xref: /freebsd/contrib/llvm-project/clang/lib/Driver/ToolChains/Arch/AArch64.cpp (revision d11f81afd5a4a71d5f725950b0592ca212084780)
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/TargetParser.h"
15 #include "llvm/Support/Host.h"
16 
17 using namespace clang::driver;
18 using namespace clang::driver::tools;
19 using namespace clang;
20 using namespace llvm::opt;
21 
22 /// \returns true if the given triple can determine the default CPU type even
23 /// if -arch is not specified.
24 static bool isCPUDeterminedByTriple(const llvm::Triple &Triple) {
25   return Triple.isOSDarwin();
26 }
27 
28 /// getAArch64TargetCPU - Get the (LLVM) name of the AArch64 cpu we are
29 /// targeting. Set \p A to the Arg corresponding to the -mcpu argument if it is
30 /// provided, or to nullptr otherwise.
31 std::string aarch64::getAArch64TargetCPU(const ArgList &Args,
32                                          const llvm::Triple &Triple, Arg *&A) {
33   std::string CPU;
34   // If we have -mcpu, use that.
35   if ((A = Args.getLastArg(options::OPT_mcpu_EQ))) {
36     StringRef Mcpu = A->getValue();
37     CPU = Mcpu.split("+").first.lower();
38   }
39 
40   // Handle CPU name is 'native'.
41   if (CPU == "native")
42     return std::string(llvm::sys::getHostCPUName());
43 
44   if (CPU.size())
45     return CPU;
46 
47   if (Triple.isTargetMachineMac() &&
48       Triple.getArch() == llvm::Triple::aarch64) {
49     // Apple Silicon macs default to M1 CPUs.
50     return "apple-m1";
51   }
52 
53   // arm64e requires v8.3a and only runs on apple-a12 and later CPUs.
54   if (Triple.isArm64e())
55     return "apple-a12";
56 
57   // Make sure we pick the appropriate Apple CPU if -arch is used or when
58   // targetting a Darwin OS.
59   if (Args.getLastArg(options::OPT_arch) || Triple.isOSDarwin())
60     return Triple.getArch() == llvm::Triple::aarch64_32 ? "apple-s4"
61                                                         : "apple-a7";
62 
63   return "generic";
64 }
65 
66 // Decode AArch64 features from string like +[no]featureA+[no]featureB+...
67 static bool DecodeAArch64Features(const Driver &D, StringRef text,
68                                   std::vector<StringRef> &Features,
69                                   llvm::AArch64::ArchKind ArchKind) {
70   SmallVector<StringRef, 8> Split;
71   text.split(Split, StringRef("+"), -1, false);
72 
73   for (StringRef Feature : Split) {
74     StringRef FeatureName = llvm::AArch64::getArchExtFeature(Feature);
75     if (!FeatureName.empty())
76       Features.push_back(FeatureName);
77     else if (Feature == "neon" || Feature == "noneon")
78       D.Diag(clang::diag::err_drv_no_neon_modifier);
79     else
80       return false;
81 
82     // +sve implies +f32mm if the base architecture is v8.6A or v8.7A
83     // it isn't the case in general that sve implies both f64mm and f32mm
84     if ((ArchKind == llvm::AArch64::ArchKind::ARMV8_6A ||
85          ArchKind == llvm::AArch64::ArchKind::ARMV8_7A) && Feature == "sve")
86       Features.push_back("+f32mm");
87   }
88   return true;
89 }
90 
91 // Check if the CPU name and feature modifiers in -mcpu are legal. If yes,
92 // decode CPU and feature.
