Rename ffmpeg-4.2-fit to ffmpeg-4-fit

trunk/3rdparty/ffmpeg-4-fit/libavutil/intmath.h

@@ -0,0 +1,165 @@
+/*
+ * 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
+#if ARCH_X86
+#   include "x86/intmath.h"
+#endif
+
+#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 */
+#endif /* AV_GCC_VERSION_AT_LEAST(3,4) */
+#endif
+
+extern const uint8_t ff_log2_tab[256];
+
+#ifndef ff_log2
+#define ff_log2 ff_log2_c
+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;
+}
+#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
+#ifndef ff_ctzll
+#define ff_ctzll(v) __builtin_ctzll(v)
+#endif
+#ifndef ff_clz
+#define ff_clz(v) __builtin_clz(v)
+#endif
+#endif
+#endif
+
+#ifndef ff_ctz
+#define ff_ctz ff_ctz_c
+/**
+ * Trailing zero bit count.
+ *
+ * @param v  input value. If v is 0, the result is undefined.
+ * @return   the number of trailing 0-bits
+ */
+/* We use the De-Bruijn method outlined in:
+ * http://supertech.csail.mit.edu/papers/debruijn.pdf. */
+static av_always_inline av_const int ff_ctz_c(int v)
+{
+    static const uint8_t debruijn_ctz32[32] = {
+        0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
+        31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
+    };
+    return debruijn_ctz32[(uint32_t)((v & -v) * 0x077CB531U) >> 27];
+}
+#endif
+
+#ifndef ff_ctzll
+#define ff_ctzll ff_ctzll_c
+/* We use the De-Bruijn method outlined in:
+ * http://supertech.csail.mit.edu/papers/debruijn.pdf. */
+static av_always_inline av_const int ff_ctzll_c(long long v)
+{
+    static const uint8_t debruijn_ctz64[64] = {
+        0, 1, 2, 53, 3, 7, 54, 27, 4, 38, 41, 8, 34, 55, 48, 28,
+        62, 5, 39, 46, 44, 42, 22, 9, 24, 35, 59, 56, 49, 18, 29, 11,
+        63, 52, 6, 26, 37, 40, 33, 47, 61, 45, 43, 21, 23, 58, 17, 10,
+        51, 25, 36, 32, 60, 20, 57, 16, 50, 31, 19, 15, 30, 14, 13, 12
+    };
+    return debruijn_ctz64[(uint64_t)((v & -v) * 0x022FDD63CC95386DU) >> 58];
+}
+#endif
+
+#ifndef ff_clz
+#define ff_clz ff_clz_c
+static av_always_inline av_const unsigned ff_clz_c(unsigned x)
+{
+    unsigned i = sizeof(x) * 8;
+
+    while (x) {
+        x >>= 1;
+        i--;
+    }
+
+    return i;
+}
+#endif
+
+#if AV_GCC_VERSION_AT_LEAST(3,4)
+#ifndef av_parity
+#define av_parity __builtin_parity
+#endif
+#endif
+
+/**
+ * @}
+ */
+#endif /* AVUTIL_INTMATH_H */