forked from OSchip/llvm-project
40 lines
1.4 KiB
C
40 lines
1.4 KiB
C
/* ===-- 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 */
|
|
|
|
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 */
|
|
}
|
|
|
|
#if defined(__ARM_EABI__)
|
|
AEABI_RTABI si_int __aeabi_idiv(si_int a, si_int b) COMPILER_RT_ALIAS(__divsi3);
|
|
#endif
|