diff options
Diffstat (limited to 'src/zlib-ng/insert_string_tpl.h')
| -rw-r--r-- | src/zlib-ng/insert_string_tpl.h | 83 |
1 files changed, 51 insertions, 32 deletions
diff --git a/src/zlib-ng/insert_string_tpl.h b/src/zlib-ng/insert_string_tpl.h index 9796e51..643a5e0 100644 --- a/src/zlib-ng/insert_string_tpl.h +++ b/src/zlib-ng/insert_string_tpl.h @@ -22,27 +22,52 @@ * */ +#ifndef HASH_CALC_OFFSET +# define HASH_CALC_OFFSET 0 +#endif +#ifndef HASH_CALC_MASK +# define HASH_CALC_MASK HASH_MASK +#endif +#ifndef HASH_CALC_READ +# if BYTE_ORDER == LITTLE_ENDIAN +# define HASH_CALC_READ \ + zmemcpy_4(&val, strstart); +# else +# define HASH_CALC_READ \ + val = ((uint32_t)(strstart[0])); \ + val |= ((uint32_t)(strstart[1]) << 8); \ + val |= ((uint32_t)(strstart[2]) << 16); \ + val |= ((uint32_t)(strstart[3]) << 24); +# endif +#endif + +/* =========================================================================== + * Update a hash value with the given input byte + * IN assertion: all calls to to UPDATE_HASH are made with consecutive + * input characters, so that a running hash key can be computed from the + * previous key instead of complete recalculation each time. + */ +Z_INTERNAL uint32_t UPDATE_HASH(deflate_state *const s, uint32_t h, uint32_t val) { + (void)s; + HASH_CALC(s, h, val); + return h & HASH_CALC_MASK; +} + /* =========================================================================== * Quick 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. */ -Z_INTERNAL Pos QUICK_INSERT_STRING(deflate_state *const s, const uint32_t str) { +Z_INTERNAL Pos QUICK_INSERT_STRING(deflate_state *const s, uint32_t str) { Pos head; - uint8_t *strstart = s->window + str; - uint32_t val, hm, h = 0; - -#ifdef UNALIGNED_OK - val = *(uint32_t *)(strstart); -#else - val = ((uint32_t)(strstart[0])); - val |= ((uint32_t)(strstart[1]) << 8); - val |= ((uint32_t)(strstart[2]) << 16); - val |= ((uint32_t)(strstart[3]) << 24); -#endif + uint8_t *strstart = s->window + str + HASH_CALC_OFFSET; + uint32_t val, hm; - UPDATE_HASH(s, h, val); - hm = h & HASH_MASK; + HASH_CALC_VAR_INIT; + HASH_CALC_READ; + HASH_CALC(s, HASH_CALC_VAR, val); + HASH_CALC_VAR &= HASH_CALC_MASK; + hm = HASH_CALC_VAR; head = s->head[hm]; if (LIKELY(head != str)) { @@ -57,27 +82,21 @@ Z_INTERNAL Pos QUICK_INSERT_STRING(deflate_state *const s, const uint32_t str) { * 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). + * input characters and the first STD_MIN_MATCH bytes of str are valid + * (except for the last STD_MIN_MATCH-1 bytes of the input file). */ -Z_INTERNAL void INSERT_STRING(deflate_state *const s, const uint32_t str, uint32_t count) { - uint8_t *strstart = s->window + str; - uint8_t *strend = strstart + count - 1; /* last position */ +Z_INTERNAL void INSERT_STRING(deflate_state *const s, uint32_t str, uint32_t count) { + uint8_t *strstart = s->window + str + HASH_CALC_OFFSET; + uint8_t *strend = strstart + count; - for (Pos idx = (Pos)str; strstart <= strend; idx++, strstart++) { - uint32_t val, hm, h = 0; - -#ifdef UNALIGNED_OK - val = *(uint32_t *)(strstart); -#else - val = ((uint32_t)(strstart[0])); - val |= ((uint32_t)(strstart[1]) << 8); - val |= ((uint32_t)(strstart[2]) << 16); - val |= ((uint32_t)(strstart[3]) << 24); -#endif + for (Pos idx = (Pos)str; strstart < strend; idx++, strstart++) { + uint32_t val, hm; - UPDATE_HASH(s, h, val); - hm = h & HASH_MASK; + HASH_CALC_VAR_INIT; + HASH_CALC_READ; + HASH_CALC(s, HASH_CALC_VAR, val); + HASH_CALC_VAR &= HASH_CALC_MASK; + hm = HASH_CALC_VAR; Pos head = s->head[hm]; if (LIKELY(head != idx)) { |