1 /* Subroutines for the gcc driver.
2 Copyright (C) 2006, 2007 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 2, 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 COPYING. If not, write to
18 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
19 Boston, MA 02110-1301, USA. */
20
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "tm.h"
25 #include <stdlib.h>
26
27 const char *host_detect_local_cpu (int argc, const char **argv);
28
29 #ifdef GCC_VERSION
30 #define cpuid(num,a,b,c,d) \
31 asm volatile ("xchgl %%ebx, %1; cpuid; xchgl %%ebx, %1" \
32 : "=a" (a), "=r" (b), "=c" (c), "=d" (d) \
33 : "0" (num))
34
35 #define bit_CMPXCHG8B (1 << 8)
36 #define bit_CMOV (1 << 15)
37 #define bit_MMX (1 << 23)
38 #define bit_SSE (1 << 25)
39 #define bit_SSE2 (1 << 26)
40
41 #define bit_SSE3 (1 << 0)
42 #define bit_SSSE3 (1 << 9)
43 #define bit_SSE4a (1 << 6)
44 #define bit_CMPXCHG16B (1 << 13)
45
46 #define bit_3DNOW (1 << 31)
47 #define bit_3DNOWP (1 << 30)
48 #define bit_LM (1 << 29)
49
50 /* This will be called by the spec parser in gcc.c when it sees
51 a %:local_cpu_detect(args) construct. Currently it will be called
52 with either "arch" or "tune" as argument depending on if -march=native
53 or -mtune=native is to be substituted.
54
55 It returns a string containing new command line parameters to be
56 put at the place of the above two options, depending on what CPU
57 this is executed. E.g. "-march=k8" on an AMD64 machine
58 for -march=native.
59
60 ARGC and ARGV are set depending on the actual arguments given
61 in the spec. */
host_detect_local_cpu(int argc,const char ** argv)62 const char *host_detect_local_cpu (int argc, const char **argv)
63 {
64 const char *cpu = NULL;
65 enum processor_type processor = PROCESSOR_I386;
66 unsigned int eax, ebx, ecx, edx;
67 unsigned int max_level;
68 unsigned int vendor;
69 unsigned int ext_level;
70 unsigned char has_mmx = 0, has_3dnow = 0, has_3dnowp = 0, has_sse = 0;
71 unsigned char has_sse2 = 0, has_sse3 = 0, has_ssse3 = 0, has_cmov = 0;
72 unsigned char has_longmode = 0, has_cmpxchg8b = 0, has_sse4a = 0;
73 unsigned char is_amd = 0;
74 unsigned int family = 0;
75 bool arch;
76
77 if (argc < 1)
78 return NULL;
79
80 arch = strcmp (argv[0], "arch") == 0;
81 if (!arch && strcmp (argv[0], "tune"))
82 return NULL;
83
84 #ifndef __x86_64__
85 /* See if we can use cpuid. */
86 asm volatile ("pushfl; pushfl; popl %0; movl %0,%1; xorl %2,%0;"
87 "pushl %0; popfl; pushfl; popl %0; popfl"
88 : "=&r" (eax), "=&r" (ebx)
89 : "i" (0x00200000));
90
91 if (((eax ^ ebx) & 0x00200000) == 0)
92 goto done;
93 #endif
94
95 processor = PROCESSOR_PENTIUM;
96
97 /* Check the highest input value for eax. */
98 cpuid (0, eax, ebx, ecx, edx);
99 max_level = eax;
100 /* We only look at the first four characters. */
101 vendor = ebx;
102 if (max_level == 0)
103 goto done;
104
105 cpuid (1, eax, ebx, ecx, edx);
106 has_cmpxchg8b = !!(edx & bit_CMPXCHG8B);
107 has_cmov = !!(edx & bit_CMOV);
108 has_mmx = !!(edx & bit_MMX);
109 has_sse = !!(edx & bit_SSE);
110 has_sse2 = !!(edx & bit_SSE2);
111 has_sse3 = !!(ecx & bit_SSE3);
112 has_ssse3 = !!(ecx & bit_SSSE3);
113 /* We don't care for extended family. */
114 family = (eax >> 8) & ~(1 << 4);
115
116 cpuid (0x80000000, eax, ebx, ecx, edx);
117 ext_level = eax;
118 if (ext_level >= 0x80000000)
119 {
120 cpuid (0x80000001, eax, ebx, ecx, edx);
121 has_3dnow = !!(edx & bit_3DNOW);
122 has_3dnowp = !!(edx & bit_3DNOWP);
123 has_longmode = !!(edx & bit_LM);
