From b0a2280e45e5abc56e5301f84f33226469000d6c Mon Sep 17 00:00:00 2001 From: Marek Olšák Date: Sun, 10 May 2015 20:35:15 +0200 Subject: gallium/util: add util_last_bit64 This will be needed by radeonsi. Reviewed-by: Ilia Mirkin --- src/gallium/auxiliary/util/u_math.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'src/gallium/auxiliary') diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h index 58070a9dafa..3b4040f0ee2 100644 --- a/src/gallium/auxiliary/util/u_math.h +++ b/src/gallium/auxiliary/util/u_math.h @@ -424,6 +424,25 @@ util_last_bit(unsigned u) #endif } +/** + * Find last bit set in a word. The least significant bit is 1. + * Return 0 if no bits are set. + */ +static INLINE unsigned +util_last_bit64(uint64_t u) +{ +#if defined(HAVE___BUILTIN_CLZLL) + return u == 0 ? 0 : 64 - __builtin_clzll(u); +#else + unsigned r = 0; + while (u) { + r++; + u >>= 1; + } + return r; +#endif +} + /** * Find last bit in a word that does not match the sign bit. The least * significant bit is 1. -- cgit v1.2.3