xref: /dragonfly/contrib/gcc-4.7/gcc/config/i386/driver-i386.c (revision 0a8dc9fc45f4d0b236341a473fac4a486375f60c)
1 /* Subroutines for the gcc driver.
2    Copyright (C) 2006, 2007, 2008, 2010 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
9 any later version.
10 
11 GCC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 GNU General Public License for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3.  If not see
18 <http://www.gnu.org/licenses/>.  */
19 
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "tm.h"
24 
25 const char *host_detect_local_cpu (int argc, const char **argv);
26 
27 #ifdef __GNUC__
28 #include "cpuid.h"
29 
30 struct cache_desc
31 {
32   unsigned sizekb;
33   unsigned assoc;
34   unsigned line;
35 };
36 
37 /* Returns command line parameters that describe size and
38    cache line size of the processor caches.  */
39 
40 static char *
describe_cache(struct cache_desc level1,struct cache_desc level2)41 describe_cache (struct cache_desc level1, struct cache_desc level2)
42 {
43   char size[100], line[100], size2[100];
44 
45   /* At the moment, gcc does not use the information
46      about the associativity of the cache.  */
47 
48   snprintf (size, sizeof (size),
49               "--param l1-cache-size=%u ", level1.sizekb);
50   snprintf (line, sizeof (line),
51               "--param l1-cache-line-size=%u ", level1.line);
52 
53   snprintf (size2, sizeof (size2),
54               "--param l2-cache-size=%u ", level2.sizekb);
55 
56   return concat (size, line, size2, NULL);
57 }
58 
59 /* Detect L2 cache parameters using CPUID extended function 0x80000006.  */
60 
61 static void
detect_l2_cache(struct cache_desc * level2)62 detect_l2_cache (struct cache_desc *level2)
63 {
64   unsigned eax, ebx, ecx, edx;
65   unsigned assoc;
66 
67   __cpuid (0x80000006, eax, ebx, ecx, edx);
68 
69   level2->sizekb = (ecx >> 16) & 0xffff;
70   level2->line = ecx & 0xff;
71 
72   assoc = (ecx >> 12) & 0xf;
73   if (assoc == 6)
74     assoc = 8;
75   else if (assoc == 8)
76     assoc = 16;
77   else if (assoc >= 0xa && assoc <= 0xc)
78     assoc = 32 + (assoc - 0xa) * 16;
79   else if (assoc >= 0xd && assoc <= 0xe)
80     assoc = 96 + (assoc - 0xd) * 32;
81 
82   level2->assoc = assoc;
83 }
84 
85 /* Returns the description of caches for an AMD processor.  */
86 
87 static const char *
detect_caches_amd(unsigned max_ext_level)88 detect_caches_amd (unsigned max_ext_level)
89 {
90   unsigned eax, ebx, ecx, edx;
91 
92   struct cache_desc level1, level2 = {0, 0, 0};
93 
94   if (max_ext_level < 0x80000005)
95     return "";
96 
97   __cpuid (0x80000005, eax, ebx, ecx, edx);
98 
99   level1.sizekb = (ecx >> 24) & 0xff;
100   level1.assoc = (ecx >> 16) & 0xff;
101   level1.line = ecx & 0xff;
102 
103   if (max_ext_level >= 0x80000006)
104     detect_l2_cache (&level2);
105 
106   return describe_cache (level1, level2);
107 }
108 
109 /* Decodes the size, the associativity and the cache line size of
110    L1/L2 caches of an Intel processor.  Values are based on
111    "Intel Processor Identification and the CPUID Instruction"
112    [Application Note 485], revision -032, December 2007.  */
113 
114 static void
decode_caches_intel(unsigned reg,bool xeon_mp,struct cache_desc * level1,struct cache_desc * level2)115 decode_caches_intel (unsigned reg, bool xeon_mp,
116                          struct cache_desc *level1, struct cache_desc *level2)
117 {
118   int i;
119 
120   for (i = 24; i >= 0; i -= 8)
121     switch ((reg >> i) & 0xff)
122       {
123       case 0x0a:
124           level1->sizekb = 8; level1->assoc = 2; level1->line = 32;
125           break;
126       case 0x0c:
127           level1->sizekb = 16; level1->assoc = 4; level1->line = 32;
128           break;
129       case 0x2c:
130           level1->sizekb = 32; level1->assoc = 8; level1->line = 64;
131           break;
132       case 0x39:
133           level2->sizekb = 128; level2->assoc = 4; level2->line = 64;
134           break;
