/* memset/bzero -- set memory area to CH/0

   Highly optimized version for ix86, x>=5.

   Copyright (C) 1996-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Torbjorn Granlund, <tege@matematik.su.se>

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

#include "asm-syntax.h"

#define PARMS	4+4	/* space for 1 saved reg */

#define RTN	PARMS

#define DEST	RTN

#ifdef USE_AS_BZERO

# define LEN	DEST+4

#else

# define CHR	DEST+4

# define LEN	CHR+4

#endif

        .text

#if defined SHARED && IS_IN (libc) && !defined USE_AS_BZERO

ENTRY (__memset_chk)

	movl	12(%esp), %eax

	cmpl	%eax, 16(%esp)

	jb	HIDDEN_JUMPTARGET (__chk_fail)

END (__memset_chk)

#endif

ENTRY (memset)

	pushl	%edi

	cfi_adjust_cfa_offset (4)

	movl	DEST(%esp), %edi

	cfi_rel_offset (edi, 0)

	movl	LEN(%esp), %edx

#ifdef USE_AS_BZERO

	xorl	%eax, %eax	/* we fill with 0 */

#else

	movb	CHR(%esp), %al

	movb	%al, %ah

	movl	%eax, %ecx

	shll	$16, %eax

	movw	%cx, %ax

#endif

	cld

/* If less than 36 bytes to write, skip tricky code (it wouldn't work).  */

	cmpl	$36, %edx

	movl	%edx, %ecx	/* needed when branch is taken! */

	jl	L(2)

/* First write 0-3 bytes to make the pointer 32-bit aligned.  */

	movl	%edi, %ecx	/* Copy ptr to ecx... */

	negl	%ecx		/* ...and negate that and... */

	andl	$3, %ecx	/* ...mask to get byte count.  */

	subl	%ecx, %edx	/* adjust global byte count */

	rep

	stosb

	subl	$32, %edx	/* offset count for unrolled loop */

	movl	(%edi), %ecx	/* Fetch destination cache line */

	.align	2, 0x90		/* supply 0x90 for broken assemblers */

L(1):	movl	28(%edi), %ecx	/* allocate cache line for destination */

	subl	$32, %edx	/* decr loop count */

	movl	%eax, 0(%edi)	/* store words pairwise */

	movl	%eax, 4(%edi)

	movl	%eax, 8(%edi)

	movl	%eax, 12(%edi)

	movl	%eax, 16(%edi)

	movl	%eax, 20(%edi)

	movl	%eax, 24(%edi)

	movl	%eax, 28(%edi)

	leal	32(%edi), %edi	/* update destination pointer */

	jge	L(1)

	leal	32(%edx), %ecx	/* reset offset count */

/* Write last 0-7 full 32-bit words (up to 8 words if loop was skipped).  */

L(2):	shrl	$2, %ecx	/* convert byte count to longword count */

	rep

	stosl

/* Finally write the last 0-3 bytes.  */

	movl	%edx, %ecx

	andl	$3, %ecx

	rep

	stosb

#ifndef USE_AS_BZERO

	/* Load result (only if used as memset).  */

	movl DEST(%esp), %eax	/* start address of destination is result */

#endif

	popl	%edi

	cfi_adjust_cfa_offset (-4)

	cfi_restore (edi)

	ret

END (memset)

libc_hidden_builtin_def (memset)