xref: /netbsd-src/external/lgpl3/gmp/dist/mpn/pa64/udiv.asm (revision ce54336801cf28877c3414aa2fcb251dddd543a2)
1dnl  HP-PA 2.0 64-bit mpn_udiv_qrnnd_r.
2
3dnl  Copyright 2001-2003 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 This runs at about 280 cycles on both PA8000 and PA8500, corresponding to a
34C bit more than 4 cycles/bit.
35
36C INPUT PARAMETERS
37define(`n1',`%r26')
38define(`n0',`%r25')
39define(`d',`%r24')
40define(`remptr',`%r23')
41
42define(`q',`%r28')
43define(`dn',`%r29')
44
45define(`old_divstep',
46       `add,dc		n0,n0,n0
47	add,dc		n1,n1,n1
48	sub,*<<		n1,d,%r22
49	copy		%r22,n1')
50
51define(`divstep',
52       `add		n0,n0,n0
53	add,dc		n1,n1,n1
54	sub		n1,d,%r1
55	add,dc		q,q,q
56	cmpclr,*<<	n1,d,%r0
57	copy		%r1,n1
58')
59
60ifdef(`HAVE_ABI_2_0w',
61`	.level	2.0w
62',`	.level	2.0
63')
64PROLOGUE(mpn_udiv_qrnnd_r)
65ifdef(`HAVE_ABI_2_0n',
66`	depd		%r25,31,32,%r26
67	depd		%r23,31,32,%r24
68	copy		%r24,%r25
69	ldd		-56(%r30),%r24
70	ldw		-60(%r30),%r23
71')
72	ldi		0,q
73	cmpib,*>=	0,d,L(large_divisor)
74	ldi		8,%r31		C setup loop counter
75
76	sub		%r0,d,dn
77LDEF(Loop)
78	divstep divstep divstep divstep divstep divstep divstep divstep
79	addib,<>	-1,%r31,L(Loop)
80	nop
81
82ifdef(`HAVE_ABI_2_0n',
83`	copy		%r28,%r29
84	extrd,u		%r28,31,32,%r28
85')
86	bve		(%r2)
87	std		n1,0(remptr)	C store remainder
88
89LDEF(large_divisor)
90	extrd,u		n0,63,1,%r19	C save lsb of dividend
91	shrpd		n1,n0,1,n0	C n0 = lo(n1n0 >> 1)
92	shrpd		%r0,n1,1,n1	C n1 = hi(n1n0 >> 1)
93	extrd,u		d,63,1,%r20	C save lsb of divisor
94	shrpd		%r0,d,1,d	C d = floor(orig_d / 2)
95	add,l		%r20,d,d	C d = ceil(orig_d / 2)
96
97	sub		%r0,d,dn
98LDEF(Loop2)
99	divstep divstep divstep divstep divstep divstep divstep divstep
100	addib,<>	-1,%r31,L(Loop2)
101	nop
102
103	cmpib,*=	0,%r20,L(even_divisor)
104	shladd		n1,1,%r19,n1	C shift in omitted dividend lsb
105
106	add		d,d,d		C restore orig...
107	sub		d,%r20,d	C ...d value
108	sub		%r0,d,dn	C r21 = -d
109
110	add,*nuv	n1,q,n1		C fix remainder for omitted divisor lsb
111	add,l		n1,dn,n1	C adjust remainder if rem. fix carried
112	add,dc		%r0,q,q		C adjust quotient accordingly
113
114	sub,*<<		n1,d,%r0	C remainder >= divisor?
115	add,l		n1,dn,n1	C adjust remainder
116	add,dc		%r0,q,q		C adjust quotient
117
118LDEF(even_divisor)
119ifdef(`HAVE_ABI_2_0n',
120`	copy		%r28,%r29
121	extrd,u		%r28,31,32,%r28
122')
123	bve		(%r2)
124	std		n1,0(remptr)	C store remainder
125EPILOGUE(mpn_udiv_qrnnd_r)
126