diff --git a/include/cityhash.h b/include/cityhash.h index 3b2d1e84b..346fb673a 100644 --- a/include/cityhash.h +++ b/include/cityhash.h @@ -32,6 +32,13 @@ extern "C" { #endif +/* + * Define 1/2/3-argument specialized versions of cityhash4, which can reduce + * instruction count (especially multiplication) on some 32-bit arches. + */ +_SYS_CITYHASH_H uint64_t cityhash1(uint64_t); +_SYS_CITYHASH_H uint64_t cityhash2(uint64_t, uint64_t); +_SYS_CITYHASH_H uint64_t cityhash3(uint64_t, uint64_t, uint64_t); _SYS_CITYHASH_H uint64_t cityhash4(uint64_t, uint64_t, uint64_t, uint64_t); #ifdef __cplusplus diff --git a/lib/libzfs/libzfs.abi b/lib/libzfs/libzfs.abi index 5b0dffb03..1f1f2fdff 100644 --- a/lib/libzfs/libzfs.abi +++ b/lib/libzfs/libzfs.abi @@ -154,6 +154,9 @@ + + + @@ -9241,6 +9244,21 @@ + + + + + + + + + + + + + + + diff --git a/module/zcommon/cityhash.c b/module/zcommon/cityhash.c index 413a96df2..c758ec47d 100644 --- a/module/zcommon/cityhash.c +++ b/module/zcommon/cityhash.c @@ -49,8 +49,8 @@ cityhash_helper(uint64_t u, uint64_t v, uint64_t mul) return (b); } -uint64_t -cityhash4(uint64_t w1, uint64_t w2, uint64_t w3, uint64_t w4) +static inline uint64_t +cityhash_impl(uint64_t w1, uint64_t w2, uint64_t w3, uint64_t w4) { uint64_t mul = HASH_K2 + 64; uint64_t a = w1 * HASH_K1; @@ -59,9 +59,38 @@ cityhash4(uint64_t w1, uint64_t w2, uint64_t w3, uint64_t w4) uint64_t d = w3 * HASH_K2; return (cityhash_helper(rotate(a + b, 43) + rotate(c, 30) + d, a + rotate(b + HASH_K2, 18) + c, mul)); +} +/* + * Passing w as the 2nd argument could save one 64-bit multiplication. + */ +uint64_t +cityhash1(uint64_t w) +{ + return (cityhash_impl(0, w, 0, 0)); +} + +uint64_t +cityhash2(uint64_t w1, uint64_t w2) +{ + return (cityhash_impl(w1, w2, 0, 0)); +} + +uint64_t +cityhash3(uint64_t w1, uint64_t w2, uint64_t w3) +{ + return (cityhash_impl(w1, w2, w3, 0)); +} + +uint64_t +cityhash4(uint64_t w1, uint64_t w2, uint64_t w3, uint64_t w4) +{ + return (cityhash_impl(w1, w2, w3, w4)); } #if defined(_KERNEL) +EXPORT_SYMBOL(cityhash1); +EXPORT_SYMBOL(cityhash2); +EXPORT_SYMBOL(cityhash3); EXPORT_SYMBOL(cityhash4); #endif