Imported gcc-4.4.3

[msp430-gcc.git] / gmp / mpn / arm / invert_limb.asm

diff --git a/gmp/mpn/arm/invert_limb.asm b/gmp/mpn/arm/invert_limb.asm
new file mode 100644 (file)
index 0000000..39d3bb2
--- /dev/null
+++ b/gmp/mpn/arm/invert_limb.asm
@@ -0,0 +1,95 @@
+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 3 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.  If not, see http://www.gnu.org/licenses/.
+
+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)