/*
  * Copyright (c) 2010 Mans Rullgard <mans@mansr.com>
  *
  * 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_INTMATH_H
 #define AVUTIL_INTMATH_H
 

 #include <stdint.h>

 #include "config.h"

 #include "attributes.h"

 extern const uint32_t ff_inverse[257];
 
 #if   ARCH_ARM
 #   include "arm/intmath.h"
 #elif ARCH_X86
 #   include "x86/intmath.h"
 #endif
 

 #if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4)
 
 #ifndef av_log2

 #   define av_log2(x) (31 - __builtin_clz((x)|1))
 #   ifndef av_log2_16bit
 #      define av_log2_16bit av_log2
 #   endif

 #endif /* av_log2 */
 
 #endif /* AV_GCC_VERSION_AT_LEAST(3,4) */
 

 #ifndef FASTDIV

 #   if CONFIG_FASTDIV
 #       define FASTDIV(a,b) ((uint32_t)((((uint64_t)a) * ff_inverse[b]) >> 32))
 #   else
 #       define FASTDIV(a,b) ((a) / (b))
 #   endif

 #endif /* FASTDIV */
 

 #include "common.h"
 

 extern const uint8_t ff_sqrt_tab[256];
 
 static inline av_const unsigned int ff_sqrt(unsigned int a)
 {
     unsigned int b;
 
     if (a < 255) return (ff_sqrt_tab[a + 1] - 1) >> 4;
     else if (a < (1 << 12)) b = ff_sqrt_tab[a >> 4] >> 2;
 #if !CONFIG_SMALL
     else if (a < (1 << 14)) b = ff_sqrt_tab[a >> 6] >> 1;
     else if (a < (1 << 16)) b = ff_sqrt_tab[a >> 8]   ;
 #endif
     else {
         int s = av_log2_16bit(a >> 16) >> 1;
         unsigned int c = a >> (s + 2);
         b = ff_sqrt_tab[c >> (s + 8)];
         b = FASTDIV(c,b) + (b << s);
     }
 
     return b - (a < b * b);
 }
 

 #endif /* AVUTIL_INTMATH_H */