xref: /aosp_15_r20/external/compiler-rt/lib/builtins/moddi3.c (revision 7c3d14c8b49c529e04be81a3ce6f5cc23712e4c6)
1*7c3d14c8STreehugger Robot /*===-- moddi3.c - Implement __moddi3 -------------------------------------===
2*7c3d14c8STreehugger Robot  *
3*7c3d14c8STreehugger Robot  *                    The LLVM Compiler Infrastructure
4*7c3d14c8STreehugger Robot  *
5*7c3d14c8STreehugger Robot  * This file is dual licensed under the MIT and the University of Illinois Open
6*7c3d14c8STreehugger Robot  * Source Licenses. See LICENSE.TXT for details.
7*7c3d14c8STreehugger Robot  *
8*7c3d14c8STreehugger Robot  * ===----------------------------------------------------------------------===
9*7c3d14c8STreehugger Robot  *
10*7c3d14c8STreehugger Robot  * This file implements __moddi3 for the compiler_rt library.
11*7c3d14c8STreehugger Robot  *
12*7c3d14c8STreehugger Robot  * ===----------------------------------------------------------------------===
13*7c3d14c8STreehugger Robot  */
14*7c3d14c8STreehugger Robot 
15*7c3d14c8STreehugger Robot #include "int_lib.h"
16*7c3d14c8STreehugger Robot 
17*7c3d14c8STreehugger Robot /* Returns: a % b */
18*7c3d14c8STreehugger Robot 
19*7c3d14c8STreehugger Robot COMPILER_RT_ABI di_int
__moddi3(di_int a,di_int b)20*7c3d14c8STreehugger Robot __moddi3(di_int a, di_int b)
21*7c3d14c8STreehugger Robot {
22*7c3d14c8STreehugger Robot     const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1;
23*7c3d14c8STreehugger Robot     di_int s = b >> bits_in_dword_m1;  /* s = b < 0 ? -1 : 0 */
24*7c3d14c8STreehugger Robot     b = (b ^ s) - s;                   /* negate if s == -1 */
25*7c3d14c8STreehugger Robot     s = a >> bits_in_dword_m1;         /* s = a < 0 ? -1 : 0 */
26*7c3d14c8STreehugger Robot     a = (a ^ s) - s;                   /* negate if s == -1 */
27*7c3d14c8STreehugger Robot     du_int r;
28*7c3d14c8STreehugger Robot     __udivmoddi4(a, b, &r);
29*7c3d14c8STreehugger Robot     return ((di_int)r ^ s) - s;                /* negate if s == -1 */
30*7c3d14c8STreehugger Robot }
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