1 //===-- TargetParser - Parser for target features ---------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements a target parser to recognise hardware features such as
11 // FPU/CPU/ARCH names as well as specific support such as HDIV, etc.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/Support/ARMBuildAttributes.h"
16 #include "llvm/Support/TargetParser.h"
17 #include "llvm/ADT/StringExtras.h"
18 #include "llvm/ADT/StringSwitch.h"
19 #include "llvm/ADT/Twine.h"
20 #include <cctype>
21 
22 using namespace llvm;
23 using namespace ARM;
24 using namespace AArch64;
25 
26 namespace {
27 
28 // List of canonical FPU names (use getFPUSynonym) and which architectural
29 // features they correspond to (use getFPUFeatures).
30 // FIXME: TableGen this.
31 // The entries must appear in the order listed in ARM::FPUKind for correct indexing
32 static const struct {
33   const char *NameCStr;
34   size_t NameLength;
35   ARM::FPUKind ID;
36   ARM::FPUVersion FPUVersion;
37   ARM::NeonSupportLevel NeonSupport;
38   ARM::FPURestriction Restriction;
39 
40   StringRef getName() const { return StringRef(NameCStr, NameLength); }
41 } FPUNames[] = {
42 #define ARM_FPU(NAME, KIND, VERSION, NEON_SUPPORT, RESTRICTION) \
43   { NAME, sizeof(NAME) - 1, KIND, VERSION, NEON_SUPPORT, RESTRICTION },
44 #include "llvm/Support/ARMTargetParser.def"
45 };
46 
47 // List of canonical arch names (use getArchSynonym).
48 // This table also provides the build attribute fields for CPU arch
49 // and Arch ID, according to the Addenda to the ARM ABI, chapters
50 // 2.4 and 2.3.5.2 respectively.
51 // FIXME: SubArch values were simplified to fit into the expectations
52 // of the triples and are not conforming with their official names.
53 // Check to see if the expectation should be changed.
54 // FIXME: TableGen this.
55 template <typename T> struct ArchNames {
56   const char *NameCStr;
57   size_t NameLength;
58   const char *CPUAttrCStr;
59   size_t CPUAttrLength;
60   const char *SubArchCStr;
61   size_t SubArchLength;
62   unsigned DefaultFPU;
63   unsigned ArchBaseExtensions;
64   T ID;
65   ARMBuildAttrs::CPUArch ArchAttr; // Arch ID in build attributes.
66 
67   StringRef getName() const { return StringRef(NameCStr, NameLength); }
68 
69   // CPU class in build attributes.
70   StringRef getCPUAttr() const { return StringRef(CPUAttrCStr, CPUAttrLength); }
71 
72   // Sub-Arch name.
73   StringRef getSubArch() const { return StringRef(SubArchCStr, SubArchLength); }
74 };
75 ArchNames<ARM::ArchKind> ARCHNames[] = {
76 #define ARM_ARCH(NAME, ID, CPU_ATTR, SUB_ARCH, ARCH_ATTR, ARCH_FPU, ARCH_BASE_EXT)       \
77   {NAME, sizeof(NAME) - 1, CPU_ATTR, sizeof(CPU_ATTR) - 1, SUB_ARCH,       \
78    sizeof(SUB_ARCH) - 1, ARCH_FPU, ARCH_BASE_EXT, ARM::ArchKind::ID, ARCH_ATTR},
79 #include "llvm/Support/ARMTargetParser.def"
80 };
81 
82 ArchNames<AArch64::ArchKind> AArch64ARCHNames[] = {
83  #define AARCH64_ARCH(NAME, ID, CPU_ATTR, SUB_ARCH, ARCH_ATTR, ARCH_FPU, ARCH_BASE_EXT)       \
84    {NAME, sizeof(NAME) - 1, CPU_ATTR, sizeof(CPU_ATTR) - 1, SUB_ARCH,       \
85     sizeof(SUB_ARCH) - 1, ARCH_FPU, ARCH_BASE_EXT, AArch64::ArchKind::ID, ARCH_ATTR},
86  #include "llvm/Support/AArch64TargetParser.def"
87  };
88 
89 
90 // List of Arch Extension names.
91 // FIXME: TableGen this.
92 static const struct {
93   const char *NameCStr;
94   size_t NameLength;
95   unsigned ID;
96   const char *Feature;
97   const char *NegFeature;
98 
99   StringRef getName() const { return StringRef(NameCStr, NameLength); }
100 } ARCHExtNames[] = {
101 #define ARM_ARCH_EXT_NAME(NAME, ID, FEATURE, NEGFEATURE) \
102   { NAME, sizeof(NAME) - 1, ID, FEATURE, NEGFEATURE },
103 #include "llvm/Support/ARMTargetParser.def"
104 },AArch64ARCHExtNames[] = {
105 #define AARCH64_ARCH_EXT_NAME(NAME, ID, FEATURE, NEGFEATURE) \
106   { NAME, sizeof(NAME) - 1, ID, FEATURE, NEGFEATURE },
107 #include "llvm/Support/AArch64TargetParser.def"
108 };
109 
110 // List of HWDiv names (use getHWDivSynonym) and which architectural
111 // features they correspond to (use getHWDivFeatures).
