xref: /freebsd/contrib/llvm-project/clang/lib/Driver/ToolChains/Arch/AArch64.cpp (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 //===--- AArch64.cpp - AArch64 (not ARM) Helpers for Tools ------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "AArch64.h"
10 #include "clang/Driver/Driver.h"
11 #include "clang/Driver/DriverDiagnostic.h"
12 #include "clang/Driver/Options.h"
13 #include "llvm/Option/ArgList.h"
14 #include "llvm/Support/AArch64TargetParser.h"
15 #include "llvm/Support/TargetParser.h"
16 #include "llvm/Support/Host.h"
17 
18 using namespace clang::driver;
19 using namespace clang::driver::tools;
20 using namespace clang;
21 using namespace llvm::opt;
22 
23 /// \returns true if the given triple can determine the default CPU type even
24 /// if -arch is not specified.
25 static bool isCPUDeterminedByTriple(const llvm::Triple &Triple) {
26   return Triple.isOSDarwin();
27 }
28 
29 /// getAArch64TargetCPU - Get the (LLVM) name of the AArch64 cpu we are
30 /// targeting. Set \p A to the Arg corresponding to the -mcpu argument if it is
31 /// provided, or to nullptr otherwise.
32 std::string aarch64::getAArch64TargetCPU(const ArgList &Args,
33                                          const llvm::Triple &Triple, Arg *&A) {
34   std::string CPU;
35   // If we have -mcpu, use that.
36   if ((A = Args.getLastArg(options::OPT_mcpu_EQ))) {
37     StringRef Mcpu = A->getValue();
38     CPU = Mcpu.split("+").first.lower();
39   }
40 
41   // Handle CPU name is 'native'.
42   if (CPU == "native")
43     return std::string(llvm::sys::getHostCPUName());
44 
45   if (CPU.size())
46     return CPU;
47 
48   if (Triple.isTargetMachineMac() &&
49       Triple.getArch() == llvm::Triple::aarch64) {
50     // Apple Silicon macs default to M1 CPUs.
51     return "apple-m1";
52   }
53 
54   // arm64e requires v8.3a and only runs on apple-a12 and later CPUs.
55   if (Triple.isArm64e())
56     return "apple-a12";
57 
58   // Make sure we pick the appropriate Apple CPU if -arch is used or when
59   // targetting a Darwin OS.
60   if (Args.getLastArg(options::OPT_arch) || Triple.isOSDarwin())
61     return Triple.getArch() == llvm::Triple::aarch64_32 ? "apple-s4"
62                                                         : "apple-a7";
63 
64   return "generic";
65 }
66 
67 // Decode AArch64 features from string like +[no]featureA+[no]featureB+...
68 static bool DecodeAArch64Features(const Driver &D, StringRef text,
69                                   std::vector<StringRef> &Features,
70                                   llvm::AArch64::ArchKind ArchKind) {
71   SmallVector<StringRef, 8> Split;
72   text.split(Split, StringRef("+"), -1, false);
73 
74   for (StringRef Feature : Split) {
75     StringRef FeatureName = llvm::AArch64::getArchExtFeature(Feature);
76     if (!FeatureName.empty())
77       Features.push_back(FeatureName);
78     else if (Feature == "neon" || Feature == "noneon")
79       D.Diag(clang::diag::err_drv_no_neon_modifier);
80     else
81       return false;
82 
83     if (Feature == "sve2")
84       Features.push_back("+sve");
85     else if (Feature == "sve2-bitperm" || Feature == "sve2-sha3" ||
86              Feature == "sve2-aes" || Feature == "sve2-sm4") {
87       Features.push_back("+sve");
88       Features.push_back("+sve2");
89     } else if (Feature == "nosve") {
90       Features.push_back("-sve2");
91       Features.push_back("-sve2-bitperm");
92       Features.push_back("-sve2-sha3");
93       Features.push_back("-sve2-aes");
94       Features.push_back("-sve2-sm4");
95     } else if (Feature == "nosve2") {
96       Features.push_back("-sve2-bitperm");
97       Features.push_back("-sve2-sha3");
98       Features.push_back("-sve2-aes");
99       Features.push_back("-sve2-sm4");
100     }
101 
102     // +sve implies +f32mm if the base architecture is >= v8.6A (except v9A)
103     // It isn't the case in general that sve implies both f64mm and f32mm
104     if ((ArchKind == llvm::AArch64::ArchKind::ARMV8_6A ||
105          ArchKind == llvm::AArch64::ArchKind::ARMV8_7A ||
106          ArchKind == llvm::AArch64::ArchKind::ARMV8_8A ||
107          ArchKind == llvm::AArch64::ArchKind::ARMV9_1A ||
108          ArchKind == llvm::AArch64::ArchKind::ARMV9_2A ||
109          ArchKind == llvm::AArch64::ArchKind::ARMV9_3A) &&
110         Feature == "sve")
111       Features.push_back("+f32mm");
112   }
113   return true;
114 }
115 
116 // Check if the CPU name and feature modifiers in -mcpu are legal. If yes,
117 // decode CPU and feature.
