From b35cd9884fa5d81c9d5e7f57c9d03264ae2bd835 Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Tue, 23 May 2017 10:28:26 -0700 Subject: lib: Add shared copies of some GCC library routines Many ports (m32r, microblaze, mips, parisc, score, and sparc) use functionally identical copies of various GCC library routine files, which came up as we were submitting the RISC-V port (which also uses some of these). This patch adds a new copy of these library routine files, which are functionally identical to the various other copies. These are availiable via Kconfig as CONFIG_GENERIC_$ROUTINE, which currently isn't used anywhere. Reviewed-by: Geert Uytterhoeven Signed-off-by: Palmer Dabbelt --- lib/muldi3.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 lib/muldi3.c (limited to 'lib/muldi3.c') diff --git a/lib/muldi3.c b/lib/muldi3.c new file mode 100644 index 000000000000..88938543e10a --- /dev/null +++ b/lib/muldi3.c @@ -0,0 +1,72 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see the file COPYING, or write + * to the Free Software Foundation, Inc. + */ + +#include +#include + +#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); -- cgit v1.2.3