93 static bool DecodeAArch64Mcpu(const Driver &D, StringRef Mcpu, StringRef &CPU,
94                               std::vector<StringRef> &Features) {
95   std::pair<StringRef, StringRef> Split = Mcpu.split("+");
96   CPU = Split.first;
97   llvm::AArch64::ArchKind ArchKind = llvm::AArch64::ArchKind::ARMV8A;
98 
99   if (CPU == "native")
100     CPU = llvm::sys::getHostCPUName();
101 
102   if (CPU == "generic") {
103     Features.push_back("+neon");
104   } else {
105     ArchKind = llvm::AArch64::parseCPUArch(CPU);
106     if (!llvm::AArch64::getArchFeatures(ArchKind, Features))
107       return false;
108 
109     uint64_t Extension = llvm::AArch64::getDefaultExtensions(CPU, ArchKind);
110     if (!llvm::AArch64::getExtensionFeatures(Extension, Features))
111       return false;
112    }
113 
114    if (Split.second.size() &&
115        !DecodeAArch64Features(D, Split.second, Features, ArchKind))
116      return false;
117 
118    return true;
119 }
120 
121 static bool
122 getAArch64ArchFeaturesFromMarch(const Driver &D, StringRef March,
123                                 const ArgList &Args,
124                                 std::vector<StringRef> &Features) {
125   std::string MarchLowerCase = March.lower();
126   std::pair<StringRef, StringRef> Split = StringRef(MarchLowerCase).split("+");
127 
128   llvm::AArch64::ArchKind ArchKind = llvm::AArch64::parseArch(Split.first);
129   if (ArchKind == llvm::AArch64::ArchKind::INVALID ||
130       !llvm::AArch64::getArchFeatures(ArchKind, Features) ||
131       (Split.second.size() &&
132        !DecodeAArch64Features(D, Split.second, Features, ArchKind)))
133     return false;
134 
135   return true;
136 }
137 
138 static bool
139 getAArch64ArchFeaturesFromMcpu(const Driver &D, StringRef Mcpu,
140                                const ArgList &Args,
141                                std::vector<StringRef> &Features) {
142   StringRef CPU;
143   std::string McpuLowerCase = Mcpu.lower();
144   if (!DecodeAArch64Mcpu(D, McpuLowerCase, CPU, Features))
145     return false;
146 
147   return true;
148 }
149 
150 static bool
151 getAArch64MicroArchFeaturesFromMtune(const Driver &D, StringRef Mtune,
152                                      const ArgList &Args,
153                                      std::vector<StringRef> &Features) {
154   std::string MtuneLowerCase = Mtune.lower();
155   // Check CPU name is valid
156   std::vector<StringRef> MtuneFeatures;
157   StringRef Tune;
158   if (!DecodeAArch64Mcpu(D, MtuneLowerCase, Tune, MtuneFeatures))
159     return false;
160 
161   // Handle CPU name is 'native'.
162   if (MtuneLowerCase == "native")
163     MtuneLowerCase = std::string(llvm::sys::getHostCPUName());
164   if (MtuneLowerCase == "cyclone" ||
165       StringRef(MtuneLowerCase).startswith("apple")) {
166     Features.push_back("+zcm");
167     Features.push_back("+zcz");
168   }
169   return true;
170 }
171 
172 static bool
173 getAArch64MicroArchFeaturesFromMcpu(const Driver &D, StringRef Mcpu,
174                                     const ArgList &Args,
175                                     std::vector<StringRef> &Features) {
176   StringRef CPU;
177   std::vector<StringRef> DecodedFeature;
178   std::string McpuLowerCase = Mcpu.lower();
179   if (!DecodeAArch64Mcpu(D, McpuLowerCase, CPU, DecodedFeature))
180     return false;
181 
182   return getAArch64MicroArchFeaturesFromMtune(D, CPU, Args, Features);
183 }
184 
185 void aarch64::getAArch64TargetFeatures(const Driver &D,
186                                        const llvm::Triple &Triple,
187                                        const ArgList &Args,
188                                        std::vector<StringRef> &Features,
189                                        bool ForAS) {
190   Arg *A;
191   bool success = true;
192   // Enable NEON by default.