112 // FIXME: TableGen this.
113 static const struct {
114   const char *NameCStr;
115   size_t NameLength;
116   unsigned ID;
117 
118   StringRef getName() const { return StringRef(NameCStr, NameLength); }
119 } HWDivNames[] = {
120 #define ARM_HW_DIV_NAME(NAME, ID) { NAME, sizeof(NAME) - 1, ID },
121 #include "llvm/Support/ARMTargetParser.def"
122 };
123 
124 // List of CPU names and their arches.
125 // The same CPU can have multiple arches and can be default on multiple arches.
126 // When finding the Arch for a CPU, first-found prevails. Sort them accordingly.
127 // When this becomes table-generated, we'd probably need two tables.
128 // FIXME: TableGen this.
129 template <typename T> struct CpuNames {
130   const char *NameCStr;
131   size_t NameLength;
132   T ArchID;
133   bool Default; // is $Name the default CPU for $ArchID ?
134   unsigned DefaultExtensions;
135 
136   StringRef getName() const { return StringRef(NameCStr, NameLength); }
137 };
138 CpuNames<ARM::ArchKind> CPUNames[] = {
139 #define ARM_CPU_NAME(NAME, ID, DEFAULT_FPU, IS_DEFAULT, DEFAULT_EXT) \
140   { NAME, sizeof(NAME) - 1, ARM::ArchKind::ID, IS_DEFAULT, DEFAULT_EXT },
141 #include "llvm/Support/ARMTargetParser.def"
142 };
143 
144 CpuNames<AArch64::ArchKind> AArch64CPUNames[] = {
145  #define AARCH64_CPU_NAME(NAME, ID, DEFAULT_FPU, IS_DEFAULT, DEFAULT_EXT) \
146    { NAME, sizeof(NAME) - 1, AArch64::ArchKind::ID, IS_DEFAULT, DEFAULT_EXT },
147  #include "llvm/Support/AArch64TargetParser.def"
148  };
149 
150 } // namespace
151 
152 // ======================================================= //
153 // Information by ID
154 // ======================================================= //
155 
156 StringRef ARM::getFPUName(unsigned FPUKind) {
157   if (FPUKind >= ARM::FK_LAST)
158     return StringRef();
159   return FPUNames[FPUKind].getName();
160 }
161 
162 FPUVersion ARM::getFPUVersion(unsigned FPUKind) {
163   if (FPUKind >= ARM::FK_LAST)
164     return FPUVersion::NONE;
165   return FPUNames[FPUKind].FPUVersion;
166 }
167 
168 ARM::NeonSupportLevel ARM::getFPUNeonSupportLevel(unsigned FPUKind) {
169   if (FPUKind >= ARM::FK_LAST)
170     return ARM::NeonSupportLevel::None;
171   return FPUNames[FPUKind].NeonSupport;
172 }
173 
174 ARM::FPURestriction ARM::getFPURestriction(unsigned FPUKind) {
175   if (FPUKind >= ARM::FK_LAST)
176     return ARM::FPURestriction::None;
177   return FPUNames[FPUKind].Restriction;
178 }
179 
180 unsigned llvm::ARM::getDefaultFPU(StringRef CPU, ArchKind AK) {
181   if (CPU == "generic")
182     return ARCHNames[static_cast<unsigned>(AK)].DefaultFPU;
183 
184   return StringSwitch<unsigned>(CPU)
185 #define ARM_CPU_NAME(NAME, ID, DEFAULT_FPU, IS_DEFAULT, DEFAULT_EXT) \
186     .Case(NAME, DEFAULT_FPU)
187 #include "llvm/Support/ARMTargetParser.def"
188     .Default(ARM::FK_INVALID);
189 }
190 
191 unsigned llvm::ARM::getDefaultExtensions(StringRef CPU, ArchKind AK) {
192   if (CPU == "generic")
193     return ARCHNames[static_cast<unsigned>(AK)].ArchBaseExtensions;
194 
195   return StringSwitch<unsigned>(CPU)
196 #define ARM_CPU_NAME(NAME, ID, DEFAULT_FPU, IS_DEFAULT, DEFAULT_EXT) \
197     .Case(NAME, ARCHNames[static_cast<unsigned>(ARM::ArchKind::ID)]\
198             .ArchBaseExtensions | DEFAULT_EXT)
199 #include "llvm/Support/ARMTargetParser.def"
200     .Default(ARM::AEK_INVALID);
201 }
202 
