xref: /openbmc/u-boot/arch/m68k/lib/muldi3.c (revision ad3098f7)
1 /*
2  * muldi3.c extracted from gcc-2.7.2.3/libgcc2.c and
3  *			   gcc-2.7.2.3/longlong.h
4  *
5  * Copyright (C) 1989, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
6  *
7  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 #define SI_TYPE_SIZE 32
11 #define __BITS4 (SI_TYPE_SIZE / 4)
12 #define __ll_B (1L << (SI_TYPE_SIZE / 2))
13 #define __ll_lowpart(t) ((USItype) (t) % __ll_B)
14 #define __ll_highpart(t) ((USItype) (t) / __ll_B)
15 
16 #define umul_ppmm(w1, w0, u, v)						\
17   do {									\
18     USItype __x0, __x1, __x2, __x3;					\
19     USItype __ul, __vl, __uh, __vh;					\
20 									\
21     __ul = __ll_lowpart (u);						\
22     __uh = __ll_highpart (u);						\
23     __vl = __ll_lowpart (v);						\
24     __vh = __ll_highpart (v);						\
25 									\
26     __x0 = (USItype) __ul * __vl;					\
27     __x1 = (USItype) __ul * __vh;					\
28     __x2 = (USItype) __uh * __vl;					\
29     __x3 = (USItype) __uh * __vh;					\
30 									\
31     __x1 += __ll_highpart (__x0);/* this can't give carry */		\
32     __x1 += __x2;		/* but this indeed can */		\
33     if (__x1 < __x2)		/* did we get it? */			\
34       __x3 += __ll_B;		/* yes, add it in the proper pos. */	\
35 									\
36     (w1) = __x3 + __ll_highpart (__x1);					\
37     (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0);		\
38   } while (0)
39 
40 #define __umulsidi3(u, v) \
41   ({DIunion __w;							\
42     umul_ppmm (__w.s.high, __w.s.low, u, v);				\
43     __w.ll; })
44 
45 typedef 	 int SItype	__attribute__ ((mode (SI)));
46 typedef unsigned int USItype	__attribute__ ((mode (SI)));
47 typedef		 int DItype	__attribute__ ((mode (DI)));
48 typedef int word_type __attribute__ ((mode (__word__)));
49 
50 struct DIstruct {SItype high, low;};
51 
52 typedef union
53 {
54 	struct DIstruct s;
55 	DItype ll;
56 } DIunion;
57 
58 DItype __muldi3 (DItype u, DItype v)
59 {
60 	DIunion w;
61 	DIunion uu, vv;
62 
63 	uu.ll = u,
64 	vv.ll = v;
65 
66 	w.ll = __umulsidi3 (uu.s.low, vv.s.low);
67 	w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
68 		+ (USItype) uu.s.high * (USItype) vv.s.low);
69 
70 	return w.ll;
71 }
72