193   Features.push_back("+neon");
194   llvm::StringRef WaMArch;
195   if (ForAS)
196     for (const auto *A :
197          Args.filtered(options::OPT_Wa_COMMA, options::OPT_Xassembler))
198       for (StringRef Value : A->getValues())
199         if (Value.startswith("-march="))
200           WaMArch = Value.substr(7);
201   // Call getAArch64ArchFeaturesFromMarch only if "-Wa,-march=" or
202   // "-Xassembler -march" is detected. Otherwise it may return false
203   // and causes Clang to error out.
204   if (!WaMArch.empty())
205     success = getAArch64ArchFeaturesFromMarch(D, WaMArch, Args, Features);
206   else if ((A = Args.getLastArg(options::OPT_march_EQ)))
207     success = getAArch64ArchFeaturesFromMarch(D, A->getValue(), Args, Features);
208   else if ((A = Args.getLastArg(options::OPT_mcpu_EQ)))
209     success = getAArch64ArchFeaturesFromMcpu(D, A->getValue(), Args, Features);
210   else if (Args.hasArg(options::OPT_arch) || isCPUDeterminedByTriple(Triple))
211     success = getAArch64ArchFeaturesFromMcpu(
212         D, getAArch64TargetCPU(Args, Triple, A), Args, Features);
213 
214   if (success && (A = Args.getLastArg(clang::driver::options::OPT_mtune_EQ)))
215     success =
216         getAArch64MicroArchFeaturesFromMtune(D, A->getValue(), Args, Features);
217   else if (success && (A = Args.getLastArg(options::OPT_mcpu_EQ)))
218     success =
219         getAArch64MicroArchFeaturesFromMcpu(D, A->getValue(), Args, Features);
220   else if (success &&
221            (Args.hasArg(options::OPT_arch) || isCPUDeterminedByTriple(Triple)))
222     success = getAArch64MicroArchFeaturesFromMcpu(
223         D, getAArch64TargetCPU(Args, Triple, A), Args, Features);
224 
225   if (!success) {
226     auto Diag = D.Diag(diag::err_drv_clang_unsupported);
227     // If "-Wa,-march=" is used, 'WaMArch' will contain the argument's value,
228     // while 'A' is uninitialized. Only dereference 'A' in the other case.
229     if (!WaMArch.empty())
230       Diag << "-march=" + WaMArch.str();
231     else
232       Diag << A->getAsString(Args);
233   }
234 
235   if (Args.getLastArg(options::OPT_mgeneral_regs_only)) {
236     Features.push_back("-fp-armv8");
237     Features.push_back("-crypto");
238     Features.push_back("-neon");
239   }
240 
241   if (Arg *A = Args.getLastArg(options::OPT_mtp_mode_EQ)) {
242     StringRef Mtp = A->getValue();
243     if (Mtp == "el3")
244       Features.push_back("+tpidr-el3");
245     else if (Mtp == "el2")
246       Features.push_back("+tpidr-el2");
247     else if (Mtp == "el1")
248       Features.push_back("+tpidr-el1");
249     else if (Mtp != "el0")
250       D.Diag(diag::err_drv_invalid_mtp) << A->getAsString(Args);
251   }
252 
253   // Enable/disable straight line speculation hardening.
