invert_limb.asm revision 1.1.1.3 1 dnl AMD64 mpn_invert_limb -- Invert a normalized limb.
2
3 dnl Contributed to the GNU project by Torbjorn Granlund and Niels Mller.
4
5 dnl Copyright 2004, 2007-2009, 2011, 2012 Free Software Foundation, Inc.
6
7 dnl This file is part of the GNU MP Library.
8 dnl
9 dnl The GNU MP Library is free software; you can redistribute it and/or modify
10 dnl it under the terms of either:
11 dnl
12 dnl * the GNU Lesser General Public License as published by the Free
13 dnl Software Foundation; either version 3 of the License, or (at your
14 dnl option) any later version.
15 dnl
16 dnl or
17 dnl
18 dnl * the GNU General Public License as published by the Free Software
19 dnl Foundation; either version 2 of the License, or (at your option) any
20 dnl later version.
21 dnl
22 dnl or both in parallel, as here.
23 dnl
24 dnl The GNU MP Library is distributed in the hope that it will be useful, but
25 dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
26 dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
27 dnl for more details.
28 dnl
29 dnl You should have received copies of the GNU General Public License and the
30 dnl GNU Lesser General Public License along with the GNU MP Library. If not,
31 dnl see https://www.gnu.org/licenses/.
32
33 include(`../config.m4')
34
35
36 C cycles/limb (approx) div
37 C AMD K8,K9 48 71
38 C AMD K10 48 77
39 C Intel P4 135 161
40 C Intel core2 69 116
41 C Intel corei 55 89
42 C Intel atom 129 191
43 C VIA nano 79 157
44
45 C rax rcx rdx rdi rsi r8
46
47 ABI_SUPPORT(DOS64)
48 ABI_SUPPORT(STD64)
49
50 PROTECT(`mpn_invert_limb_table')
51
52 ASM_START()
53 TEXT
54 ALIGN(16)
55 PROLOGUE(mpn_invert_limb) C Kn C2 Ci
56 FUNC_ENTRY(1)
57 mov %rdi, %rax C 0 0 0
58 shr $55, %rax C 1 1 1
59 ifdef(`PIC',`
60 ifdef(`DARWIN',`
61 mov mpn_invert_limb_table@GOTPCREL(%rip), %r8
62 add $-512, %r8
63 ',`
64 lea -512+mpn_invert_limb_table(%rip), %r8
65 ')',`
66 movabs $-512+mpn_invert_limb_table, %r8
67 ')
68 movzwl (%r8,%rax,2), R32(%rcx) C %rcx = v0
69
70 C v1 = (v0 << 11) - (v0*v0*d40 >> 40) - 1
71 mov %rdi, %rsi C 0 0 0
72 mov R32(%rcx), R32(%rax) C 4 5 5
73 imul R32(%rcx), R32(%rcx) C 4 5 5
74 shr $24, %rsi C 1 1 1
75 inc %rsi C %rsi = d40
76 imul %rsi, %rcx C 8 10 8
77 shr $40, %rcx C 12 15 11
78 sal $11, R32(%rax) C 5 6 6
79 dec R32(%rax)
80 sub R32(%rcx), R32(%rax) C %rax = v1
81
82 C v2 = (v1 << 13) + (v1 * (2^60 - v1*d40) >> 47)
83 mov $0x1000000000000000, %rcx
84 imul %rax, %rsi C 14 17 13
85 sub %rsi, %rcx
86 imul %rax, %rcx
87 sal $13, %rax
88 shr $47, %rcx
89 add %rax, %rcx C %rcx = v2
90
91 C v3 = (v2 << 31) + (v2 * (2^96 - v2 * d63 + ((v2 >> 1) & mask)) >> 65
92 mov %rdi, %rsi C 0 0 0
93 shr %rsi C d/2
94 sbb %rax, %rax C -d0 = -(d mod 2)
95 sub %rax, %rsi C d63 = ceil(d/2)
96 imul %rcx, %rsi C v2 * d63
97 and %rcx, %rax C v2 * d0
98 shr %rax C (v2>>1) * d0
99 sub %rsi, %rax C (v2>>1) * d0 - v2 * d63
100 mul %rcx
101 sal $31, %rcx
102 shr %rdx
103 add %rdx, %rcx C %rcx = v3
104
105 mov %rdi, %rax
106 mul %rcx
107 add %rdi, %rax
108 mov %rcx, %rax
109 adc %rdi, %rdx
110 sub %rdx, %rax
111
112 FUNC_EXIT()
113 ret
114 EPILOGUE()
115 ASM_END()
116