blob: bab4aefda30ab9b7164f4a6fc8183b6de1e19d1f (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
|
/* ===-- divsi3.c - Implement __divsi3 -------------------------------------===
*
* The LLVM Compiler Infrastructure
*
* This file is dual licensed under the MIT and the University of Illinois Open
* Source Licenses. See LICENSE.TXT for details.
*
* ===----------------------------------------------------------------------===
*
* This file implements __divsi3 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "int_lib.h"
/* Returns: a / b */
ARM_EABI_FNALIAS(idiv, divsi3)
COMPILER_RT_ABI si_int
__divsi3(si_int a, si_int b)
{
const int bits_in_word_m1 = (int)(sizeof(si_int) * CHAR_BIT) - 1;
si_int s_a = a >> bits_in_word_m1; /* s_a = a < 0 ? -1 : 0 */
si_int s_b = b >> bits_in_word_m1; /* s_b = b < 0 ? -1 : 0 */
a = (a ^ s_a) - s_a; /* negate if s_a == -1 */
b = (b ^ s_b) - s_b; /* negate if s_b == -1 */
s_a ^= s_b; /* sign of quotient */
/*
* On CPUs without unsigned hardware division support,
* this calls __udivsi3 (notice the cast to su_int).
* On CPUs with unsigned hardware division support,
* this uses the unsigned division instruction.
*/
return ((su_int)a/(su_int)b ^ s_a) - s_a; /* negate if s_a == -1 */
}
|