118 static bool DecodeAArch64Mcpu(const Driver &D, StringRef Mcpu, StringRef &CPU,
119                               std::vector<StringRef> &Features) {
120   std::pair<StringRef, StringRef> Split = Mcpu.split("+");
121   CPU = Split.first;
122   llvm::AArch64::ArchKind ArchKind = llvm::AArch64::ArchKind::ARMV8A;
123 
124   if (CPU == "native")
125     CPU = llvm::sys::getHostCPUName();
126 
127   if (CPU == "generic") {
128     Features.push_back("+neon");
129   } else {
130     ArchKind = llvm::AArch64::parseCPUArch(CPU);
131     if (!llvm::AArch64::getArchFeatures(ArchKind, Features))
132       return false;
133 
134     uint64_t Extension = llvm::AArch64::getDefaultExtensions(CPU, ArchKind);
135     if (!llvm::AArch64::getExtensionFeatures(Extension, Features))
136       return false;
137    }
138 
139    if (Split.second.size() &&
140        !DecodeAArch64Features(D, Split.second, Features, ArchKind))
141      return false;
142 
143    return true;
144 }
145 
146 static bool
147 getAArch64ArchFeaturesFromMarch(const Driver &D, StringRef March,
148                                 const ArgList &Args,
149                                 std::vector<StringRef> &Features) {
150   std::string MarchLowerCase = March.lower();
151   std::pair<StringRef, StringRef> Split = StringRef(MarchLowerCase).split("+");
152 
153   llvm::AArch64::ArchKind ArchKind = llvm::AArch64::parseArch(Split.first);
154   if (ArchKind == llvm::AArch64::ArchKind::INVALID ||
155       !llvm::AArch64::getArchFeatures(ArchKind, Features))
156     return false;
157 
158   // Enable SVE2 by default on Armv9-A.
159   // It can still be disabled if +nosve2 is present.
160   // We must do this early so that DecodeAArch64Features has the correct state
161   if ((ArchKind == llvm::AArch64::ArchKind::ARMV9A ||
162        ArchKind == llvm::AArch64::ArchKind::ARMV9_1A ||
163        ArchKind == llvm::AArch64::ArchKind::ARMV9_2A)) {
164     Features.push_back("+sve");
165     Features.push_back("+sve2");
166   }
167 
168   if ((Split.second.size() &&
169        !DecodeAArch64Features(D, Split.second, Features, ArchKind)))
170     return false;
171 
172   return true;
173 }
174 
175 static bool
176 getAArch64ArchFeaturesFromMcpu(const Driver &D, StringRef Mcpu,
177                                const ArgList &Args,
178                                std::vector<StringRef> &Features) {
179   StringRef CPU;
180   std::string McpuLowerCase = Mcpu.lower();
181   if (!DecodeAArch64Mcpu(D, McpuLowerCase, CPU, Features))
182     return false;
183 
184   return true;
185 }
186 
187 static bool
188 getAArch64MicroArchFeaturesFromMtune(const Driver &D, StringRef Mtune,
189                                      const ArgList &Args,
190                                      std::vector<StringRef> &Features) {
191   std::string MtuneLowerCase = Mtune.lower();
192   // Check CPU name is valid
193   std::vector<StringRef> MtuneFeatures;
194   StringRef Tune;
195   if (!DecodeAArch64Mcpu(D, MtuneLowerCase, Tune, MtuneFeatures))
196     return false;
197 
198   // Handle CPU name is 'native'.
