1 //===-- divmodti4.c - Implement __divmodti4 -------------------------------===// 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 __divmodti4 for the compiler_rt library. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "int_lib.h" 14 15 #ifdef CRT_HAS_128BIT 16 17 // Returns: a / b, *rem = a % b 18 19 COMPILER_RT_ABI ti_int __divmodti4(ti_int a, ti_int b, ti_int *rem) { 20 const int bits_in_tword_m1 = (int)(sizeof(ti_int) * CHAR_BIT) - 1; 21 ti_int s_a = a >> bits_in_tword_m1; // s_a = a < 0 ? -1 : 0 22 ti_int s_b = b >> bits_in_tword_m1; // s_b = b < 0 ? -1 : 0 23 a = (a ^ s_a) - s_a; // negate if s_a == -1 24 b = (b ^ s_b) - s_b; // negate if s_b == -1 25 s_b ^= s_a; // sign of quotient 26 tu_int r; 27 ti_int q = (__udivmodti4(a, b, &r) ^ s_b) - s_b; // negate if s_b == -1 28 *rem = (r ^ s_a) - s_a; // negate if s_a == -1 29 return q; 30 } 31 32 #endif // CRT_HAS_128BIT 33