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 llvm::sys::getHostCPUName();
43   else if (CPU.size())
44     return CPU;
45 
46   // Make sure we pick the appropriate Apple CPU if -arch is used or when
47   // targetting a Darwin OS.
48   if (Args.getLastArg(options::OPT_arch) || Triple.isOSDarwin())
49     return Triple.getArch() == llvm::Triple::aarch64_32 ? "apple-s4"
50                                                         : "apple-a7";
51 
52   return "generic";
53 }
54 
55 // Decode AArch64 features from string like +[no]featureA+[no]featureB+...
56 static bool DecodeAArch64Features(const Driver &D, StringRef text,
57                                   std::vector<StringRef> &Features) {
58   SmallVector<StringRef, 8> Split;
59   text.split(Split, StringRef("+"), -1, false);
60 
61   for (StringRef Feature : Split) {
62     StringRef FeatureName = llvm::AArch64::getArchExtFeature(Feature);
63     if (!FeatureName.empty())
64       Features.push_back(FeatureName);
65     else if (Feature == "neon" || Feature == "noneon")
66       D.Diag(clang::diag::err_drv_no_neon_modifier);
67     else
68       return false;
69   }
70   return true;
71 }
72 
73 // Check if the CPU name and feature modifiers in -mcpu are legal. If yes,
74 // decode CPU and feature.
75 static bool DecodeAArch64Mcpu(const Driver &D, StringRef Mcpu, StringRef &CPU,
76                               std::vector<StringRef> &Features) {
77   std::pair<StringRef, StringRef> Split = Mcpu.split("+");
78   CPU = Split.first;
79 
80   if (CPU == "native")
81     CPU = llvm::sys::getHostCPUName();
82 
83   if (CPU == "generic") {
84     Features.push_back("+neon");
85   } else {
86     llvm::AArch64::ArchKind ArchKind = llvm::AArch64::parseCPUArch(CPU);
87     if (!llvm::AArch64::getArchFeatures(ArchKind, Features))
88       return false;
89 
90     unsigned Extension = llvm::AArch64::getDefaultExtensions(CPU, ArchKind);
91     if (!llvm::AArch64::getExtensionFeatures(Extension, Features))
92       return false;
93    }
94 
95   if (Split.second.size() && !DecodeAArch64Features(D, Split.second, Features))
96     return false;
97 
98   return true;
99 }
100 
101 static bool
102 getAArch64ArchFeaturesFromMarch(const Driver &D, StringRef March,
103                                 const ArgList &Args,
104                                 std::vector<StringRef> &Features) {
105   std::string MarchLowerCase = March.lower();
106   std::pair<StringRef, StringRef> Split = StringRef(MarchLowerCase).split("+");
107 
108   llvm::AArch64::ArchKind ArchKind = llvm::AArch64::parseArch(Split.first);
109   if (ArchKind == llvm::AArch64::ArchKind::INVALID ||
110       !llvm::AArch64::getArchFeatures(ArchKind, Features) ||
111       (Split.second.size() && !DecodeAArch64Features(D, Split.second, Features)))
112     return false;
113 
114   return true;
115 }
116 
117 static bool
118 getAArch64ArchFeaturesFromMcpu(const Driver &D, StringRef Mcpu,
119                                const ArgList &Args,
120                                std::vector<StringRef> &Features) {
121   StringRef CPU;
122   std::string McpuLowerCase = Mcpu.lower();
123   if (!DecodeAArch64Mcpu(D, McpuLowerCase, CPU, Features))
124     return false;
125 
126   return true;
127 }
128 
129 static bool
130 getAArch64MicroArchFeaturesFromMtune(const Driver &D, StringRef Mtune,
131                                      const ArgList &Args,
132                                      std::vector<StringRef> &Features) {
133   std::string MtuneLowerCase = Mtune.lower();
134   // Check CPU name is valid
135   std::vector<StringRef> MtuneFeatures;
136   StringRef Tune;
137   if (!DecodeAArch64Mcpu(D, MtuneLowerCase, Tune, MtuneFeatures))
138     return false;
139 
140   // Handle CPU name is 'native'.