199   if (MtuneLowerCase == "native")
200     MtuneLowerCase = std::string(llvm::sys::getHostCPUName());
201   if (MtuneLowerCase == "cyclone" ||
202       StringRef(MtuneLowerCase).startswith("apple")) {
203     Features.push_back("+zcm");
204     Features.push_back("+zcz");
205   }
206   return true;
207 }
208 
209 static bool
210 getAArch64MicroArchFeaturesFromMcpu(const Driver &D, StringRef Mcpu,
211                                     const ArgList &Args,
212                                     std::vector<StringRef> &Features) {
213   StringRef CPU;
214   std::vector<StringRef> DecodedFeature;
215   std::string McpuLowerCase = Mcpu.lower();
216   if (!DecodeAArch64Mcpu(D, McpuLowerCase, CPU, DecodedFeature))
217     return false;
218 
219   return getAArch64MicroArchFeaturesFromMtune(D, CPU, Args, Features);
220 }
221 
222 void aarch64::getAArch64TargetFeatures(const Driver &D,
223                                        const llvm::Triple &Triple,
224                                        const ArgList &Args,
225                                        llvm::opt::ArgStringList &CmdArgs,
226                                        std::vector<StringRef> &Features,
227                                        bool ForAS) {
228   Arg *A;
229   bool success = true;
230   // Enable NEON by default.
231   Features.push_back("+neon");
232   llvm::StringRef WaMArch;
233   if (ForAS)
234     for (const auto *A :
235          Args.filtered(options::OPT_Wa_COMMA, options::OPT_Xassembler))
236       for (StringRef Value : A->getValues())
237         if (Value.startswith("-march="))
238           WaMArch = Value.substr(7);
239   // Call getAArch64ArchFeaturesFromMarch only if "-Wa,-march=" or
240   // "-Xassembler -march" is detected. Otherwise it may return false
241   // and causes Clang to error out.
242   if (!WaMArch.empty())
243     success = getAArch64ArchFeaturesFromMarch(D, WaMArch, Args, Features);
244   else if ((A = Args.getLastArg(options::OPT_march_EQ)))
245     success = getAArch64ArchFeaturesFromMarch(D, A->getValue(), Args, Features);
246   else if ((A = Args.getLastArg(options::OPT_mcpu_EQ)))
247     success = getAArch64ArchFeaturesFromMcpu(D, A->getValue(), Args, Features);
248   else if (Args.hasArg(options::OPT_arch) || isCPUDeterminedByTriple(Triple))
249     success = getAArch64ArchFeaturesFromMcpu(
250         D, getAArch64TargetCPU(Args, Triple, A), Args, Features);
251   else
252     // Default to 'A' profile if the architecture is not specified.
