From 1a45c2bce7480ef1d125439aed8413bcff0ab468 Mon Sep 17 00:00:00 2001 From: Pauli Nieminen Date: Sun, 7 Feb 2010 07:36:13 +0200 Subject: [PATCH] mesa: Fix mesa_next_pow_two to return same value if parameter is pow2. Without subtracting one pow2 value would be rounded up to next pow2 which is not correct behaviour for the function. --- src/mesa/main/imports.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/src/mesa/main/imports.h b/src/mesa/main/imports.h index 81cb396b2bb..3843f50036c 100644 --- a/src/mesa/main/imports.h +++ b/src/mesa/main/imports.h @@ -417,7 +417,8 @@ static INLINE int32_t _mesa_next_pow_two_32(uint32_t x) { #ifdef __GNUC__ - return 1 << (__builtin_clz(x) ^ 31); + x--; + return 1 << ((__builtin_clz(x) ^ 31) + 1); #else x--; x |= x >> 1; @@ -434,10 +435,11 @@ static INLINE int64_t _mesa_next_pow_two_64(uint64_t x) { #ifdef __GNUC__ + x--; if (sizeof(x) == sizeof(long)) - return 1 << (__builtin_clzl(x) ^ 63); + return 1 << ((__builtin_clzl(x) ^ 63) + 1); else - return 1 << (__builtin_clzll(x) ^ 63); + return 1 << ((__builtin_clzll(x) ^ 63) + 1); #else x--; x |= x >> 1; -- 2.30.2