141   if (MtuneLowerCase == "native")
142     MtuneLowerCase = llvm::sys::getHostCPUName();
143   if (MtuneLowerCase == "cyclone" || MtuneLowerCase.find("apple") == 0) {
144     Features.push_back("+zcm");
145     Features.push_back("+zcz");
146   }
147   return true;
148 }
149 
150 static bool
151 getAArch64MicroArchFeaturesFromMcpu(const Driver &D, StringRef Mcpu,
152                                     const ArgList &Args,
153                                     std::vector<StringRef> &Features) {
154   StringRef CPU;
155   std::vector<StringRef> DecodedFeature;
156   std::string McpuLowerCase = Mcpu.lower();
157   if (!DecodeAArch64Mcpu(D, McpuLowerCase, CPU, DecodedFeature))
158     return false;
159 
160   return getAArch64MicroArchFeaturesFromMtune(D, CPU, Args, Features);
161 }
162 
163 void aarch64::getAArch64TargetFeatures(const Driver &D,
164                                        const llvm::Triple &Triple,
165                                        const ArgList &Args,
166                                        std::vector<StringRef> &Features) {
167   Arg *A;
168   bool success = true;
169   // Enable NEON by default.
170   Features.push_back("+neon");
171   if ((A = Args.getLastArg(options::OPT_march_EQ)))
172     success = getAArch64ArchFeaturesFromMarch(D, A->getValue(), Args, Features);
173   else if ((A = Args.getLastArg(options::OPT_mcpu_EQ)))
174     success = getAArch64ArchFeaturesFromMcpu(D, A->getValue(), Args, Features);
175   else if (Args.hasArg(options::OPT_arch) || isCPUDeterminedByTriple(Triple))
176     success = getAArch64ArchFeaturesFromMcpu(
177         D, getAArch64TargetCPU(Args, Triple, A), Args, Features);
178 
179   if (success && (A = Args.getLastArg(clang::driver::options::OPT_mtune_EQ)))
180     success =
181         getAArch64MicroArchFeaturesFromMtune(D, A->getValue(), Args, Features);
182   else if (success && (A = Args.getLastArg(options::OPT_mcpu_EQ)))
183     success =
184         getAArch64MicroArchFeaturesFromMcpu(D, A->getValue(), Args, Features);
185   else if (success &&
186            (Args.hasArg(options::OPT_arch) || isCPUDeterminedByTriple(Triple)))
187     success = getAArch64MicroArchFeaturesFromMcpu(
188         D, getAArch64TargetCPU(Args, Triple, A), Args, Features);
189 
190   if (!success)
191     D.Diag(diag::err_drv_clang_unsupported) << A->getAsString(Args);
192 
193   if (Args.getLastArg(options::OPT_mgeneral_regs_only)) {
194     Features.push_back("-fp-armv8");
195     Features.push_back("-crypto");
196     Features.push_back("-neon");
197   }
198 
199   if (Arg *A = Args.getLastArg(options::OPT_mtp_mode_EQ)) {
200     StringRef Mtp = A->getValue();
201     if (Mtp == "el3")
202       Features.push_back("+tpidr-el3");
203     else if (Mtp == "el2")
204       Features.push_back("+tpidr-el2");
205     else if (Mtp == "el1")
206       Features.push_back("+tpidr-el1");
207     else if (Mtp != "el0")
208       D.Diag(diag::err_drv_invalid_mtp) << A->getAsString(Args);
209   }
210 
211   // En/disable crc
212   if (Arg *A = Args.getLastArg(options::OPT_mcrc, options::OPT_mnocrc)) {
213     if (A->getOption().matches(options::OPT_mcrc))
214       Features.push_back("+crc");
215     else
216       Features.push_back("-crc");
217   }
218 
219   // Handle (arch-dependent) fp16fml/fullfp16 relationship.
220   // FIXME: this fp16fml option handling will be reimplemented after the
221   // TargetParser rewrite.
222   const auto ItRNoFullFP16 = std::find(Features.rbegin(), Features.rend(), "-fullfp16");
223   const auto ItRFP16FML = std::find(Features.rbegin(), Features.rend(), "+fp16fml");
224   if (llvm::is_contained(Features, "+v8.4a")) {
225     const auto ItRFullFP16  = std::find(Features.rbegin(), Features.rend(), "+fullfp16");
226     if (ItRFullFP16 < ItRNoFullFP16 && ItRFullFP16 < ItRFP16FML) {
227       // Only entangled feature that can be to the right of this +fullfp16 is -fp16fml.
228       // Only append the +fp16fml if there is no -fp16fml after the +fullfp16.
229       if (std::find(Features.rbegin(), ItRFullFP16, "-fp16fml") == ItRFullFP16)
230         Features.push_back("+fp16fml");
231     }
232     else
233       goto fp16_fml_fallthrough;
234   } else {
235 fp16_fml_fallthrough:
236     // In both of these cases, putting the 'other' feature on the end of the vector will
237     // result in the same effect as placing it immediately after the current feature.
