xref: /netbsd-src/external/lgpl3/gmp/dist/mpn/arm64/lshiftc.asm (revision 1daf83e636cd998f45e5597a8f995a540e2d5b4a)
1dnl  ARM64 mpn_lshiftc.
2
3dnl  Copyright 2013, 2014, 2017 Free Software Foundation, Inc.
4
5dnl  This file is part of the GNU MP Library.
6dnl
7dnl  The GNU MP Library is free software; you can redistribute it and/or modify
8dnl  it under the terms of either:
9dnl
10dnl    * the GNU Lesser General Public License as published by the Free
11dnl      Software Foundation; either version 3 of the License, or (at your
12dnl      option) any later version.
13dnl
14dnl  or
15dnl
16dnl    * the GNU General Public License as published by the Free Software
17dnl      Foundation; either version 2 of the License, or (at your option) any
18dnl      later version.
19dnl
20dnl  or both in parallel, as here.
21dnl
22dnl  The GNU MP Library is distributed in the hope that it will be useful, but
23dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
24dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
25dnl  for more details.
26dnl
27dnl  You should have received copies of the GNU General Public License and the
28dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
29dnl  see https://www.gnu.org/licenses/.
30
31include(`../config.m4')
32
33C	     cycles/limb   assumed optimal c/l
34C Cortex-A53	3.5-4.0		 3.25
35C Cortex-A57	 2.0		 2.0
36C X-Gene	 2.67		 2.5
37
38C TODO
39C  * The feed-in code used 1 ldr for odd sized and 2 ldr for even sizes.  These
40C    numbers should be 1 and 0, respectively.  The str in wind-down should also
41C    go.
42C  * Using extr and with 63 separate loops we might reach 1.5 c/l on A57.
43C  * A53's speed depends on alignment, tune/speed -w1 gives 3.5, -w0 gives 4.0.
44
45changecom(blah)
46
47define(`rp_arg', `x0')
48define(`up',     `x1')
49define(`n',      `x2')
50define(`cnt',    `x3')
51
52define(`rp',     `x16')
53
54define(`tnc',`x8')
55
56define(`PSHIFT', lsl)
57define(`NSHIFT', lsr)
58
59ASM_START()
60PROLOGUE(mpn_lshiftc)
61	add	rp, rp_arg, n, lsl #3
62	add	up, up, n, lsl #3
63	sub	tnc, xzr, cnt
64	lsr	x18, n, #2
65	tbz	n, #0, L(bx0)
66
67L(bx1):	ldr	x4, [up,#-8]
68	tbnz	n, #1, L(b11)
69
70L(b01):	NSHIFT	x0, x4, tnc
71	PSHIFT	x2, x4, cnt
72	cbnz	x18, L(gt1)
73	mvn	x2, x2
74	str	x2, [rp,#-8]
75	ret
76L(gt1):	ldp	x4, x5, [up,#-24]
77	sub	up, up, #8
78	add	rp, rp, #16
79	b	L(lo2)
80
81L(b11):	NSHIFT	x0, x4, tnc
82	PSHIFT	x2, x4, cnt
83	ldp	x6, x7, [up,#-24]!
84	b	L(lo3)
85
86L(bx0):	ldp	x4, x5, [up,#-16]
87	tbz	n, #1, L(b00)
88
89L(b10):	NSHIFT	x0, x5, tnc
90	PSHIFT	x13, x5, cnt
91	NSHIFT	x10, x4, tnc
92	PSHIFT	x2, x4, cnt
93	cbnz	x18, L(gt2)
94	eon	x10, x10, x13
95	mvn	x2, x2
96	stp	x2, x10, [rp,#-16]
97	ret
98L(gt2):	ldp	x4, x5, [up,#-32]
99	eon	x10, x10, x13
100	str	x10, [rp,#-8]
101	sub	up, up, #16
102	add	rp, rp, #8
103	b	L(lo2)
104
105L(b00):	NSHIFT	x0, x5, tnc
106	PSHIFT	x13, x5, cnt
107	NSHIFT	x10, x4, tnc
108	PSHIFT	x2, x4, cnt
109	ldp	x6, x7, [up,#-32]!
110	eon	x10, x10, x13
111	str	x10, [rp,#-8]!
112	b	L(lo0)
113
114	ALIGN(16)
115L(top):	ldp	x4, x5, [up,#-16]
116	eon	x10, x10, x13
117	eon	x11, x12, x2
118	stp	x10, x11, [rp,#-16]
119	PSHIFT	x2, x6, cnt
120L(lo2):	NSHIFT	x10, x4, tnc
121	PSHIFT	x13, x5, cnt
122	NSHIFT	x12, x5, tnc
123	ldp	x6, x7, [up,#-32]!
124	eon	x10, x10, x13
125	eon	x11, x12, x2
126	stp	x10, x11, [rp,#-32]!
127	PSHIFT	x2, x4, cnt
128L(lo0):	sub	x18, x18, #1
129L(lo3):	NSHIFT	x10, x6, tnc
130	PSHIFT	x13, x7, cnt
131	NSHIFT	x12, x7, tnc
132	cbnz	x18, L(top)
133
134L(end):	eon	x10, x10, x13
135	eon	x11, x12, x2
136	PSHIFT	x2, x6, cnt
137	stp	x10, x11, [rp,#-16]
138	mvn	x2, x2
139	str	x2, [rp,#-24]
140	ret
141EPILOGUE()
142