitch<uint64_t>(CPU)
398 #define ARM_CPU_NAME(NAME, ID, DEFAULT_FPU, IS_DEFAULT, DEFAULT_EXT)           \
399   .Case(NAME,                                                                  \
400         ARCHNames[static_cast<unsigned>(ArchKind::ID)].ArchBaseExtensions |    \
401             DEFAULT_EXT)
402 #include "llvm/Support/ARMTargetParser.def"
403   .Default(ARM::AEK_INVALID);
404 }
405 
406 bool ARM::getHWDivFeatures(uint64_t HWDivKind,
407                            std::vector<StringRef> &Features) {
408 
409   if (HWDivKind == AEK_INVALID)
410     return false;
411 
412   if (HWDivKind & AEK_HWDIVARM)
413     Features.push_back("+hwdiv-arm");
414   else
415     Features.push_back("-hwdiv-arm");
416 
417   if (HWDivKind & AEK_HWDIVTHUMB)
418     Features.push_back("+hwdiv");
419   else
420     Features.push_back("-hwdiv");
421 
422   return true;
423 }
424 
425 bool ARM::getExtensionFeatures(uint64_t Extensions,
426                                std::vector<StringRef> &Features) {
427 
428   if (Extensions == AEK_INVALID)
429     return false;
430 
431   for (const auto &AE : ARCHExtNames) {
432     if ((Extensions & AE.ID) == AE.ID && AE.Feature)
433       Features.push_back(AE.Feature);
434     else if (AE.NegFeature)
435       Features.push_back(AE.NegFeature);
436   }
437 
438   return getHWDivFeatures(Extensions, Features);
439 }
440 
441 StringRef ARM::getArchName(ARM::ArchKind AK) {
442   return ARCHNames[static_cast<unsigned>(AK)].getName();
443 }
444 
445 StringRef ARM::getCPUAttr(ARM::ArchKind AK) {
446   return ARCHNames[static_cast<unsigned>(AK)].getCPUAttr();
447 }
448 
449 StringRef ARM::getSubArch(ARM::ArchKind AK) {
450   return ARCHNames[static_cast<unsigned>(AK)].getSubArch();
451 }
452 
453 unsigned ARM::getArchAttr(ARM::ArchKind AK) {
454   return ARCHNames[static_cast<unsigned>(AK)].ArchAttr;
455 }
456 
457 StringRef ARM::getArchExtName(uint64_t ArchExtKind) {
458   for (const auto &AE : ARCHExtNames) {
459     if (ArchExtKind == AE.ID)
460       return AE.getName();
461   }
462   return StringRef();
463 }
464 
465 static bool stripNegationPrefix(StringRef &Name) {
466   if (Name.startswith("no")) {
467     Name = Name.substr(2);
468     return true;
469   }
470   return false;
471 }
472 
473 StringRef ARM::getArchExtFeature(StringRef ArchExt) {
474   bool Negated = stripNegationPrefix(ArchExt);
475   for (const auto &AE : ARCHExtNames) {
476     if (AE.Feature && ArchExt == AE.getName())
477       return StringRef(Negated ? AE.NegFeature : AE.Feature);
478   }
479 
480   return StringRef();
481 }
482 
483 static unsigned findDoublePrecisionFPU(unsigned InputFPUKind) {
484   const ARM::FPUName &InputFPU = ARM::FPUNames[InputFPUKind];
485 
486   // If the input FPU already supports double-precision, then there
487   // isn't any different FPU we can return here.
488   //
489   // The current available FPURestriction values are None (no
490   // restriction), D16 (only 16 d-regs) and SP_D16 (16 d-regs
491   // and single precision only); there's no value representing
492   // SP restriction without D16. So this test just means 'is it
493   // SP only?'.
494   if (InputFPU.Restriction != ARM::FPURestriction::SP_D16)
495     return ARM::FK_INVALID;
496 
497   // Otherwise, look for an FPU entry with all the same fields, except
498   // that SP_D16 has been replaced with just D16, representing adding
499   // double precision and not changing anything else.
