1 //===-- moddi3.c - Implement __moddi3 -------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements __moddi3 for the compiler_rt library. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "int_lib.h" 14 15 // Returns: a % b 16 17 COMPILER_RT_ABI di_int __moddi3(di_int a, di_int b) { 18 const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1; 19 di_int s = b >> bits_in_dword_m1; // s = b < 0 ? -1 : 0 20 b = (b ^ s) - s; // negate if s == -1 21 s = a >> bits_in_dword_m1; // s = a < 0 ? -1 : 0 22 a = (a ^ s) - s; // negate if s == -1 23 du_int r; 24 __udivmoddi4(a, b, &r); 25 return ((di_int)r ^ s) - s; // negate if s == -1 26 } 27