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| author | H. Peter Anvin <hpa@linux.intel.com> | 2016-11-15 14:23:54 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2016-11-15 14:23:54 -0800 |
| commit | 8d4fb26ad4eed40831261f0a37065f944c9dc04d (patch) | |
| tree | c136a5d0cd2e3b5732f4c686b86855b15939ec71 /nasmlib/ilog2.c | |
| parent | 069ad5fc18c6c7b722ce9be7e83d76283e67b1b5 (diff) | |
| download | nasm-8d4fb26ad4eed40831261f0a37065f944c9dc04d.tar.gz | |
Various fixes to the ilog2 functions
Fix several bugs in the ilog2 functions.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'nasmlib/ilog2.c')
| -rw-r--r-- | nasmlib/ilog2.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/nasmlib/ilog2.c b/nasmlib/ilog2.c index f250262d..51c3e07a 100644 --- a/nasmlib/ilog2.c +++ b/nasmlib/ilog2.c @@ -33,6 +33,7 @@ #include "compiler.h" #include "nasmlib.h" +#include <limits.h> #define ROUND(v, a, w) \ do { \ @@ -61,14 +62,20 @@ int ilog2_32(uint32_t v) { int n; +#ifdef __i686__ + __asm__("bsrl %1,%0 ; cmovz %2,%0\n" + : "=&r" (n) + : "rm" (v), "r" (0)); +#else __asm__("bsrl %1,%0 ; jnz 1f ; xorl %0,%0\n" "1:" : "=&r" (n) : "rm" (v)); - return n; +#endif + return n; } -#elif defined(HAVE___BUILTIN_CTZ) && INT_MAX == 2147483647 +#elif defined(HAVE___BUILTIN_CLZ) && INT_MAX == 2147483647 int ilog2_32(uint32_t v) { @@ -107,7 +114,7 @@ int ilog2_64(uint64_t v) return n; } -#elif defined(HAVE__BUILTIN_CTZLL) && LLONG_MAX == 9223372036854775807LL +#elif defined(HAVE__BUILTIN_CLZLL) && LLONG_MAX == 9223372036854775807LL int ilog2_64(uint64_t v) { |