238     if (ItRNoFullFP16 < ItRFP16FML)
239       Features.push_back("-fp16fml");
240     else if (ItRNoFullFP16 > ItRFP16FML)
241       Features.push_back("+fullfp16");
242   }
243 
244   // FIXME: this needs reimplementation too after the TargetParser rewrite
245   //
246   // Context sensitive meaning of Crypto:
247   // 1) For Arch >= ARMv8.4a:  crypto = sm4 + sha3 + sha2 + aes
248   // 2) For Arch <= ARMv8.3a:  crypto = sha2 + aes
249   const auto ItBegin = Features.begin();
250   const auto ItEnd = Features.end();
251   const auto ItRBegin = Features.rbegin();
252   const auto ItREnd = Features.rend();
253   const auto ItRCrypto = std::find(ItRBegin, ItREnd, "+crypto");
254   const auto ItRNoCrypto = std::find(ItRBegin, ItREnd, "-crypto");
255   const auto HasCrypto  = ItRCrypto != ItREnd;
256   const auto HasNoCrypto = ItRNoCrypto != ItREnd;
257   const ptrdiff_t PosCrypto = ItRCrypto - ItRBegin;
258   const ptrdiff_t PosNoCrypto = ItRNoCrypto - ItRBegin;
259 
260   bool NoCrypto = false;
261   if (HasCrypto && HasNoCrypto) {
262     if (PosNoCrypto < PosCrypto)
263       NoCrypto = true;
264   }
265 
266   if (std::find(ItBegin, ItEnd, "+v8.4a") != ItEnd) {
267     if (HasCrypto && !NoCrypto) {
268       // Check if we have NOT disabled an algorithm with something like:
269       //   +crypto, -algorithm
270       // And if "-algorithm" does not occur, we enable that crypto algorithm.
271       const bool HasSM4  = (std::find(ItBegin, ItEnd, "-sm4") == ItEnd);
272       const bool HasSHA3 = (std::find(ItBegin, ItEnd, "-sha3") == ItEnd);
273       const bool HasSHA2 = (std::find(ItBegin, ItEnd, "-sha2") == ItEnd);
274       const bool HasAES  = (std::find(ItBegin, ItEnd, "-aes") == ItEnd);
275       if (HasSM4)
276         Features.push_back("+sm4");
277       if (HasSHA3)
278         Features.push_back("+sha3");
279       if (HasSHA2)
280         Features.push_back("+sha2");
281       if (HasAES)
282         Features.push_back("+aes");
283     } else if (HasNoCrypto) {
284       // Check if we have NOT enabled a crypto algorithm with something like:
285       //   -crypto, +algorithm
286       // And if "+algorithm" does not occur, we disable that crypto algorithm.
287       const bool HasSM4  = (std::find(ItBegin, ItEnd, "+sm4") != ItEnd);
288       const bool HasSHA3 = (std::find(ItBegin, ItEnd, "+sha3") != ItEnd);
289       const bool HasSHA2 = (std::find(ItBegin, ItEnd, "+sha2") != ItEnd);
290       const bool HasAES  = (std::find(ItBegin, ItEnd, "+aes") != ItEnd);
291       if (!HasSM4)
292         Features.push_back("-sm4");
293       if (!HasSHA3)
294         Features.push_back("-sha3");
295       if (!HasSHA2)
296         Features.push_back("-sha2");
297       if (!HasAES)
298         Features.push_back("-aes");
299     }
300   } else {
301     if (HasCrypto && !NoCrypto) {
302       const bool HasSHA2 = (std::find(ItBegin, ItEnd, "-sha2") == ItEnd);
303       const bool HasAES = (std::find(ItBegin, ItEnd, "-aes") == ItEnd);
304       if (HasSHA2)
305         Features.push_back("+sha2");
306       if (HasAES)
307         Features.push_back("+aes");
308     } else if (HasNoCrypto) {
309       const bool HasSHA2 = (std::find(ItBegin, ItEnd, "+sha2") != ItEnd);
310       const bool HasAES  = (std::find(ItBegin, ItEnd, "+aes") != ItEnd);
311       const bool HasV82a = (std::find(ItBegin, ItEnd, "+v8.2a") != ItEnd);
312       const bool HasV83a = (std::find(ItBegin, ItEnd, "+v8.3a") != ItEnd);
313       const bool HasV84a = (std::find(ItBegin, ItEnd, "+v8.4a") != ItEnd);
314       if (!HasSHA2)
315         Features.push_back("-sha2");
316       if (!HasAES)
317         Features.push_back("-aes");
318       if (HasV82a || HasV83a || HasV84a) {
