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.
isCPUDeterminedByTriple(const llvm::Triple & Triple)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.
getAArch64TargetCPU(const ArgList & Args,const llvm::Triple & Triple,Arg * & A)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+...
DecodeAArch64Features(const Driver & D,StringRef text,std::vector<StringRef> & Features,llvm::AArch64::ArchKind ArchKind)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.
DecodeAArch64Mcpu(const Driver & D,StringRef Mcpu,StringRef & CPU,std::vector<StringRef> & Features)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
getAArch64ArchFeaturesFromMarch(const Driver & D,StringRef March,const ArgList & Args,std::vector<StringRef> & Features)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
getAArch64ArchFeaturesFromMcpu(const Driver & D,StringRef Mcpu,const ArgList & Args,std::vector<StringRef> & Features)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
getAArch64MicroArchFeaturesFromMtune(const Driver & D,StringRef Mtune,const ArgList & Args,std::vector<StringRef> & Features)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
getAArch64MicroArchFeaturesFromMcpu(const Driver & D,StringRef Mcpu,const ArgList & Args,std::vector<StringRef> & Features)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
getAArch64TargetFeatures(const Driver & D,const llvm::Triple & Triple,const ArgList & Args,std::vector<StringRef> & Features)185 void aarch64::getAArch64TargetFeatures(const Driver &D,
186 const llvm::Triple &Triple,
187 const ArgList &Args,
188 std::vector<StringRef> &Features) {
189 Arg *A;
190 bool success = true;
191 // Enable NEON by default.
192 Features.push_back("+neon");
193 if ((A = Args.getLastArg(options::OPT_march_EQ)))
194 success = getAArch64ArchFeaturesFromMarch(D, A->getValue(), Args, Features);
195 else if ((A = Args.getLastArg(options::OPT_mcpu_EQ)))
196 success = getAArch64ArchFeaturesFromMcpu(D, A->getValue(), Args, Features);
197 else if (Args.hasArg(options::OPT_arch) || isCPUDeterminedByTriple(Triple))
198 success = getAArch64ArchFeaturesFromMcpu(
199 D, getAArch64TargetCPU(Args, Triple, A), Args, Features);
200
201 if (success && (A = Args.getLastArg(clang::driver::options::OPT_mtune_EQ)))
202 success =
203 getAArch64MicroArchFeaturesFromMtune(D, A->getValue(), Args, Features);
204 else if (success && (A = Args.getLastArg(options::OPT_mcpu_EQ)))
205 success =
206 getAArch64MicroArchFeaturesFromMcpu(D, A->getValue(), Args, Features);
207 else if (success &&
208 (Args.hasArg(options::OPT_arch) || isCPUDeterminedByTriple(Triple)))
209 success = getAArch64MicroArchFeaturesFromMcpu(
210 D, getAArch64TargetCPU(Args, Triple, A), Args, Features);
211
212 if (!success)
213 D.Diag(diag::err_drv_clang_unsupported) << A->getAsString(Args);
214
215 if (Args.getLastArg(options::OPT_mgeneral_regs_only)) {
216 Features.push_back("-fp-armv8");
217 Features.push_back("-crypto");
218 Features.push_back("-neon");
219 }
220
221 if (Arg *A = Args.getLastArg(options::OPT_mtp_mode_EQ)) {
222 StringRef Mtp = A->getValue();
223 if (Mtp == "el3")
224 Features.push_back("+tpidr-el3");
225 else if (Mtp == "el2")
226 Features.push_back("+tpidr-el2");
227 else if (Mtp == "el1")
228 Features.push_back("+tpidr-el1");
229 else if (Mtp != "el0")
230 D.Diag(diag::err_drv_invalid_mtp) << A->getAsString(Args);
231 }
232
233 // Enable/disable straight line speculation hardening.