203 bool llvm::ARM::getHWDivFeatures(unsigned HWDivKind,
204                                  std::vector<StringRef> &Features) {
205 
206   if (HWDivKind == ARM::AEK_INVALID)
207     return false;
208 
209   if (HWDivKind & ARM::AEK_HWDIVARM)
210     Features.push_back("+hwdiv-arm");
211   else
212     Features.push_back("-hwdiv-arm");
213 
214   if (HWDivKind & ARM::AEK_HWDIVTHUMB)
215     Features.push_back("+hwdiv");
216   else
217     Features.push_back("-hwdiv");
218 
219   return true;
220 }
221 
222 bool llvm::ARM::getExtensionFeatures(unsigned Extensions,
223                                      std::vector<StringRef> &Features) {
224 
225   if (Extensions == ARM::AEK_INVALID)
226     return false;
227 
228   if (Extensions & ARM::AEK_CRC)
229     Features.push_back("+crc");
230   else
231     Features.push_back("-crc");
232 
233   if (Extensions & ARM::AEK_DSP)
234     Features.push_back("+dsp");
235   else
236     Features.push_back("-dsp");
237 
238   return getHWDivFeatures(Extensions, Features);
239 }
240 
241 bool llvm::ARM::getFPUFeatures(unsigned FPUKind,
242                                std::vector<StringRef> &Features) {
243 
244   if (FPUKind >= ARM::FK_LAST || FPUKind == ARM::FK_INVALID)
245     return false;
246 
247   // fp-only-sp and d16 subtarget features are independent of each other, so we
248   // must enable/disable both.
249   switch (FPUNames[FPUKind].Restriction) {
250   case ARM::FPURestriction::SP_D16:
251     Features.push_back("+fp-only-sp");
252     Features.push_back("+d16");
253     break;
254   case ARM::FPURestriction::D16:
255     Features.push_back("-fp-only-sp");
256     Features.push_back("+d16");
257     break;
258   case ARM::FPURestriction::None:
259     Features.push_back("-fp-only-sp");
260     Features.push_back("-d16");
261     break;
262   }
263 
264   // FPU version subtarget features are inclusive of lower-numbered ones, so
265   // enable the one corresponding to this version and disable all that are
266   // higher. We also have to make sure to disable fp16 when vfp4 is disabled,
267   // as +vfp4 implies +fp16 but -vfp4 does not imply -fp16.
268   switch (FPUNames[FPUKind].FPUVersion) {
269   case ARM::FPUVersion::VFPV5:
270     Features.push_back("+fp-armv8");
271     break;
272   case ARM::FPUVersion::VFPV4:
273     Features.push_back("+vfp4");
274     Features.push_back("-fp-armv8");
275     break;
276   case ARM::FPUVersion::VFPV3_FP16:
277     Features.push_back("+vfp3");
278     Features.push_back("+fp16");
279     Features.push_back("-vfp4");
280     Features.push_back("-fp-armv8");
281     break;
282   case ARM::FPUVersion::VFPV3:
283     Features.push_back("+vfp3");
284     Features.push_back("-fp16");
285     Features.push_back("-vfp4");
286     Features.push_back("-fp-armv8");
287     break;
288   case ARM::FPUVersion::VFPV2:
289     Features.push_back("+vfp2");
290     Features.push_back("-vfp3");
291     Features.push_back("-fp16");
292     Features.push_back("-vfp4");
293     Features.push_back("-fp-armv8");
294     break;
295   case ARM::FPUVersion::NONE:
296     Features.push_back("-vfp2");
297     Features.push_back("-vfp3");
298     Features.push_back("-fp16");
299     Features.push_back("-vfp4");
300     Features.push_back("-fp-armv8");
301     break;
302   }
303 
304   // crypto includes neon, so we handle this similarly to FPU version.
