Annotation of OpenXM_contrib/gmp/mpn/arm/invert_limb.asm, Revision 1.1.1.1
1.1 ohara 1: dnl ARM mpn_invert_limb -- Invert a normalized limb.
2:
3: dnl Copyright 2001 Free Software Foundation, Inc.
4:
5: dnl This file is part of the GNU MP Library.
6:
7: dnl The GNU MP Library is free software; you can redistribute it and/or modify
8: dnl it under the terms of the GNU Lesser General Public License as published
9: dnl by the Free Software Foundation; either version 2.1 of the License, or (at
10: dnl your option) any later version.
11:
12: dnl The GNU MP Library is distributed in the hope that it will be useful, but
13: dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14: dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
15: dnl License for more details.
16:
17: dnl You should have received a copy of the GNU Lesser General Public License
18: dnl along with the GNU MP Library; see the file COPYING.LIB. If not, write to
19: dnl the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
20: dnl MA 02111-1307, USA.
21:
22: include(`../config.m4')
23:
24: C INPUT PARAMETERS
25: define(`d',`r0') C number to be inverted
26:
27:
28: PROLOGUE(mpn_invert_limb)
29: stmfd sp!, {r4, lr}
30: mov r3, d, lsr #23
31: sub r3, r3, #256
32: add r2, pc, #invtab-.-8
33: mov r3, r3, lsl #1
34: ldrh r1, [r2, r3] C get initial approximation from table
35: mov r2, r1, lsl #6 C start iteration 1
36: mul ip, r2, r2
37: umull lr, r4, ip, d
38: mov r2, r4, lsl #1
39: rsb r2, r2, r1, lsl #23 C iteration 1 complete
40: umull ip, r3, r2, r2 C start iteration 2
41: umull lr, r4, r3, d
42: umull r3, r1, ip, d
43: adds lr, lr, r1
44: addcs r4, r4, #1
45: mov r3, lr, lsr #30
46: orr r4, r3, r4, lsl #2
47: mov lr, lr, lsl #2
48: cmn lr, #1
49: rsc r2, r4, r2, lsl #2 C iteration 2 complete
50: umull ip, r1, d, r2 C start adjustment step
51: add r1, r1, d
52: cmn r1, #1
53: beq L(1)
54: adds ip, ip, d
55: adc r1, r1, #0
56: add r2, r2, #1
57: L(1):
58: adds r3, ip, d
59: adcs r1, r1, #0
60: moveq r0, r2
61: addne r0, r2, #1
62: ldmfd sp!, {r4, pc}
63:
64: invtab:
65: .short 1023,1020,1016,1012,1008,1004,1000,996
66: .short 992,989,985,981,978,974,970,967
67: .short 963,960,956,953,949,946,942,939
68: .short 936,932,929,926,923,919,916,913
69: .short 910,907,903,900,897,894,891,888
70: .short 885,882,879,876,873,870,868,865
71: .short 862,859,856,853,851,848,845,842
72: .short 840,837,834,832,829,826,824,821
73: .short 819,816,814,811,809,806,804,801
74: .short 799,796,794,791,789,787,784,782
75: .short 780,777,775,773,771,768,766,764
76: .short 762,759,757,755,753,751,748,746
77: .short 744,742,740,738,736,734,732,730
78: .short 728,726,724,722,720,718,716,714
79: .short 712,710,708,706,704,702,700,699
80: .short 697,695,693,691,689,688,686,684
81: .short 682,680,679,677,675,673,672,670
82: .short 668,667,665,663,661,660,658,657
83: .short 655,653,652,650,648,647,645,644
84: .short 642,640,639,637,636,634,633,631
85: .short 630,628,627,625,624,622,621,619
86: .short 618,616,615,613,612,611,609,608
87: .short 606,605,604,602,601,599,598,597
88: .short 595,594,593,591,590,589,587,586
89: .short 585,583,582,581,579,578,577,576
90: .short 574,573,572,571,569,568,567,566
91: .short 564,563,562,561,560,558,557,556
92: .short 555,554,553,551,550,549,548,547
93: .short 546,544,543,542,541,540,539,538
94: .short 537,536,534,533,532,531,530,529
95: .short 528,527,526,525,524,523,522,521
96: .short 520,519,518,517,516,515,514,513
97: EPILOGUE(mpn_invert_limb)
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