blob: 34af72c303031ef561fbb3d222f9e1fdf2e0a8ac [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* 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
17You should have received a copy of the GNU General Public License
18along with GNU CC; see the file COPYING. If not, write to
19the Free Software Foundation, 59 Temple Place - Suite 330,
20Boston, MA 02111-1307, USA. */
21
22#define BITS_PER_UNIT 8
23#define SI_TYPE_SIZE 32
24
25#define __BITS4 (SI_TYPE_SIZE / 4)
26#define __ll_B (1L << (SI_TYPE_SIZE / 2))
27#define __ll_lowpart(t) ((USItype) (t) % __ll_B)
28#define __ll_highpart(t) ((USItype) (t) / __ll_B)
29
30#define umul_ppmm(w1, w0, u, v) \
31 do { \
32 USItype __x0, __x1, __x2, __x3; \
33 USItype __ul, __vl, __uh, __vh; \
34 \
35 __ul = __ll_lowpart (u); \
36 __uh = __ll_highpart (u); \
37 __vl = __ll_lowpart (v); \
38 __vh = __ll_highpart (v); \
39 \
40 __x0 = (USItype) __ul * __vl; \
41 __x1 = (USItype) __ul * __vh; \
42 __x2 = (USItype) __uh * __vl; \
43 __x3 = (USItype) __uh * __vh; \
44 \
45 __x1 += __ll_highpart (__x0);/* this can't give carry */ \
46 __x1 += __x2; /* but this indeed can */ \
47 if (__x1 < __x2) /* did we get it? */ \
48 __x3 += __ll_B; /* yes, add it in the proper pos. */ \
49 \
50 (w1) = __x3 + __ll_highpart (__x1); \
51 (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0); \
52 } while (0)
53
54#define __umulsidi3(u, v) \
55 ({DIunion __w; \
56 umul_ppmm (__w.s.high, __w.s.low, u, v); \
57 __w.ll; })
58
59typedef int SItype __attribute__ ((mode (SI)));
60typedef unsigned int USItype __attribute__ ((mode (SI)));
61typedef int DItype __attribute__ ((mode (DI)));
62typedef int word_type __attribute__ ((mode (__word__)));
63
64struct DIstruct {SItype high, low;};
65
66typedef union
67{
68 struct DIstruct s;
69 DItype ll;
70} DIunion;
71
72DItype
73__muldi3 (DItype u, DItype v)
74{
75 DIunion w;
76 DIunion uu, vv;
77
78 uu.ll = u,
79 vv.ll = v;
80
81 w.ll = __umulsidi3 (uu.s.low, vv.s.low);
82 w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
83 + (USItype) uu.s.high * (USItype) vv.s.low);
84
85 return w.ll;
86}