305   switch (FPUNames[FPUKind].NeonSupport) {
306   case ARM::NeonSupportLevel::Crypto:
307     Features.push_back("+neon");
308     Features.push_back("+crypto");
309     break;
310   case ARM::NeonSupportLevel::Neon:
311     Features.push_back("+neon");
312     Features.push_back("-crypto");
313     break;
314   case ARM::NeonSupportLevel::None:
315     Features.push_back("-neon");
316     Features.push_back("-crypto");
317     break;
318   }
319 
320   return true;
321 }
322 
323 StringRef llvm::ARM::getArchName(ArchKind AK) {
324   return ARCHNames[static_cast<unsigned>(AK)].getName();
325 }
326 
327 StringRef llvm::ARM::getCPUAttr(ArchKind AK) {
328   return ARCHNames[static_cast<unsigned>(AK)].getCPUAttr();
329 }
330 
331 StringRef llvm::ARM::getSubArch(ArchKind AK) {
332   return ARCHNames[static_cast<unsigned>(AK)].getSubArch();
333 }
334 
335 unsigned llvm::ARM::getArchAttr(ArchKind AK) {
336   return ARCHNames[static_cast<unsigned>(AK)].ArchAttr;
337 }
338 
339 StringRef llvm::ARM::getArchExtName(unsigned ArchExtKind) {
340   for (const auto AE : ARCHExtNames) {
341     if (ArchExtKind == AE.ID)
342       return AE.getName();
343   }
344   return StringRef();
345 }
346 
347 StringRef llvm::ARM::getArchExtFeature(StringRef ArchExt) {
348   if (ArchExt.startswith("no")) {
349     StringRef ArchExtBase(ArchExt.substr(2));
350     for (const auto AE : ARCHExtNames) {
351       if (AE.NegFeature && ArchExtBase == AE.getName())
352         return StringRef(AE.NegFeature);
353     }
354   }
355   for (const auto AE : ARCHExtNames) {
356     if (AE.Feature && ArchExt == AE.getName())
357       return StringRef(AE.Feature);
358   }
359 
360   return StringRef();
361 }
362 
363 StringRef llvm::ARM::getHWDivName(unsigned HWDivKind) {
364   for (const auto D : HWDivNames) {
365     if (HWDivKind == D.ID)
366       return D.getName();
367   }
368   return StringRef();
369 }
370 
371 StringRef llvm::ARM::getDefaultCPU(StringRef Arch) {
372   ArchKind AK = parseArch(Arch);
373   if (AK == ARM::ArchKind::INVALID)
374     return StringRef();
375 
376   // Look for multiple AKs to find the default for pair AK+Name.
377   for (const auto CPU : CPUNames) {
378     if (CPU.ArchID == AK && CPU.Default)
379       return CPU.getName();
380   }
381 
382   // If we can't find a default then target the architecture instead
383   return "generic";
384 }
385 
386 StringRef llvm::AArch64::getFPUName(unsigned FPUKind) {
387   return ARM::getFPUName(FPUKind);
388 }
389 
390 ARM::FPUVersion AArch64::getFPUVersion(unsigned FPUKind) {
391   return ARM::getFPUVersion(FPUKind);
392 }
393 
394 ARM::NeonSupportLevel AArch64::getFPUNeonSupportLevel(unsigned FPUKind) {
395   return ARM::getFPUNeonSupportLevel( FPUKind);
396 }
397 
398 ARM::FPURestriction AArch64::getFPURestriction(unsigned FPUKind) {
399   return ARM::getFPURestriction(FPUKind);
400 }
401 
402 unsigned llvm::AArch64::getDefaultFPU(StringRef CPU, ArchKind AK) {
403   if (CPU == "generic")
404     return AArch64ARCHNames[static_cast<unsigned>(AK)].DefaultFPU;
405 
406   return StringSwitch<unsigned>(CPU)
407 #define AARCH64_CPU_NAME(NAME, ID, DEFAULT_FPU, IS_DEFAULT, DEFAULT_EXT) \
408     .Case(NAME, DEFAULT_FPU)
409 #include "llvm/Support/AArch64TargetParser.def"
410     .Default(ARM::FK_INVALID);
411 }
412 
413 unsigned llvm::AArch64::getDefaultExtensions(StringRef CPU, ArchKind AK) {
414   if (CPU == "generic")
415     return AArch64ARCHNames[static_cast<unsigned>(AK)].ArchBaseExtensions;
416 
417   return StringSwitch<unsigned>(CPU)
418 #define AARCH64_CPU_NAME(NAME, ID, DEFAULT_FPU, IS_DEFAULT, DEFAULT_EXT)       \
419   .Case(NAME,                                                                  \
420         AArch64ARCHNames[static_cast<unsigned>(AArch64::ArchKind::ID)] \
421             .ArchBaseExtensions | \
422             DEFAULT_EXT)
423 #include "llvm/Support/AArch64TargetParser.def"
424     .Default(AArch64::AEK_INVALID);
425 }
426 
427 bool llvm::AArch64::getExtensionFeatures(unsigned Extensions,
428                                      std::vector<StringRef> &Features) {
429 
430   if (Extensions == AArch64::AEK_INVALID)
431     return false;
432 
433   if (Extensions & AArch64::AEK_FP)
