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view src/cpuinfo/SDL_cpuinfo.c @ 4223:63fd67e17705 SDL-1.2

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Fixed bug #727 Lorenzo Desole 2009-04-19 07:36:10 PDT I am one of the developers of a multimedia application (My Media System MMS), which uses SDL. MMS is normally running in fullscreen mode but it switches it off before launching external applications (mplayer, xine, etc.). The problem with fullscreen is that when the latter is switched off either via SDL_WM_ToggleFullScreen() or SDL_SetVideoMode(), SDL compares the current screen sizes with the ones saved when the video system was initted, and if they don't match, it calls XF86VidModeSwitchToMode() to switch to the old modeline. This makes it impossible for external programs and for MMS itself to use RandR to change the screen size, because next time fullscreen mode is turned off, it bombs out with the following error: X Error of failed request: BadValue (integer parameter out of range for operation) Major opcode of failed request: 136 (XFree86-VidModeExtension) Minor opcode of failed request: 10 (XF86VidModeSwitchToMode) [...] Obviously this happens only if the new screen resolution is smaller than the original one and XF86VidModeSwitchToMode() can't succeed. I couldn't find any way to inform SDL that the screen resolution it uses as reference is no longer valid. This can be fixed by adding "save_mode(this)" to ./src/video/x11/SDL_x11modes.c, API X11_EnterFullScreen(_THIS), like this: int X11_EnterFullScreen(_THIS) { int okay; + save_mode(this); I can't rule out possible side effects, but I don't see any. While I admit this is a minor issue for the general users, it is a major showstopper for our program where the ability to change screen resolution and refresh rate according to the movie being played, is very important. Thanks in advance.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 21 Sep 2009 11:14:36 +0000
parents 0a9a29fc00c2
children fa62bede8038
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* CPU feature detection for SDL */

#include "SDL.h"
#include "SDL_cpuinfo.h"

#if defined(__MACOSX__) && defined(__ppc__)
#include <sys/sysctl.h> /* For AltiVec check */
#elif SDL_ALTIVEC_BLITTERS && HAVE_SETJMP
#include <signal.h>
#include <setjmp.h>
#endif

#define CPU_HAS_RDTSC	0x00000001
#define CPU_HAS_MMX	0x00000002
#define CPU_HAS_MMXEXT	0x00000004
#define CPU_HAS_3DNOW	0x00000010
#define CPU_HAS_3DNOWEXT 0x00000020
#define CPU_HAS_SSE	0x00000040
#define CPU_HAS_SSE2	0x00000080
#define CPU_HAS_ALTIVEC	0x00000100

#if SDL_ALTIVEC_BLITTERS && HAVE_SETJMP && !__MACOSX__
/* This is the brute force way of detecting instruction sets...
   the idea is borrowed from the libmpeg2 library - thanks!
 */
static jmp_buf jmpbuf;
static void illegal_instruction(int sig)
{
	longjmp(jmpbuf, 1);
}
#endif /* HAVE_SETJMP */

