xref: /netbsd-src/external/lgpl3/gmp/dist/mpn/x86_64/atom/lshiftc.asm (revision ce54336801cf28877c3414aa2fcb251dddd543a2)
1dnl  AMD64 mpn_lshiftc -- mpn left shift with complement, optimised for Atom.
2
3dnl  Contributed to the GNU project by Torbjorn Granlund.
4
5dnl  Copyright 2011, 2012 Free Software Foundation, Inc.
6
7dnl  This file is part of the GNU MP Library.
8dnl
9dnl  The GNU MP Library is free software; you can redistribute it and/or modify
10dnl  it under the terms of either:
11dnl
12dnl    * the GNU Lesser General Public License as published by the Free
13dnl      Software Foundation; either version 3 of the License, or (at your
14dnl      option) any later version.
15dnl
16dnl  or
17dnl
18dnl    * the GNU General Public License as published by the Free Software
19dnl      Foundation; either version 2 of the License, or (at your option) any
20dnl      later version.
21dnl
22dnl  or both in parallel, as here.
23dnl
24dnl  The GNU MP Library is distributed in the hope that it will be useful, but
25dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
26dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
27dnl  for more details.
28dnl
29dnl  You should have received copies of the GNU General Public License and the
30dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
31dnl  see https://www.gnu.org/licenses/.
32
33include(`../config.m4')
34
35C	     cycles/limb
36C AMD K8,K9	 ?
37C AMD K10	 ?
38C Intel P4	 ?
39C Intel core2	 ?
40C Intel NHM	 ?
41C Intel SBR	 ?
42C Intel atom	 5
43C VIA nano	 ?
44
45C TODO
46C  * Consider using 4-way unrolling.  We reach 4.5 c/l, but the code is 2.5
47C    times larger.
48
49C INPUT PARAMETERS
50define(`rp',	`%rdi')
51define(`up',	`%rsi')
52define(`n',	`%rdx')
53define(`cnt',	`%rcx')
54
55ABI_SUPPORT(DOS64)
56ABI_SUPPORT(STD64)
57
58ASM_START()
59	TEXT
60	ALIGN(16)
61PROLOGUE(mpn_lshiftc)
62	FUNC_ENTRY(4)
63	lea	-8(up,n,8), up
64	lea	-8(rp,n,8), rp
65	shr	R32(n)
66	mov	(up), %rax
67	jnc	L(evn)
68
69	mov	%rax, %r11
70	shl	R8(%rcx), %r11
71	neg	R8(%rcx)
72	shr	R8(%rcx), %rax
73	test	n, n
74	jnz	L(gt1)
75	not	%r11
76	mov	%r11, (rp)
77	FUNC_EXIT()
78	ret
79
80L(gt1):	mov	-8(up), %r8
81	mov	%r8, %r10
82	shr	R8(%rcx), %r8
83	jmp	L(lo1)
84
85L(evn):	mov	%rax, %r10
86	neg	R8(%rcx)
87	shr	R8(%rcx), %rax
88	mov	-8(up), %r9
89	mov	%r9, %r11
90	shr	R8(%rcx), %r9
91	neg	R8(%rcx)
92	lea	8(rp), rp
93	lea	-8(up), up
94	jmp	L(lo0)
95
96C	ALIGN(16)
97L(top):	shl	R8(%rcx), %r10
98	or	%r10, %r9
99	shl	R8(%rcx), %r11
100	not	%r9
101	neg	R8(%rcx)
102	mov	-8(up), %r8
103	lea	-16(rp), rp
104	mov	%r8, %r10
105	shr	R8(%rcx), %r8
106	mov	%r9, 8(rp)
107L(lo1):	or	%r11, %r8
108	mov	-16(up), %r9
109	mov	%r9, %r11
110	shr	R8(%rcx), %r9
111	lea	-16(up), up
112	neg	R8(%rcx)
113	not	%r8
114	mov	%r8, (rp)
115L(lo0):	dec	n
116	jg	L(top)
117
118L(end):	shl	R8(%rcx), %r10
119	or	%r10, %r9
120	not	%r9
121	shl	R8(%rcx), %r11
122	not	%r11
123	mov	%r9, -8(rp)
124	mov	%r11, -16(rp)
125	FUNC_EXIT()
126	ret
127EPILOGUE()
128