434     Features.push_back("+fp-armv8");
435   if (Extensions & AArch64::AEK_SIMD)
436     Features.push_back("+neon");
437   if (Extensions & AArch64::AEK_CRC)
438     Features.push_back("+crc");
439   if (Extensions & AArch64::AEK_CRYPTO)
440     Features.push_back("+crypto");
441   if (Extensions & AArch64::AEK_FP16)
442     Features.push_back("+fullfp16");
443   if (Extensions & AArch64::AEK_PROFILE)
444     Features.push_back("+spe");
445   if (Extensions & AArch64::AEK_RAS)
446     Features.push_back("+ras");
447   if (Extensions & AArch64::AEK_LSE)
448     Features.push_back("+lse");
449   if (Extensions & AArch64::AEK_SVE)
450     Features.push_back("+sve");
451 
452   return true;
453 }
454 
455 bool llvm::AArch64::getFPUFeatures(unsigned FPUKind,
456                                std::vector<StringRef> &Features) {
457   return ARM::getFPUFeatures(FPUKind, Features);
458 }
459 
460 bool llvm::AArch64::getArchFeatures(AArch64::ArchKind AK,
461                                     std::vector<StringRef> &Features) {
462   if (AK == AArch64::ArchKind::ARMV8_1A)
463     Features.push_back("+v8.1a");
464   if (AK == AArch64::ArchKind::ARMV8_2A)
465     Features.push_back("+v8.2a");
466 
467   return AK != AArch64::ArchKind::INVALID;
468 }
469 
470 StringRef llvm::AArch64::getArchName(ArchKind AK) {
471   return AArch64ARCHNames[static_cast<unsigned>(AK)].getName();
472 }
473 
474 StringRef llvm::AArch64::getCPUAttr(ArchKind AK) {
475   return AArch64ARCHNames[static_cast<unsigned>(AK)].getCPUAttr();
476 }
477 
478 StringRef llvm::AArch64::getSubArch(ArchKind AK) {
479   return AArch64ARCHNames[static_cast<unsigned>(AK)].getSubArch();
480 }
481 
482 unsigned llvm::AArch64::getArchAttr(ArchKind AK) {
483   return AArch64ARCHNames[static_cast<unsigned>(AK)].ArchAttr;
484 }
485 
486 StringRef llvm::AArch64::getArchExtName(unsigned ArchExtKind) {
487   for (const auto &AE : AArch64ARCHExtNames)
488     if (ArchExtKind == AE.ID)
489       return AE.getName();
490   return StringRef();
491 }
492 
493 StringRef llvm::AArch64::getArchExtFeature(StringRef ArchExt) {
494   if (ArchExt.startswith("no")) {
495     StringRef ArchExtBase(ArchExt.substr(2));
496     for (const auto &AE : AArch64ARCHExtNames) {
497       if (AE.NegFeature && ArchExtBase == AE.getName())
498         return StringRef(AE.NegFeature);
499     }
500   }
501 
502   for (const auto &AE : AArch64ARCHExtNames)
503     if (AE.Feature && ArchExt == AE.getName())
504       return StringRef(AE.Feature);
505   return StringRef();
506 }
507 
508 StringRef llvm::AArch64::getDefaultCPU(StringRef Arch) {
509   AArch64::ArchKind AK = parseArch(Arch);
510   if (AK == ArchKind::INVALID)
511     return StringRef();
512 
513   // Look for multiple AKs to find the default for pair AK+Name.
514   for (const auto &CPU : AArch64CPUNames)
515     if (CPU.ArchID == AK && CPU.Default)
516       return CPU.getName();
517 
518   // If we can't find a default then target the architecture instead
519   return "generic";
520 }
521 
522 unsigned llvm::AArch64::checkArchVersion(StringRef Arch) {
523   if (Arch[0] == 'v' && std::isdigit(Arch[1]))
524     return (Arch[1] - 48);
525   return 0;
526 }
527 
528 // ======================================================= //
529 // Parsers
530 // ======================================================= //
531 
532 static StringRef getHWDivSynonym(StringRef HWDiv) {
533   return StringSwitch<StringRef>(HWDiv)
534       .Case("thumb,arm", "arm,thumb")
535       .Default(HWDiv);
536 }
537 
538 static StringRef getFPUSynonym(StringRef FPU) {
539   return StringSwitch<StringRef>(FPU)
540       .Cases("fpa", "fpe2", "fpe3", "maverick", "invalid") // Unsupported
541       .Case("vfp2", "vfpv2")
542       .Case("vfp3", "vfpv3")
543       .Case("vfp4", "vfpv4")
544       .Case("vfp3-d16", "vfpv3-d16")
545       .Case("vfp4-d16", "vfpv4-d16")
546       .Cases("fp4-sp-d16", "vfpv4-sp-d16", "fpv4-sp-d16")
547       .Cases("fp4-dp-d16", "fpv4-dp-d16", "vfpv4-d16")
548       .Case("fp5-sp-d16", "fpv5-sp-d16")
549       .Cases("fp5-dp-d16", "fpv5-dp-d16", "fpv5-d16")
550       // FIXME: Clang uses it, but it's bogus, since neon defaults to vfpv3.