135       case 0x3a:
136           level2->sizekb = 192; level2->assoc = 6; level2->line = 64;
137           break;
138       case 0x3b:
139           level2->sizekb = 128; level2->assoc = 2; level2->line = 64;
140           break;
141       case 0x3c:
142           level2->sizekb = 256; level2->assoc = 4; level2->line = 64;
143           break;
144       case 0x3d:
145           level2->sizekb = 384; level2->assoc = 6; level2->line = 64;
146           break;
147       case 0x3e:
148           level2->sizekb = 512; level2->assoc = 4; level2->line = 64;
149           break;
150       case 0x41:
151           level2->sizekb = 128; level2->assoc = 4; level2->line = 32;
152           break;
153       case 0x42:
154           level2->sizekb = 256; level2->assoc = 4; level2->line = 32;
155           break;
156       case 0x43:
157           level2->sizekb = 512; level2->assoc = 4; level2->line = 32;
158           break;
159       case 0x44:
160           level2->sizekb = 1024; level2->assoc = 4; level2->line = 32;
161           break;
162       case 0x45:
163           level2->sizekb = 2048; level2->assoc = 4; level2->line = 32;
164           break;
165       case 0x49:
166           if (xeon_mp)
167             break;
168           level2->sizekb = 4096; level2->assoc = 16; level2->line = 64;
169           break;
170       case 0x4e:
171           level2->sizekb = 6144; level2->assoc = 24; level2->line = 64;
172           break;
173       case 0x60:
174           level1->sizekb = 16; level1->assoc = 8; level1->line = 64;
175           break;
176       case 0x66:
177           level1->sizekb = 8; level1->assoc = 4; level1->line = 64;
178           break;
179       case 0x67:
180           level1->sizekb = 16; level1->assoc = 4; level1->line = 64;
181           break;
182       case 0x68:
183           level1->sizekb = 32; level1->assoc = 4; level1->line = 64;
184           break;
185       case 0x78:
186           level2->sizekb = 1024; level2->assoc = 4; level2->line = 64;
187           break;
188       case 0x79:
189           level2->sizekb = 128; level2->assoc = 8; level2->line = 64;
190           break;
191       case 0x7a:
192           level2->sizekb = 256; level2->assoc = 8; level2->line = 64;
193           break;
194       case 0x7b:
195           level2->sizekb = 512; level2->assoc = 8; level2->line = 64;
196           break;
197       case 0x7c:
198           level2->sizekb = 1024; level2->assoc = 8; level2->line = 64;
199           break;
200       case 0x7d:
201           level2->sizekb = 2048; level2->assoc = 8; level2->line = 64;
202           break;
203       case 0x7f:
204           level2->sizekb = 512; level2->assoc = 2; level2->line = 64;
205           break;
206       case 0x82:
207           level2->sizekb = 256; level2->assoc = 8; level2->line = 32;
208           break;
209       case 0x83:
210           level2->sizekb = 512; level2->assoc = 8; level2->line = 32;
211           break;
212       case 0x84:
213           level2->sizekb = 1024; level2->assoc = 8; level2->line = 32;
214           break;
215       case 0x85:
216           level2->sizekb = 2048; level2->assoc = 8; level2->line = 32;
217           break;
218       case 0x86:
219           level2->sizekb = 512; level2->assoc = 4; level2->line = 64;
220           break;
221       case 0x87:
222           level2->sizekb = 1024; level2->assoc = 8; level2->line = 64;
223 
224       default:
225           break;
226       }
227 }
228 
229 /* Detect cache parameters using CPUID function 2.  */
230 
231 static void
detect_caches_cpuid2(bool xeon_mp,struct cache_desc * level1,struct cache_desc * level2)232 detect_caches_cpuid2 (bool xeon_mp,
233                           struct cache_desc *level1, struct cache_desc *level2)
234 {
235   unsigned regs[4];
236   int nreps, i;
237 
238   __cpuid (2, regs[0], regs[1], regs[2], regs[3]);
239 
240   nreps = regs[0] & 0x0f;
241   regs[0] &= ~0x0f;
242 
243   while (--nreps >= 0)
244     {
