xref: /openbmc/linux/arch/m68k/lib/muldi3.c (revision f3539c12)
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 #ifdef CONFIG_CPU_HAS_NO_MULDIV64
18 
19 #define SI_TYPE_SIZE 32
20 #define __BITS4 (SI_TYPE_SIZE / 4)
21 #define __ll_B (1L << (SI_TYPE_SIZE / 2))
22 #define __ll_lowpart(t) ((USItype) (t) % __ll_B)
23 #define __ll_highpart(t) ((USItype) (t) / __ll_B)
24 
25 #define umul_ppmm(w1, w0, u, v)						\
26   do {									\
27     USItype __x0, __x1, __x2, __x3;					\
28     USItype __ul, __vl, __uh, __vh;					\
29 									\
30     __ul = __ll_lowpart (u);						\
31     __uh = __ll_highpart (u);						\
32     __vl = __ll_lowpart (v);						\
33     __vh = __ll_highpart (v);						\
34 									\
35     __x0 = (USItype) __ul * __vl;					\
36     __x1 = (USItype) __ul * __vh;					\
37     __x2 = (USItype) __uh * __vl;					\
38     __x3 = (USItype) __uh * __vh;					\
39 									\
40     __x1 += __ll_highpart (__x0);/* this can't give carry */		\
41     __x1 += __x2;		/* but this indeed can */		\
42     if (__x1 < __x2)		/* did we get it? */			\
43       __x3 += __ll_B;		/* yes, add it in the proper pos. */	\
44 									\
45     (w1) = __x3 + __ll_highpart (__x1);					\
46     (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0);		\
47   } while (0)
48 
49 #else
50 
51 #define umul_ppmm(w1, w0, u, v) \
52   __asm__ ("mulu%.l %3,%1:%0"						\
53            : "=d" ((USItype)(w0)),					\
54              "=d" ((USItype)(w1))					\
55            : "%0" ((USItype)(u)),					\
56              "dmi" ((USItype)(v)))
57 
58 #endif
59 
60 #define __umulsidi3(u, v) \
61   ({DIunion __w;							\
62     umul_ppmm (__w.s.high, __w.s.low, u, v);				\
63     __w.ll; })
64 
65 typedef 	 int SItype	__attribute__ ((mode (SI)));
66 typedef unsigned int USItype	__attribute__ ((mode (SI)));
67 typedef		 int DItype	__attribute__ ((mode (DI)));
68 typedef int word_type __attribute__ ((mode (__word__)));
69 
70 struct DIstruct {SItype high, low;};
71 
72 typedef union
73 {
74   struct DIstruct s;
75   DItype ll;
76 } DIunion;
77 
78 DItype
79 __muldi3 (DItype u, DItype v)
80 {
81   DIunion w;
82   DIunion uu, vv;
83 
84   uu.ll = u,
85   vv.ll = v;
86 
87   w.ll = __umulsidi3 (uu.s.low, vv.s.low);
88   w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
89 	       + (USItype) uu.s.high * (USItype) vv.s.low);
90 
91   return w.ll;
92 }
93