diff options
author | Theo de Raadt <deraadt@cvs.openbsd.org> | 1995-10-18 08:53:40 +0000 |
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committer | Theo de Raadt <deraadt@cvs.openbsd.org> | 1995-10-18 08:53:40 +0000 |
commit | d6583bb2a13f329cf0332ef2570eb8bb8fc0e39c (patch) | |
tree | ece253b876159b39c620e62b6c9b1174642e070e /lib/libc/arch/m68k/string/memset.S |
initial import of NetBSD tree
Diffstat (limited to 'lib/libc/arch/m68k/string/memset.S')
-rw-r--r-- | lib/libc/arch/m68k/string/memset.S | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/lib/libc/arch/m68k/string/memset.S b/lib/libc/arch/m68k/string/memset.S new file mode 100644 index 00000000000..322abc10582 --- /dev/null +++ b/lib/libc/arch/m68k/string/memset.S @@ -0,0 +1,111 @@ +/*- + * Copyright (c) 1990 The Regents of the University of California. + * All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * the Systems Programming Group of the University of Utah Computer + * Science Department. + * + * 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) + .text + /*.asciz "from: @(#)bzero.s 5.1 (Berkeley) 5/12/90"*/ + .asciz "$Id: memset.S,v 1.1 1995/10/18 08:41:31 deraadt Exp $" +#endif /* LIBC_SCCS and not lint */ + +#include "DEFS.h" + +/* + * This is probably not the best we can do, but it is still much + * faster than the C version in the portable gen directory. + * + * Things that might help: + * - unroll the longword loop (might not be good for a 68020) + * - longword, as opposed to word, align when possible (only on the 68020) + * - use nested DBcc instructions or use one and limit size to 64K + */ +ENTRY(memset) + movl d2,sp@- + movl sp@(8),a0 | destination + movl sp@(16),d0 | count + beq bzdone | nothing to do + movb sp@(15),d2 | character + movl a0,d1 + btst #0,d1 | address odd? + beq bzeven | no, skip alignment + movb d2,a0@+ | set one byte + subql #1,d0 | adjust count + beq bzdone | if zero, all done +bzeven: + cmpl #15,d0 + ble bzbloop | too small to be worthwhile + clrl d1 | replicate byte to fill longword + movb d2,d1 + movl d1,d2 + lsll #8,d1 + orl d1,d2 + lsll #8,d1 + orl d1,d2 + lsll #8,d1 + orl d1,d2 + movl d0,d1 | convert to longword count + lsrl #2,d1 +#ifdef DEBUG + moveml #0xffff,sp@- + movl d2,sp@- + movl d1,sp@- + movl d0,sp@- + movl a0,sp@- + movl #foo,sp@- + jsr _printf + addl #20,sp + moveml sp@+,#0xffff +#endif +bzlloop: + movl d2,a0@+ | set one longword + subql #1,d1 | adjust count + bne bzlloop | still more, keep going + andl #3,d0 | what remains + beq bzdone | nothing, all done +bzbloop: + movb d2,a0@+ | set one byte + subql #1,d0 | adjust count + bne bzbloop | still more, keep going +bzdone: + movl sp@(8),d0 | return destination + movl sp@+,d2 + rts + +#ifdef DEBUG + .globl _printf +foo: + .asciz "a0=%08x d0=%08x d1=%08x d2=%08x\n" +#endif |