1;! HP-PA-1.1 __mpn_addmul_1 -- Multiply a limb vector with a limb and
2;! add the result to a second limb vector.
3
4;! Copyright (C) 1992-2022 Free Software Foundation, Inc.
5
6;! This file is part of the GNU MP Library.
7
8;! The GNU MP Library is free software; you can redistribute it and/or modify
9;! it under the terms of the GNU Lesser General Public License as published by
10;! the Free Software Foundation; either version 2.1 of the License, or (at your
11;! option) any later version.
12
13;! The GNU MP Library is distributed in the hope that it will be useful, but
14;! WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15;! or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
16;! License for more details.
17
18;! You should have received a copy of the GNU Lesser General Public License
19;! along with the GNU MP Library. If not, see
20;! <https://www.gnu.org/licenses/>.
21
22
23;! INPUT PARAMETERS
24;! res_ptr r26
25;! s1_ptr r25
26;! size r24
27;! s2_limb r23
28
29;! This runs at 11 cycles/limb on a PA7000. With the used instructions, it
30;! can not become faster due to data cache contention after a store. On the
31;! PA7100 it runs at 10 cycles/limb, and that can not be improved either,
32;! since only the xmpyu does not need the integer pipeline, so the only
33;! dual-issue we will get are addc+xmpyu. Unrolling could gain a cycle/limb
34;! on the PA7100.
35
36;! There are some ideas described in mul_1.s that applies to this code too.
37
38 .text
39 .export __mpn_addmul_1
40__mpn_addmul_1:
41 .proc
42 .callinfo frame=64,no_calls
43 .entry
44
45 ldo 64(%r30),%r30
46 fldws,ma 4(%r25),%fr5
47 stw %r23,-16(%r30) ;! move s2_limb ...
48 addib,= -1,%r24,L$just_one_limb
49 fldws -16(%r30),%fr4 ;! ... into fr4
50 add %r0,%r0,%r0 ;! clear carry
51 xmpyu %fr4,%fr5,%fr6
52 fldws,ma 4(%r25),%fr7
53 fstds %fr6,-16(%r30)
54 xmpyu %fr4,%fr7,%fr8
55 ldw -12(%r30),%r20 ;! least significant limb in product
56 ldw -16(%r30),%r28
57
58 fstds %fr8,-16(%r30)
59 addib,= -1,%r24,L$end
60 ldw -12(%r30),%r1
61
62;! Main loop
63L$loop:
64 ldws 0(%r26),%r29
65 fldws,ma 4(%r25),%fr5
66 add %r29,%r20,%r20
67 stws,ma %r20,4(%r26)
68 addc %r28,%r1,%r20
69 xmpyu %fr4,%fr5,%fr6
70 ldw -16(%r30),%r28
71 fstds %fr6,-16(%r30)
72 addc %r0,%r28,%r28
73 addib,<> -1,%r24,L$loop
74 ldw -12(%r30),%r1
75
76L$end:
77 ldw 0(%r26),%r29
78 add %r29,%r20,%r20
79 stws,ma %r20,4(%r26)
80 addc %r28,%r1,%r20
81 ldw -16(%r30),%r28
82 ldws 0(%r26),%r29
83 addc %r0,%r28,%r28
84 add %r29,%r20,%r20
85 stws,ma %r20,4(%r26)
86 addc %r0,%r28,%r28
87 bv 0(%r2)
88 ldo -64(%r30),%r30
89
90L$just_one_limb:
91 xmpyu %fr4,%fr5,%fr6
92 ldw 0(%r26),%r29
93 fstds %fr6,-16(%r30)
94 ldw -12(%r30),%r1
95 ldw -16(%r30),%r28
96 add %r29,%r1,%r20
97 stw %r20,0(%r26)
98 addc %r0,%r28,%r28
99 bv 0(%r2)
100 ldo -64(%r30),%r30
101
102 .exit
103 .procend
104

source code of glibc/sysdeps/hppa/hppa1.1/addmul_1.S