diff options
Diffstat (limited to 'codecs/log2comp.h')
-rwxr-xr-x | codecs/log2comp.h | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/codecs/log2comp.h b/codecs/log2comp.h index 1a42f35d7..9a669c9c8 100755 --- a/codecs/log2comp.h +++ b/codecs/log2comp.h @@ -24,7 +24,7 @@ #if defined(WANT_ASM) && defined(_MSC_VER) && defined(_M_IX86) /* MS C Inline Asm */ # pragma warning( disable : 4035 ) -static inline int log2(int val) { __asm +static inline int ilog2(int val) { __asm { xor eax, eax dec eax @@ -33,7 +33,7 @@ static inline int log2(int val) { __asm # pragma warning( default : 4035 ) #elif defined(WANT_ASM) && defined(__GNUC__) && (defined(__i386__) || defined(i386)) /* GNU Inline Asm */ -static inline int log2(int val) +static inline int ilog2(int val) { int a; __asm__ @@ -48,12 +48,22 @@ static inline int log2(int val) ); return a; } +#elif defined(WANT_ASM) && defined(__GNUC__) && defined(__powerpc__) +static inline int ilog2(int val) +{ + int a; + __asm__ ("cntlzw %0,%1" + : "=r" (a) + : "r" (val) + ); + return 31-a; +} #else /* no ASM for this compiler and/or platform */ /* rather slow base 2 log computation * Using looped shift. */ -static inline int log2(int val) +static inline int ilog2(int val) { int i; for (i = -1; val; ++i, val >>= 1) |