234 if (Arg *A = Args.getLastArg(options::OPT_mharden_sls_EQ)) {
235 StringRef Scope = A->getValue();
236 bool EnableRetBr = false;
237 bool EnableBlr = false;
238 bool DisableComdat = false;
239 if (Scope != "none") {
240 SmallVector<StringRef, 4> Opts;
241 Scope.split(Opts, ",");
242 for (auto Opt : Opts) {
243 Opt = Opt.trim();
244 if (Opt == "all") {
245 EnableBlr = true;
246 EnableRetBr = true;
247 continue;
248 }
249 if (Opt == "retbr") {
250 EnableRetBr = true;
251 continue;
252 }
253 if (Opt == "blr") {
254 EnableBlr = true;
255 continue;
256 }
257 if (Opt == "comdat") {
258 DisableComdat = false;
259 continue;
260 }
261 if (Opt == "nocomdat") {
262 DisableComdat = true;
263 continue;
264 }
265 D.Diag(diag::err_invalid_sls_hardening)
266 << Scope << A->getAsString(Args);
267 break;
268 }
269 }
270
271 if (EnableRetBr)
272 Features.push_back("+harden-sls-retbr");
273 if (EnableBlr)
274 Features.push_back("+harden-sls-blr");
275 if (DisableComdat) {
276 Features.push_back("+harden-sls-nocomdat");
277 }
278 }
279
280 // En/disable crc
281 if (Arg *A = Args.getLastArg(options::OPT_mcrc, options::OPT_mnocrc)) {
282 if (A->getOption().matches(options::OPT_mcrc))
283 Features.push_back("+crc");
284 else
285 Features.push_back("-crc");
286 }
287
288 // Handle (arch-dependent) fp16fml/fullfp16 relationship.
289 // FIXME: this fp16fml option handling will be reimplemented after the
290 // TargetParser rewrite.
291 const auto ItRNoFullFP16 = std::find(Features.rbegin(), Features.rend(), "-fullfp16");
292 const auto ItRFP16FML = std::find(Features.rbegin(), Features.rend(), "+fp16fml");
293 if (llvm::is_contained(Features, "+v8.4a")) {
294 const auto ItRFullFP16 = std::find(Features.rbegin(), Features.rend(), "+fullfp16");
295 if (ItRFullFP16 < ItRNoFullFP16 && ItRFullFP16 < ItRFP16FML) {
296 // Only entangled feature that can be to the right of this +fullfp16 is -fp16fml.
297 // Only append the +fp16fml if there is no -fp16fml after the +fullfp16.
298 if (std::find(Features.rbegin(), ItRFullFP16, "-fp16fml") == ItRFullFP16)
299 Features.push_back("+fp16fml");
300 }
301 else
302 goto fp16_fml_fallthrough;
303 } else {
304 fp16_fml_fallthrough:
305 // In both of these cases, putting the 'other' feature on the end of the vector will
306 // result in the same effect as placing it immediately after the current feature.
307 if (ItRNoFullFP16 < ItRFP16FML)
308 Features.push_back("-fp16fml");
309 else if (ItRNoFullFP16 > ItRFP16FML)
310 Features.push_back("+fullfp16");
311 }
312
313 // FIXME: this needs reimplementation too after the TargetParser rewrite
314 //
315 // Context sensitive meaning of Crypto:
316 // 1) For Arch >= ARMv8.4a: crypto = sm4 + sha3 + sha2 + aes
317 // 2) For Arch <= ARMv8.3a: crypto = sha2 + aes
318 const auto ItBegin = Features.begin();
319 const auto ItEnd = Features.end();
320 const auto ItRBegin = Features.rbegin();
321 const auto ItREnd = Features.rend();
322 const auto ItRCrypto = std::find(ItRBegin, ItREnd, "+crypto");
323 const auto ItRNoCrypto = std::find(ItRBegin, ItREnd, "-crypto");
324 const auto HasCrypto = ItRCrypto != ItREnd;
325 const auto HasNoCrypto = ItRNoCrypto != ItREnd;
326 const ptrdiff_t PosCrypto = ItRCrypto - ItRBegin;
327 const ptrdiff_t PosNoCrypto = ItRNoCrypto - ItRBegin;
328
329 bool NoCrypto = false;
330 if (HasCrypto && HasNoCrypto) {
331 if (PosNoCrypto < PosCrypto)
332 NoCrypto = true;
333 }
334
335 if (std::find(ItBegin, ItEnd, "+v8.4a") != ItEnd) {
336 if (HasCrypto && !NoCrypto) {
337 // Check if we have NOT disabled an algorithm with something like:
338 // +crypto, -algorithm
339 // And if "-algorithm" does not occur, we enable that crypto algorithm.
