kernel/x86: Replace homegrown memcpy & memset with NetBSD's.

FreeBSD also uses NetBSD's versions (with their own modifications,
however.) So it seems to make sense for us to adopt these, too;
they look to be better tuned than ours were (like handling
non-aligned addresses better, which was a TODO before.)

src/system/kernel/lib/arch/x86/Jamfile

@@ -29,12 +29,8 @@ KernelMergeObject kernel_lib_posix_arch_$(TARGET_ARCH).o :
 	kernel_longjmp_return.c
 	kernel_setjmp_save_sigs.c
 
-	arch_string.S
+	memcpy.S
+	memset.S
 
 	: $(TARGET_KERNEL_PIC_CCFLAGS)
 ;
-
-# Explicitly tell the build system that arch_string.S includes the generated
-# asm_offsets.h.
-Includes [ FGristFiles arch_string.S ]
-	: <src!system!kernel!arch!x86>asm_offsets.h ;

src/system/kernel/lib/arch/x86/arch_string.S

@@ -1,114 +0,0 @@
-/*
- * Copyright 2008, Ingo Weinhold, ingo_weinhold@gmx.de.
- * Copyright 2018, Haiku, Inc. All rights reserved.
- * Distributed under the terms of the MIT License.
- *
- * Copyright 2001, Travis Geiselbrecht. All rights reserved.
- * Distributed under the terms of the NewOS License.
- */
-
-
-#include <asm_defs.h>
-
-
-.align 4
-FUNCTION(memcpy):
-	pushl	%esi
-	pushl	%edi
-	movl	12(%esp),%edi	/* dest */
-	movl	%edi,%eax	/* save dest ptr as return address */
-	movl	16(%esp),%esi	/* source */
-	movl	20(%esp),%ecx	/* count */
-
-	/* (count == 0 || dest == src) -> quick way out */
-	testl	%ecx, %ecx
-	je		.tail
-	cmpl	%edi, %esi
-	je		.tail
-
-	/* move by words */
-	// TODO: The addresses might not be aligned!
-	cld
-	shrl	$2,%ecx
-	rep
-	movsl
-
-	/* move any remaining data by bytes */
-	movl	20(%esp),%ecx
-	andl	$3,%ecx
-	rep
-	movsb
-
-.tail:
-	popl	%edi
-	popl	%esi
-	ret
-FUNCTION_END(memcpy)
-SYMBOL(memcpy_end):
-
-
-/* void *memset(void *dest, int value, size_t length); */
-.align 4
-FUNCTION(memset):
-	push	%ebp
-	mov		%esp, %ebp
-
-	// %eax, %ecx, and %edx are scratch registers -- we only have to save %edi
-	push	%edi
-
-	// get the parameters
-	mov		16(%ebp), %ecx
-	mov		12(%ebp), %eax
-	mov		8(%ebp), %edi
-
-	// When touching less than 12 bytes, we just do it bytewise. We might be
-	// able to process one or two lwords lwordwise, but the additional overhead
-	// isn't worth it.
-	cmp		$12, %ecx
-	jl		2f
-
-	// buffer address lword-aligned?
-	mov		%edi, %edx
-	and		$0x3, %edx
-	jz		1f
-
-	// the buffer is unaligned -- copy the first bytes bytewise
-	mov		$4, %ecx
-	sub		%edx, %ecx
-	rep 	stosb
-
-	mov		16(%ebp), %ecx
-	sub		$4, %ecx
-	add		%edx, %ecx
-
-1:	// lwordwise
-	// prepare %eax -- the low byte must be copied to the other bytes
-	mov		%al, %ah
-	mov		%eax, %edx
-	shl		$16, %eax
-	mov		%dx, %ax
-
-	// get the unaligned remainder into %edx
-	mov		%ecx, %edx
-	and		$0x3, %edx
-
-	// write words
-	shr		$2, %ecx
-	rep		stosl
-
-	mov		%edx, %ecx
-
-2:	// bytewise (remaining bytes)
-	rep 	stosb
-
-	pop		%edi
-
-	// return value is the value passed in
-	mov		8(%ebp), %eax
-
-	mov		%ebp, %esp
-	pop		%ebp
-	ret
-FUNCTION_END(memset)
-SYMBOL(memset_end):
-

