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      1 /*
      2     SDL - Simple DirectMedia Layer
      3     Copyright (C) 1997-2006 Sam Lantinga
      4 
      5     This library is free software; you can redistribute it and/or
      6     modify it under the terms of the GNU Lesser General Public
      7     License as published by the Free Software Foundation; either
      8     version 2.1 of the License, or (at your option) any later version.
      9 
     10     This library is distributed in the hope that it will be useful,
     11     but WITHOUT ANY WARRANTY; without even the implied warranty of
     12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13     Lesser General Public License for more details.
     14 
     15     You should have received a copy of the GNU Lesser General Public
     16     License along with this library; if not, write to the Free Software
     17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
     18 
     19     Sam Lantinga
     20     slouken (at) libsdl.org
     21 */
     22 #include "SDL_config.h"
     23 
     24 /* CPU feature detection for SDL */
     25 
     26 #include "SDL.h"
     27 #include "SDL_cpuinfo.h"
     28 
     29 #if defined(__MACOSX__) && defined(__ppc__)
     30 #include <sys/sysctl.h> /* For AltiVec check */
     31 #elif SDL_ALTIVEC_BLITTERS && HAVE_SETJMP
     32 #include <signal.h>
     33 #include <setjmp.h>
     34 #endif
     35 
     36 #define CPU_HAS_RDTSC	0x00000001
     37 #define CPU_HAS_MMX	0x00000002
     38 #define CPU_HAS_MMXEXT	0x00000004
     39 #define CPU_HAS_3DNOW	0x00000010
     40 #define CPU_HAS_3DNOWEXT 0x00000020
     41 #define CPU_HAS_SSE	0x00000040
     42 #define CPU_HAS_SSE2	0x00000080
     43 #define CPU_HAS_ALTIVEC	0x00000100
     44 
     45 #if SDL_ALTIVEC_BLITTERS && HAVE_SETJMP && !__MACOSX__
     46 /* This is the brute force way of detecting instruction sets...
     47    the idea is borrowed from the libmpeg2 library - thanks!
     48  */
     49 static jmp_buf jmpbuf;
     50 static void illegal_instruction(int sig)
     51 {
     52 	longjmp(jmpbuf, 1);
     53 }
     54 #endif /* HAVE_SETJMP */
     55 
     56 static __inline__ int CPU_haveCPUID(void)
     57 {
     58 	int has_CPUID = 0;
     59 #if defined(__GNUC__) && defined(i386)
     60 	__asm__ (
     61 "        pushfl                      # Get original EFLAGS             \n"
     62 "        popl    %%eax                                                 \n"
     63 "        movl    %%eax,%%ecx                                           \n"
     64 "        xorl    $0x200000,%%eax     # Flip ID bit in EFLAGS           \n"
     65 "        pushl   %%eax               # Save new EFLAGS value on stack  \n"
     66 "        popfl                       # Replace current EFLAGS value    \n"
     67 "        pushfl                      # Get new EFLAGS                  \n"
     68 "        popl    %%eax               # Store new EFLAGS in EAX         \n"
     69 "        xorl    %%ecx,%%eax         # Can not toggle ID bit,          \n"
     70 "        jz      1f                  # Processor=80486                 \n"
     71 "        movl    $1,%0               # We have CPUID support           \n"
     72 "1:                                                                    \n"
     73 	: "=m" (has_CPUID)
     74 	:
     75 	: "%eax", "%ecx"
     76 	);
     77 #elif defined(__GNUC__) && defined(__x86_64__)
     78 /* Technically, if this is being compiled under __x86_64__ then it has
     79 CPUid by definition.  But it's nice to be able to prove it.  :)      */
     80 	__asm__ (
     81 "        pushfq                      # Get original EFLAGS             \n"
     82 "        popq    %%rax                                                 \n"
     83 "        movq    %%rax,%%rcx                                           \n"
     84 "        xorl    $0x200000,%%eax     # Flip ID bit in EFLAGS           \n"
     85 "        pushq   %%rax               # Save new EFLAGS value on stack  \n"
     86 "        popfq                       # Replace current EFLAGS value    \n"
     87 "        pushfq                      # Get new EFLAGS                  \n"