253     success = getAArch64ArchFeaturesFromMarch(D, "armv8-a", Args, Features);
254 
255   if (success && (A = Args.getLastArg(clang::driver::options::OPT_mtune_EQ)))
256     success =
257         getAArch64MicroArchFeaturesFromMtune(D, A->getValue(), Args, Features);
258   else if (success && (A = Args.getLastArg(options::OPT_mcpu_EQ)))
259     success =
260         getAArch64MicroArchFeaturesFromMcpu(D, A->getValue(), Args, Features);
261   else if (success &&
262            (Args.hasArg(options::OPT_arch) || isCPUDeterminedByTriple(Triple)))
263     success = getAArch64MicroArchFeaturesFromMcpu(
264         D, getAArch64TargetCPU(Args, Triple, A), Args, Features);
265 
266   if (!success) {
267     auto Diag = D.Diag(diag::err_drv_clang_unsupported);
268     // If "-Wa,-march=" is used, 'WaMArch' will contain the argument's value,
269     // while 'A' is uninitialized. Only dereference 'A' in the other case.
270     if (!WaMArch.empty())
271       Diag << "-march=" + WaMArch.str();
272     else
273       Diag << A->getAsString(Args);
274   }
275 
276   if (Args.getLastArg(options::OPT_mgeneral_regs_only)) {
277     Features.push_back("-fp-armv8");
278     Features.push_back("-crypto");
279     Features.push_back("-neon");
280   }
281 
282   if (Arg *A = Args.getLastArg(options::OPT_mtp_mode_EQ)) {
283     StringRef Mtp = A->getValue();
284     if (Mtp == "el3")
285       Features.push_back("+tpidr-el3");
286     else if (Mtp == "el2")
287       Features.push_back("+tpidr-el2");
288     else if (Mtp == "el1")
289       Features.push_back("+tpidr-el1");
290     else if (Mtp != "el0")
291       D.Diag(diag::err_drv_invalid_mtp) << A->getAsString(Args);
292   }
293 
294   // Enable/disable straight line speculation hardening.
295   if (Arg *A = Args.getLastArg(options::OPT_mharden_sls_EQ)) {
296     StringRef Scope = A->getValue();
297     bool EnableRetBr = false;
298     bool EnableBlr = false;
299     bool DisableComdat = false;
300     if (Scope != "none") {
301       SmallVector<StringRef, 4> Opts;
302       Scope.split(Opts, ",");
303       for (auto Opt : Opts) {
304         Opt = Opt.trim();
305         if (Opt == "all") {
306           EnableBlr = true;
307           EnableRetBr = true;
308           continue;
309         }
310         if (Opt == "retbr") {
311           EnableRetBr = true;
312           continue;
313         }
314         if (Opt == "blr") {
315           EnableBlr = true;
316           continue;
317         }
318         if (Opt == "comdat") {
319           DisableComdat = false;
320           continue;
321         }
322         if (Opt == "nocomdat") {
323           DisableComdat = true;
324           continue;
325         }
326         D.Diag(diag::err_invalid_sls_hardening)
327             << Scope << A->getAsString(Args);
328         break;
329       }
330     }
331 
332     if (EnableRetBr)
333       Features.push_back("+harden-sls-retbr");
334     if (EnableBlr)
335       Features.push_back("+harden-sls-blr");
336     if (DisableComdat) {
337       Features.push_back("+harden-sls-nocomdat");
338     }
339   }
340 
341   // En/disable crc
342   if (Arg *A = Args.getLastArg(options::OPT_mcrc, options::OPT_mnocrc)) {
343     if (A->getOption().matches(options::OPT_mcrc))
344       Features.push_back("+crc");
345     else
346       Features.push_back("-crc");
347   }
348 
349   // Handle (arch-dependent) fp16fml/fullfp16 relationship.
350   // FIXME: this fp16fml option handling will be reimplemented after the
351   // TargetParser rewrite.
352   const auto ItRNoFullFP16 = std::find(Features.rbegin(), Features.rend(), "-fullfp16");
353   const auto ItRFP16FML = std::find(Features.rbegin(), Features.rend(), "+fp16fml");
354   if (llvm::is_contained(Features, "+v8.4a")) {
355     const auto ItRFullFP16  = std::find(Features.rbegin(), Features.rend(), "+fullfp16");
356     if (ItRFullFP16 < ItRNoFullFP16 && ItRFullFP16 < ItRFP16FML) {
357       // Only entangled feature that can be to the right of this +fullfp16 is -fp16fml.
