1*0957b409SSimon J. Gerraty /*
2*0957b409SSimon J. Gerraty * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
3*0957b409SSimon J. Gerraty *
4*0957b409SSimon J. Gerraty * Permission is hereby granted, free of charge, to any person obtaining
5*0957b409SSimon J. Gerraty * a copy of this software and associated documentation files (the
6*0957b409SSimon J. Gerraty * "Software"), to deal in the Software without restriction, including
7*0957b409SSimon J. Gerraty * without limitation the rights to use, copy, modify, merge, publish,
8*0957b409SSimon J. Gerraty * distribute, sublicense, and/or sell copies of the Software, and to
9*0957b409SSimon J. Gerraty * permit persons to whom the Software is furnished to do so, subject to
10*0957b409SSimon J. Gerraty * the following conditions:
11*0957b409SSimon J. Gerraty *
12*0957b409SSimon J. Gerraty * The above copyright notice and this permission notice shall be
13*0957b409SSimon J. Gerraty * included in all copies or substantial portions of the Software.
14*0957b409SSimon J. Gerraty *
15*0957b409SSimon J. Gerraty * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16*0957b409SSimon J. Gerraty * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17*0957b409SSimon J. Gerraty * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18*0957b409SSimon J. Gerraty * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19*0957b409SSimon J. Gerraty * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20*0957b409SSimon J. Gerraty * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21*0957b409SSimon J. Gerraty * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22*0957b409SSimon J. Gerraty * SOFTWARE.
23*0957b409SSimon J. Gerraty */
24*0957b409SSimon J. Gerraty
25*0957b409SSimon J. Gerraty #include "inner.h"
26*0957b409SSimon J. Gerraty
27*0957b409SSimon J. Gerraty /* see inner.h */
28*0957b409SSimon J. Gerraty uint32_t
br_divrem(uint32_t hi,uint32_t lo,uint32_t d,uint32_t * r)29*0957b409SSimon J. Gerraty br_divrem(uint32_t hi, uint32_t lo, uint32_t d, uint32_t *r)
30*0957b409SSimon J. Gerraty {
31*0957b409SSimon J. Gerraty /* TODO: optimize this */
32*0957b409SSimon J. Gerraty uint32_t q;
33*0957b409SSimon J. Gerraty uint32_t ch, cf;
34*0957b409SSimon J. Gerraty int k;
35*0957b409SSimon J. Gerraty
36*0957b409SSimon J. Gerraty q = 0;
37*0957b409SSimon J. Gerraty ch = EQ(hi, d);
38*0957b409SSimon J. Gerraty hi = MUX(ch, 0, hi);
39*0957b409SSimon J. Gerraty for (k = 31; k > 0; k --) {
40*0957b409SSimon J. Gerraty int j;
41*0957b409SSimon J. Gerraty uint32_t w, ctl, hi2, lo2;
42*0957b409SSimon J. Gerraty
43*0957b409SSimon J. Gerraty j = 32 - k;
44*0957b409SSimon J. Gerraty w = (hi << j) | (lo >> k);
45*0957b409SSimon J. Gerraty ctl = GE(w, d) | (hi >> k);
46*0957b409SSimon J. Gerraty hi2 = (w - d) >> j;
47*0957b409SSimon J. Gerraty lo2 = lo - (d << k);
48*0957b409SSimon J. Gerraty hi = MUX(ctl, hi2, hi);
49*0957b409SSimon J. Gerraty lo = MUX(ctl, lo2, lo);
50*0957b409SSimon J. Gerraty q |= ctl << k;
51*0957b409SSimon J. Gerraty }
52*0957b409SSimon J. Gerraty cf = GE(lo, d) | hi;
53*0957b409SSimon J. Gerraty q |= cf;
54*0957b409SSimon J. Gerraty *r = MUX(cf, lo - d, lo);
55*0957b409SSimon J. Gerraty return q;
56*0957b409SSimon J. Gerraty }
57