254   if (Arg *A = Args.getLastArg(options::OPT_mharden_sls_EQ)) {
255     StringRef Scope = A->getValue();
256     bool EnableRetBr = false;
257     bool EnableBlr = false;
258     bool DisableComdat = false;
259     if (Scope != "none") {
260       SmallVector<StringRef, 4> Opts;
261       Scope.split(Opts, ",");
262       for (auto Opt : Opts) {
263         Opt = Opt.trim();
264         if (Opt == "all") {
265           EnableBlr = true;
266           EnableRetBr = true;
267           continue;
268         }
269         if (Opt == "retbr") {
270           EnableRetBr = true;
271           continue;
272         }
273         if (Opt == "blr") {
274           EnableBlr = true;
275           continue;
276         }
277         if (Opt == "comdat") {
278           DisableComdat = false;
279           continue;
280         }
281         if (Opt == "nocomdat") {
282           DisableComdat = true;
283           continue;
284         }
285         D.Diag(diag::err_invalid_sls_hardening)
286             << Scope << A->getAsString(Args);
287         break;
288       }
289     }
290 
291     if (EnableRetBr)
292       Features.push_back("+harden-sls-retbr");
293     if (EnableBlr)
294       Features.push_back("+harden-sls-blr");
295     if (DisableComdat) {
296       Features.push_back("+harden-sls-nocomdat");
297     }
298   }
299 
300   // En/disable crc
301   if (Arg *A = Args.getLastArg(options::OPT_mcrc, options::OPT_mnocrc)) {
302     if (A->getOption().matches(options::OPT_mcrc))
303       Features.push_back("+crc");
304     else
305       Features.push_back("-crc");
306   }
307 
308   // Handle (arch-dependent) fp16fml/fullfp16 relationship.
309   // FIXME: this fp16fml option handling will be reimplemented after the
310   // TargetParser rewrite.
311   const auto ItRNoFullFP16 = std::find(Features.rbegin(), Features.rend(), "-fullfp16");
312   const auto ItRFP16FML = std::find(Features.rbegin(), Features.rend(), "+fp16fml");
313   if (llvm::is_contained(Features, "+v8.4a")) {
314     const auto ItRFullFP16  = std::find(Features.rbegin(), Features.rend(), "+fullfp16");
315     if (ItRFullFP16 < ItRNoFullFP16 && ItRFullFP16 < ItRFP16FML) {
316       // Only entangled feature that can be to the right of this +fullfp16 is -fp16fml.
317       // Only append the +fp16fml if there is no -fp16fml after the +fullfp16.
318       if (std::find(Features.rbegin(), ItRFullFP16, "-fp16fml") == ItRFullFP16)
319         Features.push_back("+fp16fml");
320     }
321     else
322       goto fp16_fml_fallthrough;
323   } else {
324 fp16_fml_fallthrough:
325     // In both of these cases, putting the 'other' feature on the end of the vector will
326     // result in the same effect as placing it immediately after the current feature.
327     if (ItRNoFullFP16 < ItRFP16FML)
328       Features.push_back("-fp16fml");
329     else if (ItRNoFullFP16 > ItRFP16FML)
330       Features.push_back("+fullfp16");
331   }
332 
333   // FIXME: this needs reimplementation too after the TargetParser rewrite
334   //
335   // Context sensitive meaning of Crypto:
336   // 1) For Arch >= ARMv8.4a:  crypto = sm4 + sha3 + sha2 + aes
337   // 2) For Arch <= ARMv8.3a:  crypto = sha2 + aes
338   const auto ItBegin = Features.begin();
339   const auto ItEnd = Features.end();
340   const auto ItRBegin = Features.rbegin();
341   const auto ItREnd = Features.rend();
342   const auto ItRCrypto = std::find(ItRBegin, ItREnd, "+crypto");
343   const auto ItRNoCrypto = std::find(ItRBegin, ItREnd, "-crypto");
344   const auto HasCrypto  = ItRCrypto != ItREnd;
345   const auto HasNoCrypto = ItRNoCrypto != ItREnd;
346   const ptrdiff_t PosCrypto = ItRCrypto - ItRBegin;
347   const ptrdiff_t PosNoCrypto = ItRNoCrypto - ItRBegin;
348 
349   bool NoCrypto = false;
350   if (HasCrypto && HasNoCrypto) {
351     if (PosNoCrypto < PosCrypto)
352       NoCrypto = true;
353   }
354 
355   if (std::find(ItBegin, ItEnd, "+v8.4a") != ItEnd) {
356     if (HasCrypto && !NoCrypto) {
357       // Check if we have NOT disabled an algorithm with something like:
358       //   +crypto, -algorithm
359       // And if "-algorithm" does not occur, we enable that crypto algorithm.