245       for (i = 0; i < 4; i++)
246           if (regs[i] && !((regs[i] >> 31) & 1))
247             decode_caches_intel (regs[i], xeon_mp, level1, level2);
248 
249       if (nreps)
250           __cpuid (2, regs[0], regs[1], regs[2], regs[3]);
251     }
252 }
253 
254 /* Detect cache parameters using CPUID function 4. This
255    method doesn't require hardcoded tables.  */
256 
257 enum cache_type
258 {
259   CACHE_END = 0,
260   CACHE_DATA = 1,
261   CACHE_INST = 2,
262   CACHE_UNIFIED = 3
263 };
264 
265 static void
detect_caches_cpuid4(struct cache_desc * level1,struct cache_desc * level2,struct cache_desc * level3)266 detect_caches_cpuid4 (struct cache_desc *level1, struct cache_desc *level2,
267                           struct cache_desc *level3)
268 {
269   struct cache_desc *cache;
270 
271   unsigned eax, ebx, ecx, edx;
272   int count;
273 
274   for (count = 0;; count++)
275     {
276       __cpuid_count(4, count, eax, ebx, ecx, edx);
277       switch (eax & 0x1f)
278           {
279           case CACHE_END:
280             return;
281           case CACHE_DATA:
282           case CACHE_UNIFIED:
283             {
284               switch ((eax >> 5) & 0x07)
285                 {
286                 case 1:
287                     cache = level1;
288                     break;
289                 case 2:
290                     cache = level2;
291                     break;
292                 case 3:
293                     cache = level3;
294                     break;
295                 default:
296                     cache = NULL;
297                 }
298 
299               if (cache)
300                 {
301                     unsigned sets = ecx + 1;
302                     unsigned part = ((ebx >> 12) & 0x03ff) + 1;
303 
304                     cache->assoc = ((ebx >> 22) & 0x03ff) + 1;
305                     cache->line = (ebx & 0x0fff) + 1;
306 
307                     cache->sizekb = (cache->assoc * part
308                                          * cache->line * sets) / 1024;
309                 }
310             }
311           default:
312             break;
313           }
314     }
315 }
316 
317 /* Returns the description of caches for an Intel processor.  */
318 
319 static const char *
detect_caches_intel(bool xeon_mp,unsigned max_level,unsigned max_ext_level,unsigned * l2sizekb)320 detect_caches_intel (bool xeon_mp, unsigned max_level,
321                          unsigned max_ext_level, unsigned *l2sizekb)
322 {
323   struct cache_desc level1 = {0, 0, 0}, level2 = {0, 0, 0}, level3 = {0, 0, 0};
324 
325   if (max_level >= 4)
326     detect_caches_cpuid4 (&level1, &level2, &level3);
327   else if (max_level >= 2)
328     detect_caches_cpuid2 (xeon_mp, &level1, &level2);
329   else
330     return "";
331 
332   if (level1.sizekb == 0)
333     return "";
334 
335   /* Let the L3 replace the L2. This assumes inclusive caches
336      and single threaded program for now. */
337   if (level3.sizekb)
338     level2 = level3;
339 
340   /* Intel CPUs are equipped with AMD style L2 cache info.  Try this
341      method if other methods fail to provide L2 cache parameters.  */
342   if (level2.sizekb == 0 && max_ext_level >= 0x80000006)
343     detect_l2_cache (&level2);
344 
345   *l2sizekb = level2.sizekb;
346 
347   return describe_cache (level1, level2);
348 }
349 
350 enum vendor_signatures
351 {
352   SIG_INTEL =       0x756e6547 /* Genu */,
353   SIG_AMD =         0x68747541 /* Auth */,
354   SIG_CENTAUR =     0x746e6543 /* Cent */,
355   SIG_CYRIX =       0x69727943 /* Cyri */,
356   SIG_NSC =         0x646f6547 /* Geod */
357 };
358 
359 enum processor_signatures
360 {
361   SIG_GEODE =       0x646f6547 /* Geod */
362 };
363 
364 /* This will be called by the spec parser in gcc.c when it sees
365    a %:local_cpu_detect(args) construct.  Currently it will be called
366    with either "arch" or "tune" as argument depending on if -march=native
367    or -mtune=native is to be substituted.
