1 /*****************************************************************************
2 * cpu.c: CPU detection code
3 *****************************************************************************
4 * Copyright (C) 1998-2004 VideoLAN
7 * Authors: Samuel Hocevar <sam@zoy.org>
8 * Christophe Massiot <massiot@via.ecp.fr>
9 * Eugenio Jarosiewicz <ej0@cise.ufl.eduEujenio>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
24 *****************************************************************************/
26 /*****************************************************************************
28 *****************************************************************************/
32 # include <signal.h> /* SIGHUP, SIGINT, SIGKILL */
33 # include <setjmp.h> /* longjmp, setjmp */
37 #include <sys/sysctl.h>
42 /*****************************************************************************
44 *****************************************************************************/
46 static void SigHandler ( int );
49 /*****************************************************************************
50 * Global variables - they're needed for signal handling
51 *****************************************************************************/
55 #if defined( __i386__ )
56 static char *psz_capability;
60 /*****************************************************************************
61 * CPUCapabilities: get the CPU capabilities
62 *****************************************************************************
63 * This function is called to list extensions the CPU may have.
64 *****************************************************************************/
65 uint32_t CPUCapabilities( void )
67 volatile uint32_t i_capabilities = CPU_CAPABILITY_NONE;
69 #if defined( SYS_DARWIN )
70 int selectors[2] = { CTL_HW, HW_VECTORUNIT };
71 int i_has_altivec = 0;
72 size_t i_length = sizeof( i_has_altivec );
73 int i_error = sysctl( selectors, 2, &i_has_altivec, &i_length, NULL, 0);
75 i_capabilities |= CPU_CAPABILITY_FPU;
77 if( i_error == 0 && i_has_altivec != 0 )
78 i_capabilities |= CPU_CAPABILITY_ALTIVEC;
80 return i_capabilities;
82 #elif defined( __i386__ )
83 volatile unsigned int i_eax, i_ebx, i_ecx, i_edx;
84 volatile vlc_bool_t b_amd;
86 /* Needed for x86 CPU capabilities detection */
87 # define cpuid( reg ) \
88 asm volatile ( "pushl %%ebx\n\t" \
99 # if defined( CAN_COMPILE_SSE ) || defined ( CAN_COMPILE_3DNOW ) \
100 && defined( HAVE_SIGNAL_H )
101 void (*pf_sigill) (int) = signal( SIGILL, SigHandler );
104 i_capabilities |= CPU_CAPABILITY_FPU;
106 /* test for a 486 CPU */
107 asm volatile ( "pushl %%ebx\n\t"
110 "movl %%eax, %%ebx\n\t"
111 "xorl $0x200000, %%eax\n\t"
125 # if defined( CAN_COMPILE_SSE ) || defined ( CAN_COMPILE_3DNOW ) \
126 && defined( HAVE_SIGNAL_H )
127 signal( SIGILL, pf_sigill );
129 return i_capabilities;
132 i_capabilities |= CPU_CAPABILITY_486;
134 /* the CPU supports the CPUID instruction - get its level */
139 # if defined( CAN_COMPILE_SSE ) || defined ( CAN_COMPILE_3DNOW ) \
140 && defined( HAVE_SIGNAL_H )
141 signal( SIGILL, pf_sigill );
143 return i_capabilities;
146 /* FIXME: this isn't correct, since some 486s have cpuid */
147 i_capabilities |= CPU_CAPABILITY_586;
149 /* borrowed from mpeg2dec */
150 b_amd = ( i_ebx == 0x68747541 ) && ( i_ecx == 0x444d4163 )
151 && ( i_edx == 0x69746e65 );