500   for (const ARM::FPUName &CandidateFPU : ARM::FPUNames) {
501     if (CandidateFPU.FPUVer == InputFPU.FPUVer &&
502         CandidateFPU.NeonSupport == InputFPU.NeonSupport &&
503         CandidateFPU.Restriction == ARM::FPURestriction::D16) {
504       return CandidateFPU.ID;
505     }
506   }
507 
508   // nothing found
509   return ARM::FK_INVALID;
510 }
511 
512 bool ARM::appendArchExtFeatures(StringRef CPU, ARM::ArchKind AK,
513                                 StringRef ArchExt,
514                                 std::vector<StringRef> &Features,
515                                 unsigned &ArgFPUID) {
516 
517   size_t StartingNumFeatures = Features.size();
518   const bool Negated = stripNegationPrefix(ArchExt);
519   uint64_t ID = parseArchExt(ArchExt);
520 
521   if (ID == AEK_INVALID)
522     return false;
523 
524   for (const auto &AE : ARCHExtNames) {
525     if (Negated) {
526       if ((AE.ID & ID) == ID && AE.NegFeature)
527         Features.push_back(AE.NegFeature);
528     } else {
529       if ((AE.ID & ID) == AE.ID && AE.Feature)
530         Features.push_back(AE.Feature);
531     }
532   }
533 
534   if (CPU == "")
535     CPU = "generic";
536 
537   if (ArchExt == "fp" || ArchExt == "fp.dp") {
538     unsigned FPUKind;
539     if (ArchExt == "fp.dp") {
540       if (Negated) {
541         Features.push_back("-fp64");
542         return true;
543       }
544       FPUKind = findDoublePrecisionFPU(getDefaultFPU(CPU, AK));
545     } else if (Negated) {
546       FPUKind = ARM::FK_NONE;
547     } else {
548       FPUKind = getDefaultFPU(CPU, AK);
549     }
550     ArgFPUID = FPUKind;
551     return ARM::getFPUFeatures(FPUKind, Features);
552   }
553   return StartingNumFeatures != Features.size();
554 }
555 
556 StringRef ARM::getDefaultCPU(StringRef Arch) {
557   ArchKind AK = parseArch(Arch);
558   if (AK == ArchKind::INVALID)
559     return StringRef();
560 
561   // Look for multiple AKs to find the default for pair AK+Name.
562   for (const auto &CPU : CPUNames) {
563     if (CPU.ArchID == AK && CPU.Default)
564       return CPU.getName();
565   }
566 
567   // If we can't find a default then target the architecture instead
568   return "generic";
569 }
570 
571 uint64_t ARM::parseHWDiv(StringRef HWDiv) {
572   StringRef Syn = getHWDivSynonym(HWDiv);
573   for (const auto &D : HWDivNames) {
574     if (Syn == D.getName())
575       return D.ID;
576   }
577   return AEK_INVALID;
578 }
579 
580 uint64_t ARM::parseArchExt(StringRef ArchExt) {
581   for (const auto &A : ARCHExtNames) {
582     if (ArchExt == A.getName())
583       return A.ID;
584   }
585   return AEK_INVALID;
586 }
587 
588 ARM::ArchKind ARM::parseCPUArch(StringRef CPU) {
589   for (const auto &C : CPUNames) {
590     if (CPU == C.getName())
591       return C.ArchID;
592   }
593   return ArchKind::INVALID;
594 }
595 
596 void ARM::fillValidCPUArchList(SmallVectorImpl<StringRef> &Values) {
597   for (const CpuNames<ArchKind> &Arch : CPUNames) {
598     if (Arch.ArchID != ArchKind::INVALID)
599       Values.push_back(Arch.getName());
600   }
601 }
602 
603 StringRef ARM::computeDefaultTargetABI(const Triple &TT, StringRef CPU) {
604   StringRef ArchName =
605       CPU.empty() ? TT.getArchName() : getArchName(parseCPUArch(CPU));
606 
607   if (TT.isOSBinFormatMachO()) {
608     if (TT.getEnvironment() == Triple::EABI ||
609         TT.getOS() == Triple::UnknownOS ||
610         parseArchProfile(ArchName) == ProfileKind::M)
611       return "aapcs";
612     if (TT.isWatchABI())
613       return "aapcs16";
614     return "apcs-gnu";
615   } else if (TT.isOSWindows())
616     // FIXME: this is invalid for WindowsCE.
617     return "aapcs";
618 
619   // Select the default based on the platform.
620   switch (TT.getEnvironment()) {
621   case Triple::Android:
622   case Triple::GNUEABI:
623   case Triple::GNUEABIHF:
624   case Triple::MuslEABI:
625   case Triple::MuslEABIHF:
626     return "aapcs-linux";
627   case Triple::EABIHF:
628   case Triple::EABI:
629     return "aapcs";
630   default:
631     if (TT.isOSNetBSD())
632       return "apcs-gnu";
633     if (TT.isOSOpenBSD())
634       return "aapcs-linux";
635     return "aapcs";
636   }
637 }
638