On Tuesday, 2018-05-22 23:06:16 +0200, Karol Herbst wrote: > From: Pierre Moreau <[email protected]> > > Signed-off-by: Karol Herbst <[email protected]> > --- > src/gallium/auxiliary/util/u_math.h | 55 +++++++++++++++++++++++++++++ > src/util/bitscan.h | 11 ++++++ > 2 files changed, 66 insertions(+) > > diff --git a/src/gallium/auxiliary/util/u_math.h > b/src/gallium/auxiliary/util/u_math.h > index 46d02978fd6..504d67664b2 100644 > --- a/src/gallium/auxiliary/util/u_math.h > +++ b/src/gallium/auxiliary/util/u_math.h > @@ -421,6 +421,23 @@ util_logbase2(unsigned n) > #endif > } > > +static inline uint64_t > +util_logbase2_64(uint64_t n) > +{ > +#if defined(HAVE___BUILTIN_CLZLL) > + return ((sizeof(uint64_t) * 8ll - 1ll) - __builtin_clzll(n | 1ll)); > +#else > + uint64_t pos = 0ll; > + if (n >= 1ll<<32ll) { n >>= 32ll; pos += 32ll; } > + if (n >= 1ll<<16ll) { n >>= 16ll; pos += 16ll; } > + if (n >= 1ll<< 8ll) { n >>= 8ll; pos += 8ll; } > + if (n >= 1ll<< 4ll) { n >>= 4ll; pos += 4ll; } > + if (n >= 1ll<< 2ll) { n >>= 2ll; pos += 2ll; } > + if (n >= 1ll<< 1ll) { pos += 1ll; } ^^ `ll` is being added a bit too much (although it's harmless); for instance, in this function I believe this one is the only one that does anything, and technically only on the first line (`1ll<<32`).
They should be unsigned though, ie. `ull`; with that: Reviewed-by: Eric Engestrom <[email protected]> > + return pos; > +#endif > +} > + > /** > * Returns the ceiling of log n base 2, and 0 when n == 0. Equivalently, > * returns the smallest x such that n <= 2**x. > @@ -434,6 +451,15 @@ util_logbase2_ceil(unsigned n) > return 1 + util_logbase2(n - 1); > } > > +static inline uint64_t > +util_logbase2_ceil64(uint64_t n) > +{ > + if (n <= 1ll) > + return 0ll; > + > + return 1ll + util_logbase2_64(n - 1ll); > +} > + > /** > * Returns the smallest power of two >= x > */ > @@ -465,6 +491,35 @@ util_next_power_of_two(unsigned x) > #endif > } > > +static inline uint64_t > +util_next_power_of_two64(uint64_t x) > +{ > +#if defined(HAVE___BUILTIN_CLZLL) > + if (x <= 1ll) > + return 1ll; > + > + return (1ll << ((sizeof(uint64_t) * 8ll) - __builtin_clzll(x - 1ll))); > +#else > + uint64_t val = x; > + > + if (x <= 1ll) > + return 1ll; > + > + if (util_is_power_of_two_or_zero64(x)) > + return x; > + > + val--; > + val = (val >> 1ll) | val; > + val = (val >> 2ll) | val; > + val = (val >> 4ll) | val; > + val = (val >> 8ll) | val; > + val = (val >> 16ll) | val; > + val = (val >> 32ll) | val; > + val++; > + return val; > +#endif > +} > + > > /** > * Return number of bits set in n. > diff --git a/src/util/bitscan.h b/src/util/bitscan.h > index 5cc75f0beba..310b4ed2e37 100644 > --- a/src/util/bitscan.h > +++ b/src/util/bitscan.h > @@ -123,6 +123,17 @@ util_is_power_of_two_or_zero(unsigned v) > return (v & (v - 1)) == 0; > } > > +/* Determine if an uint64_t value is a power of two. > + * > + * \note > + * Zero is treated as a power of two. > + */ > +static inline bool > +util_is_power_of_two_or_zero64(uint64_t v) > +{ > + return (v & (v - 1ll)) == 0ll; > +} > + > /* Determine if an unsigned value is a power of two. > * > * \note > -- > 2.17.0 > > _______________________________________________ > mesa-dev mailing list > [email protected] > https://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/mesa-dev