340 const bool HasSM4 = (std::find(ItBegin, ItEnd, "-sm4") == ItEnd);
341 const bool HasSHA3 = (std::find(ItBegin, ItEnd, "-sha3") == ItEnd);
342 const bool HasSHA2 = (std::find(ItBegin, ItEnd, "-sha2") == ItEnd);
343 const bool HasAES = (std::find(ItBegin, ItEnd, "-aes") == ItEnd);
344 if (HasSM4)
345 Features.push_back("+sm4");
346 if (HasSHA3)
347 Features.push_back("+sha3");
348 if (HasSHA2)
349 Features.push_back("+sha2");
350 if (HasAES)
351 Features.push_back("+aes");
352 } else if (HasNoCrypto) {
353 // Check if we have NOT enabled a crypto algorithm with something like:
354 // -crypto, +algorithm
355 // And if "+algorithm" does not occur, we disable that crypto algorithm.
356 const bool HasSM4 = (std::find(ItBegin, ItEnd, "+sm4") != ItEnd);
357 const bool HasSHA3 = (std::find(ItBegin, ItEnd, "+sha3") != ItEnd);
358 const bool HasSHA2 = (std::find(ItBegin, ItEnd, "+sha2") != ItEnd);
359 const bool HasAES = (std::find(ItBegin, ItEnd, "+aes") != ItEnd);
360 if (!HasSM4)
361 Features.push_back("-sm4");
362 if (!HasSHA3)
363 Features.push_back("-sha3");
364 if (!HasSHA2)
365 Features.push_back("-sha2");
366 if (!HasAES)
367 Features.push_back("-aes");
368 }
369 } else {
370 if (HasCrypto && !NoCrypto) {
371 const bool HasSHA2 = (std::find(ItBegin, ItEnd, "-sha2") == ItEnd);
372 const bool HasAES = (std::find(ItBegin, ItEnd, "-aes") == ItEnd);
373 if (HasSHA2)
374 Features.push_back("+sha2");
375 if (HasAES)
376 Features.push_back("+aes");
377 } else if (HasNoCrypto) {
378 const bool HasSHA2 = (std::find(ItBegin, ItEnd, "+sha2") != ItEnd);
379 const bool HasAES = (std::find(ItBegin, ItEnd, "+aes") != ItEnd);
380 const bool HasV82a = (std::find(ItBegin, ItEnd, "+v8.2a") != ItEnd);
381 const bool HasV83a = (std::find(ItBegin, ItEnd, "+v8.3a") != ItEnd);
382 const bool HasV84a = (std::find(ItBegin, ItEnd, "+v8.4a") != ItEnd);
383 if (!HasSHA2)
384 Features.push_back("-sha2");
385 if (!HasAES)
386 Features.push_back("-aes");
387 if (HasV82a || HasV83a || HasV84a) {
388 Features.push_back("-sm4");
389 Features.push_back("-sha3");
390 }
391 }
392 }
393
394 auto V8_6Pos = llvm::find(Features, "+v8.6a");
395 if (V8_6Pos != std::end(Features))
396 V8_6Pos = Features.insert(std::next(V8_6Pos), {"+i8mm", "+bf16"});
397
398 if (Arg *A = Args.getLastArg(options::OPT_mno_unaligned_access,
399 options::OPT_munaligned_access)) {
400 if (A->getOption().matches(options::OPT_mno_unaligned_access))
401 Features.push_back("+strict-align");
402 } else if (Triple.isOSOpenBSD())
403 Features.push_back("+strict-align");
404
405 if (Args.hasArg(options::OPT_ffixed_x1))
406 Features.push_back("+reserve-x1");
407
408 if (Args.hasArg(options::OPT_ffixed_x2))
409 Features.push_back("+reserve-x2");
410
411 if (Args.hasArg(options::OPT_ffixed_x3))
412 Features.push_back("+reserve-x3");
413
414 if (Args.hasArg(options::OPT_ffixed_x4))
415 Features.push_back("+reserve-x4");
