xref: /openbmc/u-boot/arch/microblaze/lib/muldi3.c (revision ae485b54)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * U-Boot - muldi3.c contains routines for mult and div
4  *
5  */
6 
7 /* Generic function got from GNU gcc package, libgcc2.c */
8 #ifndef SI_TYPE_SIZE
9 #define SI_TYPE_SIZE 32
10 #endif
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 #define BITS_PER_UNIT 8
15 
16 #if !defined(umul_ppmm)
17 #define umul_ppmm(w1, w0, u, v)						\
18 	do {								\
19 	USItype __x0, __x1, __x2, __x3;					\
20 	USItype __ul, __vl, __uh, __vh;					\
21 									\
22 		__ul = __ll_lowpart(u);					\
23 		__uh = __ll_highpart(u);				\
24 		__vl = __ll_lowpart(v);					\
25 		__vh = __ll_highpart(v);				\
26 									\
27 	__x0 = (USItype) __ul * __vl;					\
28 	__x1 = (USItype) __ul * __vh;					\
29 	__x2 = (USItype) __uh * __vl;					\
30 	__x3 = (USItype) __uh * __vh;					\
31 									\
32 		__x1 += __ll_highpart(__x0); /* this can't give carry */\
33 		__x1 += __x2; /* but this indeed can */			\
34 		if (__x1 < __x2) /* did we get it? */			\
35 		__x3 += __ll_B;	/* yes, add it in the proper pos. */	\
36 									\
37 		(w1) = __x3 + __ll_highpart(__x1);			\
38 		(w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
39 	} while (0)
40 #endif
41 
42 #if !defined(__umulsidi3)
43 #define __umulsidi3(u, v)						\
44 	({DIunion __w;							\
45 	umul_ppmm(__w.s.high, __w.s.low, u, v);		\
46 	__w.ll; })
47 #endif
48 
49 typedef unsigned int USItype __attribute__ ((mode(SI)));
50 typedef int SItype __attribute__ ((mode(SI)));
51 typedef int DItype __attribute__ ((mode(DI)));
52 typedef int word_type __attribute__ ((mode(__word__)));
53 
54 struct DIstruct {
55 	SItype low, high;
56 };
57 typedef union {
58 	struct DIstruct s;
59 	DItype ll;
60 } DIunion;
61 
62 DItype __muldi3(DItype u, DItype v)
63 {
64 	DIunion w;
65 	DIunion uu, vv;
66 
67 	uu.ll = u, vv.ll = v;
68 	/*  panic("kernel panic for __muldi3"); */
69 	w.ll = __umulsidi3(uu.s.low, vv.s.low);
70 	w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
71 		     + (USItype) uu.s.high * (USItype) vv.s.low);
72 
73 	return w.ll;
74 }
75