1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * muldi3.c extracted from gcc-2.7.2.3/libgcc2.c and
4 * gcc-2.7.2.3/longlong.h
5 *
6 * Copyright (C) 1989, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
7 */
8
9 #define SI_TYPE_SIZE 32
10 #define __BITS4 (SI_TYPE_SIZE / 4)
11 #define __ll_B (1L << (SI_TYPE_SIZE / 2))
12 #define __ll_lowpart(t) ((USItype) (t) % __ll_B)
13 #define __ll_highpart(t) ((USItype) (t) / __ll_B)
14
15 #define umul_ppmm(w1, w0, u, v) \
16 do { \
17 USItype __x0, __x1, __x2, __x3; \
18 USItype __ul, __vl, __uh, __vh; \
19 \
20 __ul = __ll_lowpart (u); \
21 __uh = __ll_highpart (u); \
22 __vl = __ll_lowpart (v); \
23 __vh = __ll_highpart (v); \
24 \
25 __x0 = (USItype) __ul * __vl; \
26 __x1 = (USItype) __ul * __vh; \
27 __x2 = (USItype) __uh * __vl; \
28 __x3 = (USItype) __uh * __vh; \
29 \
30 __x1 += __ll_highpart (__x0);/* this can't give carry */ \
31 __x1 += __x2; /* but this indeed can */ \
32 if (__x1 < __x2) /* did we get it? */ \
33 __x3 += __ll_B; /* yes, add it in the proper pos. */ \
34 \
35 (w1) = __x3 + __ll_highpart (__x1); \
36 (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0); \
37 } while (0)
38
39 #define __umulsidi3(u, v) \
40 ({DIunion __w; \
41 umul_ppmm (__w.s.high, __w.s.low, u, v); \
42 __w.ll; })
43
44 typedef int SItype __attribute__ ((mode (SI)));
45 typedef unsigned int USItype __attribute__ ((mode (SI)));
46 typedef int DItype __attribute__ ((mode (DI)));
47 typedef int word_type __attribute__ ((mode (__word__)));
48
49 struct DIstruct {SItype high, low;};
50
51 typedef union
52 {
53 struct DIstruct s;
54 DItype ll;
55 } DIunion;
56
__muldi3(DItype u,DItype v)57 DItype __muldi3 (DItype u, DItype v)
58 {
59 DIunion w;
60 DIunion uu, vv;
61
62 uu.ll = u,
63 vv.ll = v;
64
65 w.ll = __umulsidi3 (uu.s.low, vv.s.low);
66 w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
67 + (USItype) uu.s.high * (USItype) vv.s.low);
68
69 return w.ll;
70 }
71