1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
dnl PowerPC-64 mpn_invert_limb -- Invert a normalized limb.
dnl Copyright 2004, 2005, 2006 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 cycles/limb
C POWER3/PPC630: ?
C POWER4/PPC970: 75 (including call+ret)
C This was generated by GCC, then roughly hand optimized. There is probably
C more optimization headroom.
ASM_START()
PROLOGUE(mpn_invert_limb)
LEA( r12, approx_tab)
srdi r11, r3, 32 C r11 = d >> 32
rlwinm r9, r11, 10, 23, 30 C r9 = ((d >> 55) & 0xff) << 1
lhzx r0, r12, r9 C load initial approximation
rldic r10, r0, 6, 42
mulld r8, r10, r10
sldi r9, r10, 17
mulld r0, r8, r11
srdi r0, r0, 31
subf r10, r0, r9
mulld r8, r10, r10
sldi r11, r10, 33
mulhdu r0, r8, r3
sldi r9, r0, 1
subf r10, r9, r11
sldi r11, r10, 2
mulhdu r0, r10, r10
mulld r8, r10, r10
mulhdu r10, r8, r3
mulld r9, r0, r3
mulhdu r0, r0, r3
addc r8, r9, r10
addze r10, r0
srdi r0, r8, 62
rldimi r0, r10, 2, 0
sldi r9, r8, 2
subfic r10, r9, 0
subfe r8, r0, r11
mulhdu r10, r3, r8
add r10, r10, r3
mulld r9, r3, r8
subf r11, r10, r8
addi r0, r10, 1
addi r8, r11, -1
and r0, r3, r0
addc r11, r9, r0
addze r10, r10
addc r0, r11, r3
addze r10, r10
subf r3, r10, r8
blr
EPILOGUE()
DEF_OBJECT(approx_tab)
.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
END_OBJECT(approx_tab)
ASM_END()
|
