Libc-498.tar.gz

[apple/libc.git] / string / FreeBSD / strspn.c

diff --git a/string/FreeBSD/strspn.c b/string/FreeBSD/strspn.c
index ae28642636dc335b49fcb41cac4905084d4f2a55..3b96365dd6602df6f11ce83c13f72a4ff16e4273 100644 (file)
--- a/string/FreeBSD/strspn.c
+++ b/string/FreeBSD/strspn.c
@@ -1,6 +1,6 @@
-/*
- * Copyright (c) 1989, 1993
- *     The Regents of the University of California.  All rights reserved.
+/*-
+ * Copyright (c) 2005 David Schultz <das@FreeBSD.ORG>
+ * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -10,18 +10,11 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *     This product includes software developed by the University of
- *     California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- *    may be used to endorse or promote products derived from this software
- *    without specific prior written permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
@@ -31,32 +24,48 @@
  * SUCH DAMAGE.
  */
 
-#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)strspn.c   8.1 (Berkeley) 6/4/93";
-#endif /* LIBC_SCCS and not lint */
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: src/lib/libc/string/strspn.c,v 1.4 2002/03/21 18:44:54 obrien Exp $");
+__FBSDID("$FreeBSD: src/lib/libc/string/strspn.c,v 1.5 2005/04/02 18:52:44 das Exp $");
 
+#include <sys/types.h>
+#include <limits.h>
 #include <string.h>
 
-/*
- * Span the string s2 (skip characters that are in s2).
- */
+#define        IDX(c)  ((u_char)(c) / LONG_BIT)
+#define        BIT(c)  ((u_long)1 << ((u_char)(c) % LONG_BIT))
+
 size_t
-strspn(s1, s2)
-       const char *s1;
-       const char *s2;
+strspn(const char *s, const char *charset)
 {
-       const char *p = s1, *spanp;
-       char c, sc;
-
        /*
-        * Skip any characters in s2, excluding the terminating \0.
+        * NB: idx and bit are temporaries whose use causes gcc 3.4.2 to
+        * generate better code.  Without them, gcc gets a little confused.
         */
-cont:
-       c = *p++;
-       for (spanp = s2; (sc = *spanp++) != 0;)
-               if (sc == c)
-                       goto cont;
-       return (p - 1 - s1);
+       const char *s1;
+       u_long bit;
+       u_long tbl[(UCHAR_MAX + 1) / LONG_BIT];
+       int idx;
+
+       if(*s == '\0')
+               return (0);
+
+#if LONG_BIT == 64     /* always better to unroll on 64-bit architectures */
+       tbl[3] = tbl[2] = tbl[1] = tbl[0] = 0;
+#else
+       for (idx = 0; idx < sizeof(tbl) / sizeof(tbl[0]); idx++)
+               tbl[idx] = 0;
+#endif
+       for (; *charset != '\0'; charset++) {
+               idx = IDX(*charset);
+               bit = BIT(*charset);
+               tbl[idx] |= bit;
+       }
+
+       for(s1 = s; ; s1++) {
+               idx = IDX(*s1);
+               bit = BIT(*s1);
+               if ((tbl[idx] & bit) == 0)
+                       break;
+       }
+       return (s1 - s);
 }