551       .Case("neon-vfpv3", "neon")
552       .Default(FPU);
553 }
554 
555 static StringRef getArchSynonym(StringRef Arch) {
556   return StringSwitch<StringRef>(Arch)
557       .Case("v5", "v5t")
558       .Case("v5e", "v5te")
559       .Case("v6j", "v6")
560       .Case("v6hl", "v6k")
561       .Cases("v6m", "v6sm", "v6s-m", "v6-m")
562       .Cases("v6z", "v6zk", "v6kz")
563       .Cases("v7", "v7a", "v7hl", "v7l", "v7-a")
564       .Case("v7r", "v7-r")
565       .Case("v7m", "v7-m")
566       .Case("v7em", "v7e-m")
567       .Cases("v8", "v8a", "aarch64", "arm64", "v8-a")
568       .Case("v8.1a", "v8.1-a")
569       .Case("v8.2a", "v8.2-a")
570       .Case("v8r", "v8-r")
571       .Case("v8m.base", "v8-m.base")
572       .Case("v8m.main", "v8-m.main")
573       .Default(Arch);
574 }
575 
576 // MArch is expected to be of the form (arm|thumb)?(eb)?(v.+)?(eb)?, but
577 // (iwmmxt|xscale)(eb)? is also permitted. If the former, return
578 // "v.+", if the latter, return unmodified string, minus 'eb'.
579 // If invalid, return empty string.
580 StringRef llvm::ARM::getCanonicalArchName(StringRef Arch) {
581   size_t offset = StringRef::npos;
582   StringRef A = Arch;
583   StringRef Error = "";
584 
585   // Begins with "arm" / "thumb", move past it.
586   if (A.startswith("arm64"))
587     offset = 5;
588   else if (A.startswith("arm"))
589     offset = 3;
590   else if (A.startswith("thumb"))
591     offset = 5;
592   else if (A.startswith("aarch64")) {
593     offset = 7;
594     // AArch64 uses "_be", not "eb" suffix.
595     if (A.find("eb") != StringRef::npos)
596       return Error;
597     if (A.substr(offset, 3) == "_be")
598       offset += 3;
599   }
600 
601   // Ex. "armebv7", move past the "eb".
602   if (offset != StringRef::npos && A.substr(offset, 2) == "eb")
603     offset += 2;
604   // Or, if it ends with eb ("armv7eb"), chop it off.
605   else if (A.endswith("eb"))
606     A = A.substr(0, A.size() - 2);
607   // Trim the head
608   if (offset != StringRef::npos)
609     A = A.substr(offset);
610 
611   // Empty string means offset reached the end, which means it's valid.
612   if (A.empty())
613     return Arch;
614 
615   // Only match non-marketing names
616   if (offset != StringRef::npos) {
617     // Must start with 'vN'.
618     if (A[0] != 'v' || !std::isdigit(A[1]))
619       return Error;
620     // Can't have an extra 'eb'.
621     if (A.find("eb") != StringRef::npos)
622       return Error;
623   }
624 
625   // Arch will either be a 'v' name (v7a) or a marketing name (xscale).
626   return A;
627 }
628 
629 unsigned llvm::ARM::parseHWDiv(StringRef HWDiv) {
630   StringRef Syn = getHWDivSynonym(HWDiv);
631   for (const auto D : HWDivNames) {
632     if (Syn == D.getName())
633       return D.ID;
634   }
635   return ARM::AEK_INVALID;
636 }
637 
638 unsigned llvm::ARM::parseFPU(StringRef FPU) {
639   StringRef Syn = getFPUSynonym(FPU);
640   for (const auto F : FPUNames) {
641     if (Syn == F.getName())
642       return F.ID;
643   }
644   return ARM::FK_INVALID;
645 }
646 
647 // Allows partial match, ex. "v7a" matches "armv7a".
