aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/vax/strchr.s
diff options
context:
space:
mode:
authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /sysdeps/vax/strchr.s
downloadglibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.tar
glibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.tar.gz
glibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.tar.bz2
glibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.zip
initial import
Diffstat (limited to 'sysdeps/vax/strchr.s')
-rw-r--r--sysdeps/vax/strchr.s105
1 files changed, 105 insertions, 0 deletions
diff --git a/sysdeps/vax/strchr.s b/sysdeps/vax/strchr.s
new file mode 100644
index 0000000000..18b53838ec
--- /dev/null
+++ b/sysdeps/vax/strchr.s
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 1988 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 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
+ * 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
+ * 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)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+ .asciz "@(#)strchr.s 5.4 (Berkeley) 6/1/90"
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * Find the first occurence of c in the string cp.
+ * Return pointer to match or null pointer.
+ *
+ * char *
+ * strchr(cp, c)
+ * char *cp, c;
+ */
+#include "DEFS.h"
+
+ .lcomm tbl,256
+
+ENTRY(strchr, 0)
+ movzwl $65535,r4 /* handy constant */
+ movq 4(ap),r1 /* r1 = cp; r2 = c */
+ movzbl r2,r2
+ beql Lzero /* special case for c == '\0' */
+
+/*
+ * Fancy scanc version. Alas, it is not reentrant.
+ */
+ movab tbl,r3 /* r3 = base of table */
+ bbss $0,(r3),Lreent /* ensure not reentering */
+ movab (r3)[r2],r5
+ incb (r5) /* mark both '\0' and c */
+0:
+ scanc r4,(r1),(r3),$1 /* look for c or '\0' */
+ beql 0b /* still looking */
+ movl r1,r0 /* return whatever we found */
+ tstb (r0)
+ bneq 1f # unless it was '\0':
+ clrl r0 # then return NULL
+1:
+ clrb (r5) /* clean up table */
+ clrb (r3)
+ ret
+
+/*
+ * Special case for \0.
+ */
+Lzero:
+ locc r2,r4,(r1) /* just find end of string */
+ beql Lzero /* still looking */
+ movl r1,r0 /* found it */
+ ret
+
+/*
+ * Slower reentrant version is two two-step searches. The first
+ * phase runs until we know where the string ends; it locates the
+ * first occurrence of c within a 65535-byte block. If we find
+ * the end of the string first, we switch to the second phase,
+ * were we look only up to the known end of string.
+ */
+Lreent:
+0: /* first phase */
+ movl r1,r3
+ locc $0,r4,(r3) /* look for '\0' */
+ bneq 1f
+ locc r2,r4,(r3) /* look for c */
+ beql 0b /* not found: reset pointer and loop */
+ movl r1,r0 /* found: return it */
+ ret
+1: /* second phase */
+ subl3 r3,r1,r0 /* length of short block */
+ locc r2,r0,(r3) /* look for c */
+ beql 2f /* not found: return NULL */
+ movl r1,r0
+2: ret