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+/*-
+ * Copyright (c) 1990 The 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 "@(#)memchr.s 5.1 (Berkeley) 5/29/90"
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * Find the first occurence of c in the memory at cp (length n).
+ * Return pointer to match or null pointer.
+ *
+ * This code optimises the usual case (0 < n < 65535).
+ *
+ * void *
+ * memchr(cp, c, n)
+ * char *cp, c;
+ * size_t n;
+ */
+
+#include "DEFS.h"
+
+ENTRY(memchr, 0)
+ movq 4(ap),r1 # r1 = cp; r2 = c
+ movl 12(ap),r0 # r0 = n
+ movzwl $65535,r4 # handy constant
+0:
+ cmpl r0,r4 # check for annoying locc limit
+ bgtru 3f
+
+ /* n <= 65535 */
+ locc r2,r0,(r1) # search n bytes for c
+ beql 2f # done if not found (r0 already 0)
+1: /* found character c at (r1) */
+ movl r1,r0
+2:
+ ret
+
+3: /* n > 65535 */
+ locc r2,r4,(r1) # search 65535 bytes for c
+ beql 1b # done if found
+ decw r0 # from 0 to 65535
+ subl2 r0,r4 # adjust n
+ brb 0b # and loop