cpu_accel.c

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/*
 * cpu_accel.c
 * Copyright (C) 2000-2004 Michel Lespinasse <walken@zoy.org>
 * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
 *
 * This file is part of mpeg2dec, a free MPEG-2 video stream decoder.
 * See http://libmpeg2.sourceforge.net/ for updates.
 *
 * mpeg2dec 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.
 *
 * mpeg2dec 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
 */

#include "config.h"

#include <inttypes.h>

#include "mpeg2.h"
#include "attributes.h"
#include "mpeg2_internal.h"

#ifdef ARCH_X86
static inline uint32_t arch_accel (uint32_t accel)
{
    if (accel & (MPEG2_ACCEL_X86_3DNOW | MPEG2_ACCEL_X86_MMXEXT))
        accel |= MPEG2_ACCEL_X86_MMX;
        
    if (accel & (MPEG2_ACCEL_X86_SSE2 | MPEG2_ACCEL_X86_SSE3))
        accel |= MPEG2_ACCEL_X86_MMXEXT;
        
    if (accel & (MPEG2_ACCEL_X86_SSE3))
        accel |= MPEG2_ACCEL_X86_SSE2;

#ifdef ACCEL_DETECT
    if (accel & MPEG2_ACCEL_DETECT) {
        uint32_t eax, ebx, ecx, edx;
        int AMD;

#if defined(__x86_64__) || (!defined(PIC) && !defined(__PIC__))
#define cpuid(op,eax,ebx,ecx,edx)       \
    __asm__ ("cpuid"                    \
             : "=a" (eax),              \
               "=b" (ebx),              \
               "=c" (ecx),              \
               "=d" (edx)               \
             : "a" (op)                 \
             : "cc")
#else   /* PIC version : save ebx (not needed on x86_64) */
#define cpuid(op,eax,ebx,ecx,edx)       \
    __asm__ ("pushl %%ebx\n\t"          \
             "cpuid\n\t"                \
             "movl %%ebx,%1\n\t"        \
             "popl %%ebx"               \
             : "=a" (eax),              \
               "=r" (ebx),              \
               "=c" (ecx),              \
               "=d" (edx)               \
             : "a" (op)                 \
             : "cc")
#endif

#ifndef __x86_64__ /* x86_64 supports the cpuid op */
        __asm__ ("pushf\n\t"
                 "pushf\n\t"
                 "pop %0\n\t"
                 "movl %0,%1\n\t"
                 "xorl $0x200000,%0\n\t"
                 "push %0\n\t"
                 "popf\n\t"
                 "pushf\n\t"
                 "pop %0\n\t"
                 "popf"
                 : "=r" (eax),
                 "=r" (ebx)
                 :
                 : "cc");

        if (eax == ebx)                 /* no cpuid */
            return accel;
#endif

        cpuid (0x00000000, eax, ebx, ecx, edx);
        if (!eax)                       /* vendor string only */
            return accel;

        AMD = (ebx == 0x68747541 && ecx == 0x444d4163 && edx == 0x69746e65);

        cpuid (0x00000001, eax, ebx, ecx, edx);
        if (! (edx & 0x00800000))       /* no MMX */
            return accel;

        accel |= MPEG2_ACCEL_X86_MMX;
        if (edx & 0x02000000)           /* SSE - identical to AMD MMX ext. */
            accel |= MPEG2_ACCEL_X86_MMXEXT;

        if (edx & 0x04000000)           /* SSE2 */
            accel |= MPEG2_ACCEL_X86_SSE2;

        if (ecx & 0x00000001)           /* SSE3 */
            accel |= MPEG2_ACCEL_X86_SSE3;

        cpuid (0x80000000, eax, ebx, ecx, edx);
        if (eax < 0x80000001)           /* no extended capabilities */
            return accel;

        cpuid (0x80000001, eax, ebx, ecx, edx);

        if (edx & 0x80000000)
            accel |= MPEG2_ACCEL_X86_3DNOW;

        if (AMD && (edx & 0x00400000))  /* AMD MMX extensions */
            accel |= MPEG2_ACCEL_X86_MMXEXT;
    }
#endif /* ACCEL_DETECT */

    return accel;
}
#endif /* ARCH_X86 */

#if defined(ACCEL_DETECT) && (defined(ARCH_PPC) || defined(ARCH_SPARC))
#include <signal.h>
#include <setjmp.h>

static sigjmp_buf jmpbuf;
static volatile sig_atomic_t canjump = 0;

static RETSIGTYPE sigill_handler (int sig)
{
    if (!canjump) {
        signal (sig, SIG_DFL);
        raise (sig);
    }

    canjump = 0;
    siglongjmp (jmpbuf, 1);
}
#endif /* ACCEL_DETECT && (ARCH_PPC || ARCH_SPARC) */

