/*
 * Cpu detection code, extracted from mmx.h ((c)1997-99 by H. Dietz
 * and R. Fisher). Converted to C and improved by Fabrice Bellard
 *
 * This file is part of uniaud.dll.
 *
 * Copyright (c) 2010 Mensys BV
 * Copyright (c) 2007 Vlad Stelmahovsky aka Vladest
 *
 * 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 3 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 and the GNU General Public License along with this library.
 * If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
//#include "../dsputil.h"
#define MM_MMX    0x0001 /* standard MMX */
#define MM_3DNOW  0x0004 /* AMD 3DNOW */
#define MM_MMXEXT 0x0002 /* SSE integer functions or AMD MMX ext */
#define MM_SSE    0x0008 /* SSE functions */
#define MM_SSE2   0x0010 /* PIV SSE2 functions */


/* ebx saving is necessary for PIC. gcc seems unable to see it alone */

/* Function to test if multimedia instructions are supported...  */
int mm_support(void)
{
    int rval;
    int Reax, Rebx, Recx, Redx;

#pragma disable_message (200)
void cpuid(unsigned long index);
#pragma aux cpuid = \
	"mov esi, ebx" \
	"cpuid" \
	"xchg esi, ebx" \
	"mov Reax, eax" \
	"mov Rebx, esi" \
	"mov Recx, ecx" \
	"mov Redx, edx" \
	parm [eax] \
	modify [eax ebx ecx edx esi]

	_asm {
		/* See if CPUID instruction is supported ... */
		/* ... Get copies of EFLAGS into eax and ecx */
		pushfd
		pop		eax
		mov		Recx, eax

		/* ... Toggle the ID bit in one copy and store */
		/*     to the EFLAGS reg */
		xor		eax, 0x00200000
		push	eax
		popfd

		/* ... Get the (hopefully modified) EFLAGS */
		pushfd
		pop		Reax		
	}

    if (Reax == Recx) return 0; /* CPUID not supported */

    cpuid(0);

    if (Rebx == 0x756e6547 &&
        Redx == 0x49656e69 &&
        Recx == 0x6c65746e) {

        /* intel */
    inteltest:
        cpuid(1);
        if ((Redx & 0x00800000) == 0) return 0;
        rval = MM_MMX;
        if (Redx & 0x02000000) rval |= MM_MMXEXT | MM_SSE;
        if (Redx & 0x04000000) rval |= MM_SSE2;
        return rval;
    } else if (Rebx == 0x68747541 &&
               Redx == 0x69746e65 &&
               Recx == 0x444d4163) {
        /* AMD */
        cpuid(0x80000000);
        if ((unsigned)Reax < 0x80000001) goto inteltest;
        cpuid(0x80000001);
        if ((Redx & 0x00800000) == 0) return 0;
        rval = MM_MMX;
        if (Redx & 0x80000000) rval |= MM_3DNOW;
        if (Redx & 0x00400000) rval |= MM_MMXEXT;
        return rval;
    } else if (Rebx == 0x746e6543 &&
               Redx == 0x48727561 &&
               Recx == 0x736c7561) {  /*  "CentaurHauls" */
        /* VIA C3 */
        cpuid(0x80000000);
        if ((unsigned)Reax < 0x80000001) goto inteltest;	
	cpuid(0x80000001);
	rval = 0;
	if( Redx & ( 1 << 31) ) rval |= MM_3DNOW;
	if( Redx & ( 1 << 23) ) rval |= MM_MMX;
	if( Redx & ( 1 << 24) ) rval |= MM_MMXEXT;
	return rval;
    } else if (Rebx == 0x69727943 &&
               Redx == 0x736e4978 &&
               Recx == 0x64616574) {
        /* Cyrix Section */
        /* See if extended CPUID level 80000001 is supported */
        /* The value of CPUID/80000001 for the 6x86MX is undefined
           according to the Cyrix CPU Detection Guide (Preliminary
           Rev. 1.01 table 1), so we'll check the value of eax for
           CPUID/0 to see if standard CPUID level 2 is supported.
           According to the table, the only CPU which supports level
           2 is also the only one which supports extended CPUID levels.
        */
        if (Reax != 2) goto inteltest;
        cpuid(0x80000001);
        if ((Reax & 0x00800000) == 0) return 0;
        rval = MM_MMX;
        if (Reax & 0x01000000) rval |= MM_MMXEXT;
        return rval;
    } else {
        return 0;
    }
}
#pragma enable_message (200)

#ifdef __TEST__
int main ( void )
{
  int mm_flags;
  mm_flags = mm_support();
  printf("mm_support = 0x%08u\n",mm_flags);
  return 0;
}
#endif