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bitmath.h : Minor improvements. 

This is part of a larger patch from lvqcl.

Patch-from: lvqcl <lvqcl.mail@gmail.com>
This commit is contained in:
Erik de Castro Lopo 2013-09-08 12:15:40 +10:00
parent ce6832bb62
commit d11c66ffce
1 changed files with 11 additions and 3 deletions
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14
src/libFLAC/include/private/bitmath.h
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@ -78,10 +78,10 @@ static inline unsigned int FLAC__clz_uint32(FLAC__uint32 v)
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 rutine in exotic machines. */
* -march= setting or to a software routine in exotic machines. */
return __builtin_clz(v);
#elif defined(_MSC_VER) && (_MSC_VER >= 1400)
FLAC__uint32 idx;
unsigned long idx;
_BitScanReverse(&idx, v);
return idx ^ 31U;
#else
@ -122,11 +122,19 @@ static inline unsigned int FLAC__clz2_uint32(FLAC__uint32 v)
static inline unsigned FLAC__bitmath_ilog2(FLAC__uint32 v)
{
#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 */
#ifdef FLAC__INTEGER_ONLY_LIBRARY /* Unused otherwise */
static inline unsigned FLAC__bitmath_ilog2_wide(FLAC__uint64 v)
{