| //===-- divmodsi4.c - Implement __divmodsi4 |
| //--------------------------------===// |
| // |
| // 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 __divmodsi4 for the compiler_rt library. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "int_lib.h" |
| |
| // Returns: a / b, *rem = a % b |
| |
| COMPILER_RT_ABI si_int __divmodsi4(si_int a, si_int b, si_int *rem) { |
| const int bits_in_word_m1 = (int)(sizeof(si_int) * CHAR_BIT) - 1; |
| si_int s_a = a >> bits_in_word_m1; // s_a = a < 0 ? -1 : 0 |
| si_int s_b = b >> bits_in_word_m1; // s_b = b < 0 ? -1 : 0 |
| a = (a ^ s_a) - s_a; // negate if s_a == -1 |
| b = (b ^ s_b) - s_b; // negate if s_b == -1 |
| s_b ^= s_a; // sign of quotient |
| su_int r; |
| si_int q = (__udivmodsi4(a, b, &r) ^ s_b) - s_b; // negate if s_b == -1 |
| *rem = (r ^ s_a) - s_a; // negate if s_a == -1 |
| return q; |
| } |
