xref: /openbmc/u-boot/arch/m68k/lib/muldi3.c (revision cbd2fba1)
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 
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