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authorRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
committerRoland McGrath <roland@gnu.org>1995-02-18 01:27:10 +0000
commit28f540f45bbacd939bfd07f213bcad2bf730b1bf (patch)
tree15f07c4c43d635959c6afee96bde71fb1b3614ee /sysdeps/i386/sub_n.S
downloadglibc-28f540f45bbacd939bfd07f213bcad2bf730b1bf.tar.gz
initial import
Diffstat (limited to 'sysdeps/i386/sub_n.S')
-rw-r--r--sysdeps/i386/sub_n.S94
1 files changed, 94 insertions, 0 deletions
diff --git a/sysdeps/i386/sub_n.S b/sysdeps/i386/sub_n.S
new file mode 100644
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+++ b/sysdeps/i386/sub_n.S
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+/* i80386 __mpn_sub_n -- Add two limb vectors of the same length > 0 and store
+ sum in a third limb vector.
+
+Copyright (C) 1992, 1994 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP 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 MP 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 MP Library; see the file COPYING.LIB. If not, write to
+the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+/*
+ INPUT PARAMETERS
+ res_ptr (sp + 4)
+ s1_ptr (sp + 8)
+ s2_ptr (sp + 12)
+ size (sp + 16)
+*/
+
+#include "sysdep.h"
+#include "asm-syntax.h"
+
+.text
+ ALIGN (3)
+ .globl C_SYMBOL_NAME(__mpn_sub_n)
+C_SYMBOL_NAME(__mpn_sub_n:)
+ pushl %edi
+ pushl %esi
+
+ movl 12(%esp),%edi /* res_ptr */
+ movl 16(%esp),%esi /* s1_ptr */
+ movl 20(%esp),%edx /* s2_ptr */
+ movl 24(%esp),%ecx /* size */
+
+ movl %ecx,%eax
+ shrl $3,%ecx /* compute count for unrolled loop */
+ negl %eax
+ andl $7,%eax /* get index where to start loop */
+ jz Loop /* necessary special case for 0 */
+ incl %ecx /* adjust loop count */
+ shll $2,%eax /* adjustment for pointers... */
+ subl %eax,%edi /* ... since they are offset ... */
+ subl %eax,%esi /* ... by a constant when we ... */
+ subl %eax,%edx /* ... enter the loop */
+ shrl $2,%eax /* restore previous value */
+ leal (Loop - 3)(%eax,%eax,8),%eax /* calc start addr in loop */
+ jmp *%eax /* jump into loop */
+ ALIGN (3)
+Loop: movl (%esi),%eax
+ sbbl (%edx),%eax
+ movl %eax,(%edi)
+ movl 4(%esi),%eax
+ sbbl 4(%edx),%eax
+ movl %eax,4(%edi)
+ movl 8(%esi),%eax
+ sbbl 8(%edx),%eax
+ movl %eax,8(%edi)
+ movl 12(%esi),%eax
+ sbbl 12(%edx),%eax
+ movl %eax,12(%edi)
+ movl 16(%esi),%eax
+ sbbl 16(%edx),%eax
+ movl %eax,16(%edi)
+ movl 20(%esi),%eax
+ sbbl 20(%edx),%eax
+ movl %eax,20(%edi)
+ movl 24(%esi),%eax
+ sbbl 24(%edx),%eax
+ movl %eax,24(%edi)
+ movl 28(%esi),%eax
+ sbbl 28(%edx),%eax
+ movl %eax,28(%edi)
+ leal 32(%edi),%edi
+ leal 32(%esi),%esi
+ leal 32(%edx),%edx
+ decl %ecx
+ jnz Loop
+
+ sbbl %eax,%eax
+ negl %eax
+
+ popl %esi
+ popl %edi
+ ret