360       const bool HasSM4  = (std::find(ItBegin, ItEnd, "-sm4") == ItEnd);
361       const bool HasSHA3 = (std::find(ItBegin, ItEnd, "-sha3") == ItEnd);
362       const bool HasSHA2 = (std::find(ItBegin, ItEnd, "-sha2") == ItEnd);
363       const bool HasAES  = (std::find(ItBegin, ItEnd, "-aes") == ItEnd);
364       if (HasSM4)
365         Features.push_back("+sm4");
366       if (HasSHA3)
367         Features.push_back("+sha3");
368       if (HasSHA2)
369         Features.push_back("+sha2");
370       if (HasAES)
371         Features.push_back("+aes");
372     } else if (HasNoCrypto) {
373       // Check if we have NOT enabled a crypto algorithm with something like:
374       //   -crypto, +algorithm
375       // And if "+algorithm" does not occur, we disable that crypto algorithm.
376       const bool HasSM4  = (std::find(ItBegin, ItEnd, "+sm4") != ItEnd);
377       const bool HasSHA3 = (std::find(ItBegin, ItEnd, "+sha3") != ItEnd);
378       const bool HasSHA2 = (std::find(ItBegin, ItEnd, "+sha2") != ItEnd);
379       const bool HasAES  = (std::find(ItBegin, ItEnd, "+aes") != ItEnd);
380       if (!HasSM4)
381         Features.push_back("-sm4");
382       if (!HasSHA3)
383         Features.push_back("-sha3");
384       if (!HasSHA2)
385         Features.push_back("-sha2");
386       if (!HasAES)
387         Features.push_back("-aes");
388     }
389   } else {
390     if (HasCrypto && !NoCrypto) {
391       const bool HasSHA2 = (std::find(ItBegin, ItEnd, "-sha2") == ItEnd);
392       const bool HasAES = (std::find(ItBegin, ItEnd, "-aes") == ItEnd);
393       if (HasSHA2)
394         Features.push_back("+sha2");
395       if (HasAES)
396         Features.push_back("+aes");
397     } else if (HasNoCrypto) {
398       const bool HasSHA2 = (std::find(ItBegin, ItEnd, "+sha2") != ItEnd);
399       const bool HasAES  = (std::find(ItBegin, ItEnd, "+aes") != ItEnd);
400       const bool HasV82a = (std::find(ItBegin, ItEnd, "+v8.2a") != ItEnd);
401       const bool HasV83a = (std::find(ItBegin, ItEnd, "+v8.3a") != ItEnd);
402       const bool HasV84a = (std::find(ItBegin, ItEnd, "+v8.4a") != ItEnd);
403       if (!HasSHA2)
404         Features.push_back("-sha2");
405       if (!HasAES)
406         Features.push_back("-aes");
407       if (HasV82a || HasV83a || HasV84a) {
408         Features.push_back("-sm4");
409         Features.push_back("-sha3");
410       }
411     }
412   }
413 
414   auto V8_6Pos = llvm::find(Features, "+v8.6a");
415   if (V8_6Pos != std::end(Features))
416     V8_6Pos = Features.insert(std::next(V8_6Pos), {"+i8mm", "+bf16"});
417 
418   if (Arg *A = Args.getLastArg(options::OPT_mno_unaligned_access,
419                                options::OPT_munaligned_access)) {
420     if (A->getOption().matches(options::OPT_mno_unaligned_access))
421       Features.push_back("+strict-align");
422   } else if (Triple.isOSOpenBSD())
423     Features.push_back("+strict-align");
424 
425   if (Args.hasArg(options::OPT_ffixed_x1))
426     Features.push_back("+reserve-x1");
427 
428   if (Args.hasArg(options::OPT_ffixed_x2))
429     Features.push_back("+reserve-x2");
430 
431   if (Args.hasArg(options::OPT_ffixed_x3))
432     Features.push_back("+reserve-x3");