#ifdef ARCH_PPC
static uint32_t arch_accel (uint32_t accel)
{
#if defined(ACCEL_DETECT) && defined(HAVE_ALTIVEC)
    if ((accel & (MPEG2_ACCEL_PPC_ALTIVEC | MPEG2_ACCEL_DETECT)) ==
        MPEG2_ACCEL_DETECT) {
        static RETSIGTYPE (* oldsig) (int);

        oldsig = signal (SIGILL, sigill_handler);
        if (sigsetjmp (jmpbuf, 1)) {
            signal (SIGILL, oldsig);
            return accel;
        }

        canjump = 1;

#if defined(HAVE_ALTIVEC_H) && !defined(__APPLE__)      /* gnu */
#define VAND(a,b,c) "vand " #a "," #b "," #c "\n\t"
#else                   /* apple */
#define VAND(a,b,c) "vand v" #a ",v" #b ",v" #c "\n\t"
#endif
        asm volatile ("mtspr 256, %0\n\t"
                      VAND (0, 0, 0)
                      :
                      : "r" (-1));

        canjump = 0;
        accel |= MPEG2_ACCEL_PPC_ALTIVEC;

        signal (SIGILL, oldsig);
    }
#endif /* ACCEL_DETECT */

    return accel;
}
#endif /* ARCH_PPC */

#ifdef ARCH_SPARC
static uint32_t arch_accel (uint32_t accel)
{
    if (accel & MPEG2_ACCEL_SPARC_VIS2)
        accel |= MPEG2_ACCEL_SPARC_VIS;

#ifdef ACCEL_DETECT
    if ((accel & (MPEG2_ACCEL_SPARC_VIS2 | MPEG2_ACCEL_DETECT)) ==
        MPEG2_ACCEL_DETECT) {
        static RETSIGTYPE (* oldsig) (int);

        oldsig = signal (SIGILL, sigill_handler);
        if (sigsetjmp (jmpbuf, 1)) {
            signal (SIGILL, oldsig);
            return accel;
        }

        canjump = 1;

        /* pdist %f0, %f0, %f0 */
        __asm__ __volatile__(".word\t0x81b007c0");

        canjump = 0;
        accel |= MPEG2_ACCEL_SPARC_VIS;

        if (sigsetjmp (jmpbuf, 1)) {
            signal (SIGILL, oldsig);
            return accel;
        }

        canjump = 1;

        /* edge8n %g0, %g0, %g0 */
        __asm__ __volatile__(".word\t0x81b00020");

        canjump = 0;
        accel |= MPEG2_ACCEL_SPARC_VIS2;

        signal (SIGILL, oldsig);
    }
#endif /* ACCEL_DETECT */

    return accel;
}
#endif /* ARCH_SPARC */

#ifdef ARCH_ALPHA
static inline uint32_t arch_accel (uint32_t accel)
{
    if (accel & MPEG2_ACCEL_ALPHA_MVI)
        accel |= MPEG2_ACCEL_ALPHA;

#ifdef ACCEL_DETECT
    if (accel & MPEG2_ACCEL_DETECT) {
        uint64_t no_mvi;

        asm volatile ("amask %1, %0"
                      : "=r" (no_mvi)
                      : "rI" (256));    /* AMASK_MVI */
        accel |= no_mvi ? MPEG2_ACCEL_ALPHA : (MPEG2_ACCEL_ALPHA |
                                               MPEG2_ACCEL_ALPHA_MVI);
    }
#endif /* ACCEL_DETECT */

    return accel;
}
#endif /* ARCH_ALPHA */

uint32_t mpeg2_detect_accel (uint32_t accel)
{
#if defined (ARCH_X86) || defined (ARCH_PPC) || defined (ARCH_ALPHA) || defined (ARCH_SPARC)
    accel = arch_accel (accel);
#endif
    return accel;
}

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