blob: 54c8b3123376bc0a17c3dec743fd9c42a8231fab [file] [log] [blame]
Palmer Dabbeltb35cd982017-05-23 10:28:26 -07001/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, see the file COPYING, or write
14 * to the Free Software Foundation, Inc.
15 */
16
17#include <linux/export.h>
Christoph Hellwig4db2b602017-11-22 11:47:28 +010018#include <linux/libgcc.h>
Palmer Dabbeltb35cd982017-05-23 10:28:26 -070019
20#define W_TYPE_SIZE 32
21
22#define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2))
23#define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1))
24#define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2))
25
26/* If we still don't have umul_ppmm, define it using plain C. */
27#if !defined(umul_ppmm)
28#define umul_ppmm(w1, w0, u, v) \
29 do { \
30 unsigned long __x0, __x1, __x2, __x3; \
31 unsigned short __ul, __vl, __uh, __vh; \
32 \
33 __ul = __ll_lowpart(u); \
34 __uh = __ll_highpart(u); \
35 __vl = __ll_lowpart(v); \
36 __vh = __ll_highpart(v); \
37 \
38 __x0 = (unsigned long) __ul * __vl; \
39 __x1 = (unsigned long) __ul * __vh; \
40 __x2 = (unsigned long) __uh * __vl; \
41 __x3 = (unsigned long) __uh * __vh; \
42 \
43 __x1 += __ll_highpart(__x0); /* this can't give carry */\
44 __x1 += __x2; /* but this indeed can */ \
45 if (__x1 < __x2) /* did we get it? */ \
46 __x3 += __ll_B; /* yes, add it in the proper pos */ \
47 \
48 (w1) = __x3 + __ll_highpart(__x1); \
49 (w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
50 } while (0)
51#endif
52
53#if !defined(__umulsidi3)
54#define __umulsidi3(u, v) ({ \
55 DWunion __w; \
56 umul_ppmm(__w.s.high, __w.s.low, u, v); \
57 __w.ll; \
58 })
59#endif
60
61long long notrace __muldi3(long long u, long long v)
62{
63 const DWunion uu = {.ll = u};
64 const DWunion vv = {.ll = v};
65 DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};
66
67 w.s.high += ((unsigned long) uu.s.low * (unsigned long) vv.s.high
68 + (unsigned long) uu.s.high * (unsigned long) vv.s.low);
69
70 return w.ll;
71}
72EXPORT_SYMBOL(__muldi3);