358       // Only append the +fp16fml if there is no -fp16fml after the +fullfp16.
359       if (std::find(Features.rbegin(), ItRFullFP16, "-fp16fml") == ItRFullFP16)
360         Features.push_back("+fp16fml");
361     }
362     else
363       goto fp16_fml_fallthrough;
364   } else {
365 fp16_fml_fallthrough:
366     // In both of these cases, putting the 'other' feature on the end of the vector will
367     // result in the same effect as placing it immediately after the current feature.
368     if (ItRNoFullFP16 < ItRFP16FML)
369       Features.push_back("-fp16fml");
370     else if (ItRNoFullFP16 > ItRFP16FML)
371       Features.push_back("+fullfp16");
372   }
373 
374   // FIXME: this needs reimplementation too after the TargetParser rewrite
375   //
376   // Context sensitive meaning of Crypto:
377   // 1) For Arch >= ARMv8.4a:  crypto = sm4 + sha3 + sha2 + aes
378   // 2) For Arch <= ARMv8.3a:  crypto = sha2 + aes
379   const auto ItBegin = Features.begin();
380   const auto ItEnd = Features.end();
381   const auto ItRBegin = Features.rbegin();
382   const auto ItREnd = Features.rend();
383   const auto ItRCrypto = std::find(ItRBegin, ItREnd, "+crypto");
384   const auto ItRNoCrypto = std::find(ItRBegin, ItREnd, "-crypto");
385   const auto HasCrypto  = ItRCrypto != ItREnd;
386   const auto HasNoCrypto = ItRNoCrypto != ItREnd;
387   const ptrdiff_t PosCrypto = ItRCrypto - ItRBegin;
388   const ptrdiff_t PosNoCrypto = ItRNoCrypto - ItRBegin;
389 
390   bool NoCrypto = false;
391   if (HasCrypto && HasNoCrypto) {
392     if (PosNoCrypto < PosCrypto)
393       NoCrypto = true;
394   }
395 
396   if (std::find(ItBegin, ItEnd, "+v8.4a") != ItEnd ||
397       std::find(ItBegin, ItEnd, "+v8.8a") != ItEnd ||
398       std::find(ItBegin, ItEnd, "+v9a") != ItEnd ||
399       std::find(ItBegin, ItEnd, "+v9.1a") != ItEnd ||
400       std::find(ItBegin, ItEnd, "+v9.2a") != ItEnd ||
401       std::find(ItBegin, ItEnd, "+v9.3a") != ItEnd) {
402     if (HasCrypto && !NoCrypto) {
403       // Check if we have NOT disabled an algorithm with something like:
404       //   +crypto, -algorithm
405       // And if "-algorithm" does not occur, we enable that crypto algorithm.
406       const bool HasSM4  = (std::find(ItBegin, ItEnd, "-sm4") == ItEnd);
407       const bool HasSHA3 = (std::find(ItBegin, ItEnd, "-sha3") == ItEnd);
408       const bool HasSHA2 = (std::find(ItBegin, ItEnd, "-sha2") == ItEnd);
409       const bool HasAES  = (std::find(ItBegin, ItEnd, "-aes") == ItEnd);
410       if (HasSM4)
411         Features.push_back("+sm4");
412       if (HasSHA3)
413         Features.push_back("+sha3");
414       if (HasSHA2)
415         Features.push_back("+sha2");
416       if (HasAES)
417         Features.push_back("+aes");
418     } else if (HasNoCrypto) {
419       // Check if we have NOT enabled a crypto algorithm with something like:
420       //   -crypto, +algorithm
421       // And if "+algorithm" does not occur, we disable that crypto algorithm.