648 ARM::ArchKind ARM::parseArch(StringRef Arch) {
649   Arch = getCanonicalArchName(Arch);
650   StringRef Syn = getArchSynonym(Arch);
651   for (const auto A : ARCHNames) {
652     if (A.getName().endswith(Syn))
653       return A.ID;
654   }
655   return ARM::ArchKind::INVALID;
656 }
657 
658 unsigned llvm::ARM::parseArchExt(StringRef ArchExt) {
659   for (const auto A : ARCHExtNames) {
660     if (ArchExt == A.getName())
661       return A.ID;
662   }
663   return ARM::AEK_INVALID;
664 }
665 
666 ARM::ArchKind llvm::ARM::parseCPUArch(StringRef CPU) {
667   for (const auto C : CPUNames) {
668     if (CPU == C.getName())
669       return C.ArchID;
670   }
671   return ARM::ArchKind::INVALID;
672 }
673 
674 // ARM, Thumb, AArch64
675 ARM::ISAKind ARM::parseArchISA(StringRef Arch) {
676   return StringSwitch<ARM::ISAKind>(Arch)
677       .StartsWith("aarch64", ARM::ISAKind::AARCH64)
678       .StartsWith("arm64", ARM::ISAKind::AARCH64)
679       .StartsWith("thumb", ARM::ISAKind::THUMB)
680       .StartsWith("arm", ARM::ISAKind::ARM)
681       .Default(ARM::ISAKind::INVALID);
682 }
683 
684 // Little/Big endian
685 ARM::EndianKind ARM::parseArchEndian(StringRef Arch) {
686   if (Arch.startswith("armeb") || Arch.startswith("thumbeb") ||
687       Arch.startswith("aarch64_be"))
688     return ARM::EndianKind::BIG;
689 
690   if (Arch.startswith("arm") || Arch.startswith("thumb")) {
691     if (Arch.endswith("eb"))
692       return ARM::EndianKind::BIG;
693     else
694       return ARM::EndianKind::LITTLE;
695   }
696 
697   if (Arch.startswith("aarch64"))
698     return ARM::EndianKind::LITTLE;
699 
700   return ARM::EndianKind::INVALID;
701 }
702 
703 // Profile A/R/M
704 ARM::ProfileKind ARM::parseArchProfile(StringRef Arch) {
705   Arch = getCanonicalArchName(Arch);
706   switch (parseArch(Arch)) {
707   case ARM::ArchKind::ARMV6M:
708   case ARM::ArchKind::ARMV7M:
709   case ARM::ArchKind::ARMV7EM:
710   case ARM::ArchKind::ARMV8MMainline:
711   case ARM::ArchKind::ARMV8MBaseline:
712     return ARM::ProfileKind::M;
713   case ARM::ArchKind::ARMV7R:
714   case ARM::ArchKind::ARMV8R:
715     return ARM::ProfileKind::R;
716   case ARM::ArchKind::ARMV7A:
717   case ARM::ArchKind::ARMV7VE:
718   case ARM::ArchKind::ARMV7K:
719   case ARM::ArchKind::ARMV8A:
720   case ARM::ArchKind::ARMV8_1A:
721   case ARM::ArchKind::ARMV8_2A:
722     return ARM::ProfileKind::A;
723     LLVM_FALLTHROUGH;
724   case ARM::ArchKind::ARMV2:
725   case ARM::ArchKind::ARMV2A:
726   case ARM::ArchKind::ARMV3:
727   case ARM::ArchKind::ARMV3M:
728   case ARM::ArchKind::ARMV4:
729   case ARM::ArchKind::ARMV4T:
730   case ARM::ArchKind::ARMV5T:
731   case ARM::ArchKind::ARMV5TE:
732   case ARM::ArchKind::ARMV5TEJ:
733   case ARM::ArchKind::ARMV6:
734   case ARM::ArchKind::ARMV6K:
735   case ARM::ArchKind::ARMV6T2:
736   case ARM::ArchKind::ARMV6KZ:
737   case ARM::ArchKind::ARMV7S:
738   case ARM::ArchKind::IWMMXT:
739   case ARM::ArchKind::IWMMXT2:
740   case ARM::ArchKind::XSCALE:
741   case ARM::ArchKind::INVALID:
742     return ARM::ProfileKind::INVALID;
743   }
744   llvm_unreachable("Unhandled architecture");
745 }
746 
747 // Version number (ex. v7 = 7).
