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Improve strtr(), str_replace() and substr_count() performance

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Use SSE2 to calculate number of occurrences of a given character in a string
This commit is contained in:
Dmitry Stogov
2021-11-09 22:26:37 +03:00
parent c149d37611
commit 085b360abb
1 changed files with 78 additions and 33 deletions
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ext/standard/string.c
+78 -33
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@@ -3007,23 +3007,69 @@ static void php_strtr_array(zval *return_value, zend_string *input, HashTable *p
}
/* }}} */
/* {{{ count_chars */
static zend_always_inline zend_long count_chars(const char *p, zend_long length, char ch)
{
zend_long count = 0;
const char *endp;
#ifdef __SSE2__
if (length >= sizeof(__m128i)) {
__m128i search = _mm_set1_epi8(ch);
do {
__m128i src = _mm_loadu_si128((__m128i*)(p));
uint32_t mask = _mm_movemask_epi8(_mm_cmpeq_epi8(src, search));
// TODO: It would be great to use POPCNT, but it's available only with SSE4.1
#if 1
while (mask != 0) {
count++;
mask = mask & (mask - 1);
}
#else
if (mask) {
mask = mask - ((mask >> 1) & 0x5555);
mask = (mask & 0x3333) + ((mask >> 2) & 0x3333);
mask = (mask + (mask >> 4)) & 0x0F0F;
mask = (mask + (mask >> 8)) & 0x00ff;
count += mask;
}
#endif
p += sizeof(__m128i);
length -= sizeof(__m128i);
} while (length >= sizeof(__m128i));
}
endp = p + length;
while (p != endp) {
count += (*p == ch);
p++;
}
#else
endp = p + length;
while ((p = memchr(p, ch, endp-p))) {
count++;
p++;
}
#endif
return count;
}
/* }}} */
/* {{{ php_char_to_str_ex */
static zend_string* php_char_to_str_ex(zend_string *str, char from, char *to, size_t to_len, int case_sensitivity, zend_long *replace_count)
{
zend_string *result;
size_t char_count = 0;
size_t char_count;
int lc_from = 0;
const char *source, *source_end= ZSTR_VAL(str) + ZSTR_LEN(str);
const char *source, *source_end;
char *target;
if (case_sensitivity) {
char *p = ZSTR_VAL(str), *e = p + ZSTR_LEN(str);
while ((p = memchr(p, from, (e - p)))) {
char_count++;
p++;
}
char_count = count_chars(ZSTR_VAL(str), ZSTR_LEN(str), from);
} else {
lc_from = tolower(from);
char_count = 0;
source_end = ZSTR_VAL(str) + ZSTR_LEN(str);
for (source = ZSTR_VAL(str); source < source_end; source++) {
if (tolower(*source) == lc_from) {
char_count++;
@@ -3035,6 +3081,10 @@ static zend_string* php_char_to_str_ex(zend_string *str, char from, char *to, si
return zend_string_copy(str);
}
if (replace_count) {
*replace_count += char_count;
}
if (to_len > 0) {
result = zend_string_safe_alloc(char_count, to_len - 1, ZSTR_LEN(str), 0);
} else {
@@ -3044,6 +3094,7 @@ static zend_string* php_char_to_str_ex(zend_string *str, char from, char *to, si
if (case_sensitivity) {
char *p = ZSTR_VAL(str), *e = p + ZSTR_LEN(str), *s = ZSTR_VAL(str);
while ((p = memchr(p, from, (e - p)))) {
memcpy(target, s, (p - s));
target += p - s;
@@ -3051,20 +3102,16 @@ static zend_string* php_char_to_str_ex(zend_string *str, char from, char *to, si
target += to_len;
p++;
s = p;
if (replace_count) {
*replace_count += 1;
}
if (--char_count == 0) break;
}
if (s < e) {
memcpy(target, s, (e - s));
target += e - s;
}
} else {
source_end = ZSTR_VAL(str) + ZSTR_LEN(str);
for (source = ZSTR_VAL(str); source < source_end; source++) {
if (tolower(*source) == lc_from) {
if (replace_count) {
*replace_count += 1;
}
memcpy(target, to, to_len);
target += to_len;
} else {
@@ -5550,10 +5597,9 @@ PHP_FUNCTION(substr_count)
char *haystack, *needle;
zend_long offset = 0, length = 0;
bool length_is_null = 1;
zend_long count = 0;
zend_long count;
size_t haystack_len, needle_len;
const char *p, *endp;
char cmp;
ZEND_PARSE_PARAMETERS_START(2, 4)
Z_PARAM_STRING(haystack, haystack_len)
@@ -5569,37 +5615,36 @@ PHP_FUNCTION(substr_count)
}
p = haystack;
endp = p + haystack_len;
if (offset < 0) {
offset += (zend_long)haystack_len;
if (offset) {
if (offset < 0) {
offset += (zend_long)haystack_len;
}
if ((offset < 0) || ((size_t)offset > haystack_len)) {
zend_argument_value_error(3, "must be contained in argument #1 ($haystack)");
RETURN_THROWS();
}
p += offset;
haystack_len -= offset;
}
if ((offset < 0) || ((size_t)offset > haystack_len)) {
zend_argument_value_error(3, "must be contained in argument #1 ($haystack)");
RETURN_THROWS();
}
p += offset;
if (!length_is_null) {
if (length < 0) {
length += (haystack_len - offset);
length += haystack_len;
}
if (length < 0 || ((size_t)length > (haystack_len - offset))) {
if (length < 0 || ((size_t)length > haystack_len)) {
zend_argument_value_error(4, "must be contained in argument #1 ($haystack)");
RETURN_THROWS();
}
endp = p + length;
} else {
length = haystack_len;
}
if (needle_len == 1) {
cmp = needle[0];
while ((p = memchr(p, cmp, endp - p))) {
count++;
p++;
}
count = count_chars(p, length, needle[0]);
} else {
count = 0;
endp = p + length;
while ((p = (char*)php_memnstr(p, needle, needle_len, endp))) {
p += needle_len;
count++;