From: Dmitry Stogov <dmitry@zend.com>
Date: Tue, 30 May 2017 14:14:08 +0000 (+0300)
Subject: trim() micro-optimization
X-Git-Tag: php-7.2.0alpha1~41
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3a4fcee767981290c0665761030443782aef790e;p=php

trim() micro-optimization
---

diff --git a/ext/standard/string.c b/ext/standard/string.c
index 4c46099ccc..b740779b66 100644
--- a/ext/standard/string.c
+++ b/ext/standard/string.c
@@ -791,113 +791,114 @@ static inline int php_charmask(unsigned char *input, size_t len, char *mask)
 }
 /* }}} */
 
-/* {{{ php_trim()
+/* {{{ php_trim_int()
  * mode 1 : trim left
  * mode 2 : trim right
  * mode 3 : trim left and right
  * what indicates which chars are to be trimmed. NULL->default (' \t\n\r\v\0')
  */
-PHPAPI zend_string *php_trim(zend_string *str, char *what, size_t what_len, int mode)
+static zend_always_inline zend_string *php_trim_int(zend_string *str, char *what, size_t what_len, int mode)
 {
-	const char *c = ZSTR_VAL(str);
-	size_t len = ZSTR_LEN(str);
-	register size_t i;
-	size_t trimmed = 0;
+	const char *start = ZSTR_VAL(str);
+	const char *end = start + ZSTR_LEN(str);
 	char mask[256];
 
 	if (what) {
 		if (what_len == 1) {
 			char p = *what;
 			if (mode & 1) {
-				for (i = 0; i < len; i++) {
-					if (c[i] == p) {
-						trimmed++;
+				while (start != end) {
+					if (*start == p) {
+						start++;
 					} else {
 						break;
 					}
 				}
-				len -= trimmed;
-				c += trimmed;
 			}
 			if (mode & 2) {
-				if (len > 0) {
-					i = len - 1;
-					do {
-						if (c[i] == p) {
-							len--;
-						} else {
-							break;
-						}
-					} while (i-- != 0);
+				while (start != end) {
+					if (*(end-1) == p) {
+						end--;
+					} else {
+						break;
+					}
 				}
 			}
 		} else {
 			php_charmask((unsigned char*)what, what_len, mask);
 
 			if (mode & 1) {
-				for (i = 0; i < len; i++) {
-					if (mask[(unsigned char)c[i]]) {
-						trimmed++;
+				while (start != end) {
+					if (mask[(unsigned char)*start]) {
+						start++;
 					} else {
 						break;
 					}
 				}
-				len -= trimmed;
-				c += trimmed;
 			}
 			if (mode & 2) {
-				if (len > 0) {
-					i = len - 1;
-					do {
-						if (mask[(unsigned char)c[i]]) {
-							len--;
-						} else {
-							break;
-						}
-					} while (i-- != 0);
+				while (start != end) {
+					if (mask[(unsigned char)*(end-1)]) {
+						end--;
+					} else {
+						break;
+					}
 				}
 			}
 		}
 	} else {
 		if (mode & 1) {
-			for (i = 0; i < len; i++) {
-				if ((unsigned char)c[i] <= ' ' &&
-				    (c[i] == ' ' || c[i] == '\n' || c[i] == '\r' || c[i] == '\t' || c[i] == '\v' || c[i] == '\0')) {
-					trimmed++;
+			while (start != end) {
+				unsigned char c = (unsigned char)*start;
+
+				if (c <= ' ' &&
+				    (c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == '\v' || c == '\0')) {
+					start++;
 				} else {
 					break;
 				}
 			}
-			len -= trimmed;
-			c += trimmed;
 		}
 		if (mode & 2) {
-			if (len > 0) {
-				i = len - 1;
-				do {
-					if ((unsigned char)c[i] <= ' ' &&
-					    (c[i] == ' ' || c[i] == '\n' || c[i] == '\r' || c[i] == '\t' || c[i] == '\v' || c[i] == '\0')) {
-						len--;
-					} else {
-						break;
-					}
-				} while (i-- != 0);
+			while (start != end) {
+				unsigned char c = (unsigned char)*(end-1);
+
+				if (c <= ' ' &&
+				    (c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == '\v' || c == '\0')) {
+					end--;
+				} else {
+					break;
+				}
 			}
 		}
 	}
 
-	if (ZSTR_LEN(str) == len) {
+	if (ZSTR_LEN(str) == end - start) {
 		return zend_string_copy(str);
+	} else if (end - start == 0) {
+		return ZSTR_EMPTY_ALLOC();
 	} else {
-		return zend_string_init(c, len, 0);
+		return zend_string_init(start, end - start, 0);
 	}
 }
 /* }}} */
 
+/* {{{ php_trim_int()
+ * mode 1 : trim left
+ * mode 2 : trim right
+ * mode 3 : trim left and right
+ * what indicates which chars are to be trimmed. NULL->default (' \t\n\r\v\0')
+ */
+PHPAPI zend_string *php_trim(zend_string *str, char *what, size_t what_len, int mode)
+{
+	return php_trim_int(str, what, what_len, mode);
+}
+/* }}} */
+
 /* {{{ php_do_trim
  * Base for trim(), rtrim() and ltrim() functions.
  */
-static void php_do_trim(INTERNAL_FUNCTION_PARAMETERS, int mode)
+static zend_always_inline void php_do_trim(INTERNAL_FUNCTION_PARAMETERS, int mode)
 {
 	zend_string *str;
 	zend_string *what = NULL;
@@ -908,7 +909,7 @@ static void php_do_trim(INTERNAL_FUNCTION_PARAMETERS, int mode)
 		Z_PARAM_STR(what)
 	ZEND_PARSE_PARAMETERS_END();
 
-	ZVAL_STR(return_value, php_trim(str, (what ? ZSTR_VAL(what) : NULL), (what ? ZSTR_LEN(what) : 0), mode));
+	ZVAL_STR(return_value, php_trim_int(str, (what ? ZSTR_VAL(what) : NULL), (what ? ZSTR_LEN(what) : 0), mode));
 }
 /* }}} */