1 #include <linux/module.h>
3 #include "libgcc.h"
5 #define DWtype long long
6 #define UWtype unsigned long
7 #define UHWtype unsigned short
9 #define W_TYPE_SIZE 32
11 #define __ll_B ((UWtype) 1 << (W_TYPE_SIZE / 2))
12 #define __ll_lowpart(t) ((UWtype) (t) & (__ll_B - 1))
13 #define __ll_highpart(t) ((UWtype) (t) >> (W_TYPE_SIZE / 2))
15 /* If we still don't have umul_ppmm, define it using plain C.  */
16 #if !defined(umul_ppmm)
17 #define umul_ppmm(w1, w0, u, v)                                         \
18         do {                                                            \
19                 UWtype __x0, __x1, __x2, __x3;                          \
20                 UHWtype __ul, __vl, __uh, __vh;                         \
21                                                                         \
22                 __ul = __ll_lowpart(u);                                 \
23                 __uh = __ll_highpart(u);                                \
24                 __vl = __ll_lowpart(v);                                 \
25                 __vh = __ll_highpart(v);                                \
26                                                                         \
27                 __x0 = (UWtype) __ul * __vl;                            \
28                 __x1 = (UWtype) __ul * __vh;                            \
29                 __x2 = (UWtype) __uh * __vl;                            \
30                 __x3 = (UWtype) __uh * __vh;                            \
31                                                                         \
32                 __x1 += __ll_highpart(__x0); /* this can't give carry */\
33                 __x1 += __x2; /* but this indeed can */                 \
34                 if (__x1 < __x2) /* did we get it? */                   \
35                 __x3 += __ll_B; /* yes, add it in the proper pos */     \
36                                                                         \
37                 (w1) = __x3 + __ll_highpart(__x1);                      \
38                 (w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
39         } while (0)
40 #endif
42 #if !defined(__umulsidi3)
43 #define __umulsidi3(u, v) ({                            \
44         DWunion __w;                                    \
45         umul_ppmm(__w.s.high, __w.s.low, u, v);         \
46         __w.ll;                                         \
47         })
48 #endif
50 DWtype __muldi3(DWtype u, DWtype v)
51 {
52         const DWunion uu = {.ll = u};
53         const DWunion vv = {.ll = v};
54         DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};
56         w.s.high += ((UWtype) uu.s.low * (UWtype) vv.s.high
57                 + (UWtype) uu.s.high * (UWtype) vv.s.low);
59         return w.ll;
60 }
61 EXPORT_SYMBOL(__muldi3);