diff options
Diffstat (limited to 'src/gallium/auxiliary/util/u_math.h')
| -rw-r--r-- | src/gallium/auxiliary/util/u_math.h | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h index 4c6c2bc00e..cd6a9fcc09 100644 --- a/src/gallium/auxiliary/util/u_math.h +++ b/src/gallium/auxiliary/util/u_math.h @@ -283,6 +283,14 @@ util_fast_pow(float x, float y) return util_fast_exp2(util_fast_log2(x) * y); } +/* Note that this counts zero as a power of two. + */ +static INLINE boolean +util_is_power_of_two( unsigned v ) +{ + return (v & (v-1)) == 0; +} + /** * Floor(x), returned as int. @@ -341,10 +349,22 @@ util_is_inf_or_nan(float x) /** + * Test whether x is a power of two. + */ +static INLINE boolean +util_is_pot(unsigned x) +{ + return (x & (x - 1)) == 0; +} + + +/** * Find first bit set in word. Least significant bit is 1. * Return 0 if no bits set. */ -#if defined(_MSC_VER) && _MSC_VER >= 1300 +#if defined(_MSC_VER) && _MSC_VER >= 1300 && (_M_IX86 || _M_AMD64 || _M_IA64) +unsigned char _BitScanForward(unsigned long* Index, unsigned long Mask); +#pragma intrinsic(_BitScanForward) static INLINE unsigned long ffs( unsigned long u ) { |