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