422       const bool HasSM4  = (std::find(ItBegin, ItEnd, "+sm4") != ItEnd);
423       const bool HasSHA3 = (std::find(ItBegin, ItEnd, "+sha3") != ItEnd);
424       const bool HasSHA2 = (std::find(ItBegin, ItEnd, "+sha2") != ItEnd);
425       const bool HasAES  = (std::find(ItBegin, ItEnd, "+aes") != ItEnd);
426       if (!HasSM4)
427         Features.push_back("-sm4");
428       if (!HasSHA3)
429         Features.push_back("-sha3");
430       if (!HasSHA2)
431         Features.push_back("-sha2");
432       if (!HasAES)
433         Features.push_back("-aes");
434     }
435   } else {
436     if (HasCrypto && !NoCrypto) {
437       const bool HasSHA2 = (std::find(ItBegin, ItEnd, "-sha2") == ItEnd);
438       const bool HasAES = (std::find(ItBegin, ItEnd, "-aes") == ItEnd);
439       if (HasSHA2)
440         Features.push_back("+sha2");
441       if (HasAES)
442         Features.push_back("+aes");
443     } else if (HasNoCrypto) {
444       const bool HasSHA2 = (std::find(ItBegin, ItEnd, "+sha2") != ItEnd);
445       const bool HasAES  = (std::find(ItBegin, ItEnd, "+aes") != ItEnd);
446       const bool HasV82a = (std::find(ItBegin, ItEnd, "+v8.2a") != ItEnd);
447       const bool HasV83a = (std::find(ItBegin, ItEnd, "+v8.3a") != ItEnd);
448       const bool HasV84a = (std::find(ItBegin, ItEnd, "+v8.4a") != ItEnd);
449       if (!HasSHA2)
450         Features.push_back("-sha2");
451       if (!HasAES)
452         Features.push_back("-aes");
453       if (HasV82a || HasV83a || HasV84a) {
454         Features.push_back("-sm4");
455         Features.push_back("-sha3");
456       }
457     }
458   }
459 
460   const char *Archs[] = {"+v8.6a", "+v8.7a", "+v8.8a",
461                          "+v9.1a", "+v9.2a", "+v9.3a"};
462   auto Pos = std::find_first_of(Features.begin(), Features.end(),
463                                 std::begin(Archs), std::end(Archs));
464   if (Pos != std::end(Features))
465     Pos = Features.insert(std::next(Pos), {"+i8mm", "+bf16"});
466 
467   if (Arg *A = Args.getLastArg(options::OPT_mno_unaligned_access,
468                                options::OPT_munaligned_access)) {
469     if (A->getOption().matches(options::OPT_mno_unaligned_access)) {
470       Features.push_back("+strict-align");
471       if (!ForAS)
472         CmdArgs.push_back("-Wunaligned-access");
473     }
474   } else if (Triple.isOSOpenBSD()) {
475     Features.push_back("+strict-align");
476     if (!ForAS)
477       CmdArgs.push_back("-Wunaligned-access");
478   }
479 
480   if (Args.hasArg(options::OPT_ffixed_x1))
481     Features.push_back("+reserve-x1");
482 
483   if (Args.hasArg(options::OPT_ffixed_x2))
484     Features.push_back("+reserve-x2");
485 
486   if (Args.hasArg(options::OPT_ffixed_x3))
487     Features.push_back("+reserve-x3");
488 
489   if (Args.hasArg(options::OPT_ffixed_x4))
490     Features.push_back("+reserve-x4");
491 
492   if (Args.hasArg(options::OPT_ffixed_x5))
493     Features.push_back("+reserve-x5");
494 
495   if (Args.hasArg(options::OPT_ffixed_x6))
496     Features.push_back("+reserve-x6");
497 
498   if (Args.hasArg(options::OPT_ffixed_x7))
499     Features.push_back("+reserve-x7");
500 
501   if (Args.hasArg(options::OPT_ffixed_x9))
502     Features.push_back("+reserve-x9");
503 
504   if (Args.hasArg(options::OPT_ffixed_x10))