static __inline__ int CPU_haveCPUID(void)
{
	int has_CPUID = 0;
#if defined(__GNUC__) && defined(i386)
	__asm__ (
"        pushfl                      # Get original EFLAGS             \n"
"        popl    %%eax                                                 \n"
"        movl    %%eax,%%ecx                                           \n"
"        xorl    $0x200000,%%eax     # Flip ID bit in EFLAGS           \n"
"        pushl   %%eax               # Save new EFLAGS value on stack  \n"
"        popfl                       # Replace current EFLAGS value    \n"
"        pushfl                      # Get new EFLAGS                  \n"
"        popl    %%eax               # Store new EFLAGS in EAX         \n"
"        xorl    %%ecx,%%eax         # Can not toggle ID bit,          \n"
"        jz      1f                  # Processor=80486                 \n"
"        movl    $1,%0               # We have CPUID support           \n"
"1:                                                                    \n"
	: "=m" (has_CPUID)
	:
	: "%eax", "%ecx"
	);
#elif defined(__GNUC__) && defined(__x86_64__)
/* Technically, if this is being compiled under __x86_64__ then it has 
CPUid by definition.  But it's nice to be able to prove it.  :)      */
	__asm__ (
"        pushfq                      # Get original EFLAGS             \n"
"        popq    %%rax                                                 \n"
"        movq    %%rax,%%rcx                                           \n"
"        xorl    $0x200000,%%eax     # Flip ID bit in EFLAGS           \n"
"        pushq   %%rax               # Save new EFLAGS value on stack  \n"
"        popfq                       # Replace current EFLAGS value    \n"
"        pushfq                      # Get new EFLAGS                  \n"
"        popq    %%rax               # Store new EFLAGS in EAX         \n"
"        xorl    %%ecx,%%eax         # Can not toggle ID bit,          \n"
"        jz      1f                  # Processor=80486                 \n"
"        movl    $1,%0               # We have CPUID support           \n"
"1:                                                                    \n"
	: "=m" (has_CPUID)
	:
	: "%rax", "%rcx"
	);
#elif (defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)
	__asm {
        pushfd                      ; Get original EFLAGS
        pop     eax
        mov     ecx, eax
        xor     eax, 200000h        ; Flip ID bit in EFLAGS
        push    eax                 ; Save new EFLAGS value on stack
        popfd                       ; Replace current EFLAGS value
        pushfd                      ; Get new EFLAGS
        pop     eax                 ; Store new EFLAGS in EAX
        xor     eax, ecx            ; Can not toggle ID bit,
        jz      done                ; Processor=80486
        mov     has_CPUID,1         ; We have CPUID support
done:
	}
#elif defined(__sun) && defined(__i386)
	__asm (
"       pushfl                 \n"
"	popl    %eax           \n"
"	movl    %eax,%ecx      \n"
"	xorl    $0x200000,%eax \n"
"	pushl   %eax           \n"
"	popfl                  \n"
"	pushfl                 \n"
"	popl    %eax           \n"
"	xorl    %ecx,%eax      \n"
"	jz      1f             \n"
"	movl    $1,-8(%ebp)    \n"
"1:                            \n"
	);
#elif defined(__sun) && defined(__amd64)
	__asm (
"       pushfq                 \n"
"       popq    %rax           \n"
"       movq    %rax,%rcx      \n"
"       xorl    $0x200000,%eax \n"
"       pushq   %rax           \n"
"       popfq                  \n"
"       pushfq                 \n"
"       popq    %rax           \n"
"       xorl    %ecx,%eax      \n"
"       jz      1f             \n"
"       movl    $1,-8(%rbp)    \n"
"1:                            \n"
	);
#endif
	return has_CPUID;
}

static __inline__ int CPU_getCPUIDFeatures(void)
{
	int features = 0;
#if defined(__GNUC__) && defined(i386)
	__asm__ (
"        movl    %%ebx,%%edi\n"
"        xorl    %%eax,%%eax         # Set up for CPUID instruction    \n"
"        cpuid                       # Get and save vendor ID          \n"
"        cmpl    $1,%%eax            # Make sure 1 is valid input for CPUID\n"
"        jl      1f                  # We dont have the CPUID instruction\n"
"        xorl    %%eax,%%eax                                           \n"
"        incl    %%eax                                                 \n"
"        cpuid                       # Get family/model/stepping/features\n"
"        movl    %%edx,%0                                              \n"
"1:                                                                    \n"
"        movl    %%edi,%%ebx\n"
	: "=m" (features)
	:
	: "%eax", "%ecx", "%edx", "%edi"
	);
#elif defined(__GNUC__) && defined(__x86_64__)
	__asm__ (
"        movq    %%rbx,%%rdi\n"
"        xorl    %%eax,%%eax         # Set up for CPUID instruction    \n"
"        cpuid                       # Get and save vendor ID          \n"
"        cmpl    $1,%%eax            # Make sure 1 is valid input for CPUID\n"
"        jl      1f                  # We dont have the CPUID instruction\n"
"        xorl    %%eax,%%eax                                           \n"
"        incl    %%eax                                                 \n"
"        cpuid                       # Get family/model/stepping/features\n"
"        movl    %%edx,%0                                              \n"
"1:                                                                    \n"
"        movq    %%rdi,%%rbx\n"
	: "=m" (features)
	:
	: "%rax", "%rcx", "%rdx", "%rdi"
	);
#elif (defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)
	__asm {
        xor     eax, eax            ; Set up for CPUID instruction
        cpuid                       ; Get and save vendor ID
        cmp     eax, 1              ; Make sure 1 is valid input for CPUID
        jl      done                ; We dont have the CPUID instruction
        xor     eax, eax
        inc     eax
        cpuid                       ; Get family/model/stepping/features
        mov     features, edx
done:
	}
#elif defined(__sun) && (defined(__i386) || defined(__amd64))
	    __asm(
"        movl    %ebx,%edi\n"
"        xorl    %eax,%eax         \n"
"        cpuid                     \n"
"        cmpl    $1,%eax           \n"
"        jl      1f                \n"
"        xorl    %eax,%eax         \n"
"        incl    %eax              \n"
"        cpuid                     \n"
#ifdef __i386
"        movl    %edx,-8(%ebp)     \n"
#else
"        movl    %edx,-8(%rbp)     \n"
#endif
"1:                                \n"
"        movl    %edi,%ebx\n" );
#endif
	return features;
}

