xref: /openbmc/u-boot/arch/microblaze/lib/muldi3.c (revision 713cb680)
1 /*
2  * U-boot - muldi3.c contains routines for mult and div
3  *
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
21  * MA 02110-1301 USA
22  */
23 
24 /* Generic function got from GNU gcc package, libgcc2.c */
25 #ifndef SI_TYPE_SIZE
26 #define SI_TYPE_SIZE 32
27 #endif
28 #define __ll_B (1L << (SI_TYPE_SIZE / 2))
29 #define __ll_lowpart(t) ((USItype) (t) % __ll_B)
30 #define __ll_highpart(t) ((USItype) (t) / __ll_B)
31 #define BITS_PER_UNIT 8
32 
33 #if !defined(umul_ppmm)
34 #define umul_ppmm(w1, w0, u, v)						\
35 	do {								\
36 	USItype __x0, __x1, __x2, __x3;					\
37 	USItype __ul, __vl, __uh, __vh;					\
38 									\
39 		__ul = __ll_lowpart(u);					\
40 		__uh = __ll_highpart(u);				\
41 		__vl = __ll_lowpart(v);					\
42 		__vh = __ll_highpart(v);				\
43 									\
44 	__x0 = (USItype) __ul * __vl;					\
45 	__x1 = (USItype) __ul * __vh;					\
46 	__x2 = (USItype) __uh * __vl;					\
47 	__x3 = (USItype) __uh * __vh;					\
48 									\
49 		__x1 += __ll_highpart(__x0); /* this can't give carry */\
50 		__x1 += __x2; /* but this indeed can */			\
51 		if (__x1 < __x2) /* did we get it? */			\
52 		__x3 += __ll_B;	/* yes, add it in the proper pos. */	\
53 									\
54 		(w1) = __x3 + __ll_highpart(__x1);			\
55 		(w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
56 	} while (0)
57 #endif
58 
59 #if !defined(__umulsidi3)
60 #define __umulsidi3(u, v)						\
61 	({DIunion __w;							\
62 	umul_ppmm(__w.s.high, __w.s.low, u, v);		\
63 	__w.ll; })
64 #endif
65 
66 typedef unsigned int USItype __attribute__ ((mode(SI)));
67 typedef int SItype __attribute__ ((mode(SI)));
68 typedef int DItype __attribute__ ((mode(DI)));
69 typedef int word_type __attribute__ ((mode(__word__)));
70 
71 struct DIstruct {
72 	SItype low, high;
73 };
74 typedef union {
75 	struct DIstruct s;
76 	DItype ll;
77 } DIunion;
78 
79 DItype __muldi3(DItype u, DItype v)
80 {
81 	DIunion w;
82 	DIunion uu, vv;
83 
84 	uu.ll = u, vv.ll = v;
85 	/*  panic("kernel panic for __muldi3"); */
86 	w.ll = __umulsidi3(uu.s.low, vv.s.low);
87 	w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
88 		     + (USItype) uu.s.high * (USItype) vv.s.low);
89 
90 	return w.ll;
91 }
92