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Diffstat (limited to 'sysdeps/vax/strncpy.s')
| -rw-r--r-- | sysdeps/vax/strncpy.s | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/sysdeps/vax/strncpy.s b/sysdeps/vax/strncpy.s new file mode 100644 index 0000000000..03a09b7bda --- /dev/null +++ b/sysdeps/vax/strncpy.s @@ -0,0 +1,84 @@ +/* + * Copyright (c) 1983 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 "@(#)strncpy.s 5.6 (Berkeley) 6/1/90" +#endif /* LIBC_SCCS and not lint */ + +/* + * Copy string s2 over top of string s1. + * Truncate or null-pad to n bytes. + * + * char * + * strncpy(s1, s2, n) + * char *s1, *s2; + */ +#include "DEFS.h" + +ENTRY(strncpy, R6) + movl 12(ap),r6 # r6 = n + bleq done # n <= 0 + movl 4(ap),r3 # r3 = s1 + movl 8(ap),r1 # r1 = s2 +1: + movzwl $65535,r2 # r2 = bytes in first chunk + cmpl r6,r2 # r2 = min(bytes in chunk, n); + jgeq 2f + movl r6,r2 +2: + subl2 r2,r6 # update n + locc $0,r2,(r1) # '\0' found? + jneq 3f + subl2 r2,r1 # back up pointer updated by locc + movc3 r2,(r1),(r3) # copy in next piece + tstl r6 # run out of space? + jneq 1b + jbr done +3: # copy up to '\0' logic + addl2 r0,r6 # r6 = number of null-pad bytes + subl2 r0,r2 # r2 = number of bytes to move + subl2 r2,r1 # back up pointer updated by locc + movc3 r2,(r1),(r3) # copy in last piece +4: # null-pad logic + movzwl $65535,r2 # r2 = bytes in first chunk + cmpl r6,r2 # r2 = min(bytes in chunk, n); + jgeq 5f + movl r6,r2 +5: + subl2 r2,r6 # update n + movc5 $0,(r3),$0,r2,(r3)# pad with '\0's + tstl r6 # finished padding? + jneq 4b +done: + movl 4(ap),r0 # return s1 + ret |