Bring code in from obsolesent bcopy.S

Optimise to avoid mis-predicted braches and 'rep movsb' for small %cx.

lib/libc/arch/i386/string/memcpy.S

@@ -1,4 +1,133 @@
-/*	$NetBSD: memcpy.S,v 1.2 1998/01/09 03:45:07 perry Exp $	*/
+/*	$NetBSD: memcpy.S,v 1.3 2005/02/03 22:31:44 dsl Exp $	*/
 
-#define MEMCOPY
-#include "bcopy.S"
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from locore.s.
+ * Optimised by David Laight 2003
+ *
+ * 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. 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.
+ */
+
+#include <machine/asm.h>
+
+#if defined(LIBC_SCCS)
+	RCSID("$NetBSD: memcpy.S,v 1.3 2005/02/03 22:31:44 dsl Exp $")
+#endif
+
+	/*
+	 * (ov)bcopy (src,dst,cnt)
+	 *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
+	 */
+
+#ifdef BCOPY
+ENTRY(bcopy)
+#else
+#ifdef MEMMOVE
+ENTRY(memmove)
+#else
+#define MEMCPY
+#define NO_OVERLAP
+ENTRY(memcpy)
+#endif
+#endif
+	push	%esi
+	mov	%edi,%edx
+#if defined(MEMCPY) || defined(MEMMOVE)
+	movl	8(%esp),%edi
+	movl	12(%esp),%esi
+#else
+	movl	8(%esp),%esi
+	movl	12(%esp),%edi
+#endif
+	movl	16(%esp),%ecx
+#if defined(NO_OVERLAP)
+	movl	%ecx,%eax
+#else
+	movl	%edi,%eax
+	subl	%esi,%eax
+	cmpl	%ecx,%eax	/* overlapping? */
+	movl	%ecx,%eax
+	jb	backwards
+#endif
+	cld			/* nope, copy forwards. */
+	shrl	$2,%ecx		/* copy by words */
+	rep
+	movsl
+	and	$3,%eax		/* any bytes left? */
+	jnz	trailing
+done:
+#if defined(MEMCPY) || defined(MEMMOVE)
+	movl	8(%esp),%eax
+#endif
+	mov	%edx,%edi
+	pop	%esi
+	ret
+
+trailing:
+	cmp	$2,%eax
+	jb	1f
+	movw	(%esi),%ax
+	movw	%ax,(%edi)
+	je	done
+	movb	2(%esi),%al
+	movb	%al,2(%edi)
+	jmp	done
+1:	movb	(%esi),%al
+	movb	%al,(%edi)
+	jmp	done
+
+#if !defined(NO_OVERLAP)
+backwards:
+	addl	%ecx,%edi	/* copy backwards. */
+	addl	%ecx,%esi
+	and	$3,%eax		/* any fractional bytes? */
+	jnz	back_align
+back_aligned:
+	shrl	$2,%ecx
+	subl	$4,%esi
+	subl	$4,%edi
+	std
+	rep
+	movsl
+	cld
+	jmp	done
+
+back_align:
+	sub	%eax,%esi
+	sub	%eax,%edi
+	cmp	$2,%eax
+	jb	1f
+	je	2f
+	movb	2(%esi),%al
+	movb	%al,2(%edi)
+2:	movw	(%esi),%ax
+	movw	%ax,(%edi)
+	jmp	back_aligned
+1:	movb	(%esi),%al
+	movb	%al,(%edi)
+	jmp	back_aligned
+#endif

lib/libc/arch/i386/string/memmove.S

@@ -1,4 +1,4 @@
-/*	$NetBSD: memmove.S,v 1.4 1998/01/09 03:45:08 perry Exp $	*/
+/*	$NetBSD: memmove.S,v 1.5 2005/02/03 22:31:44 dsl Exp $	*/
 
 #define MEMMOVE
-#include "bcopy.S"
+#include "memcpy.S"