static __inline__ int CPU_getCPUIDFeaturesExt(void)
{
	int features = 0;
#if defined(__GNUC__) && defined(i386)
	__asm__ (
"        movl    %%ebx,%%edi\n"
"        movl    $0x80000000,%%eax   # Query for extended functions    \n"
"        cpuid                       # Get extended function limit     \n"
"        cmpl    $0x80000001,%%eax                                     \n"
"        jl      1f                  # Nope, we dont have function 800000001h\n"
"        movl    $0x80000001,%%eax   # Setup extended function 800000001h\n"
"        cpuid                       # and get the information         \n"
"        movl    %%edx,%0                                              \n"
"1:                                                                    \n"
"        movl    %%edi,%%ebx\n"
	: "=m" (features)
	:
	: "%eax", "%ecx", "%edx", "%edi"
	);
#elif defined(__GNUC__) && defined (__x86_64__)
	__asm__ (
"        movq    %%rbx,%%rdi\n"
"        movl    $0x80000000,%%eax   # Query for extended functions    \n"
"        cpuid                       # Get extended function limit     \n"
"        cmpl    $0x80000001,%%eax                                     \n"
"        jl      1f                  # Nope, we dont have function 800000001h\n"
"        movl    $0x80000001,%%eax   # Setup extended function 800000001h\n"
"        cpuid                       # and get the information         \n"
"        movl    %%edx,%0                                              \n"
"1:                                                                    \n"
"        movq    %%rdi,%%rbx\n"
	: "=m" (features)
	:
	: "%rax", "%rcx", "%rdx", "%rdi"
	);
#elif (defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)
	__asm {
        mov     eax,80000000h       ; Query for extended functions
        cpuid                       ; Get extended function limit
        cmp     eax,80000001h
        jl      done                ; Nope, we dont have function 800000001h
        mov     eax,80000001h       ; Setup extended function 800000001h
        cpuid                       ; and get the information
        mov     features,edx
done:
	}
#elif defined(__sun) && ( defined(__i386) || defined(__amd64) )
	    __asm (
"        movl    %ebx,%edi\n"
"        movl    $0x80000000,%eax \n"
"        cpuid                    \n"
"        cmpl    $0x80000001,%eax \n"
"        jl      1f               \n"
"        movl    $0x80000001,%eax \n"
"        cpuid                    \n"
#ifdef __i386
"        movl    %edx,-8(%ebp)   \n"
#else
"        movl    %edx,-8(%rbp)   \n"
#endif
"1:                               \n"
"        movl    %edi,%ebx\n"
	    );
#endif
	return features;
}

static __inline__ int CPU_haveRDTSC(void)
{
	if ( CPU_haveCPUID() ) {
		return (CPU_getCPUIDFeatures() & 0x00000010);
	}
	return 0;
}

static __inline__ int CPU_haveMMX(void)
{
	if ( CPU_haveCPUID() ) {
		return (CPU_getCPUIDFeatures() & 0x00800000);
	}
	return 0;
}

static __inline__ int CPU_haveMMXExt(void)
{
	if ( CPU_haveCPUID() ) {
		return (CPU_getCPUIDFeaturesExt() & 0x00400000);
	}
	return 0;
}

static __inline__ int CPU_have3DNow(void)
{
	if ( CPU_haveCPUID() ) {
		return (CPU_getCPUIDFeaturesExt() & 0x80000000);
	}
	return 0;
}

static __inline__ int CPU_have3DNowExt(void)
{
	if ( CPU_haveCPUID() ) {
		return (CPU_getCPUIDFeaturesExt() & 0x40000000);
	}
	return 0;
}

static __inline__ int CPU_haveSSE(void)
{
	if ( CPU_haveCPUID() ) {
		return (CPU_getCPUIDFeatures() & 0x02000000);
	}
	return 0;
}

static __inline__ int CPU_haveSSE2(void)
{
	if ( CPU_haveCPUID() ) {
		return (CPU_getCPUIDFeatures() & 0x04000000);
	}
	return 0;
}

