Index: src/libFLAC/include/private/bitmath.h |
diff --git a/src/libFLAC/include/private/bitmath.h b/src/libFLAC/include/private/bitmath.h |
index 87fa0facd6b9b06e4884da46ebec77b1555b1062..22d894f831ab10c262b7de1d03e2b14cf9a5f063 100644 |
--- a/src/libFLAC/include/private/bitmath.h |
+++ b/src/libFLAC/include/private/bitmath.h |
@@ -1,5 +1,6 @@ |
/* libFLAC - Free Lossless Audio Codec library |
- * Copyright (C) 2001,2002,2003,2004,2005,2006,2007 Josh Coalson |
+ * Copyright (C) 2001-2009 Josh Coalson |
+ * Copyright (C) 2011-2014 Xiph.Org Foundation |
* |
* Redistribution and use in source and binary forms, with or without |
* modification, are permitted provided that the following conditions |
@@ -33,9 +34,152 @@ |
#define FLAC__PRIVATE__BITMATH_H |
#include "FLAC/ordinals.h" |
+#include "FLAC/assert.h" |
+ |
+/* for CHAR_BIT */ |
+#include <limits.h> |
+#include "share/compat.h" |
+ |
+#if defined(_MSC_VER) && (_MSC_VER >= 1400) |
+#include <intrin.h> /* for _BitScanReverse* */ |
+#endif |
+ |
+/* Will never be emitted for MSVC, GCC, Intel compilers */ |
+static inline unsigned int FLAC__clz_soft_uint32(unsigned int word) |
+{ |
+ static const unsigned char byte_to_unary_table[] = { |
+ 8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, |
+ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, |
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, |
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, |
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
+ }; |
+ |
+ return (word) > 0xffffff ? byte_to_unary_table[(word) >> 24] : |
+ (word) > 0xffff ? byte_to_unary_table[(word) >> 16] + 8 : |
+ (word) > 0xff ? byte_to_unary_table[(word) >> 8] + 16 : |
+ byte_to_unary_table[(word)] + 24; |
+} |
+ |
+static inline unsigned int FLAC__clz_uint32(FLAC__uint32 v) |
+{ |
+/* Never used with input 0 */ |
+ FLAC__ASSERT(v > 0); |
+#if defined(__INTEL_COMPILER) |
+ return _bit_scan_reverse(v) ^ 31U; |
+#elif defined(__GNUC__) && (__GNUC__ >= 4 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)) |
+/* This will translate either to (bsr ^ 31U), clz , ctlz, cntlz, lzcnt depending on |
+ * -march= setting or to a software routine in exotic machines. */ |
+ return __builtin_clz(v); |
+#elif defined(_MSC_VER) && (_MSC_VER >= 1400) |
+ { |
+ unsigned long idx; |
+ _BitScanReverse(&idx, v); |
+ return idx ^ 31U; |
+ } |
+#else |
+ return FLAC__clz_soft_uint32(v); |
+#endif |
+} |
+ |
+/* This one works with input 0 */ |
+static inline unsigned int FLAC__clz2_uint32(FLAC__uint32 v) |
+{ |
+ if (!v) |
+ return 32; |
+ return FLAC__clz_uint32(v); |
+} |
+ |
+/* An example of what FLAC__bitmath_ilog2() computes: |
+ * |
+ * ilog2( 0) = assertion failure |
+ * ilog2( 1) = 0 |
+ * ilog2( 2) = 1 |
+ * ilog2( 3) = 1 |
+ * ilog2( 4) = 2 |
+ * ilog2( 5) = 2 |
+ * ilog2( 6) = 2 |
+ * ilog2( 7) = 2 |
+ * ilog2( 8) = 3 |
+ * ilog2( 9) = 3 |
+ * ilog2(10) = 3 |
+ * ilog2(11) = 3 |
+ * ilog2(12) = 3 |
+ * ilog2(13) = 3 |
+ * ilog2(14) = 3 |
+ * ilog2(15) = 3 |
+ * ilog2(16) = 4 |
+ * ilog2(17) = 4 |
+ * ilog2(18) = 4 |
+ */ |
+ |
+static inline unsigned FLAC__bitmath_ilog2(FLAC__uint32 v) |
+{ |
+ FLAC__ASSERT(v > 0); |
+#if defined(__INTEL_COMPILER) |
+ return _bit_scan_reverse(v); |
+#elif defined(_MSC_VER) && (_MSC_VER >= 1400) |
+ { |
+ unsigned long idx; |
+ _BitScanReverse(&idx, v); |
+ return idx; |
+ } |
+#else |
+ return sizeof(FLAC__uint32) * CHAR_BIT - 1 - FLAC__clz_uint32(v); |
+#endif |
+} |
+ |
+ |
+#ifdef FLAC__INTEGER_ONLY_LIBRARY /* Unused otherwise */ |
+ |
+static inline unsigned FLAC__bitmath_ilog2_wide(FLAC__uint64 v) |
+{ |
+ FLAC__ASSERT(v > 0); |
+#if defined(__GNUC__) && (__GNUC__ >= 4 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)) |
+ return sizeof(FLAC__uint64) * CHAR_BIT - 1 - __builtin_clzll(v); |
+/* Sorry, only supported in x64/Itanium.. and both have fast FPU which makes integer-only encoder pointless */ |
+#elif (defined(_MSC_VER) && (_MSC_VER >= 1400)) && (defined(_M_IA64) || defined(_M_X64)) |
+ { |
+ unsigned long idx; |
+ _BitScanReverse64(&idx, v); |
+ return idx; |
+ } |
+#else |
+/* Brain-damaged compilers will use the fastest possible way that is, |
+ de Bruijn sequences (http://supertech.csail.mit.edu/papers/debruijn.pdf) |
+ (C) Timothy B. Terriberry (tterribe@xiph.org) 2001-2009 CC0 (Public domain). |
+*/ |
+ { |
+ static const unsigned char DEBRUIJN_IDX64[64]={ |
+ 0, 1, 2, 7, 3,13, 8,19, 4,25,14,28, 9,34,20,40, |
+ 5,17,26,38,15,46,29,48,10,31,35,54,21,50,41,57, |
+ 63, 6,12,18,24,27,33,39,16,37,45,47,30,53,49,56, |
+ 62,11,23,32,36,44,52,55,61,22,43,51,60,42,59,58 |
+ }; |
+ v|= v>>1; |
+ v|= v>>2; |
+ v|= v>>4; |
+ v|= v>>8; |
+ v|= v>>16; |
+ v|= v>>32; |
+ v= (v>>1)+1; |
+ return DEBRUIJN_IDX64[v*0x218A392CD3D5DBF>>58&0x3F]; |
+ } |
+#endif |
+} |
+#endif |
-unsigned FLAC__bitmath_ilog2(FLAC__uint32 v); |
-unsigned FLAC__bitmath_ilog2_wide(FLAC__uint64 v); |
unsigned FLAC__bitmath_silog2(int v); |
unsigned FLAC__bitmath_silog2_wide(FLAC__int64 v); |