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authorRoland McGrath <roland@gnu.org>1996-03-27 23:23:59 +0000
committerRoland McGrath <roland@gnu.org>1996-03-27 23:23:59 +0000
commit53f770e0f9d405ea8d1888254c6f7ce431b04c6e (patch)
tree5f70c2032007667e315d94e29320f2c8d650f448 /sysdeps/i386/i586/memset.S
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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.
Diffstat (limited to 'sysdeps/i386/i586/memset.S')
-rw-r--r--sysdeps/i386/i586/memset.S101
1 files changed, 101 insertions, 0 deletions
diff --git a/sysdeps/i386/i586/memset.S b/sysdeps/i386/i586/memset.S
new file mode 100644
index 0000000000..3a68fa16d1
--- /dev/null
+++ b/sysdeps/i386/i586/memset.S
@@ -0,0 +1,101 @@
+/* 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