From fdb3e75f7e796d88c8e3cd478e2830754116baf0 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Jos=C3=A9=20Fonseca?= Date: Sat, 29 Aug 2009 09:15:10 +0100 Subject: [PATCH] util: Add util_unsigned_logbase2. Cherry picked from Keith's commit f911c3b9897b90132c8621a72bfeb824eb3b01e5. --- src/gallium/auxiliary/util/u_math.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h index 57410e7..b0807c1 100644 --- a/src/gallium/auxiliary/util/u_math.h +++ b/src/gallium/auxiliary/util/u_math.h @@ -375,6 +375,18 @@ unsigned ffs( unsigned u ) #endif +/* Could also binary search for the highest bit. + */ +static INLINE unsigned +util_unsigned_logbase2(unsigned n) +{ + unsigned log2 = 0; + while (n >>= 1) + ++log2; + return log2; +} + + /** * Return float bits. */ -- 2.7.4