1 /* memset/bzero -- set memory area to CH/0
2 Highly optimized version for ix85, x>=5.
3 Copyright (C) 1996 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5 Contributed by Torbjorn Granlund, <tege@matematik.su.se>
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Library General Public License as
9 published by the Free Software Foundation; either version 2 of the
10 License, or (at your option) any later version.
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Library General Public License for more details.
17 You should have received a copy of the GNU Library General Public
18 License along with the GNU C Library; see the file COPYING.LIB. If
19 not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
27 dst (sp + 4) dst (sp + 4)
28 ch (sp + 8) len (sp + 8)
37 movl 8(%esp), %edi /* destination pointer */
39 xorl %eax, %eax /* we fill with 0 */
40 movl 12(%esp), %edx /* size (in 8-bit words) */
42 movb 12(%esp), %al /* use CH to fill */
43 movl 16(%esp), %edx /* size (in 8-bit words) */
52 /* If less than 36 bytes to write, skip tricky code (it wouldn't work). */
54 movl %edx, %ecx /* needed when branch is taken! */
57 /* First write 0-3 bytes to make the pointer 32-bit aligned. */
58 movl %edi, %ecx /* Copy ptr to ecx... */
59 negl %ecx /* ...and negate that and... */
60 andl $3, %ecx /* ...mask to get byte count. */
61 subl %ecx, %edx /* adjust global byte count */
65 subl $32, %edx /* offset count for unrolled loop */
66 movl (%edi), %ecx /* Fetch destination cache line */
68 .align 2, 0x90 /* supply 0x90 for broken assemblers */
69 L1: movl 28(%edi), %ecx /* allocate cache line for destination */
70 subl $32, %edx /* decr loop count */
71 movl %eax, 0(%edi) /* store words pairwise */
79 leal 32(%edi), %edi /* update destination pointer */
82 leal 32(%edx), %ecx /* reset offset count */
84 /* Write last 0-7 full 32-bit words (up to 8 words if loop was skipped). */
85 L2: shrl $2, %ecx /* convert byte count to longword count */
89 /* Finally write the last 0-3 bytes. */
95 /* Load result (only if used as memset). */