     88 "        popq    %%rax               # Store new EFLAGS in EAX         \n"
     89 "        xorl    %%ecx,%%eax         # Can not toggle ID bit,          \n"
     90 "        jz      1f                  # Processor=80486                 \n"
     91 "        movl    $1,%0               # We have CPUID support           \n"
     92 "1:                                                                    \n"
     93 	: "=m" (has_CPUID)
     94 	:
     95 	: "%rax", "%rcx"
     96 	);
     97 #elif (defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)
     98 	__asm {
     99         pushfd                      ; Get original EFLAGS
    100         pop     eax
    101         mov     ecx, eax
    102         xor     eax, 200000h        ; Flip ID bit in EFLAGS
    103         push    eax                 ; Save new EFLAGS value on stack
    104         popfd                       ; Replace current EFLAGS value
    105         pushfd                      ; Get new EFLAGS
    106         pop     eax                 ; Store new EFLAGS in EAX
    107         xor     eax, ecx            ; Can not toggle ID bit,
    108         jz      done                ; Processor=80486
    109         mov     has_CPUID,1         ; We have CPUID support
    110 done:
    111 	}
    112 #elif defined(__sun) && defined(__i386)
    113 	__asm (
    114 "       pushfl                 \n"
    115 "	popl    %eax           \n"
    116 "	movl    %eax,%ecx      \n"
    117 "	xorl    $0x200000,%eax \n"
    118 "	pushl   %eax           \n"
    119 "	popfl                  \n"
    120 "	pushfl                 \n"
    121 "	popl    %eax           \n"
    122 "	xorl    %ecx,%eax      \n"
    123 "	jz      1f             \n"
    124 "	movl    $1,-8(%ebp)    \n"
    125 "1:                            \n"
    126 	);
    127 #elif defined(__sun) && defined(__amd64)
    128 	__asm (
    129 "       pushfq                 \n"
    130 "       popq    %rax           \n"
    131 "       movq    %rax,%rcx      \n"
    132 "       xorl    $0x200000,%eax \n"
    133 "       pushq   %rax           \n"
    134 "       popfq                  \n"
    135 "       pushfq                 \n"
    136 "       popq    %rax           \n"
    137 "       xorl    %ecx,%eax      \n"
    138 "       jz      1f             \n"
    139 "       movl    $1,-8(%rbp)    \n"
    140 "1:                            \n"
    141 	);
    142 #endif
    143 	return has_CPUID;
    144 }
    145 
    146 static __inline__ int CPU_getCPUIDFeatures(void)
    147 {
    148 	int features = 0;
    149 #if defined(__GNUC__) && ( defined(i386) || defined(__x86_64__) )
    150 	__asm__ (
    151 "        movl    %%ebx,%%edi\n"
    152 "        xorl    %%eax,%%eax         # Set up for CPUID instruction    \n"
    153 "        cpuid                       # Get and save vendor ID          \n"
    154 "        cmpl    $1,%%eax            # Make sure 1 is valid input for CPUID\n"
    155 "        jl      1f                  # We dont have the CPUID instruction\n"
    156 "        xorl    %%eax,%%eax                                           \n"
    157 "        incl    %%eax                                                 \n"
    158 "        cpuid                       # Get family/model/stepping/features\n"
    159 "        movl    %%edx,%0                                              \n"
    160 "1:                                                                    \n"
    161 "        movl    %%edi,%%ebx\n"
    162 	: "=m" (features)
    163 	:
    164 	: "%eax", "%ecx", "%edx", "%edi"
    165 	);
    166 #elif (defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)
    167 	__asm {
    168         xor     eax, eax            ; Set up for CPUID instruction
    169         cpuid                       ; Get and save vendor ID
    170         cmp     eax, 1              ; Make sure 1 is valid input for CPUID
    171         jl      done                ; We dont have the CPUID instruction
    172         xor     eax, eax
    173         inc     eax
    174         cpuid                       ; Get family/model/stepping/features
    175         mov     features, edx
    176 done:
