2009-04-23 Mike Burgess <wizardsguild@earthlink.net>

        * libc/string/strcasecmp.c: Optimized rewrite.
        * libc/string/strncasecmp.c: Fix description.
        * libc/string/strlwr.c: Avoid passing signed char to tolower.
        * libc/string/strupr.c: Avoid passing signed char to tolower.

4 files changed, 26 insertions, 29 deletions

diff --git a/newlib/libc/string/strcasecmp.c b/newlib/libc/string/strcasecmp.c
index f96f7f5c9..73cf8661e 100644
--- a/newlib/libc/string/strcasecmp.c
+++ b/newlib/libc/string/strcasecmp.c
@@ -22,7 +22,7 @@ DESCRIPTION
 RETURNS 
 
 	If <<*<[a]>>> sorts lexicographically after <<*<[b]>>> (after
-	both are converted to uppercase), <<strcasecmp>> returns a
+	both are converted to lowercase), <<strcasecmp>> returns a
 	number greater than zero.  If the two strings match,
 	<<strcasecmp>> returns zero.  If <<*<[a]>>> sorts
 	lexicographically before <<*<[b]>>>, <<strcasecmp>> returns a
@@ -35,7 +35,7 @@ PORTABILITY
 tolower() from elsewhere in this library.
 
 QUICKREF
-	strcasecmp 
+	strcasecmp
 */
 
 #include <string.h>
@@ -46,11 +46,15 @@ _DEFUN (strcasecmp, (s1, s2),
 	_CONST char *s1 _AND
 	_CONST char *s2)
 {
-  while (*s1 != '\0' && tolower(*s1) == tolower(*s2))
+  _CONST unsigned char *ucs1 = (_CONST unsigned char *) s1;
+  _CONST unsigned char *ucs2 = (_CONST unsigned char *) s2;
+  int d = 0;
+  for ( ; ; )
     {
-      s1++;
-      s2++;
+      _CONST int c1 = tolower(*ucs1++);
+      _CONST int c2 = tolower(*ucs2++);
+      if (((d = c1 - c2) != 0) || (c2 == '\0'))
+        break;
     }
-
-  return tolower(*(unsigned char *) s1) - tolower(*(unsigned char *) s2);
+  return d;
 }
diff --git a/newlib/libc/string/strlwr.c b/newlib/libc/string/strlwr.c
index 47096d430..3b73dba4b 100644
--- a/newlib/libc/string/strlwr.c
+++ b/newlib/libc/string/strlwr.c
@@ -34,17 +34,13 @@ QUICKREF
 #include <ctype.h>
 
 char *
-strlwr (a)
-     char *a;
+_DEFUN (strlwr, (s),
+	char *s)
 {
-  char *ret = a;
-
-  while (*a != '\0')
+  unsigned char *ucs = (unsigned char *) s;
+  for ( ; *ucs != '\0'; ucs++)
     {
-      if (isupper (*a))
-	*a = tolower (*a);
-      ++a;
+      *ucs = tolower(*ucs);
     }
-
-  return ret;
+  return s;
 }
diff --git a/newlib/libc/string/strncasecmp.c b/newlib/libc/string/strncasecmp.c
index c2eb5b86c..6909018a8 100644
--- a/newlib/libc/string/strncasecmp.c
+++ b/newlib/libc/string/strncasecmp.c
@@ -24,7 +24,7 @@ DESCRIPTION
 RETURNS
 
 	If <<*<[a]>>> sorts lexicographically after <<*<[b]>>> (after
-	both are converted to uppercase), <<strncasecmp>> returns a
+	both are converted to lowercase), <<strncasecmp>> returns a
 	number greater than zero.  If the two strings are equivalent,
 	<<strncasecmp>> returns zero.  If <<*<[a]>>> sorts
 	lexicographically before <<*<[b]>>>, <<strncasecmp>> returns a
diff --git a/newlib/libc/string/strupr.c b/newlib/libc/string/strupr.c
index 3f346b840..350618e78 100644
--- a/newlib/libc/string/strupr.c
+++ b/newlib/libc/string/strupr.c
@@ -27,23 +27,20 @@ PORTABILITY
 <<strupr>> requires no supporting OS subroutines.
 
 QUICKREF
-	strupr */
+	strupr
+*/
 
 #include <string.h>
 #include <ctype.h>
 
 char *
-strupr (a)
-     char *a;
+_DEFUN (strupr, (s),
+	char *s)
 {
-  char *ret = a;
-
-  while (*a != '\0')
+  unsigned char *ucs = (unsigned char *) s;
+  for ( ; *ucs != '\0'; ucs++)
     {
-      if (islower (*a))
-	*a = toupper (*a);
-      ++a;
+      *ucs = toupper(*ucs);
     }
-
-  return ret;
+  return s;
 }