libbpg-0.9.3

libavutil/intmath.h

@@ -0,0 +1,178 @@
+/*
+ * 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"
+
+#if ARCH_ARM
+#   include "arm/intmath.h"
+#endif
+
+/**
+ * @addtogroup lavu_internal
+ * @{
+ */
+
+#if HAVE_FAST_CLZ
+#if AV_GCC_VERSION_AT_LEAST(3,4)
+#ifndef ff_log2
+#   define ff_log2(x) (31 - __builtin_clz((x)|1))
+#   ifndef ff_log2_16bit
+#      define ff_log2_16bit av_log2
+#   endif
+#endif /* ff_log2 */
+#elif defined( __INTEL_COMPILER )
+#ifndef ff_log2
+#   define ff_log2(x) (_bit_scan_reverse(x|1))
+#   ifndef ff_log2_16bit
+#      define ff_log2_16bit av_log2
+#   endif
+#endif /* ff_log2 */
+#endif
+#endif /* AV_GCC_VERSION_AT_LEAST(3,4) */
+
+extern const uint8_t ff_log2_tab[256];
+
+#ifndef ff_log2
+#define ff_log2 ff_log2_c
+#if !defined( _MSC_VER )
+static av_always_inline av_const int ff_log2_c(unsigned int v)
+{
+    int n = 0;
+    if (v & 0xffff0000) {
+        v >>= 16;
+        n += 16;
+    }
+    if (v & 0xff00) {
+        v >>= 8;
+        n += 8;
+    }
+    n += ff_log2_tab[v];
+
+    return n;
+}
+#else
+static av_always_inline av_const int ff_log2_c(unsigned int v)
+{
+    unsigned long n;
+    _BitScanReverse(&n, v|1);
+    return n;
+}
+#define ff_log2_16bit av_log2
+#endif
+#endif
+
+#ifndef ff_log2_16bit
+#define ff_log2_16bit ff_log2_16bit_c
+static av_always_inline av_const int ff_log2_16bit_c(unsigned int v)
+{
+    int n = 0;
+    if (v & 0xff00) {
+        v >>= 8;
+        n += 8;
+    }
+    n += ff_log2_tab[v];
+
+    return n;
+}
+#endif
+
+#define av_log2       ff_log2
+#define av_log2_16bit ff_log2_16bit
+
+/**
+ * @}
+ */
+
+/**
+ * @addtogroup lavu_math
+ * @{
+ */
+
+#if HAVE_FAST_CLZ
+#if AV_GCC_VERSION_AT_LEAST(3,4)
+#ifndef ff_ctz
+#define ff_ctz(v) __builtin_ctz(v)
+#endif
+#elif defined( __INTEL_COMPILER )
+#ifndef ff_ctz
+#define ff_ctz(v) _bit_scan_forward(v)
+#endif
+#endif
+#endif
+
+#ifndef ff_ctz
+#define ff_ctz ff_ctz_c
+#if !defined( _MSC_VER )
+static av_always_inline av_const int ff_ctz_c(int v)
+{
+    int c;
+
+    if (v & 0x1)
+        return 0;
+
+    c = 1;
+    if (!(v & 0xffff)) {
+        v >>= 16;
+        c += 16;
+    }
+    if (!(v & 0xff)) {
+        v >>= 8;
+        c += 8;
+    }
+    if (!(v & 0xf)) {
+        v >>= 4;
+        c += 4;
+    }
+    if (!(v & 0x3)) {
+        v >>= 2;
+        c += 2;
+    }
+    c -= v & 0x1;
+
+    return c;
+}
+#else
+static av_always_inline av_const int ff_ctz_c( int v )
+{
+    unsigned long c;
+    _BitScanForward(&c, v);
+    return c;
+}
+#endif
+#endif
+
+/**
+ * Trailing zero bit count.
+ *
+ * @param v  input value. If v is 0, the result is undefined.
+ * @return   the number of trailing 0-bits
+ */
+int av_ctz(int v);
+
+/**
+ * @}
+ */
+#endif /* AVUTIL_INTMATH_H */