xref: /aosp_15_r20/external/compiler-rt/lib/builtins/modti3.c (revision 7c3d14c8b49c529e04be81a3ce6f5cc23712e4c6)
1*7c3d14c8STreehugger Robot /* ===-- modti3.c - Implement __modti3 -------------------------------------===
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 __modti3 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 #ifdef CRT_HAS_128BIT
18*7c3d14c8STreehugger Robot 
19*7c3d14c8STreehugger Robot /*Returns: a % b */
20*7c3d14c8STreehugger Robot 
21*7c3d14c8STreehugger Robot COMPILER_RT_ABI ti_int
__modti3(ti_int a,ti_int b)22*7c3d14c8STreehugger Robot __modti3(ti_int a, ti_int b)
23*7c3d14c8STreehugger Robot {
24*7c3d14c8STreehugger Robot     const int bits_in_tword_m1 = (int)(sizeof(ti_int) * CHAR_BIT) - 1;
25*7c3d14c8STreehugger Robot     ti_int s = b >> bits_in_tword_m1;  /* s = b < 0 ? -1 : 0 */
26*7c3d14c8STreehugger Robot     b = (b ^ s) - s;                   /* negate if s == -1 */
27*7c3d14c8STreehugger Robot     s = a >> bits_in_tword_m1;         /* s = a < 0 ? -1 : 0 */
28*7c3d14c8STreehugger Robot     a = (a ^ s) - s;                   /* negate if s == -1 */
29*7c3d14c8STreehugger Robot     tu_int r;
30*7c3d14c8STreehugger Robot     __udivmodti4(a, b, &r);
31*7c3d14c8STreehugger Robot     return ((ti_int)r ^ s) - s;                /* negate if s == -1 */
32*7c3d14c8STreehugger Robot }
33*7c3d14c8STreehugger Robot 
34*7c3d14c8STreehugger Robot #endif /* CRT_HAS_128BIT */
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