sync to ragge

1 files changed, 94 insertions, 0 deletions

diff --git a/lib/libc/arch/vax/string/memcpy.S b/lib/libc/arch/vax/string/memcpy.S
new file mode 100644
index 00000000000..54f7ce842c4
--- /dev/null
+++ b/lib/libc/arch/vax/string/memcpy.S
@@ -0,0 +1,94 @@
+/*	$NetBSD: memcpy.S,v 1.1 1996/05/19 15:57:45 ragge Exp $	*/
+/*-
+ * Copyright (c) 1990, 1993
+ *	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 "@(#)memcpy.s	8.1 (Berkeley) 6/4/93"
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * void *memcpy(dst, src, size)
+ * returns dst
+ *
+ * This optimises the usual case (count < 65536) at the expense
+ * of some extra memory references and branches when count >= 65536.
+ */
+
+#include "DEFS.h"
+
+ENTRY(memcpy, 0)
+	movzwl	$65535,r0	/* r0 = 64K (needed below) */
+	movq	8(ap),r1	/* r1 = src, r2 = length */
+	movl	4(ap),r3	/* r3 = dst */
+	cmpl	r1,r3
+	bgtru	1f		/* normal forward case */
+	beql	2f		/* equal, nothing to do */
+	addl2	r2,r1		/* overlaps iff src<dst but src+len>dst */
+	cmpl	r1,r3
+	bgtru	4f		/* overlapping, must move backwards */
+	subl2	r2,r1
+
+1:	/* move forward */
+	cmpl	r2,r0
+	bgtru	3f		/* stupid movc3 limitation */
+	movc3	r2,(r1),(r3)	/* move it all */
+2:
+	movl	4(ap),r0	/* return original dst */
+	ret
+3:
+	subl2	r0,12(ap)	/* adjust length by 64K */
+	movc3	r0,(r1),(r3)	/* move 64K */
+	movl	12(ap),r2
+	decw	r0		/* from 0 to 65535 */
+	brb	1b		/* retry */
+
+4:	/* move backward */
+	addl2	r2,r3
+5:
+	cmpl	r2,r0
+	bgtru	6f		/* stupid movc3 limitation */
+	subl2	r2,r1
+	subl2	r2,r3
+	movc3	r2,(r1),(r3)	/* move it all */
+	movl	4(ap),r0	/* return original dst */
+	ret
+6:
+	subl2	r0,12(ap)	/* adjust length by 64K */
+	subl2	r0,r1
+	subl2	r0,r3
+	movc3	r0,(r1),(r3)	/* move 64K */
+	movl	12(ap),r2
+	decw	r0
+	subl2	r0,r1
+	subl2	r0,r3
+	brb	5b