/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997-2004 Sam Lantinga

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Library General Public

License as published by the Free Software Foundation; either

version 2 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

Library General Public License for more details.

You should have received a copy of the GNU Library General Public

License along with this library; if not, write to the Free

Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Sam Lantinga

slouken@libsdl.org

*/

#ifdef SAVE_RCSID

static char rcsid =

"@(#) $Id$";

#endif

/* CPU feature detection for SDL */

#ifdef unix /* FIXME: Better setjmp detection? */

#define USE_SETJMP

#include <signal.h>

#include <setjmp.h>

#endif

#include "SDL.h"

#include "SDL_cpuinfo.h"

#ifdef MACOSX

#include <sys/sysctl.h> /* For AltiVec check */

#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

#ifdef USE_SETJMP

/* 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 // USE_SETJMP

static __inline__ int CPU_haveCPUID()

{

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)

__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:

}

#endif

return has_CPUID;

}

static __inline__ int CPU_getCPUIDFeatures()

{

int features = 0;

#if defined(__GNUC__) && ( defined(i386) || defined(__x86_64__) )

__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(_MSC_VER)

__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:

}

#endif

return features;

}

static __inline__ int CPU_getCPUIDFeaturesExt()

{

int features = 0;

#if defined(__GNUC__) && (defined(i386) || defined (__x86_64__) )

__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(_MSC_VER)

__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:

}

#endif

return features;

}

static __inline__ int CPU_haveRDTSC()

{

if ( CPU_haveCPUID() ) {

return (CPU_getCPUIDFeatures() & 0x00000010);

}

return 0;

}

static __inline__ int CPU_haveMMX()

{

if ( CPU_haveCPUID() ) {

return (CPU_getCPUIDFeatures() & 0x00800000);

}

return 0;

}

static __inline__ int CPU_haveMMXExt()

{

if ( CPU_haveCPUID() ) {

return (CPU_getCPUIDFeaturesExt() & 0x00400000);

}

return 0;

}

static __inline__ int CPU_have3DNow()

{

if ( CPU_haveCPUID() ) {

return (CPU_getCPUIDFeaturesExt() & 0x80000000);

}

return 0;

}

static __inline__ int CPU_have3DNowExt()

{

if ( CPU_haveCPUID() ) {

return (CPU_getCPUIDFeaturesExt() & 0x40000000);

}

return 0;

}

static __inline__ int CPU_haveSSE()

{

if ( CPU_haveCPUID() ) {

return (CPU_getCPUIDFeatures() & 0x02000000);

}

return 0;

}

static __inline__ int CPU_haveSSE2()

{

if ( CPU_haveCPUID() ) {

return (CPU_getCPUIDFeatures() & 0x04000000);

}

return 0;

}

static __inline__ int CPU_haveAltiVec()

{

volatile int altivec = 0;

#ifdef MACOSX

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 defined(USE_SETJMP) && defined(GCC_ALTIVEC)

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()

{

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()

{

if ( SDL_GetCPUFeatures() & CPU_HAS_RDTSC ) {

return SDL_TRUE;

}

return SDL_FALSE;

}

SDL_bool SDL_HasMMX()

{

if ( SDL_GetCPUFeatures() & CPU_HAS_MMX ) {

return SDL_TRUE;

}

return SDL_FALSE;

}

SDL_bool SDL_HasMMXExt()

{

if ( SDL_GetCPUFeatures() & CPU_HAS_MMXEXT ) {

return SDL_TRUE;

}

return SDL_FALSE;

}

SDL_bool SDL_Has3DNow()

{

if ( SDL_GetCPUFeatures() & CPU_HAS_3DNOW ) {

return SDL_TRUE;

}

return SDL_FALSE;

}

SDL_bool SDL_Has3DNowExt()

{

if ( SDL_GetCPUFeatures() & CPU_HAS_3DNOWEXT ) {

return SDL_TRUE;

}

return SDL_FALSE;

}

SDL_bool SDL_HasSSE()

{

if ( SDL_GetCPUFeatures() & CPU_HAS_SSE ) {

return SDL_TRUE;

}

return SDL_FALSE;

}

SDL_bool SDL_HasSSE2()

{

if ( SDL_GetCPUFeatures() & CPU_HAS_SSE2 ) {

return SDL_TRUE;

}

return SDL_FALSE;

}

SDL_bool SDL_HasAltiVec()

{

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 */