/*
 * Copyright (c) 2003 Matteo Frigo
 * Copyright (c) 2003 Massachusetts Institute of Technology
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

/* $Id: sse.c,v 1.10 2003/05/15 20:53:16 stevenj Exp $ */

#include "ifftw.h"
#include "simd.h"

#if HAVE_SSE

#include <signal.h>
#include <setjmp.h>

static inline int cpuid_edx(int op)
{
#ifdef _MSC_VER
     int ret;
     _asm {
	  push ebx
	  mov eax,op
          cpuid
	  mov ret,edx
          pop ebx
     }
     return ret;
#else
     int eax, ecx, edx;

     __asm__("push %%ebx\n\tcpuid\n\tpop %%ebx"
	     : "=a" (eax), "=c" (ecx), "=d" (edx)
	     : "a" (op));
     return edx;
#endif
}

static jmp_buf jb;

static void sighandler(int x)
{
     UNUSED(x);
     longjmp(jb, 1);
}

static int sse_works(void)
{
     void (*oldsig)(int);
     oldsig = signal(SIGILL, sighandler);
     if (setjmp(jb)) {
	  signal(SIGILL, oldsig);
	  return 0;
     } else {
#ifdef _MSC_VER
	  _asm { xorps xmm0,xmm0 }
#else
	  __asm__ __volatile__ ("xorps %xmm0, %xmm0");
#endif
	  signal(SIGILL, oldsig);
	  return 1;
     }
}

int RIGHT_CPU(void)
{
     static int init = 0, res;
     CK(ALIGNED(&X(sse_mpmp))); /* compiler bug? */
     if (!init) {
	  res =   (cpuid_edx(1) & (1 << 25)) 
	       && sse_works();
	  init = 1;
     }
     return res;
}
#endif
