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Austin Schuhbb1338c2024-06-15 19:31:16 -07001dnl IBM POWER mpn_lshift -- Shift a number left.
2
3dnl Copyright 1992, 1994, 1999-2001 Free Software Foundation, Inc.
4
5dnl This file is part of the GNU MP Library.
6dnl
7dnl The GNU MP Library is free software; you can redistribute it and/or modify
8dnl it under the terms of either:
9dnl
10dnl * the GNU Lesser General Public License as published by the Free
11dnl Software Foundation; either version 3 of the License, or (at your
12dnl option) any later version.
13dnl
14dnl or
15dnl
16dnl * the GNU General Public License as published by the Free Software
17dnl Foundation; either version 2 of the License, or (at your option) any
18dnl later version.
19dnl
20dnl or both in parallel, as here.
21dnl
22dnl The GNU MP Library is distributed in the hope that it will be useful, but
23dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
24dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
25dnl for more details.
26dnl
27dnl You should have received copies of the GNU General Public License and the
28dnl GNU Lesser General Public License along with the GNU MP Library. If not,
29dnl see https://www.gnu.org/licenses/.
30
31
32dnl INPUT PARAMETERS
33dnl res_ptr r3
34dnl s_ptr r4
35dnl size r5
36dnl cnt r6
37
38include(`../config.m4')
39
40ASM_START()
41PROLOGUE(mpn_lshift)
42 sli 0,5,2
43 cax 9,3,0
44 cax 4,4,0
45 sfi 8,6,32
46 mtctr 5 C put limb count in CTR loop register
47 lu 0,-4(4) C read most significant limb
48 sre 3,0,8 C compute carry out limb, and init MQ register
49 bdz Lend2 C if just one limb, skip loop
50 lu 0,-4(4) C read 2:nd most significant limb
51 sreq 7,0,8 C compute most significant limb of result
52 bdz Lend C if just two limb, skip loop
53Loop: lu 0,-4(4) C load next lower limb
54 stu 7,-4(9) C store previous result during read latency
55 sreq 7,0,8 C compute result limb
56 bdn Loop C loop back until CTR is zero
57Lend: stu 7,-4(9) C store 2:nd least significant limb
58Lend2: sle 7,0,6 C compute least significant limb
59 st 7,-4(9) C store it
60 br
61EPILOGUE(mpn_lshift)