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Lionel Debieve6bda5472020-01-02 11:09:03 +01001/* ===-- divdi3.c - Implement __divdi3 -------------------------------------===
2 *
3 * The LLVM Compiler Infrastructure
4 *
5 * This file is dual licensed under the MIT and the University of Illinois Open
6 * Source Licenses. See LICENSE.TXT for details.
7 *
8 * ===----------------------------------------------------------------------===
9 *
10 * This file implements __divdi3 for the compiler_rt library.
11 *
12 * ===----------------------------------------------------------------------===
13 */
14
15#include "int_lib.h"
16
17/* Returns: a / b */
18
19COMPILER_RT_ABI di_int
20__divdi3(di_int a, di_int b)
21{
22 const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1;
23 di_int s_a = a >> bits_in_dword_m1; /* s_a = a < 0 ? -1 : 0 */
24 di_int s_b = b >> bits_in_dword_m1; /* s_b = b < 0 ? -1 : 0 */
25 a = (a ^ s_a) - s_a; /* negate if s_a == -1 */
26 b = (b ^ s_b) - s_b; /* negate if s_b == -1 */
27 s_a ^= s_b; /*sign of quotient */
28 return (__udivmoddi4(a, b, (du_int*)0) ^ s_a) - s_a; /* negate if s_a == -1 */
29}