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
5This file is part of GNU CC.
6
7GNU CC is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 2, or (at your option)
10any later version.
11
12GNU CC is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15GNU 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
69typedef int SItype __mode(SI);
70typedef unsigned int USItype __mode(SI);
71typedef int DItype __mode(DI);
72typedef int word_type __mode(__word__);
73
74struct DIstruct {SItype high, low;};
75
76typedef union
77{
78 struct DIstruct s;
79 DItype ll;
80} DIunion;
81
82DItype
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}
97EXPORT_SYMBOL(__muldi3);
98

source code of linux/arch/m68k/lib/muldi3.c