X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=include%2Flinux%2Fhash.h;h=d0494c399392c801dfce96d8a141d935d750a22e;hp=bd1754c7ecef49a121a74fea6efaac15234384a5;hb=23d0db76ffa13ffb95229946e4648568c3c29db5;hpb=72d931046030beb2d13dad6d205be0e228618432 diff --git a/include/linux/hash.h b/include/linux/hash.h index bd1754c7ecef..d0494c399392 100644 --- a/include/linux/hash.h +++ b/include/linux/hash.h @@ -37,6 +37,9 @@ static __always_inline u64 hash_64(u64 val, unsigned int bits) { u64 hash = val; +#if defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64 + hash = hash * GOLDEN_RATIO_PRIME_64; +#else /* Sigh, gcc can't optimise this alone like it does for 32 bits. */ u64 n = hash; n <<= 18; @@ -51,6 +54,7 @@ static __always_inline u64 hash_64(u64 val, unsigned int bits) hash += n; n <<= 2; hash += n; +#endif /* High bits are more random, so use them. */ return hash >> (64 - bits);