nasm/nasmlib/perfhash.c
H. Peter Anvin (Intel) b14dbb95a1 phash: simplify the code generators
Simplify the code generators by merging the two hash constant arrays
into one. The hash is effectively the same, although the order of the
constants differ (possibly in a way which makes the indexing easier.)
The main difference is the amount of code is necessary to generate
each of the output C files.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
2020-07-10 19:26:52 -07:00

56 lines
2.2 KiB
C

/* ----------------------------------------------------------------------- *
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#include "perfhash.h"
#include "hashtbl.h" /* For crc64i() */
int perfhash_find(const struct perfect_hash *hash, const char *str)
{
uint32_t k1, k2;
uint64_t crc;
uint16_t ix;
crc = crc64i(hash->crcinit, str);
k1 = (uint32_t)crc & hash->hashmask;
k2 = ((uint32_t)(crc >> 32) & hash->hashmask) + 1;
ix = hash->hashvals[k1] + hash->hashvals[k2];
if (ix >= hash->tbllen ||
!hash->strings[ix] ||
nasm_stricmp(str, hash->strings[ix]))
return hash->errval;
return hash->tbloffs + ix;
}