ReactOS 0.4.15-dev-8413-gc1c91f2
math.c
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1/* Math functions for i387.
2 Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by John C. Bowman <bowman@ipp-garching.mpg.de>, 1995.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, write to the Free
18 Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
19 Boston, MA 02110-1301, USA.
20*/
21
22#include <win32k.h>
23
24INT
27 _In_ INT iMultiplicand,
28 _In_ INT iMultiplier,
29 _In_ INT iDivisor)
30{
31 INT64 i64Multiplied, i64Result;
32
33 /* Check for divide by zero */
34 if (iDivisor == 0)
35 {
36 /* Quick sign check and return "infinite" */
37 return ((iMultiplicand ^ iMultiplier) < 0) ? INT_MIN : INT_MAX;
38 }
39
40 /* We want to deal with a positive divisor to simplify the logic. */
41 if (iDivisor < 0)
42 {
43 iMultiplicand = -iMultiplicand;
44 iDivisor = -iDivisor;
45 }
46
47 /* Do the multiplication */
48 i64Multiplied = Int32x32To64(iMultiplicand, iMultiplier);
49
50 /* If the result is positive, we add to round, else we subtract to round. */
51 if (i64Multiplied >= 0)
52 {
53 i64Multiplied += (iDivisor / 2);
54 }
55 else
56 {
57 i64Multiplied -= (iDivisor / 2);
58 }
59
60 /* Now do the divide */
61 i64Result = i64Multiplied / iDivisor;
62
63 /* Check for positive overflow */
64 if (i64Result > INT_MAX)
65 {
66 return INT_MAX;
67 }
68
69 /* Check for negative overflow. */
70 if (i64Result < INT_MIN)
71 {
72 return INT_MIN;
73 }
74
75 return (INT)i64Result;
76}
77
signed long long INT64
#define APIENTRY
Definition: api.h:79
#define INT_MIN
Definition: limits.h:39
#define INT_MAX
Definition: limits.h:40
#define _In_
Definition: ms_sal.h:308
#define Int32x32To64(a, b)
int32_t INT
Definition: typedefs.h:58
INT APIENTRY EngMulDiv(_In_ INT iMultiplicand, _In_ INT iMultiplier, _In_ INT iDivisor)
Definition: math.c:26