319         Features.push_back("-sm4");
320         Features.push_back("-sha3");
321       }
322     }
323   }
324 
325   if (Arg *A = Args.getLastArg(options::OPT_mno_unaligned_access,
326                                options::OPT_munaligned_access))
327     if (A->getOption().matches(options::OPT_mno_unaligned_access))
328       Features.push_back("+strict-align");
329 
330   if (Args.hasArg(options::OPT_ffixed_x1))
331     Features.push_back("+reserve-x1");
332 
333   if (Args.hasArg(options::OPT_ffixed_x2))
334     Features.push_back("+reserve-x2");
335 
336   if (Args.hasArg(options::OPT_ffixed_x3))
337     Features.push_back("+reserve-x3");
338 
339   if (Args.hasArg(options::OPT_ffixed_x4))
340     Features.push_back("+reserve-x4");
341 
342   if (Args.hasArg(options::OPT_ffixed_x5))
343     Features.push_back("+reserve-x5");
344 
345   if (Args.hasArg(options::OPT_ffixed_x6))
346     Features.push_back("+reserve-x6");
347 
348   if (Args.hasArg(options::OPT_ffixed_x7))
349     Features.push_back("+reserve-x7");
350 
351   if (Args.hasArg(options::OPT_ffixed_x9))
352     Features.push_back("+reserve-x9");
353 
354   if (Args.hasArg(options::OPT_ffixed_x10))
355     Features.push_back("+reserve-x10");
356 
357   if (Args.hasArg(options::OPT_ffixed_x11))
358     Features.push_back("+reserve-x11");
359 
360   if (Args.hasArg(options::OPT_ffixed_x12))
361     Features.push_back("+reserve-x12");
362 
363   if (Args.hasArg(options::OPT_ffixed_x13))
364     Features.push_back("+reserve-x13");
365 
366   if (Args.hasArg(options::OPT_ffixed_x14))
367     Features.push_back("+reserve-x14");
368 
369   if (Args.hasArg(options::OPT_ffixed_x15))
370     Features.push_back("+reserve-x15");
371 
372   if (Args.hasArg(options::OPT_ffixed_x18))
373     Features.push_back("+reserve-x18");
374 
375   if (Args.hasArg(options::OPT_ffixed_x20))
376     Features.push_back("+reserve-x20");
377 
378   if (Args.hasArg(options::OPT_ffixed_x21))
379     Features.push_back("+reserve-x21");
380 
381   if (Args.hasArg(options::OPT_ffixed_x22))
382     Features.push_back("+reserve-x22");
383 
384   if (Args.hasArg(options::OPT_ffixed_x23))
385     Features.push_back("+reserve-x23");
386 
387   if (Args.hasArg(options::OPT_ffixed_x24))
388     Features.push_back("+reserve-x24");
389 
390   if (Args.hasArg(options::OPT_ffixed_x25))
391     Features.push_back("+reserve-x25");
392 
393   if (Args.hasArg(options::OPT_ffixed_x26))
394     Features.push_back("+reserve-x26");
395 
396   if (Args.hasArg(options::OPT_ffixed_x27))
397     Features.push_back("+reserve-x27");
398 
399   if (Args.hasArg(options::OPT_ffixed_x28))
400     Features.push_back("+reserve-x28");
401 
402   if (Args.hasArg(options::OPT_fcall_saved_x8))
403     Features.push_back("+call-saved-x8");
404 
405   if (Args.hasArg(options::OPT_fcall_saved_x9))
406     Features.push_back("+call-saved-x9");
407 
408   if (Args.hasArg(options::OPT_fcall_saved_x10))
409     Features.push_back("+call-saved-x10");
410 
411   if (Args.hasArg(options::OPT_fcall_saved_x11))
412     Features.push_back("+call-saved-x11");
413 
414   if (Args.hasArg(options::OPT_fcall_saved_x12))
415     Features.push_back("+call-saved-x12");
416 
417   if (Args.hasArg(options::OPT_fcall_saved_x13))
418     Features.push_back("+call-saved-x13");
419 
420   if (Args.hasArg(options::OPT_fcall_saved_x14))
421     Features.push_back("+call-saved-x14");
422 
423   if (Args.hasArg(options::OPT_fcall_saved_x15))
424     Features.push_back("+call-saved-x15");
425 
426   if (Args.hasArg(options::OPT_fcall_saved_x18))
427     Features.push_back("+call-saved-x18");
428 
429   if (Args.hasArg(options::OPT_mno_neg_immediates))
430     Features.push_back("+no-neg-immediates");
431 }
432