748 unsigned llvm::ARM::parseArchVersion(StringRef Arch) {
749   Arch = getCanonicalArchName(Arch);
750   switch (parseArch(Arch)) {
751   case ARM::ArchKind::ARMV2:
752   case ARM::ArchKind::ARMV2A:
753     return 2;
754   case ARM::ArchKind::ARMV3:
755   case ARM::ArchKind::ARMV3M:
756     return 3;
757   case ARM::ArchKind::ARMV4:
758   case ARM::ArchKind::ARMV4T:
759     return 4;
760   case ARM::ArchKind::ARMV5T:
761   case ARM::ArchKind::ARMV5TE:
762   case ARM::ArchKind::IWMMXT:
763   case ARM::ArchKind::IWMMXT2:
764   case ARM::ArchKind::XSCALE:
765   case ARM::ArchKind::ARMV5TEJ:
766     return 5;
767   case ARM::ArchKind::ARMV6:
768   case ARM::ArchKind::ARMV6K:
769   case ARM::ArchKind::ARMV6T2:
770   case ARM::ArchKind::ARMV6KZ:
771   case ARM::ArchKind::ARMV6M:
772     return 6;
773   case ARM::ArchKind::ARMV7A:
774   case ARM::ArchKind::ARMV7VE:
775   case ARM::ArchKind::ARMV7R:
776   case ARM::ArchKind::ARMV7M:
777   case ARM::ArchKind::ARMV7S:
778   case ARM::ArchKind::ARMV7EM:
779   case ARM::ArchKind::ARMV7K:
780     return 7;
781   case ARM::ArchKind::ARMV8A:
782   case ARM::ArchKind::ARMV8_1A:
783   case ARM::ArchKind::ARMV8_2A:
784   case ARM::ArchKind::ARMV8R:
785   case ARM::ArchKind::ARMV8MBaseline:
786   case ARM::ArchKind::ARMV8MMainline:
787     return 8;
788   case ARM::ArchKind::INVALID:
789     return 0;
790   }
791   llvm_unreachable("Unhandled architecture");
792 }
793 
794 StringRef llvm::ARM::computeDefaultTargetABI(const Triple &TT, StringRef CPU) {
795   StringRef ArchName =
796       CPU.empty() ? TT.getArchName() : ARM::getArchName(ARM::parseCPUArch(CPU));
797 
798   if (TT.isOSBinFormatMachO()) {
799     if (TT.getEnvironment() == Triple::EABI ||
800         TT.getOS() == Triple::UnknownOS ||
801         llvm::ARM::parseArchProfile(ArchName) == ARM::ProfileKind::M)
802       return "aapcs";
803     if (TT.isWatchABI())
804       return "aapcs16";
805     return "apcs-gnu";
806   } else if (TT.isOSWindows())
807     // FIXME: this is invalid for WindowsCE.
808     return "aapcs";
809 
810   // Select the default based on the platform.
811   switch (TT.getEnvironment()) {
812   case Triple::Android:
813   case Triple::GNUEABI:
814   case Triple::GNUEABIHF:
815   case Triple::MuslEABI:
816   case Triple::MuslEABIHF:
817     return "aapcs-linux";
818   case Triple::EABIHF:
819   case Triple::EABI:
820     return "aapcs";
821   default:
822     if (TT.isOSNetBSD())
823       return "apcs-gnu";
824     if (TT.isOSOpenBSD())
825       return "aapcs-linux";
826     return "aapcs";
827   }
828 }
829 
830 StringRef llvm::AArch64::getCanonicalArchName(StringRef Arch) {
831   return ARM::getCanonicalArchName(Arch);
832 }
833 
834 unsigned llvm::AArch64::parseFPU(StringRef FPU) {
835   return ARM::parseFPU(FPU);
836 }
837 
838 // Allows partial match, ex. "v8a" matches "armv8a".
839 AArch64::ArchKind AArch64::parseArch(StringRef Arch) {
840   Arch = getCanonicalArchName(Arch);
841   if (checkArchVersion(Arch) < 8)
842     return ArchKind::INVALID;
843 
844   StringRef Syn = getArchSynonym(Arch);
845   for (const auto A : AArch64ARCHNames) {
846     if (A.getName().endswith(Syn))
847       return A.ID;
848   }
849   return ArchKind::INVALID;
850 }
851 
852 unsigned llvm::AArch64::parseArchExt(StringRef ArchExt) {
853   for (const auto A : AArch64ARCHExtNames) {
854     if (ArchExt == A.getName())
855       return A.ID;
856   }
857   return AArch64::AEK_INVALID;
858 }
859 
860 AArch64::ArchKind llvm::AArch64::parseCPUArch(StringRef CPU) {
861   for (const auto C : AArch64CPUNames) {
862     if (CPU == C.getName())
863       return C.ArchID;
864   }
865   return ArchKind::INVALID;
866 }
867 
868 // ARM, Thumb, AArch64
869 ARM::ISAKind AArch64::parseArchISA(StringRef Arch) {
870   return ARM::parseArchISA(Arch);
871 }
872 
873 // Little/Big endian
874 ARM::EndianKind AArch64::parseArchEndian(StringRef Arch) {
875   return ARM::parseArchEndian(Arch);
876 }
877 
878 // Profile A/R/M
879 ARM::ProfileKind AArch64::parseArchProfile(StringRef Arch) {
880   return ARM::parseArchProfile(Arch);
881 }
882 
883 // Version number (ex. v8 = 8).
884 unsigned llvm::AArch64::parseArchVersion(StringRef Arch) {
885   return ARM::parseArchVersion(Arch);
886 }
887