add better tolower to go with the toupper

src/include/switch_utils.h

@@ -42,7 +42,9 @@
 
 SWITCH_BEGIN_EXTERN_C 
 
-/* https://code.google.com/p/stringencoders/wiki/PerformanceAscii */
+/* https://code.google.com/p/stringencoders/wiki/PerformanceAscii 
+   http://www.azillionmonkeys.com/qed/asmexample.html
+*/
 static inline uint32_t switch_toupper(uint32_t eax)
 {
 	uint32_t ebx = (0x7f7f7f7ful & eax) + 0x05050505ul;
@@ -51,6 +53,17 @@ static inline uint32_t switch_toupper(uint32_t eax)
 	return eax - ebx;
 }
 
+/* https://code.google.com/p/stringencoders/wiki/PerformanceAscii 
+   http://www.azillionmonkeys.com/qed/asmexample.html
+*/
+static inline uint32_t switch_tolower(uint32_t eax)
+{
+	uint32_t ebx = (0x7f7f7f7ful & eax) + 0x25252525ul;
+	ebx = (0x7f7f7f7ful & ebx) + 0x1a1a1a1aul;
+	ebx = ((ebx & ~eax) >> 2)  & 0x20202020ul;
+	return eax + ebx;
+}
+
 #ifdef FS_64BIT
 
 static inline void switch_toupper_max(char *s)
@@ -81,6 +94,34 @@ static inline void switch_toupper_max(char *s)
 
 }
 
+static inline void switch_tolower_max(char *s)
+{
+	uint64_t *b,*p;
+	char *c;
+	size_t l;
+
+	l = strlen(s);
+
+	p = (uint64_t *) s;
+
+	while (l > 8) {
+		b = p;
+		*b = (uint32_t) switch_tolower(*b);
+		b++;
+		p++;
+		l -= 8;
+	}
+
+	c = (char *)p;
+
+	while(l > 0) {
+		*c = (char) switch_tolower(*c);
+		c++;
+		l--;
+	}
+
+}
+
 #else 
 
 static inline void switch_toupper_max(char *s)
@@ -109,12 +150,40 @@ static inline void switch_toupper_max(char *s)
 		l--;
 	}
 	
+}
+
+static inline void switch_tolower_max(char *s)
+{
+	uint32_t *b,*p;
+	char *c;
+	size_t l;
+
+	l = strlen(s);
+
+	p = (uint32_t *) s;
+
+	while (l > 4) {
+		b = p;
+		*b = (uint32_t) switch_tolower(*b);
+		b++;
+		p++;
+		l -= 4;
+	}
+
+	c = (char *)p;
+
+	while(l > 0) {
+		*c = (char) switch_tolower(*c);
+		c++;
+		l--;
+	}
+	
 }
 #endif
 
 
 SWITCH_DECLARE(int) old_switch_toupper(int c);
-SWITCH_DECLARE(int) switch_tolower(int c);
+SWITCH_DECLARE(int) old_switch_tolower(int c);
 SWITCH_DECLARE(int) switch_isalnum(int c);
 SWITCH_DECLARE(int) switch_isalpha(int c);
 SWITCH_DECLARE(int) switch_iscntrl(int c);

src/switch_utils.c

@@ -2656,7 +2656,7 @@ const short _switch_C_tolower_[1 + SWITCH_CTYPE_NUM_CHARS] = {
 
 const short *_switch_tolower_tab_ = _switch_C_tolower_;
 
-SWITCH_DECLARE(int) switch_tolower(int c)
+SWITCH_DECLARE(int) old_switch_tolower(int c)
 {
 	if ((unsigned int) c > 255)
 		return (c);