368 
369    It returns a string containing new command line parameters to be
370    put at the place of the above two options, depending on what CPU
371    this is executed.  E.g. "-march=k8" on an AMD64 machine
372    for -march=native.
373 
374    ARGC and ARGV are set depending on the actual arguments given
375    in the spec.  */
376 
host_detect_local_cpu(int argc,const char ** argv)377 const char *host_detect_local_cpu (int argc, const char **argv)
378 {
379   enum processor_type processor = PROCESSOR_I386;
380   const char *cpu = "i386";
381 
382   const char *cache = "";
383   const char *options = "";
384 
385   unsigned int eax, ebx, ecx, edx;
386 
387   unsigned int max_level, ext_level;
388 
389   unsigned int vendor;
390   unsigned int model, family;
391 
392   unsigned int has_sse3, has_ssse3, has_cmpxchg16b;
393   unsigned int has_cmpxchg8b, has_cmov, has_mmx, has_sse, has_sse2;
394 
395   /* Extended features */
396   unsigned int has_lahf_lm = 0, has_sse4a = 0;
397   unsigned int has_longmode = 0, has_3dnowp = 0, has_3dnow = 0;
398   unsigned int has_movbe = 0, has_sse4_1 = 0, has_sse4_2 = 0;
399   unsigned int has_popcnt = 0, has_aes = 0, has_avx = 0, has_avx2 = 0;
400   unsigned int has_pclmul = 0, has_abm = 0, has_lwp = 0;
401   unsigned int has_fma = 0, has_fma4 = 0, has_xop = 0;
402   unsigned int has_bmi = 0, has_bmi2 = 0, has_tbm = 0, has_lzcnt = 0;
403   unsigned int has_rdrnd = 0, has_f16c = 0, has_fsgsbase = 0;
404   unsigned int has_osxsave = 0;
405 
406   bool arch;
407 
408   unsigned int l2sizekb = 0;
409 
410   if (argc < 1)
411     return NULL;
412 
413   arch = !strcmp (argv[0], "arch");
414 
415   if (!arch && strcmp (argv[0], "tune"))
416     return NULL;
417 
418   max_level = __get_cpuid_max (0, &vendor);
419   if (max_level < 1)
420     goto done;
421 
422   __cpuid (1, eax, ebx, ecx, edx);
423 
424   model = (eax >> 4) & 0x0f;
425   family = (eax >> 8) & 0x0f;
426   if (vendor == SIG_INTEL)
427     {
428       unsigned int extended_model, extended_family;
429 
430       extended_model = (eax >> 12) & 0xf0;
431       extended_family = (eax >> 20) & 0xff;
432       if (family == 0x0f)
433           {
434             family += extended_family;
435             model += extended_model;
436           }
437       else if (family == 0x06)
438           model += extended_model;
439     }
440 
441   has_sse3 = ecx & bit_SSE3;
442   has_ssse3 = ecx & bit_SSSE3;
443   has_sse4_1 = ecx & bit_SSE4_1;
444   has_sse4_2 = ecx & bit_SSE4_2;
445   has_avx = ecx & bit_AVX;
446   has_osxsave = ecx & bit_OSXSAVE;
447   has_cmpxchg16b = ecx & bit_CMPXCHG16B;
448   has_movbe = ecx & bit_MOVBE;
449   has_popcnt = ecx & bit_POPCNT;
450   has_aes = ecx & bit_AES;
451   has_pclmul = ecx & bit_PCLMUL;
452   has_fma = ecx & bit_FMA;
453   has_f16c = ecx & bit_F16C;
454   has_rdrnd = ecx & bit_RDRND;
455 
456   has_cmpxchg8b = edx & bit_CMPXCHG8B;
457   has_cmov = edx & bit_CMOV;
458   has_mmx = edx & bit_MMX;
459   has_sse = edx & bit_SSE;
460   has_sse2 = edx & bit_SSE2;
461 
462   if (max_level >= 7)
463     {
464       __cpuid_count (7, 0, eax, ebx, ecx, edx);
465 
466       has_bmi = ebx & bit_BMI;
467       has_avx2 = ebx & bit_AVX2;
468       has_bmi2 = ebx & bit_BMI2;
469       has_fsgsbase = ebx & bit_FSGSBASE;
470     }
471 
472   /* Check cpuid level of extended features.  */
473   __cpuid (0x80000000, ext_level, ebx, ecx, edx);
474 
475   if (ext_level > 0x80000000)
476     {
477       __cpuid (0x80000001, eax, ebx, ecx, edx);
478 
479       has_lahf_lm = ecx & bit_LAHF_LM;
480       has_sse4a = ecx & bit_SSE4a;
481       has_abm = ecx & bit_ABM;
482       has_lwp = ecx & bit_LWP;
483       has_fma4 = ecx & bit_FMA4;
484       has_xop = ecx & bit_XOP;