153 /* test for the MMX flag */
156 if( ! (i_edx & 0x00800000) )
158 # if defined( CAN_COMPILE_SSE ) || defined ( CAN_COMPILE_3DNOW ) \
159 && defined( HAVE_SIGNAL_H )
160 signal( SIGILL, pf_sigill );
162 return i_capabilities;
165 i_capabilities |= CPU_CAPABILITY_MMX;
167 if( i_edx & 0x02000000 )
169 i_capabilities |= CPU_CAPABILITY_MMXEXT;
171 # ifdef CAN_COMPILE_SSE
172 /* We test if OS supports the SSE instructions */
173 psz_capability = "SSE";
176 if( setjmp( env ) == 0 )
178 /* Test a SSE instruction */
179 __asm__ __volatile__ ( "xorps %%xmm0,%%xmm0\n" : : );
184 i_capabilities |= CPU_CAPABILITY_SSE;
189 if( i_edx & 0x04000000 )
191 # if defined(CAN_COMPILE_SSE)
192 /* We test if OS supports the SSE instructions */
193 psz_capability = "SSE2";
196 if( setjmp( env ) == 0 )
198 /* Test a SSE2 instruction */
199 __asm__ __volatile__ ( "movupd %%xmm0, %%xmm0\n" : : );
204 i_capabilities |= CPU_CAPABILITY_SSE2;
209 /* test for additional capabilities */
212 if( i_eax < 0x80000001 )
214 # if defined( CAN_COMPILE_SSE ) || defined ( CAN_COMPILE_3DNOW ) \
215 && defined( HAVE_SIGNAL_H )
216 signal( SIGILL, pf_sigill );
218 return i_capabilities;
221 /* list these additional capabilities */
224 # ifdef CAN_COMPILE_3DNOW
225 if( i_edx & 0x80000000 )
227 psz_capability = "3D Now!";
230 if( setjmp( env ) == 0 )
232 /* Test a 3D Now! instruction */
233 __asm__ __volatile__ ( "pfadd %%mm0,%%mm0\n" "femms\n" : : );
238 i_capabilities |= CPU_CAPABILITY_3DNOW;
243 if( b_amd && ( i_edx & 0x00400000 ) )
245 i_capabilities |= CPU_CAPABILITY_MMXEXT;
248 # if defined( CAN_COMPILE_SSE ) || defined ( CAN_COMPILE_3DNOW ) \
249 && defined( HAVE_SIGNAL_H )
250 signal( SIGILL, pf_sigill );
252 return i_capabilities;
254 #elif defined( __powerpc__ )
256 # ifdef CAN_COMPILE_ALTIVEC && defined( HAVE_SIGNAL_H )
257 void (*pf_sigill) (int) = signal( SIGILL, SigHandler );
259 i_capabilities |= CPU_CAPABILITY_FPU;
263 if( setjmp( env ) == 0 )
265 asm volatile ("mtspr 256, %0\n\t"
266 "vand %%v0, %%v0, %%v0"
273 i_capabilities |= CPU_CAPABILITY_ALTIVEC;
276 signal( SIGILL, pf_sigill );
279 return i_capabilities;
281 #elif defined( __sparc__ )
283 i_capabilities |= CPU_CAPABILITY_FPU;
284 return i_capabilities;
286 #elif defined( _MSC_VER )
287 i_capabilities |= CPU_CAPABILITY_FPU;
288 return i_capabilities;
291 /* default behaviour */
292 return i_capabilities;
297 /*****************************************************************************
298 * SigHandler: system signal handler
299 *****************************************************************************
300 * This function is called when an illegal instruction signal is received by
301 * the program. We use this function to test OS and CPU capabilities
302 *****************************************************************************/
303 #if defined( HAVE_SIGNAL_H )
304 static void SigHandler( int i_signal )
306 /* Acknowledge the signal received */
310 sigrelse( i_signal );
313 #if defined( __i386__ )
314 fprintf( stderr, "warning: your CPU has %s instructions, but not your "
315 "operating system.\n", psz_capability );
316 fprintf( stderr, " some optimizations will be disabled unless "
317 "you upgrade your OS\n" );
318 # if defined( SYS_LINUX )
319 fprintf( stderr, " (for instance Linux kernel 2.4.x or later)\n" );