1/* Add two limb vectors of the same length > 0 and store sum in a third
2 limb vector.
3 Copyright (C) 1992-2024 Free Software Foundation, Inc.
4 This file is part of the GNU MP Library.
5
6 The GNU MP Library is free software; you can redistribute it and/or modify
7 it under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or (at your
9 option) any later version.
10
11 The GNU MP Library is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
14 License for more details.
15
16 You should have received a copy of the GNU Lesser General Public License
17 along with the GNU MP Library; see the file COPYING.LIB. If not,
18 see <https://www.gnu.org/licenses/>. */
19
20#include <sysdep.h>
21#include "asm-syntax.h"
22
23#define PARMS 4+8 /* space for 2 saved regs */
24#define RES PARMS
25#define S1 RES+4
26#define S2 S1+4
27#define SIZE S2+4
28
29 .text
30#ifdef PIC
31L(1): addl (%esp), %eax
32 ret
33#endif
34ENTRY (__mpn_add_n)
35
36 pushl %edi
37 cfi_adjust_cfa_offset (4)
38 pushl %esi
39 cfi_adjust_cfa_offset (4)
40
41 movl RES(%esp),%edi
42 cfi_rel_offset (edi, 4)
43 movl S1(%esp),%esi
44 cfi_rel_offset (esi, 0)
45 movl S2(%esp),%edx
46 movl SIZE(%esp),%ecx
47 movl %ecx,%eax
48 shrl $3,%ecx /* compute count for unrolled loop */
49 negl %eax
50 andl $7,%eax /* get index where to start loop */
51 jz L(oop) /* necessary special case for 0 */
52 incl %ecx /* adjust loop count */
53 shll $2,%eax /* adjustment for pointers... */
54 subl %eax,%edi /* ... since they are offset ... */
55 subl %eax,%esi /* ... by a constant when we ... */
56 subl %eax,%edx /* ... enter the loop */
57 shrl $2,%eax /* restore previous value */
58#ifdef PIC
59/* Calculate start address in loop for PIC. */
60 leal (L(oop)-L(0)-3)(%eax,%eax,8),%eax
61 call L(1)
62L(0):
63#else
64/* Calculate start address in loop for non-PIC. */
65 leal (L(oop) - 3)(%eax,%eax,8),%eax
66#endif
67 jmp *%eax /* jump into loop */
68 ALIGN (3)
69L(oop): movl (%esi),%eax
70 adcl (%edx),%eax
71 movl %eax,(%edi)
72 movl 4(%esi),%eax
73 adcl 4(%edx),%eax
74 movl %eax,4(%edi)
75 movl 8(%esi),%eax
76 adcl 8(%edx),%eax
77 movl %eax,8(%edi)
78 movl 12(%esi),%eax
79 adcl 12(%edx),%eax
80 movl %eax,12(%edi)
81 movl 16(%esi),%eax
82 adcl 16(%edx),%eax
83 movl %eax,16(%edi)
84 movl 20(%esi),%eax
85 adcl 20(%edx),%eax
86 movl %eax,20(%edi)
87 movl 24(%esi),%eax
88 adcl 24(%edx),%eax
89 movl %eax,24(%edi)
90 movl 28(%esi),%eax
91 adcl 28(%edx),%eax
92 movl %eax,28(%edi)
93 leal 32(%edi),%edi
94 leal 32(%esi),%esi
95 leal 32(%edx),%edx
96 decl %ecx
97 jnz L(oop)
98
99 sbbl %eax,%eax
100 negl %eax
101
102 popl %esi
103 cfi_adjust_cfa_offset (-4)
104 cfi_restore (esi)
105 popl %edi
106 cfi_adjust_cfa_offset (-4)
107 cfi_restore (edi)
108
109 ret
110END (__mpn_add_n)
111

source code of glibc/sysdeps/i386/i686/add_n.S