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authorTheo de Raadt <deraadt@cvs.openbsd.org>1995-10-18 08:53:40 +0000
committerTheo de Raadt <deraadt@cvs.openbsd.org>1995-10-18 08:53:40 +0000
commitd6583bb2a13f329cf0332ef2570eb8bb8fc0e39c (patch)
treeece253b876159b39c620e62b6c9b1174642e070e /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.S111
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
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+++ 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