xref: /netbsd-src/external/lgpl3/gmp/dist/mpn/pa64/udiv.asm (revision a4ddc2c8fb9af816efe3b1c375a5530aef0e89e9)
1dnl  HP-PA 2.0 64-bit mpn_udiv_qrnnd_r.
2
3dnl  Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
4
5dnl  This file is part of the GNU MP Library.
6
7dnl  The GNU MP Library is free software; you can redistribute it and/or modify
8dnl  it under the terms of the GNU Lesser General Public License as published
9dnl  by the Free Software Foundation; either version 3 of the License, or (at
10dnl  your option) any later version.
11
12dnl  The GNU MP Library is distributed in the hope that it will be useful, but
13dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
15dnl  License for more details.
16
17dnl  You should have received a copy of the GNU Lesser General Public License
18dnl  along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.
19
20include(`../config.m4')
21
22C This runs at about 280 cycles on both PA8000 and PA8500, corresponding to a
23C bit more than 4 cycles/bit.
24
25C INPUT PARAMETERS
26define(`n1',`%r26')
27define(`n0',`%r25')
28define(`d',`%r24')
29define(`remptr',`%r23')
30
31define(`q',`%r28')
32define(`dn',`%r29')
33
34define(`old_divstep',
35       `add,dc		n0,n0,n0
36	add,dc		n1,n1,n1
37	sub,*<<		n1,d,%r22
38	copy		%r22,n1')
39
40define(`divstep',
41       `add		n0,n0,n0
42	add,dc		n1,n1,n1
43	sub		n1,d,%r1
44	add,dc		q,q,q
45	cmpclr,*<<	n1,d,%r0
46	copy		%r1,n1
47')
48
49ifdef(`HAVE_ABI_2_0w',
50`	.level	2.0w
51',`	.level	2.0
52')
53PROLOGUE(mpn_udiv_qrnnd_r)
54ifdef(`HAVE_ABI_2_0n',
55`	depd		%r25,31,32,%r26
56	depd		%r23,31,32,%r24
57	copy		%r24,%r25
58	ldd		-56(%r30),%r24
59	ldw		-60(%r30),%r23
60')
61	ldi		0,q
62	cmpib,*>=	0,d,L(large_divisor)
63	ldi		8,%r31		C setup loop counter
64
65	sub		%r0,d,dn
66LDEF(Loop)
67	divstep divstep divstep divstep divstep divstep divstep divstep
68	addib,<>	-1,%r31,L(Loop)
69	nop
70
71ifdef(`HAVE_ABI_2_0n',
72`	copy		%r28,%r29
73	extrd,u		%r28,31,32,%r28
74')
75	bve		(%r2)
76	std		n1,0(remptr)	C store remainder
77
78LDEF(large_divisor)
79	extrd,u		n0,63,1,%r19	C save lsb of dividend
80	shrpd		n1,n0,1,n0	C n0 = lo(n1n0 >> 1)
81	shrpd		%r0,n1,1,n1	C n1 = hi(n1n0 >> 1)
82	extrd,u		d,63,1,%r20	C save lsb of divisor
83	shrpd		%r0,d,1,d	C d = floor(orig_d / 2)
84	add,l		%r20,d,d	C d = ceil(orig_d / 2)
85
86	sub		%r0,d,dn
87LDEF(Loop2)
88	divstep divstep divstep divstep divstep divstep divstep divstep
89	addib,<>	-1,%r31,L(Loop2)
90	nop
91
92	cmpib,*=	0,%r20,L(even_divisor)
93	shladd		n1,1,%r19,n1	C shift in omitted dividend lsb
94
95	add		d,d,d		C restore orig...
96	sub		d,%r20,d	C ...d value
97	sub		%r0,d,dn	C r21 = -d
98
99	add,*nuv	n1,q,n1		C fix remainder for omitted divisor lsb
100	add,l		n1,dn,n1	C adjust remainder if rem. fix carried
101	add,dc		%r0,q,q		C adjust quotient accordingly
102
103	sub,*<<		n1,d,%r0	C remainder >= divisor?
104	add,l		n1,dn,n1	C adjust remainder
105	add,dc		%r0,q,q		C adjust quotient
106
107LDEF(even_divisor)
108ifdef(`HAVE_ABI_2_0n',
109`	copy		%r28,%r29
110	extrd,u		%r28,31,32,%r28
111')
112	bve		(%r2)
113	std		n1,0(remptr)	C store remainder
114EPILOGUE(mpn_udiv_qrnnd_r)
115