    177 	}
    178 #elif defined(__sun) && (defined(__i386) || defined(__amd64))
    179 	    __asm(
    180 "        movl    %ebx,%edi\n"
    181 "        xorl    %eax,%eax         \n"
    182 "        cpuid                     \n"
    183 "        cmpl    $1,%eax           \n"
    184 "        jl      1f                \n"
    185 "        xorl    %eax,%eax         \n"
    186 "        incl    %eax              \n"
    187 "        cpuid                     \n"
    188 #ifdef __i386
    189 "        movl    %edx,-8(%ebp)     \n"
    190 #else
    191 "        movl    %edx,-8(%rbp)     \n"
    192 #endif
    193 "1:                                \n"
    194 "        movl    %edi,%ebx\n" );
    195 #endif
    196 	return features;
    197 }
    198 
    199 static __inline__ int CPU_getCPUIDFeaturesExt(void)
    200 {
    201 	int features = 0;
    202 #if defined(__GNUC__) && (defined(i386) || defined (__x86_64__) )
    203 	__asm__ (
    204 "        movl    %%ebx,%%edi\n"
    205 "        movl    $0x80000000,%%eax   # Query for extended functions    \n"
    206 "        cpuid                       # Get extended function limit     \n"
    207 "        cmpl    $0x80000001,%%eax                                     \n"
    208 "        jl      1f                  # Nope, we dont have function 800000001h\n"
    209 "        movl    $0x80000001,%%eax   # Setup extended function 800000001h\n"
    210 "        cpuid                       # and get the information         \n"
    211 "        movl    %%edx,%0                                              \n"
    212 "1:                                                                    \n"
    213 "        movl    %%edi,%%ebx\n"
    214 	: "=m" (features)
    215 	:
    216 	: "%eax", "%ecx", "%edx", "%edi"
    217 	);
    218 #elif (defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)
    219 	__asm {
    220         mov     eax,80000000h       ; Query for extended functions
    221         cpuid                       ; Get extended function limit
    222         cmp     eax,80000001h
    223         jl      done                ; Nope, we dont have function 800000001h
    224         mov     eax,80000001h       ; Setup extended function 800000001h
    225         cpuid                       ; and get the information
    226         mov     features,edx
    227 done:
    228 	}
    229 #elif defined(__sun) && ( defined(__i386) || defined(__amd64) )
    230 	    __asm (
    231 "        movl    %ebx,%edi\n"
    232 "        movl    $0x80000000,%eax \n"
    233 "        cpuid                    \n"
    234 "        cmpl    $0x80000001,%eax \n"
    235 "        jl      1f               \n"
    236 "        movl    $0x80000001,%eax \n"
    237 "        cpuid                    \n"
    238 #ifdef __i386
    239 "        movl    %edx,-8(%ebp)   \n"
    240 #else
    241 "        movl    %edx,-8(%rbp)   \n"
    242 #endif
    243 "1:                               \n"
    244 "        movl    %edi,%ebx\n"
    245 	    );
    246 #endif
    247 	return features;
    248 }
    249 
    250 static __inline__ int CPU_haveRDTSC(void)
    251 {
    252 	if ( CPU_haveCPUID() ) {
    253 		return (CPU_getCPUIDFeatures() & 0x00000010);
    254 	}
    255 	return 0;
    256 }
    257 
    258 static __inline__ int CPU_haveMMX(void)
    259 {
    260 	if ( CPU_haveCPUID() ) {
    261 		return (CPU_getCPUIDFeatures() & 0x00800000);
    262 	}
    263 	return 0;
    264 }
    265 
    266 static __inline__ int CPU_haveMMXExt(void)
    267 {
    268 	if ( CPU_haveCPUID() ) {
    269 		return (CPU_getCPUIDFeaturesExt() & 0x00400000);
    270 	}
    271 	return 0;
    272 }
    273 
    274 static __inline__ int CPU_have3DNow(void)
    275 {
    276 	if ( CPU_haveCPUID() ) {
    277 		return (CPU_getCPUIDFeaturesExt() & 0x80000000);
    278 	}
    279 	return 0;
    280 }
    281 
    282 static __inline__ int CPU_have3DNowExt(void)
    283 {
    284 	if ( CPU_haveCPUID() ) {
    285 		return (CPU_getCPUIDFeaturesExt() & 0x40000000);
    286 	}
    287 	return 0;
    288 }
    289 
    290 static __inline__ int CPU_haveSSE(void)
    291 {
    292 	if ( CPU_haveCPUID() ) {
