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
44typedef		 int SItype	__attribute__ ((mode (SI)));
45typedef unsigned int USItype	__attribute__ ((mode (SI)));
46typedef		 int DItype	__attribute__ ((mode (DI)));
47typedef int word_type __attribute__ ((mode (__word__)));
48
49struct DIstruct {SItype high, low;};
50
51typedef union
52{
53	struct DIstruct s;
54	DItype ll;
55} DIunion;
56
57DItype __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