xref: /rk3399_ARM-atf/lib/compiler-rt/builtins/divdi3.c (revision 8c80c86573898eb59127a32b089e753f40e254fb)
1*8c80c865SLionel Debieve /* ===-- divdi3.c - Implement __divdi3 -------------------------------------===
2*8c80c865SLionel Debieve  *
3*8c80c865SLionel Debieve  *                     The LLVM Compiler Infrastructure
4*8c80c865SLionel Debieve  *
5*8c80c865SLionel Debieve  * This file is dual licensed under the MIT and the University of Illinois Open
6*8c80c865SLionel Debieve  * Source Licenses. See LICENSE.TXT for details.
7*8c80c865SLionel Debieve  *
8*8c80c865SLionel Debieve  * ===----------------------------------------------------------------------===
9*8c80c865SLionel Debieve  *
10*8c80c865SLionel Debieve  * This file implements __divdi3 for the compiler_rt library.
11*8c80c865SLionel Debieve  *
12*8c80c865SLionel Debieve  * ===----------------------------------------------------------------------===
13*8c80c865SLionel Debieve  */
14*8c80c865SLionel Debieve 
15*8c80c865SLionel Debieve #include "int_lib.h"
16*8c80c865SLionel Debieve 
17*8c80c865SLionel Debieve /* Returns: a / b */
18*8c80c865SLionel Debieve 
19*8c80c865SLionel Debieve COMPILER_RT_ABI di_int
20*8c80c865SLionel Debieve __divdi3(di_int a, di_int b)
21*8c80c865SLionel Debieve {
22*8c80c865SLionel Debieve     const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1;
23*8c80c865SLionel Debieve     di_int s_a = a >> bits_in_dword_m1;           /* s_a = a < 0 ? -1 : 0 */
24*8c80c865SLionel Debieve     di_int s_b = b >> bits_in_dword_m1;           /* s_b = b < 0 ? -1 : 0 */
25*8c80c865SLionel Debieve     a = (a ^ s_a) - s_a;                         /* negate if s_a == -1 */
26*8c80c865SLionel Debieve     b = (b ^ s_b) - s_b;                         /* negate if s_b == -1 */
27*8c80c865SLionel Debieve     s_a ^= s_b;                                  /*sign of quotient */
28*8c80c865SLionel Debieve     return (__udivmoddi4(a, b, (du_int*)0) ^ s_a) - s_a;  /* negate if s_a == -1 */
29*8c80c865SLionel Debieve }
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