xref: /linux/arch/m68k/lib/muldi3.c (revision 8e3ed5440b0c305dcd1d5fa7419bd8066d22ef42)
1 /* muldi3.c extracted from gcc-2.7.2.3/libgcc2.c and
2 			   gcc-2.7.2.3/longlong.h which is: */
3 /* Copyright (C) 1989, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
4 
5 This file is part of GNU CC.
6 
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
10 any later version.
11 
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 GNU General Public License for more details. */
16 
17 #include <linux/compiler.h>
18 #include <linux/export.h>
19 #include <linux/libgcc.h>
20 
21 #ifdef CONFIG_CPU_HAS_NO_MULDIV64
22 
23 #define SI_TYPE_SIZE 32
24 #define __BITS4 (SI_TYPE_SIZE / 4)
25 #define __ll_B (1L << (SI_TYPE_SIZE / 2))
26 #define __ll_lowpart(t) ((USItype) (t) % __ll_B)
27 #define __ll_highpart(t) ((USItype) (t) / __ll_B)
28 
29 #define umul_ppmm(w1, w0, u, v)						\
30   do {									\
31     USItype __x0, __x1, __x2, __x3;					\
32     USItype __ul, __vl, __uh, __vh;					\
33 									\
34     __ul = __ll_lowpart (u);						\
35     __uh = __ll_highpart (u);						\
36     __vl = __ll_lowpart (v);						\
37     __vh = __ll_highpart (v);						\
38 									\
39     __x0 = (USItype) __ul * __vl;					\
40     __x1 = (USItype) __ul * __vh;					\
41     __x2 = (USItype) __uh * __vl;					\
42     __x3 = (USItype) __uh * __vh;					\
43 									\
44     __x1 += __ll_highpart (__x0);/* this can't give carry */		\
45     __x1 += __x2;		/* but this indeed can */		\
46     if (__x1 < __x2)		/* did we get it? */			\
47       __x3 += __ll_B;		/* yes, add it in the proper pos. */	\
48 									\
49     (w1) = __x3 + __ll_highpart (__x1);					\
50     (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0);		\
51   } while (0)
52 
53 #else
54 
55 #define umul_ppmm(w1, w0, u, v) \
56   __asm__ ("mulu%.l %3,%1:%0"						\
57            : "=d" ((USItype)(w0)),					\
58              "=d" ((USItype)(w1))					\
59            : "%0" ((USItype)(u)),					\
60              "dmi" ((USItype)(v)))
61 
62 #endif
63 
64 #define __umulsidi3(u, v) \
65   ({DIunion __w;							\
66     umul_ppmm (__w.s.high, __w.s.low, u, v);				\
67     __w.ll; })
68 
69 typedef 	 int SItype	__mode(SI);
70 typedef unsigned int USItype	__mode(SI);
71 typedef		 int DItype	__mode(DI);
72 typedef int word_type           __mode(__word__);
73 
74 struct DIstruct {SItype high, low;};
75 
76 typedef union
77 {
78   struct DIstruct s;
79   DItype ll;
80 } DIunion;
81 
82 DItype
83 __muldi3 (DItype u, DItype v)
84 {
85   DIunion w;
86   DIunion uu, vv;
87 
88   uu.ll = u;
89   vv.ll = v;
90 
91   w.ll = __umulsidi3 (uu.s.low, vv.s.low);
92   w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
93 	       + (USItype) uu.s.high * (USItype) vv.s.low);
94 
95   return w.ll;
96 }
97 EXPORT_SYMBOL(__muldi3);
98