485       has_tbm = ecx & bit_TBM;
486       has_lzcnt = ecx & bit_LZCNT;
487 
488       has_longmode = edx & bit_LM;
489       has_3dnowp = edx & bit_3DNOWP;
490       has_3dnow = edx & bit_3DNOW;
491     }
492 
493   /* Get XCR_XFEATURE_ENABLED_MASK register with xgetbv.  */
494 #define XCR_XFEATURE_ENABLED_MASK       0x0
495 #define XSTATE_FP                       0x1
496 #define XSTATE_SSE                      0x2
497 #define XSTATE_YMM                      0x4
498   if (has_osxsave)
499     asm (".byte 0x0f; .byte 0x01; .byte 0xd0"
500            : "=a" (eax), "=d" (edx)
501            : "c" (XCR_XFEATURE_ENABLED_MASK));
502 
503   /* Check if SSE and YMM states are supported.  */
504   if (!has_osxsave
505       || (eax & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM))
506     {
507       has_avx = 0;
508       has_avx2 = 0;
509       has_fma = 0;
510       has_fma4 = 0;
511       has_f16c = 0;
512       has_xop = 0;
513     }
514 
515   if (!arch)
516     {
517       if (vendor == SIG_AMD
518             || vendor == SIG_CENTAUR
519             || vendor == SIG_CYRIX
520             || vendor == SIG_NSC)
521           cache = detect_caches_amd (ext_level);
522       else if (vendor == SIG_INTEL)
523           {
524             bool xeon_mp = (family == 15 && model == 6);
525             cache = detect_caches_intel (xeon_mp, max_level,
526                                                ext_level, &l2sizekb);
527           }
528     }
529 
530   if (vendor == SIG_AMD)
531     {
532       unsigned int name;
533 
534       /* Detect geode processor by its processor signature.  */
535       if (ext_level > 0x80000001)
536           __cpuid (0x80000002, name, ebx, ecx, edx);
537       else
538           name = 0;
539 
540       if (name == SIG_GEODE)
541           processor = PROCESSOR_GEODE;
542       else if (has_bmi)
543         processor = PROCESSOR_BDVER2;
544       else if (has_xop)
545           processor = PROCESSOR_BDVER1;
546       else if (has_sse4a && has_ssse3)
547         processor = PROCESSOR_BTVER1;
548       else if (has_sse4a)
549           processor = PROCESSOR_AMDFAM10;
550       else if (has_sse2 || has_longmode)
551           processor = PROCESSOR_K8;
552       else if (has_3dnowp && family == 6)
553           processor = PROCESSOR_ATHLON;
554       else if (has_mmx)
555           processor = PROCESSOR_K6;
556       else
557           processor = PROCESSOR_PENTIUM;
558     }
559   else if (vendor == SIG_CENTAUR)
560     {
561       if (arch)
562           {
563             switch (family)
564               {
565               case 6:
566                 if (model > 9)
567                     /* Use the default detection procedure.  */
568                     processor = PROCESSOR_GENERIC32;
569                 else if (model == 9)
570                     cpu = "c3-2";
571                 else if (model >= 6)
572                     cpu = "c3";
573                 else
574                     processor = PROCESSOR_GENERIC32;
575                 break;
576               case 5:
577                 if (has_3dnow)
578                     cpu = "winchip2";
579                 else if (has_mmx)
580                     cpu = "winchip2-c6";
581                 else
582                     processor = PROCESSOR_GENERIC32;
583                 break;
584               default:
585                 /* We have no idea.  */
586                 processor = PROCESSOR_GENERIC32;
587               }
588           }
589     }
590   else
591     {
592       switch (family)
593           {
594           case 4:
595             processor = PROCESSOR_I486;
596             break;
597           case 5:
598             processor = PROCESSOR_PENTIUM;
599             break;
