| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 1 | /* |
| 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> |
| 18 | #include <linux/libgcc.h> |
| 19 | |
| 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 | |
| 61 | long 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 | } |
| 72 | EXPORT_SYMBOL(__muldi3); |