505     Features.push_back("+reserve-x10");
506 
507   if (Args.hasArg(options::OPT_ffixed_x11))
508     Features.push_back("+reserve-x11");
509 
510   if (Args.hasArg(options::OPT_ffixed_x12))
511     Features.push_back("+reserve-x12");
512 
513   if (Args.hasArg(options::OPT_ffixed_x13))
514     Features.push_back("+reserve-x13");
515 
516   if (Args.hasArg(options::OPT_ffixed_x14))
517     Features.push_back("+reserve-x14");
518 
519   if (Args.hasArg(options::OPT_ffixed_x15))
520     Features.push_back("+reserve-x15");
521 
522   if (Args.hasArg(options::OPT_ffixed_x18))
523     Features.push_back("+reserve-x18");
524 
525   if (Args.hasArg(options::OPT_ffixed_x20))
526     Features.push_back("+reserve-x20");
527 
528   if (Args.hasArg(options::OPT_ffixed_x21))
529     Features.push_back("+reserve-x21");
530 
531   if (Args.hasArg(options::OPT_ffixed_x22))
532     Features.push_back("+reserve-x22");
533 
534   if (Args.hasArg(options::OPT_ffixed_x23))
535     Features.push_back("+reserve-x23");
536 
537   if (Args.hasArg(options::OPT_ffixed_x24))
538     Features.push_back("+reserve-x24");
539 
540   if (Args.hasArg(options::OPT_ffixed_x25))
541     Features.push_back("+reserve-x25");
542 
543   if (Args.hasArg(options::OPT_ffixed_x26))
544     Features.push_back("+reserve-x26");
545 
546   if (Args.hasArg(options::OPT_ffixed_x27))
547     Features.push_back("+reserve-x27");
548 
549   if (Args.hasArg(options::OPT_ffixed_x28))
550     Features.push_back("+reserve-x28");
551 
552   if (Args.hasArg(options::OPT_ffixed_x30))
553     Features.push_back("+reserve-x30");
554 
555   if (Args.hasArg(options::OPT_fcall_saved_x8))
556     Features.push_back("+call-saved-x8");
557 
558   if (Args.hasArg(options::OPT_fcall_saved_x9))
559     Features.push_back("+call-saved-x9");
560 
561   if (Args.hasArg(options::OPT_fcall_saved_x10))
562     Features.push_back("+call-saved-x10");
563 
564   if (Args.hasArg(options::OPT_fcall_saved_x11))
565     Features.push_back("+call-saved-x11");
566 
567   if (Args.hasArg(options::OPT_fcall_saved_x12))
568     Features.push_back("+call-saved-x12");
569 
570   if (Args.hasArg(options::OPT_fcall_saved_x13))
571     Features.push_back("+call-saved-x13");
572 
573   if (Args.hasArg(options::OPT_fcall_saved_x14))
574     Features.push_back("+call-saved-x14");
575 
576   if (Args.hasArg(options::OPT_fcall_saved_x15))
577     Features.push_back("+call-saved-x15");
578 
579   if (Args.hasArg(options::OPT_fcall_saved_x18))
580     Features.push_back("+call-saved-x18");
581 
582   if (Args.hasArg(options::OPT_mno_neg_immediates))
583     Features.push_back("+no-neg-immediates");
584 
585   if (Arg *A = Args.getLastArg(options::OPT_mfix_cortex_a53_835769,
586                                options::OPT_mno_fix_cortex_a53_835769)) {
587     if (A->getOption().matches(options::OPT_mfix_cortex_a53_835769))
588       Features.push_back("+fix-cortex-a53-835769");
589     else
590       Features.push_back("-fix-cortex-a53-835769");
591   } else if (Triple.isAndroid()) {
592     // Enabled A53 errata (835769) workaround by default on android
593     Features.push_back("+fix-cortex-a53-835769");
594   }
595 
596   if (Args.getLastArg(options::OPT_mno_bti_at_return_twice))
597     Features.push_back("+no-bti-at-return-twice");
598 }
599