static __inline__ int CPU_haveAltiVec(void)
{
	volatile int altivec = 0;
#if defined(__MACOSX__) && defined(__ppc__)
	int selectors[2] = { CTL_HW, HW_VECTORUNIT }; 
	int hasVectorUnit = 0; 
	size_t length = sizeof(hasVectorUnit); 
	int error = sysctl(selectors, 2, &hasVectorUnit, &length, NULL, 0); 
	if( 0 == error )
		altivec = (hasVectorUnit != 0); 
#elif SDL_ALTIVEC_BLITTERS && HAVE_SETJMP
	void (*handler)(int sig);
	handler = signal(SIGILL, illegal_instruction);
	if ( setjmp(jmpbuf) == 0 ) {
		asm volatile ("mtspr 256, %0\n\t"
			      "vand %%v0, %%v0, %%v0"
			      :
			      : "r" (-1));
		altivec = 1;
	}
	signal(SIGILL, handler);
#endif
	return altivec; 
}

static Uint32 SDL_CPUFeatures = 0xFFFFFFFF;

static Uint32 SDL_GetCPUFeatures(void)
{
	if ( SDL_CPUFeatures == 0xFFFFFFFF ) {
		SDL_CPUFeatures = 0;
		if ( CPU_haveRDTSC() ) {
			SDL_CPUFeatures |= CPU_HAS_RDTSC;
		}
		if ( CPU_haveMMX() ) {
			SDL_CPUFeatures |= CPU_HAS_MMX;
		}
		if ( CPU_haveMMXExt() ) {
			SDL_CPUFeatures |= CPU_HAS_MMXEXT;
		}
		if ( CPU_have3DNow() ) {
			SDL_CPUFeatures |= CPU_HAS_3DNOW;
		}
		if ( CPU_have3DNowExt() ) {
			SDL_CPUFeatures |= CPU_HAS_3DNOWEXT;
		}
		if ( CPU_haveSSE() ) {
			SDL_CPUFeatures |= CPU_HAS_SSE;
		}
		if ( CPU_haveSSE2() ) {
			SDL_CPUFeatures |= CPU_HAS_SSE2;
		}
		if ( CPU_haveAltiVec() ) {
			SDL_CPUFeatures |= CPU_HAS_ALTIVEC;
		}
	}
	return SDL_CPUFeatures;
}

SDL_bool SDL_HasRDTSC(void)
{
	if ( SDL_GetCPUFeatures() & CPU_HAS_RDTSC ) {
		return SDL_TRUE;
	}
	return SDL_FALSE;
}

SDL_bool SDL_HasMMX(void)
{
	if ( SDL_GetCPUFeatures() & CPU_HAS_MMX ) {
		return SDL_TRUE;
	}
	return SDL_FALSE;
}

SDL_bool SDL_HasMMXExt(void)
{
	if ( SDL_GetCPUFeatures() & CPU_HAS_MMXEXT ) {
		return SDL_TRUE;
	}
	return SDL_FALSE;
}

SDL_bool SDL_Has3DNow(void)
{
	if ( SDL_GetCPUFeatures() & CPU_HAS_3DNOW ) {
		return SDL_TRUE;
	}
	return SDL_FALSE;
}

SDL_bool SDL_Has3DNowExt(void)
{
	if ( SDL_GetCPUFeatures() & CPU_HAS_3DNOWEXT ) {
		return SDL_TRUE;
	}
	return SDL_FALSE;
}

SDL_bool SDL_HasSSE(void)
{
	if ( SDL_GetCPUFeatures() & CPU_HAS_SSE ) {
		return SDL_TRUE;
	}
	return SDL_FALSE;
}

SDL_bool SDL_HasSSE2(void)
{
	if ( SDL_GetCPUFeatures() & CPU_HAS_SSE2 ) {
		return SDL_TRUE;
	}
	return SDL_FALSE;
}

SDL_bool SDL_HasAltiVec(void)
{
	if ( SDL_GetCPUFeatures() & CPU_HAS_ALTIVEC ) {
		return SDL_TRUE;
	}
	return SDL_FALSE;
}

#ifdef TEST_MAIN

#include <stdio.h>

int main()
{
	printf("RDTSC: %d\n", SDL_HasRDTSC());
	printf("MMX: %d\n", SDL_HasMMX());
	printf("MMXExt: %d\n", SDL_HasMMXExt());
	printf("3DNow: %d\n", SDL_Has3DNow());
	printf("3DNowExt: %d\n", SDL_Has3DNowExt());
	printf("SSE: %d\n", SDL_HasSSE());
	printf("SSE2: %d\n", SDL_HasSSE2());
	printf("AltiVec: %d\n", SDL_HasAltiVec());
	return 0;
}

#endif /* TEST_MAIN */