600           case 6:
601             processor = PROCESSOR_PENTIUMPRO;
602             break;
603           case 15:
604             processor = PROCESSOR_PENTIUM4;
605             break;
606           default:
607             /* We have no idea.  */
608             processor = PROCESSOR_GENERIC32;
609           }
610     }
611 
612   switch (processor)
613     {
614     case PROCESSOR_I386:
615       /* Default.  */
616       break;
617     case PROCESSOR_I486:
618       cpu = "i486";
619       break;
620     case PROCESSOR_PENTIUM:
621       if (arch && has_mmx)
622           cpu = "pentium-mmx";
623       else
624           cpu = "pentium";
625       break;
626     case PROCESSOR_PENTIUMPRO:
627       switch (model)
628           {
629           case 0x1c:
630           case 0x26:
631             /* Atom.  */
632             cpu = "atom";
633             break;
634           case 0x0f:
635             /* Merom.  */
636           case 0x17:
637           case 0x1d:
638             /* Penryn.  */
639             cpu = "core2";
640             break;
641           case 0x1a:
642           case 0x1e:
643           case 0x1f:
644           case 0x2e:
645             /* Nehalem.  */
646           case 0x25:
647           case 0x2c:
648           case 0x2f:
649             /* Westmere.  */
650             cpu = "corei7";
651             break;
652           case 0x2a:
653           case 0x2d:
654             /* Sandy Bridge.  */
655             cpu = "corei7-avx";
656             break;
657           case 0x3a:
658           case 0x3e:
659             /* Ivy Bridge.  */
660             cpu = "core-avx-i";
661             break;
662           default:
663             if (arch)
664               {
665                 /* This is unknown family 0x6 CPU.  */
666                 if (has_avx)
667                     /* Assume Sandy Bridge.  */
668                     cpu = "corei7-avx";
669                 else if (has_sse4_2)
670                     /* Assume Core i7.  */
671                     cpu = "corei7";
672                 else if (has_ssse3)
673                     {
674                       if (has_movbe)
675                         /* Assume Atom.  */
676                         cpu = "atom";
677                       else
678                         /* Assume Core 2.  */
679                         cpu = "core2";
680                     }
681                 else if (has_sse3)
682                     /* It is Core Duo.  */
683                     cpu = "pentium-m";
684                 else if (has_sse2)
685                     /* It is Pentium M.  */
686                     cpu = "pentium-m";
687                 else if (has_sse)
688                     /* It is Pentium III.  */
689                     cpu = "pentium3";
690                 else if (has_mmx)
691                     /* It is Pentium II.  */
692                     cpu = "pentium2";
693                 else
694                     /* Default to Pentium Pro.  */
695                     cpu = "pentiumpro";
696               }
697             else
698               /* For -mtune, we default to -mtune=generic.  */
699               cpu = "generic";
700             break;
701           }
702       break;
703     case PROCESSOR_PENTIUM4:
704       if (has_sse3)
705           {
706             if (has_longmode)
707               cpu = "nocona";
708             else
709               cpu = "prescott";
710           }
711       else
712           cpu = "pentium4";
713       break;
714     case PROCESSOR_GEODE:
715       cpu = "geode";
716       break;
717     case PROCESSOR_K6:
718       if (arch && has_3dnow)
719           cpu = "k6-3";
720       else
721           cpu = "k6";
722       break;
723     case PROCESSOR_ATHLON:
