X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavutil%2Fintmath.h;h=e6a2e102c414fd648f4d38d04a3a9cef904b1aaa;hb=804d7a1aa6fd33fbe405698d90d02121423e540c;hp=39e14c28ae3270b721f2024fe90ae026d08bc317;hpb=544f5a922f63faae775edcf04918c0d0ab87c470;p=ffmpeg

diff --git a/libavutil/intmath.h b/libavutil/intmath.h
index 39e14c28ae3..e6a2e102c41 100644
--- a/libavutil/intmath.h
+++ b/libavutil/intmath.h
@@ -1,41 +1,87 @@
 /*
  * Copyright (c) 2010 Mans Rullgard <mans@mansr.com>
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; 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 "common.h"
-
-#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4)
+#include "attributes.h"
 
-#ifndef av_log2
+/**
+ * @addtogroup lavu_internal
+ * @{
+ */
 
-#define av_log2(x) (31 - __builtin_clz((x)|1))
+extern const uint32_t ff_inverse[257];
 
-#ifndef av_log2_16bit
-#define av_log2_16bit av_log2
+#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 */