433 
434   if (Args.hasArg(options::OPT_ffixed_x4))
435     Features.push_back("+reserve-x4");
436 
437   if (Args.hasArg(options::OPT_ffixed_x5))
438     Features.push_back("+reserve-x5");
439 
440   if (Args.hasArg(options::OPT_ffixed_x6))
441     Features.push_back("+reserve-x6");
442 
443   if (Args.hasArg(options::OPT_ffixed_x7))
444     Features.push_back("+reserve-x7");
445 
446   if (Args.hasArg(options::OPT_ffixed_x9))
447     Features.push_back("+reserve-x9");
448 
449   if (Args.hasArg(options::OPT_ffixed_x10))
450     Features.push_back("+reserve-x10");
451 
452   if (Args.hasArg(options::OPT_ffixed_x11))
453     Features.push_back("+reserve-x11");
454 
455   if (Args.hasArg(options::OPT_ffixed_x12))
456     Features.push_back("+reserve-x12");
457 
458   if (Args.hasArg(options::OPT_ffixed_x13))
459     Features.push_back("+reserve-x13");
460 
461   if (Args.hasArg(options::OPT_ffixed_x14))
462     Features.push_back("+reserve-x14");
463 
464   if (Args.hasArg(options::OPT_ffixed_x15))
465     Features.push_back("+reserve-x15");
466 
467   if (Args.hasArg(options::OPT_ffixed_x18))
468     Features.push_back("+reserve-x18");
469 
470   if (Args.hasArg(options::OPT_ffixed_x20))
471     Features.push_back("+reserve-x20");
472 
473   if (Args.hasArg(options::OPT_ffixed_x21))
474     Features.push_back("+reserve-x21");
475 
476   if (Args.hasArg(options::OPT_ffixed_x22))
477     Features.push_back("+reserve-x22");
478 
479   if (Args.hasArg(options::OPT_ffixed_x23))
480     Features.push_back("+reserve-x23");
481 
482   if (Args.hasArg(options::OPT_ffixed_x24))
483     Features.push_back("+reserve-x24");
484 
485   if (Args.hasArg(options::OPT_ffixed_x25))
486     Features.push_back("+reserve-x25");
487 
488   if (Args.hasArg(options::OPT_ffixed_x26))
489     Features.push_back("+reserve-x26");
490 
491   if (Args.hasArg(options::OPT_ffixed_x27))
492     Features.push_back("+reserve-x27");
493 
494   if (Args.hasArg(options::OPT_ffixed_x28))
495     Features.push_back("+reserve-x28");
496 
497   if (Args.hasArg(options::OPT_ffixed_x30))
498     Features.push_back("+reserve-x30");
499 
500   if (Args.hasArg(options::OPT_fcall_saved_x8))
501     Features.push_back("+call-saved-x8");
502 
503   if (Args.hasArg(options::OPT_fcall_saved_x9))
504     Features.push_back("+call-saved-x9");
505 
506   if (Args.hasArg(options::OPT_fcall_saved_x10))
507     Features.push_back("+call-saved-x10");
508 
509   if (Args.hasArg(options::OPT_fcall_saved_x11))
510     Features.push_back("+call-saved-x11");
511 
512   if (Args.hasArg(options::OPT_fcall_saved_x12))
513     Features.push_back("+call-saved-x12");
514 
515   if (Args.hasArg(options::OPT_fcall_saved_x13))
516     Features.push_back("+call-saved-x13");
517 
518   if (Args.hasArg(options::OPT_fcall_saved_x14))
519     Features.push_back("+call-saved-x14");
520 
521   if (Args.hasArg(options::OPT_fcall_saved_x15))
522     Features.push_back("+call-saved-x15");
523 
524   if (Args.hasArg(options::OPT_fcall_saved_x18))
525     Features.push_back("+call-saved-x18");
526 
527   if (Args.hasArg(options::OPT_mno_neg_immediates))
528     Features.push_back("+no-neg-immediates");
529 }
530