FFmpeg/libavutil/timer.h

/**
 * @file libavutil/timer.h
 * high precision timer, useful to profile code
 *
 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg 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 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg 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 along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef AVUTIL_TIMER_H
#define AVUTIL_TIMER_H

#include <stdlib.h>
#include <stdint.h>
#include "config.h"

#if ARCH_X86 || ARCH_PPC || ARCH_BFIN
#define AV_READ_TIME read_time
#if ARCH_X86
static inline uint64_t read_time(void)
{
    uint32_t a, d;
    __asm__ volatile("rdtsc\n\t"
                 : "=a" (a), "=d" (d));
    return ((uint64_t)d << 32) + a;
}
#elif ARCH_BFIN
static inline uint64_t read_time(void)
{
    union {
        struct {
            unsigned lo;
            unsigned hi;
        } p;
        unsigned long long c;
    } t;
    __asm__ volatile ("%0=cycles; %1=cycles2;" : "=d" (t.p.lo), "=d" (t.p.hi));
    return t.c;
}
#else //FIXME check ppc64
static inline uint64_t read_time(void)
{
    uint32_t tbu, tbl, temp;

     /* from section 2.2.1 of the 32-bit PowerPC PEM */
     __asm__ volatile(
         "1:\n"
         "mftbu  %2\n"
         "mftb   %0\n"
         "mftbu  %1\n"
         "cmpw   %2,%1\n"
         "bne    1b\n"
     : "=r"(tbl), "=r"(tbu), "=r"(temp)
     :
     : "cc");

     return (((uint64_t)tbu)<<32) | (uint64_t)tbl;
}
#endif
#elif HAVE_GETHRTIME
#define AV_READ_TIME gethrtime
#endif

#ifdef AV_READ_TIME
#define START_TIMER \
uint64_t tend;\
uint64_t tstart= AV_READ_TIME();\

#define STOP_TIMER(id) \
tend= AV_READ_TIME();\
{\
    static uint64_t tsum=0;\
    static int tcount=0;\
    static int tskip_count=0;\
    if(tcount<2 || tend - tstart < 8*tsum/tcount || tend - tstart < 2000){\
        tsum+= tend - tstart;\
        tcount++;\
    }else\
        tskip_count++;\
    if(((tcount+tskip_count)&(tcount+tskip_count-1))==0){\
        av_log(NULL, AV_LOG_ERROR, "%"PRIu64" dezicycles in %s, %d runs, %d skips\n",\
               tsum*10/tcount, id, tcount, tskip_count);\
    }\
}
#else
#define START_TIMER
#define STOP_TIMER(id) {}
#endif

#endif /* AVUTIL_TIMER_H */