    293 		return (CPU_getCPUIDFeatures() & 0x02000000);
    294 	}
    295 	return 0;
    296 }
    297 
    298 static __inline__ int CPU_haveSSE2(void)
    299 {
    300 	if ( CPU_haveCPUID() ) {
    301 		return (CPU_getCPUIDFeatures() & 0x04000000);
    302 	}
    303 	return 0;
    304 }
    305 
    306 static __inline__ int CPU_haveAltiVec(void)
    307 {
    308 	volatile int altivec = 0;
    309 #if defined(__MACOSX__) && defined(__ppc__)
    310 	int selectors[2] = { CTL_HW, HW_VECTORUNIT };
    311 	int hasVectorUnit = 0;
    312 	size_t length = sizeof(hasVectorUnit);
    313 	int error = sysctl(selectors, 2, &hasVectorUnit, &length, NULL, 0);
    314 	if( 0 == error )
    315 		altivec = (hasVectorUnit != 0);
    316 #elif SDL_ALTIVEC_BLITTERS && HAVE_SETJMP
    317 	void (*handler)(int sig);
    318 	handler = signal(SIGILL, illegal_instruction);
    319 	if ( setjmp(jmpbuf) == 0 ) {
    320 		asm volatile ("mtspr 256, %0\n\t"
    321 			      "vand %%v0, %%v0, %%v0"
    322 			      :
    323 			      : "r" (-1));
    324 		altivec = 1;
    325 	}
    326 	signal(SIGILL, handler);
    327 #endif
    328 	return altivec;
    329 }
    330 
    331 static Uint32 SDL_CPUFeatures = 0xFFFFFFFF;
    332 
    333 static Uint32 SDL_GetCPUFeatures(void)
    334 {
    335 	if ( SDL_CPUFeatures == 0xFFFFFFFF ) {
    336 		SDL_CPUFeatures = 0;
    337 		if ( CPU_haveRDTSC() ) {
    338 			SDL_CPUFeatures |= CPU_HAS_RDTSC;
    339 		}
    340 		if ( CPU_haveMMX() ) {
    341 			SDL_CPUFeatures |= CPU_HAS_MMX;
    342 		}
    343 		if ( CPU_haveMMXExt() ) {
    344 			SDL_CPUFeatures |= CPU_HAS_MMXEXT;
    345 		}
    346 		if ( CPU_have3DNow() ) {
    347 			SDL_CPUFeatures |= CPU_HAS_3DNOW;
    348 		}
    349 		if ( CPU_have3DNowExt() ) {
    350 			SDL_CPUFeatures |= CPU_HAS_3DNOWEXT;
    351 		}
    352 		if ( CPU_haveSSE() ) {
    353 			SDL_CPUFeatures |= CPU_HAS_SSE;
    354 		}
    355 		if ( CPU_haveSSE2() ) {
    356 			SDL_CPUFeatures |= CPU_HAS_SSE2;
    357 		}
    358 		if ( CPU_haveAltiVec() ) {
    359 			SDL_CPUFeatures |= CPU_HAS_ALTIVEC;
    360 		}
    361 	}
    362 	return SDL_CPUFeatures;
    363 }
    364 
    365 SDL_bool SDL_HasRDTSC(void)
    366 {
    367 	if ( SDL_GetCPUFeatures() & CPU_HAS_RDTSC ) {
    368 		return SDL_TRUE;
    369 	}
    370 	return SDL_FALSE;
    371 }
    372 
    373 SDL_bool SDL_HasMMX(void)
    374 {
    375 	if ( SDL_GetCPUFeatures() & CPU_HAS_MMX ) {
    376 		return SDL_TRUE;
    377 	}
    378 	return SDL_FALSE;
    379 }
    380 
    381 SDL_bool SDL_HasMMXExt(void)
    382 {
    383 	if ( SDL_GetCPUFeatures() & CPU_HAS_MMXEXT ) {
    384 		return SDL_TRUE;
    385 	}
    386 	return SDL_FALSE;
    387 }
    388 
    389 SDL_bool SDL_Has3DNow(void)
    390 {
    391 	if ( SDL_GetCPUFeatures() & CPU_HAS_3DNOW ) {
    392 		return SDL_TRUE;
    393 	}
    394 	return SDL_FALSE;
    395 }
    396 
    397 SDL_bool SDL_Has3DNowExt(void)
    398 {
    399 	if ( SDL_GetCPUFeatures() & CPU_HAS_3DNOWEXT ) {
    400 		return SDL_TRUE;
    401 	}
    402 	return SDL_FALSE;
    403 }
    404 
    405 SDL_bool SDL_HasSSE(void)
    406 {
    407 	if ( SDL_GetCPUFeatures() & CPU_HAS_SSE ) {
    408 		return SDL_TRUE;
    409 	}
    410 	return SDL_FALSE;
    411 }
    412 
    413 SDL_bool SDL_HasSSE2(void)
    414 {
    415 	if ( SDL_GetCPUFeatures() & CPU_HAS_SSE2 ) {
    416 		return SDL_TRUE;
    417 	}
    418 	return SDL_FALSE;
    419 }
    420 
    421 SDL_bool SDL_HasAltiVec(void)
    422 {
    423 	if ( SDL_GetCPUFeatures() & CPU_HAS_ALTIVEC ) {
    424 		return SDL_TRUE;
    425 	}
    426 	return SDL_FALSE;
    427 }
    428 
    429 #ifdef TEST_MAIN
    430 
    431 #include <stdio.h>
    432 
    433 int main()
    434 {
    435 	printf("RDTSC: %d\n", SDL_HasRDTSC());
    436 	printf("MMX: %d\n", SDL_HasMMX());
    437 	printf("MMXExt: %d\n", SDL_HasMMXExt());
    438 	printf("3DNow: %d\n", SDL_Has3DNow());
    439 	printf("3DNowExt: %d\n", SDL_Has3DNowExt());
    440 	printf("SSE: %d\n", SDL_HasSSE());
    441 	printf("SSE2: %d\n", SDL_HasSSE2());
    442 	printf("AltiVec: %d\n", SDL_HasAltiVec());
    443 	return 0;
    444 }
    445 
    446 #endif /* TEST_MAIN */
    447