// SPDX-License-Identifier: GPL-2.0-or-later /* */ #include <linux/export.h> #include <linux/libgcc.h> #define W_TYPE_SIZE 32 #define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2)) #define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1)) #define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2)) /* If we still don't have umul_ppmm, define it using plain C. */ #if !defined(umul_ppmm) #define umul_ppmm(w1, w0, u, v) \ do { \ unsigned long __x0, __x1, __x2, __x3; \ unsigned short __ul, __vl, __uh, __vh; \ \ __ul = __ll_lowpart(u); \ __uh = __ll_highpart(u); \ __vl = __ll_lowpart(v); \ __vh = __ll_highpart(v); \ \ __x0 = (unsigned long) __ul * __vl; \ __x1 = (unsigned long) __ul * __vh; \ __x2 = (unsigned long) __uh * __vl; \ __x3 = (unsigned long) __uh * __vh; \ \ __x1 += __ll_highpart(__x0); /* this can't give carry */\ __x1 += __x2; /* but this indeed can */ \ if (__x1 < __x2) /* did we get it? */ \ __x3 += __ll_B; /* yes, add it in the proper pos */ \ \ (w1) = __x3 + __ll_highpart(__x1); \ (w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\ } while (0) #endif #if !defined(__umulsidi3) #define __umulsidi3(u, v) ({ \ DWunion __w; \ umul_ppmm(__w.s.high, __w.s.low, u, v); \ __w.ll; \ }) #endif long long notrace __muldi3(long long u, long long v) { const DWunion uu = {.ll = u}; const DWunion vv = {.ll = v}; DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)}; w.s.high += ((unsigned long) uu.s.low * (unsigned long) vv.s.high + (unsigned long) uu.s.high * (unsigned long) vv.s.low); return w.ll; } EXPORT_SYMBOL(__muldi3);