1 // SPDX-License-Identifier: GPL-2.0-or-later 1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* 2 /*
3 */ 3 */
4 4
5 #include <linux/export.h> 5 #include <linux/export.h>
6 #include <linux/libgcc.h> 6 #include <linux/libgcc.h>
7 7
8 #define W_TYPE_SIZE 32 8 #define W_TYPE_SIZE 32
9 9
10 #define __ll_B ((unsigned long) 1 << (W_TYPE_S 10 #define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2))
11 #define __ll_lowpart(t) ((unsigned long) (t) & 11 #define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1))
12 #define __ll_highpart(t) ((unsigned long) (t) 12 #define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2))
13 13
14 /* If we still don't have umul_ppmm, define it 14 /* If we still don't have umul_ppmm, define it using plain C. */
15 #if !defined(umul_ppmm) 15 #if !defined(umul_ppmm)
16 #define umul_ppmm(w1, w0, u, v) 16 #define umul_ppmm(w1, w0, u, v) \
17 do { 17 do { \
18 unsigned long __x0, __x1, __x2 18 unsigned long __x0, __x1, __x2, __x3; \
19 unsigned short __ul, __vl, __u 19 unsigned short __ul, __vl, __uh, __vh; \
20 20 \
21 __ul = __ll_lowpart(u); 21 __ul = __ll_lowpart(u); \
22 __uh = __ll_highpart(u); 22 __uh = __ll_highpart(u); \
23 __vl = __ll_lowpart(v); 23 __vl = __ll_lowpart(v); \
24 __vh = __ll_highpart(v); 24 __vh = __ll_highpart(v); \
25 25 \
26 __x0 = (unsigned long) __ul * 26 __x0 = (unsigned long) __ul * __vl; \
27 __x1 = (unsigned long) __ul * 27 __x1 = (unsigned long) __ul * __vh; \
28 __x2 = (unsigned long) __uh * 28 __x2 = (unsigned long) __uh * __vl; \
29 __x3 = (unsigned long) __uh * 29 __x3 = (unsigned long) __uh * __vh; \
30 30 \
31 __x1 += __ll_highpart(__x0); / 31 __x1 += __ll_highpart(__x0); /* this can't give carry */\
32 __x1 += __x2; /* but this inde 32 __x1 += __x2; /* but this indeed can */ \
33 if (__x1 < __x2) /* did we get 33 if (__x1 < __x2) /* did we get it? */ \
34 __x3 += __ll_B; /* yes, add it 34 __x3 += __ll_B; /* yes, add it in the proper pos */ \
35 35 \
36 (w1) = __x3 + __ll_highpart(__ 36 (w1) = __x3 + __ll_highpart(__x1); \
37 (w0) = __ll_lowpart(__x1) * __ 37 (w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
38 } while (0) 38 } while (0)
39 #endif 39 #endif
40 40
41 #if !defined(__umulsidi3) 41 #if !defined(__umulsidi3)
42 #define __umulsidi3(u, v) ({ 42 #define __umulsidi3(u, v) ({ \
43 DWunion __w; 43 DWunion __w; \
44 umul_ppmm(__w.s.high, __w.s.low, u, v) 44 umul_ppmm(__w.s.high, __w.s.low, u, v); \
45 __w.ll; 45 __w.ll; \
46 }) 46 })
47 #endif 47 #endif
48 48
49 long long notrace __muldi3(long long u, long l 49 long long notrace __muldi3(long long u, long long v)
50 { 50 {
51 const DWunion uu = {.ll = u}; 51 const DWunion uu = {.ll = u};
52 const DWunion vv = {.ll = v}; 52 const DWunion vv = {.ll = v};
53 DWunion w = {.ll = __umulsidi3(uu.s.lo 53 DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};
54 54
55 w.s.high += ((unsigned long) uu.s.low 55 w.s.high += ((unsigned long) uu.s.low * (unsigned long) vv.s.high
56 + (unsigned long) uu.s.high * 56 + (unsigned long) uu.s.high * (unsigned long) vv.s.low);
57 57
58 return w.ll; 58 return w.ll;
59 } 59 }
60 EXPORT_SYMBOL(__muldi3); 60 EXPORT_SYMBOL(__muldi3);
61 61
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