aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/cxxsupp/builtins/moddi3.c
blob: a04279e3875f553d63f013e31cfcd1f82fd43bfe (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
/*===-- moddi3.c - Implement __moddi3 -------------------------------------===
 *
 *                    The LLVM Compiler Infrastructure
 *
 * This file is dual licensed under the MIT and the University of Illinois Open
 * Source Licenses. See LICENSE.TXT for details.
 *
 * ===----------------------------------------------------------------------===
 *
 * This file implements __moddi3 for the compiler_rt library.
 *
 * ===----------------------------------------------------------------------===
 */

#include "int_lib.h"

/* Returns: a % b */

COMPILER_RT_ABI di_int
__moddi3(di_int a, di_int b)
{
    const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1;
    di_int s = b >> bits_in_dword_m1;  /* s = b < 0 ? -1 : 0 */
    b = (b ^ s) - s;                   /* negate if s == -1 */
    s = a >> bits_in_dword_m1;         /* s = a < 0 ? -1 : 0 */
    a = (a ^ s) - s;                   /* negate if s == -1 */
    du_int r;
    __udivmoddi4(a, b, &r);
    return ((di_int)r ^ s) - s;                /* negate if s == -1 */
}