No hash function is perfect, but some are useful.

wyhash and wyrand are the ideal 64-bit hash function and PRNG respectively:

solid: wyhash passed SMHasher, wyrand passed BigCrush, practrand.

portable: 64-bit/32-bit system, big/little endian.

fastest: Efficient on 64-bit machines, especially for short keys.

simplest: In the sense of code size.

salted: We use dynamic secret to avoid intended attack.

wyhash is the default hashing algorithm of the great Zig, V, Nim and Go (since 1.17) language.

Simple Example:

#include  "wyhash.h"
uint64_t _wyp[4];
make_secret(time(NULL),_wyp);
string  s="fcdskhfjs";
uint64_t h=wyhash(s.c_str(),s.size(),0,_wyp);

g++-9 benchmark.cpp t1ha/src/t1ha2.c -o benchmark -Ofast -s -Wall -march=native

/usr/share/dict/words

hash function	short hash/us	bulk_256B GB/s	bulk_64KB GB/s
wyhash_final3	419.63	20.97	25.10
wyhash_final2	204.08	21.12	25.10
wyhash_final1	196.33	15.56	17.92
wyhash_gamma (dangerous)	399.92	19.16	25.80
wyhash_beta	180.51	18.20	17.37
wyhash_alpha	204.50	20.54	25.92
wyhash_v6 (avx2)	164.08	12.08	41.35
wyhash_v5	221.59	15.40	16.78
wyhash_v4	153.03	13.89	16.81
wyhash_v3	191.32	13.55	15.72
wyhash_v2	94.28	11.91	11.22
wyhash_v1	91.66	16.03	18.95
wyhash32 (32 bit)	149.78	5.45	4.89
xxh3_scalar	152.47	8.39	13.05
xxh3_avx2	144.62	9.85	44.82