416
417 if (Args.hasArg(options::OPT_ffixed_x5))
418 Features.push_back("+reserve-x5");
419
420 if (Args.hasArg(options::OPT_ffixed_x6))
421 Features.push_back("+reserve-x6");
422
423 if (Args.hasArg(options::OPT_ffixed_x7))
424 Features.push_back("+reserve-x7");
425
426 if (Args.hasArg(options::OPT_ffixed_x9))
427 Features.push_back("+reserve-x9");
428
429 if (Args.hasArg(options::OPT_ffixed_x10))
430 Features.push_back("+reserve-x10");
431
432 if (Args.hasArg(options::OPT_ffixed_x11))
433 Features.push_back("+reserve-x11");
434
435 if (Args.hasArg(options::OPT_ffixed_x12))
436 Features.push_back("+reserve-x12");
437
438 if (Args.hasArg(options::OPT_ffixed_x13))
439 Features.push_back("+reserve-x13");
440
441 if (Args.hasArg(options::OPT_ffixed_x14))
442 Features.push_back("+reserve-x14");
443
444 if (Args.hasArg(options::OPT_ffixed_x15))
445 Features.push_back("+reserve-x15");
446
447 if (Args.hasArg(options::OPT_ffixed_x18))
448 Features.push_back("+reserve-x18");
449
450 if (Args.hasArg(options::OPT_ffixed_x20))
451 Features.push_back("+reserve-x20");
452
453 if (Args.hasArg(options::OPT_ffixed_x21))
454 Features.push_back("+reserve-x21");
455
456 if (Args.hasArg(options::OPT_ffixed_x22))
457 Features.push_back("+reserve-x22");
458
459 if (Args.hasArg(options::OPT_ffixed_x23))
460 Features.push_back("+reserve-x23");
461
462 if (Args.hasArg(options::OPT_ffixed_x24))
463 Features.push_back("+reserve-x24");
464
465 if (Args.hasArg(options::OPT_ffixed_x25))
466 Features.push_back("+reserve-x25");
467
468 if (Args.hasArg(options::OPT_ffixed_x26))
469 Features.push_back("+reserve-x26");
470
471 if (Args.hasArg(options::OPT_ffixed_x27))
472 Features.push_back("+reserve-x27");
473
474 if (Args.hasArg(options::OPT_ffixed_x28))
475 Features.push_back("+reserve-x28");
476
477 if (Args.hasArg(options::OPT_ffixed_x30))
478 Features.push_back("+reserve-x30");
479
480 if (Args.hasArg(options::OPT_fcall_saved_x8))
481 Features.push_back("+call-saved-x8");
482
483 if (Args.hasArg(options::OPT_fcall_saved_x9))
484 Features.push_back("+call-saved-x9");
485
486 if (Args.hasArg(options::OPT_fcall_saved_x10))
487 Features.push_back("+call-saved-x10");
488
489 if (Args.hasArg(options::OPT_fcall_saved_x11))
490 Features.push_back("+call-saved-x11");
491
492 if (Args.hasArg(options::OPT_fcall_saved_x12))
493 Features.push_back("+call-saved-x12");
494
495 if (Args.hasArg(options::OPT_fcall_saved_x13))
496 Features.push_back("+call-saved-x13");
497
498 if (Args.hasArg(options::OPT_fcall_saved_x14))
499 Features.push_back("+call-saved-x14");
500
501 if (Args.hasArg(options::OPT_fcall_saved_x15))
502 Features.push_back("+call-saved-x15");
503
504 if (Args.hasArg(options::OPT_fcall_saved_x18))
505 Features.push_back("+call-saved-x18");
506
507 if (Args.hasArg(options::OPT_mno_neg_immediates))
508 Features.push_back("+no-neg-immediates");
509 }
510