glibc/sysdeps/i386/i586/memset.S
Roland McGrath 53f770e0f9 Wed Mar 27 14:52:11 1996 Roland McGrath <roland@charlie-brown.gnu.ai.mit.edu>
* elf/rtld.c (dl_main): Call _dl_sysdep_start_cleanup after
	_dl_relocate_object loop.  Avoid relocating RTLD_MAP in that loop, and
	do it individually if necessary after _dl_sysdep_start_cleanup call.

	* stdlib/Makefile (mpn-routines): Add divrem.

Tue Mar 26 22:54:14  Ulrich Drepper  <drepper@gnu.ai.mit.edu>

	* stdio-common/printf_fp.c (__printf_fp): Use mpn_divmod
	instead of __mpn_divmod.

Wed Mar 27 10:26:21 1996  David Mosberger-Tang  <davidm@azstarnet.com>

	* sysdeps/alpha/setjmp.S: Must establish global pointer before
 	address of __sigsetjmp_aux can be loaded.

Wed Mar 27 02:23:19 1996 Ulrich Drepper <drepper@gnu.ai.mit.edu>

	* sysdeps/i386/i586/memset.S: New file.  Highly optimized
	version for i586 contributed by Torbjorn Granlund.
	Adapted for use as bzero.
	* sysdeps/i386/i586/bzero.S: Use sysdeps/i386/i586/memset.S
	code to implement bzero().

Tue Mar 26 20:01:17 1996  Roland McGrath  <roland@charlie-brown.gnu.ai.mit.edu>

	* stdlib/Makefile (mpn-routines): Remove divmod.
1996-03-27 23:23:59 +00:00

102 lines
2.8 KiB
ArmAsm

/* memset/bzero -- set memory area to CH/0
Highly optimized version for ix85, x>=5.
Copyright (C) 1996 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <sysdep.h>
/*
INPUT PARAMETERS:
(memset) (bzero)
dst (sp + 4) dst (sp + 4)
ch (sp + 8) len (sp + 8)
len (sp + 12)
*/
.text
ENTRY (memset)
pushl %edi
movl 8(%esp), %edi /* destination pointer */
#ifdef memset
xorl %eax, %eax /* we fill with 0 */
movl 12(%esp), %edx /* size (in 8-bit words) */
#else
movb 12(%esp), %al /* use CH to fill */
movl 16(%esp), %edx /* size (in 8-bit words) */
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 L2
/* 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 */
L1: 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 L1
leal 32(%edx), %ecx /* reset offset count */
/* Write last 0-7 full 32-bit words (up to 8 words if loop was skipped). */
L2: 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
/* Load result (only if used as memset). */
#ifndef memset
movl 8(%esp), %eax
#endif
popl %edi
ret