124 has_sse4a = !!(ecx & bit_SSE4a);
125 }
126
127 is_amd = vendor == *(unsigned int*)"Auth";
128
129 if (is_amd)
130 {
131 if (has_mmx)
132 processor = PROCESSOR_K6;
133 if (has_3dnowp)
134 processor = PROCESSOR_ATHLON;
135 if (has_sse2 || has_longmode)
136 processor = PROCESSOR_K8;
137 if (has_sse4a)
138 processor = PROCESSOR_AMDFAM10;
139 }
140 else
141 {
142 switch (family)
143 {
144 case 5:
145 /* Default is PROCESSOR_PENTIUM. */
146 break;
147 case 6:
148 processor = PROCESSOR_PENTIUMPRO;
149 break;
150 case 15:
151 processor = PROCESSOR_PENTIUM4;
152 break;
153 default:
154 /* We have no idea. Use something reasonable. */
155 if (arch)
156 {
157 if (has_ssse3)
158 cpu = "core2";
159 else if (has_sse3)
160 {
161 if (has_longmode)
162 cpu = "nocona";
163 else
164 cpu = "prescott";
165 }
166 else if (has_sse2)
167 cpu = "pentium4";
168 else if (has_cmov)
169 cpu = "pentiumpro";
170 else if (has_mmx)
171 cpu = "pentium-mmx";
172 else if (has_cmpxchg8b)
173 cpu = "pentium";
174 else
175 cpu = "i386";
176 }
177 else
178 cpu = "generic";
179 goto done;
180 break;
181 }
182 }
183
184 switch (processor)
185 {
186 case PROCESSOR_I386:
187 cpu = "i386";
188 break;
189 case PROCESSOR_I486:
190 cpu = "i486";
191 break;
192 case PROCESSOR_PENTIUM:
193 if (has_mmx)
194 cpu = "pentium-mmx";
195 else
196 cpu = "pentium";
197 break;
198 case PROCESSOR_PENTIUMPRO:
199 if (arch)
200 {
201 if (has_sse3)
202 {
203 if (has_longmode)
204 {
205 /* It is Core 2 Duo. */
206 cpu = "nocona";
207 }
208 else
209 {
210 /* It is Core Duo. */
211 cpu = "prescott";
212 }
213 }
214 else if (has_sse2)
215 {
216 /* It is Pentium M. */
217 cpu = "pentium4";
218 }
219 else if (has_sse)
220 {
221 /* It is Pentium III. */
222 cpu = "pentium3";
223 }
224 else if (has_mmx)
225 {
226 /* It is Pentium II. */
227 cpu = "pentium2";
228 }
229 else
230 {
231 /* Default to Pentium Pro. */
232 cpu = "pentiumpro";
233 }
234 }
235 else
236 {
237 /* For -mtune, we default to -mtune=generic. */
238 cpu = "generic";
239 }
240 break;
241 case PROCESSOR_GEODE:
242 cpu = "geode";
243 break;
244 case PROCESSOR_K6:
245 if (has_3dnow)
246 cpu = "k6-3";
247 else
248 cpu = "k6";
249 break;
250 case PROCESSOR_ATHLON:
251 if (has_sse)
252 cpu = "athlon-4";
253 else
254 cpu = "athlon";
255 break;
256 case PROCESSOR_PENTIUM4:
257 if (has_sse3)
258 {
259 if (has_longmode)
260 cpu = "nocona";
261 else
262 cpu = "prescott";
263 }
264 else
265 cpu = "pentium4";
266 break;
267 case PROCESSOR_K8:
268 cpu = "k8";
269 break;
270 case PROCESSOR_NOCONA:
271 cpu = "nocona";
272 break;
273 case PROCESSOR_AMDFAM10:
274 cpu = "amdfam10";
275 break;
276 case PROCESSOR_GENERIC32:
277 case PROCESSOR_GENERIC64:
278 cpu = "generic";
279 break;
280 default:
281 abort ();
282 break;
283 }
284
285 done:
286 return concat ("-m", argv[0], "=", cpu, NULL);
287 }
288 #else
289 /* If we aren't compiling with GCC we just provide a minimal
290 default value. */
host_detect_local_cpu(int argc,const char ** argv)291 const char *host_detect_local_cpu (int argc, const char **argv)
292 {
293 const char *cpu;
294 bool arch;
295
296 if (argc < 1)
297 return NULL;
298
299 arch = strcmp (argv[0], "arch") == 0;
300 if (!arch && strcmp (argv[0], "tune"))
301 return NULL;
302
303 if (arch)
304 {
305 /* FIXME: i386 is wrong for 64bit compiler. How can we tell if
306 we are generating 64bit or 32bit code? */
307 cpu = "i386";
308 }
309 else
310 cpu = "generic";
311
312 return concat ("-m", argv[0], "=", cpu, NULL);
313 }
314 #endif /* GCC_VERSION */
315