eqemu-server/libs/zlibng/arch/x86/insert_string_sse.c
2019-06-30 18:28:11 -07:00

57 lines
1.7 KiB
C

/* insert_string_sse -- insert_string variant using SSE4.2's CRC instructions
*
* Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
* For conditions of distribution and use, see copyright notice in zlib.h
*
*/
#include "zbuild.h"
#include "deflate.h"
/* ===========================================================================
* Insert string str in the dictionary and set match_head to the previous head
* of the hash chain (the most recent string with same hash key). Return
* the previous length of the hash chain.
* IN assertion: all calls to to INSERT_STRING are made with consecutive
* input characters and the first MIN_MATCH bytes of str are valid
* (except for the last MIN_MATCH-1 bytes of the input file).
*/
#ifdef X86_SSE4_2_CRC_HASH
ZLIB_INTERNAL Pos insert_string_sse(deflate_state *const s, const Pos str, unsigned int count) {
Pos ret = 0;
unsigned int idx;
unsigned int *ip, val, h;
for (idx = 0; idx < count; idx++) {
ip = (unsigned *)&s->window[str+idx];
memcpy(&val, ip, sizeof(val));
h = 0;
if (s->level >= TRIGGER_LEVEL)
val &= 0xFFFFFF;
#ifdef _MSC_VER
h = _mm_crc32_u32(h, val);
#elif defined(X86_SSE4_2_CRC_INTRIN)
h = __builtin_ia32_crc32si(h, val);
#else
__asm__ __volatile__ (
"crc32 %1,%0\n\t"
: "+r" (h)
: "r" (val)
);
#endif
Pos head = s->head[h & s->hash_mask];
if (head != str+idx) {
s->prev[(str+idx) & s->w_mask] = head;
s->head[h & s->hash_mask] = str+idx;
if (idx == count-1)
ret = head;
} else if (idx == count - 1) {
ret = str + idx;
}
}
return ret;
}
#endif