gstreamer/gst/gstcpu.c
David Schleef 0622e9e391 gst/gstcpu.c: Add workaround for gcc-3.2 generating bad code around the cpu detection asm code.
Original commit message from CVS:
* gst/gstcpu.c: (gst_cpuid_i386): Add workaround for gcc-3.2
generating bad code around the cpu detection asm code.
2004-04-15 03:20:23 +00:00

136 lines
3.6 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
* 2003 Colin Walters <walters@verbum.org>
*
* gstcpu.c: CPU detection and architecture-specific routines
*
* 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 Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <glib.h>
#include "gst_private.h"
#include "gstcpu.h"
#include "gstinfo.h"
static guint32 _gst_cpu_flags = 0;
#ifdef HAVE_CPU_I386
#define _gst_cpu_initialize_arch _gst_cpu_initialize_i386
gboolean _gst_cpu_initialize_i386 (gulong * flags, GString * featurelist);
#else
#define _gst_cpu_initialize_arch _gst_cpu_initialize_none
gboolean _gst_cpu_initialize_none (gulong * flags, GString * featurelist);
#endif
void
_gst_cpu_initialize (gboolean opt)
{
GString *featurelist = g_string_new ("");
gulong flags = 0;
if (opt) {
if (!_gst_cpu_initialize_arch (&flags, featurelist))
g_string_append (featurelist, "NONE");
} else
g_string_append (featurelist, "(DISABLED)");
GST_CAT_INFO (GST_CAT_GST_INIT, "CPU features: (%08lx) %s", flags,
featurelist->str);
g_string_free (featurelist, TRUE);
}
gboolean
_gst_cpu_initialize_none (gulong * flags, GString * featurelist)
{
return FALSE;
}
#ifdef HAVE_CPU_I386
static void
gst_cpuid_i386 (int x, unsigned long *eax, unsigned long *ebx,
unsigned long *ecx, unsigned long *edx)
{
unsigned long regs[4];
asm (
/* GCC-3.2 (and possibly others) don't clobber ebx properly,
* so we save/restore it directly. */
" pushl %%ebx\n" " cpuid\n" " movl %%eax, %0\n" " movl %%ebx, %1\n" " movl %%ecx, %2\n" " movl %%edx, %3\n" " popl %%ebx\n":"=o" (regs[0]),
"=o" (regs[1]),
"=o" (regs[2]), "=o" (regs[3])
: "a" (x)
: "ebx", "ecx", "edx");
*eax = regs[0];
*ebx = regs[1];
*ecx = regs[2];
*edx = regs[3];
}
gboolean
_gst_cpu_initialize_i386 (gulong * flags, GString * featurelist)
{
gboolean AMD;
gulong eax = 0, ebx = 0, ecx = 0, edx = 0;
gst_cpuid_i386 (0, &eax, &ebx, &ecx, &edx);
AMD = (ebx == 0x68747541) && (ecx == 0x444d4163) && (edx == 0x69746e65);
gst_cpuid_i386 (1, &eax, &ebx, &ecx, &edx);
if (edx & (1 << 23)) {
_gst_cpu_flags |= GST_CPU_FLAG_MMX;
g_string_append (featurelist, "MMX ");
if (edx & (1 << 25)) {
_gst_cpu_flags |= GST_CPU_FLAG_SSE;
_gst_cpu_flags |= GST_CPU_FLAG_MMXEXT;
g_string_append (featurelist, "SSE ");
}
gst_cpuid_i386 (0x80000000, &eax, &ebx, &ecx, &edx);
if (eax >= 0x80000001) {
gst_cpuid_i386 (0x80000001, &eax, &ebx, &ecx, &edx);
if (edx & (1 << 31)) {
_gst_cpu_flags |= GST_CPU_FLAG_3DNOW;
g_string_append (featurelist, "3DNOW ");
}
if (AMD && (edx & (1 << 22))) {
_gst_cpu_flags |= GST_CPU_FLAG_MMXEXT;
g_string_append (featurelist, "MMXEXT ");
}
}
}
*flags = eax;
if (_gst_cpu_flags)
return TRUE;
return FALSE;
}
#endif
GstCPUFlags
gst_cpu_get_flags (void)
{
return _gst_cpu_flags;
}