freebsd-skq/contrib/compiler-rt/lib/moddi3.c
Ed Schouten 7686ff743c Upgrade libcompiler_rt to upstream revision 147390.
This version of libcompiler_rt adds support for __mulo[sdt]i4(), which
computes a multiply and its overflow flag. There are also a lot of
cleanup fixes to headers that don't really affect us.

Updating to this revision should make it a bit easier to contribute
changes back to the LLVM developers.
2011-12-31 19:01:48 +00:00

33 lines
1.1 KiB
C

/*===-- moddi3.c - Implement __moddi3 -------------------------------------===
*
* 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 __moddi3 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "int_lib.h"
COMPILER_RT_ABI du_int __udivmoddi4(du_int a, du_int b, du_int* rem);
/* Returns: a % b */
COMPILER_RT_ABI di_int
__moddi3(di_int a, di_int b)
{
const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1;
di_int s = b >> bits_in_dword_m1; /* s = b < 0 ? -1 : 0 */
b = (b ^ s) - s; /* negate if s == -1 */
s = a >> bits_in_dword_m1; /* s = a < 0 ? -1 : 0 */
a = (a ^ s) - s; /* negate if s == -1 */
di_int r;
__udivmoddi4(a, b, (du_int*)&r);
return (r ^ s) - s; /* negate if s == -1 */
}