about summary refs log tree commit diff
path: root/sysdeps/i386/add_n.S
blob: f52897686695cd70ef3c6a2e907b2c422bd99d70 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
/* i80386 __mpn_add_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_add_n)
C_SYMBOL_NAME(__mpn_add_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
	adcl	(%edx),%eax
	movl	%eax,(%edi)
	movl	4(%esi),%eax
	adcl	4(%edx),%eax
	movl	%eax,4(%edi)
	movl	8(%esi),%eax
	adcl	8(%edx),%eax
	movl	%eax,8(%edi)
	movl	12(%esi),%eax
	adcl	12(%edx),%eax
	movl	%eax,12(%edi)
	movl	16(%esi),%eax
	adcl	16(%edx),%eax
	movl	%eax,16(%edi)
	movl	20(%esi),%eax
	adcl	20(%edx),%eax
	movl	%eax,20(%edi)
	movl	24(%esi),%eax
	adcl	24(%edx),%eax
	movl	%eax,24(%edi)
	movl	28(%esi),%eax
	adcl	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