llvm-project/compiler-rt/lib/builtins/moddi3.c

30 lines
1.0 KiB
C

/*===-- moddi3.c - Implement __moddi3 -------------------------------------===
*
* Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
* See https://llvm.org/LICENSE.txt for license information.
* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
*
* ===----------------------------------------------------------------------===
*
* 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 */
}