1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/export.h>
3
4 #include "libgcc.h"
5
6 #define W_TYPE_SIZE 32
7
8 #define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2))
9 #define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1))
10 #define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2))
11
12 /* If we still don't have umul_ppmm, define it using plain C. */
13 #if !defined(umul_ppmm)
14 #define umul_ppmm(w1, w0, u, v) \
15 do { \
16 unsigned long __x0, __x1, __x2, __x3; \
17 unsigned short __ul, __vl, __uh, __vh; \
18 \
19 __ul = __ll_lowpart(u); \
20 __uh = __ll_highpart(u); \
21 __vl = __ll_lowpart(v); \
22 __vh = __ll_highpart(v); \
23 \
24 __x0 = (unsigned long) __ul * __vl; \
25 __x1 = (unsigned long) __ul * __vh; \
26 __x2 = (unsigned long) __uh * __vl; \
27 __x3 = (unsigned long) __uh * __vh; \
28 \
29 __x1 += __ll_highpart(__x0); /* this can't give carry */\
30 __x1 += __x2; /* but this indeed can */ \
31 if (__x1 < __x2) /* did we get it? */ \
32 __x3 += __ll_B; /* yes, add it in the proper pos */ \
33 \
34 (w1) = __x3 + __ll_highpart(__x1); \
35 (w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
36 } while (0)
37 #endif
38
39 #if !defined(__umulsidi3)
40 #define __umulsidi3(u, v) ({ \
41 DWunion __w; \
42 umul_ppmm(__w.s.high, __w.s.low, u, v); \
43 __w.ll; \
44 })
45 #endif
46
47 long long __muldi3(long long u, long long v)
48 {
49 const DWunion uu = {.ll = u};
50 const DWunion vv = {.ll = v};
51 DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};
52
53 w.s.high += ((unsigned long) uu.s.low * (unsigned long) vv.s.high
54 + (unsigned long) uu.s.high * (unsigned long) vv.s.low);
55
56 return w.ll;
57 }
58 EXPORT_SYMBOL(__muldi3);
59
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