File: [local] / OpenXM_contrib / gmp / mpn / arm / Attic / invert_limb.asm (download)
Revision 1.1.1.1 (vendor branch), Mon Aug 25 16:06:18 2003 UTC (21 years ago) by ohara
Branch: GMP
CVS Tags: VERSION_4_1_2, RELEASE_1_2_3, RELEASE_1_2_2_KNOPPIX_b, RELEASE_1_2_2_KNOPPIX Changes since 1.1: +0 -0
lines
Import gmp 4.1.2
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dnl ARM mpn_invert_limb -- Invert a normalized limb.
dnl Copyright 2001 Free Software Foundation, Inc.
dnl This file is part of the GNU MP Library.
dnl The GNU MP Library is free software; you can redistribute it and/or modify
dnl it under the terms of the GNU Lesser General Public License as published
dnl by the Free Software Foundation; either version 2.1 of the License, or (at
dnl your option) any later version.
dnl The GNU MP Library is distributed in the hope that it will be useful, but
dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
dnl License for more details.
dnl You should have received a copy of the GNU Lesser General Public License
dnl along with the GNU MP Library; see the file COPYING.LIB. If not, write to
dnl the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
dnl MA 02111-1307, USA.
include(`../config.m4')
C INPUT PARAMETERS
define(`d',`r0') C number to be inverted
PROLOGUE(mpn_invert_limb)
stmfd sp!, {r4, lr}
mov r3, d, lsr #23
sub r3, r3, #256
add r2, pc, #invtab-.-8
mov r3, r3, lsl #1
ldrh r1, [r2, r3] C get initial approximation from table
mov r2, r1, lsl #6 C start iteration 1
mul ip, r2, r2
umull lr, r4, ip, d
mov r2, r4, lsl #1
rsb r2, r2, r1, lsl #23 C iteration 1 complete
umull ip, r3, r2, r2 C start iteration 2
umull lr, r4, r3, d
umull r3, r1, ip, d
adds lr, lr, r1
addcs r4, r4, #1
mov r3, lr, lsr #30
orr r4, r3, r4, lsl #2
mov lr, lr, lsl #2
cmn lr, #1
rsc r2, r4, r2, lsl #2 C iteration 2 complete
umull ip, r1, d, r2 C start adjustment step
add r1, r1, d
cmn r1, #1
beq L(1)
adds ip, ip, d
adc r1, r1, #0
add r2, r2, #1
L(1):
adds r3, ip, d
adcs r1, r1, #0
moveq r0, r2
addne r0, r2, #1
ldmfd sp!, {r4, pc}
invtab:
.short 1023,1020,1016,1012,1008,1004,1000,996
.short 992,989,985,981,978,974,970,967
.short 963,960,956,953,949,946,942,939
.short 936,932,929,926,923,919,916,913
.short 910,907,903,900,897,894,891,888
.short 885,882,879,876,873,870,868,865
.short 862,859,856,853,851,848,845,842
.short 840,837,834,832,829,826,824,821
.short 819,816,814,811,809,806,804,801
.short 799,796,794,791,789,787,784,782
.short 780,777,775,773,771,768,766,764
.short 762,759,757,755,753,751,748,746
.short 744,742,740,738,736,734,732,730
.short 728,726,724,722,720,718,716,714
.short 712,710,708,706,704,702,700,699
.short 697,695,693,691,689,688,686,684
.short 682,680,679,677,675,673,672,670
.short 668,667,665,663,661,660,658,657
.short 655,653,652,650,648,647,645,644
.short 642,640,639,637,636,634,633,631
.short 630,628,627,625,624,622,621,619
.short 618,616,615,613,612,611,609,608
.short 606,605,604,602,601,599,598,597
.short 595,594,593,591,590,589,587,586
.short 585,583,582,581,579,578,577,576
.short 574,573,572,571,569,568,567,566
.short 564,563,562,561,560,558,557,556
.short 555,554,553,551,550,549,548,547
.short 546,544,543,542,541,540,539,538
.short 537,536,534,533,532,531,530,529
.short 528,527,526,525,524,523,522,521
.short 520,519,518,517,516,515,514,513
EPILOGUE(mpn_invert_limb)