1 //===-- divmoddi4.c - Implement __divmoddi4 -------------------------------===//
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 __divmoddi4 for the compiler_rt library.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "int_lib.h"
14 
15 // Returns: a / b, *rem = a % b
16 
__divmoddi4(di_int a,di_int b,di_int * rem)17 COMPILER_RT_ABI di_int __divmoddi4(di_int a, di_int b, di_int *rem) {
18   const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1;
19   di_int s_a = a >> bits_in_dword_m1;                   // s_a = a < 0 ? -1 : 0
20   di_int s_b = b >> bits_in_dword_m1;                   // s_b = b < 0 ? -1 : 0
21   a = (a ^ s_a) - s_a;                                  // negate if s_a == -1
22   b = (b ^ s_b) - s_b;                                  // negate if s_b == -1
23   s_b ^= s_a;                                           // sign of quotient
24   du_int r;
25   di_int q = (__udivmoddi4(a, b, &r) ^ s_b) - s_b;      // negate if s_b == -1
26   *rem = (r ^ s_a) - s_a;                               // negate if s_a == -1
27   return q;
28 }
29