src/system/kernel/lib/arch/x86/memcpy.S

@@ -0,0 +1,143 @@
+/*	$NetBSD: memcpy.S,v 1.4 2014/03/22 19:38:46 jakllsch Exp $	*/
+
+/*-
+ * 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.
+ */
+
+#ifdef __HAIKU__
+#include <asm_defs.h>
+#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
+.align 4
+FUNCTION(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	.Lbackwards
+#endif
+	/* nope, copy forwards. */
+	shrl	$2,%ecx		/* copy by words */
+	rep
+	movsl
+	and	$3,%eax		/* any bytes left? */
+	jnz	.Ltrailing
+.Ldone:
+#if defined(MEMCPY) || defined(MEMMOVE)
+	movl	8(%esp),%eax
+#endif
+	mov	%edx,%edi
+	pop	%esi
+	ret
+
+.Ltrailing:
+	cmp	$2,%eax
+	jb	1f
+	movw	(%esi),%ax
+	movw	%ax,(%edi)
+	je	.Ldone
+	movb	2(%esi),%al
+	movb	%al,2(%edi)
+	jmp	.Ldone
+1:	movb	(%esi),%al
+	movb	%al,(%edi)
+	jmp	.Ldone
+
+#if !defined(NO_OVERLAP)
+.Lbackwards:
+	addl	%ecx,%edi	/* copy backwards. */
+	addl	%ecx,%esi
+	and	$3,%eax		/* any fractional bytes? */
+	jnz	.Lback_align
+.Lback_aligned:
+	shrl	$2,%ecx
+	subl	$4,%esi
+	subl	$4,%edi
+	std
+	rep
+	movsl
+	cld
+	jmp	.Ldone
+
+.Lback_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	.Lback_aligned
+1:	movb	(%esi),%al
+	movb	%al,(%edi)
+	jmp	.Lback_aligned
+#endif
+
+#ifdef BCOPY
+END(bcopy)
+#else
+#ifdef MEMMOVE
+END(memmove)
+#else
+FUNCTION_END(memcpy)
+SYMBOL(memcpy_end):
+#endif
+#endif

src/system/kernel/lib/arch/x86/memset.S

@@ -0,0 +1,111 @@
+/*	$NetBSD: memset.S,v 1.5 2014/05/23 03:17:31 uebayasi Exp $	*/
+
+/*-
+ * Copyright (c) 2003 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by David Laight.
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+#ifdef __HAIKU__
+#include <asm_defs.h>
+#endif
+
+#ifdef BZERO
+ENTRY(bzero)
+#else
+.align 4
+FUNCTION(memset):
+#endif
+#ifdef BZERO
+	movl	8(%esp),%ecx
+	xor	%eax,%eax
+#else
+	movl	12(%esp),%ecx
+	movzbl	8(%esp),%eax		/* unsigned char, zero extend */
+#endif
+	cmpl	$0x0f,%ecx		/* avoid mispredicted branch... */
+
+	pushl	%edi
+	movl	8(%esp),%edi
+
+	/*
+	 * if the string is too short, it's really not worth the overhead
+	 * of aligning to word boundries, etc.  So we jump to a plain
+	 * unaligned set.
+	 *
+	 * NB aligning the transfer is actually pointless on my athlon 700,
+	 * It does make a difference to a PII though.
+	 *
+	 * The PII, PIII and PIV all seem to have a massive performance
+	 * drop when the initial target address is an odd multiple of 4.
+	 */
+	jbe	.Lby_bytes
+
+#ifndef BZERO
+	movb	%al,%ah			/* copy char to all bytes in word */
+	movl	%eax,%edx
+	sall	$16,%eax
+	orl	%edx,%eax
+#endif
+
+	movl	%edi,%edx		/* detect misalignment */
+	neg	%edx
+	andl	$7,%edx
+	jnz	.Lalign
+.Laligned:
+	movl	%eax,-4(%edi,%ecx)	/* zap last 4 bytes */
+	shrl	$2,%ecx			/* zero by words */
+	rep
+	stosl
+.Ldone:
+#ifndef BZERO
+	movl	8(%esp),%eax		/* return address of buffer */
+#endif
+	pop	%edi
+	ret
+
+.Lalign:
+	movl	%eax,(%edi)		/* zap first 8 bytes */
+	movl	%eax,4(%edi)
+	subl	%edx,%ecx		/* remove from main count */
+	add	%edx,%edi
+	jmp	.Laligned
+
+.Lby_bytes:
+	rep
+	stosb
+
+#ifndef BZERO
+	movl	8(%esp),%eax		/* return address of buffer */
+#endif
+	popl	%edi
+	ret
+#ifdef BZERO
+END(bzero)
+#else
+FUNCTION_END(memset)
+SYMBOL(memset_end):
+#endif