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1 /* ===-- 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 
19 di_int
__divdi3(di_int a,di_int b)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 }
30