724       if (arch && has_sse)
725           cpu = "athlon-4";
726       else
727           cpu = "athlon";
728       break;
729     case PROCESSOR_K8:
730       if (arch && has_sse3)
731           cpu = "k8-sse3";
732       else
733           cpu = "k8";
734       break;
735     case PROCESSOR_AMDFAM10:
736       cpu = "amdfam10";
737       break;
738     case PROCESSOR_BDVER1:
739       cpu = "bdver1";
740       break;
741     case PROCESSOR_BDVER2:
742       cpu = "bdver2";
743       break;
744     case PROCESSOR_BTVER1:
745       cpu = "btver1";
746       break;
747 
748     default:
749       /* Use something reasonable.  */
750       if (arch)
751           {
752             if (has_ssse3)
753               cpu = "core2";
754             else if (has_sse3)
755               {
756                 if (has_longmode)
757                     cpu = "nocona";
758                 else
759                     cpu = "prescott";
760               }
761             else if (has_sse2)
762               cpu = "pentium4";
763             else if (has_cmov)
764               cpu = "pentiumpro";
765             else if (has_mmx)
766               cpu = "pentium-mmx";
767             else if (has_cmpxchg8b)
768               cpu = "pentium";
769           }
770       else
771           cpu = "generic";
772     }
773 
774   if (arch)
775     {
776       const char *cx16 = has_cmpxchg16b ? " -mcx16" : " -mno-cx16";
777       const char *sahf = has_lahf_lm ? " -msahf" : " -mno-sahf";
778       const char *movbe = has_movbe ? " -mmovbe" : " -mno-movbe";
779       const char *ase = has_aes ? " -maes" : " -mno-aes";
780       const char *pclmul = has_pclmul ? " -mpclmul" : " -mno-pclmul";
781       const char *popcnt = has_popcnt ? " -mpopcnt" : " -mno-popcnt";
782       const char *abm = has_abm ? " -mabm" : " -mno-abm";
783       const char *lwp = has_lwp ? " -mlwp" : " -mno-lwp";
784       const char *fma = has_fma ? " -mfma" : " -mno-fma";
785       const char *fma4 = has_fma4 ? " -mfma4" : " -mno-fma4";
786       const char *xop = has_xop ? " -mxop" : " -mno-xop";
787       const char *bmi = has_bmi ? " -mbmi" : " -mno-bmi";
788       const char *bmi2 = has_bmi2 ? " -mbmi2" : " -mno-bmi2";
789       const char *tbm = has_tbm ? " -mtbm" : " -mno-tbm";
790       const char *avx = has_avx ? " -mavx" : " -mno-avx";
791       const char *avx2 = has_avx2 ? " -mavx2" : " -mno-avx2";
792       const char *sse4_2 = has_sse4_2 ? " -msse4.2" : " -mno-sse4.2";
793       const char *sse4_1 = has_sse4_1 ? " -msse4.1" : " -mno-sse4.1";
794       const char *lzcnt = has_lzcnt ? " -mlzcnt" : " -mno-lzcnt";
795       const char *rdrnd = has_rdrnd ? " -mrdrnd" : " -mno-rdrnd";
796       const char *f16c = has_f16c ? " -mf16c" : " -mno-f16c";
797       const char *fsgsbase = has_fsgsbase ? " -mfsgsbase" : " -mno-fsgsbase";
798 
799       options = concat (options, cx16, sahf, movbe, ase, pclmul,
800                               popcnt, abm, lwp, fma, fma4, xop, bmi, bmi2,
801                               tbm, avx, avx2, sse4_2, sse4_1, lzcnt, rdrnd,
802                               f16c, fsgsbase, NULL);
803     }
804 
805 done:
806   return concat (cache, "-m", argv[0], "=", cpu, options, NULL);
807 }
808 #else
809 
810 /* If we aren't compiling with GCC then the driver will just ignore
811    -march and -mtune "native" target and will leave to the newly
812    built compiler to generate code for its default target.  */
813 
host_detect_local_cpu(int argc ATTRIBUTE_UNUSED,const char ** argv ATTRIBUTE_UNUSED)814 const char *host_detect_local_cpu (int argc ATTRIBUTE_UNUSED,
815                                            const char **argv ATTRIBUTE_UNUSED)
816 {
817   return NULL;
818 }
819 #endif /* __GNUC__ */
820