mirror of
https://github.com/freebsd/freebsd-src
synced 2024-10-18 22:33:39 +00:00
7686ff743c
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.
34 lines
939 B
C
34 lines
939 B
C
/* ===-- ffsdi2.c - Implement __ffsdi2 -------------------------------------===
|
|
*
|
|
* 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 __ffsdi2 for the compiler_rt library.
|
|
*
|
|
* ===----------------------------------------------------------------------===
|
|
*/
|
|
|
|
#include "int_lib.h"
|
|
|
|
/* Returns: the index of the least significant 1-bit in a, or
|
|
* the value zero if a is zero. The least significant bit is index one.
|
|
*/
|
|
|
|
COMPILER_RT_ABI si_int
|
|
__ffsdi2(di_int a)
|
|
{
|
|
dwords x;
|
|
x.all = a;
|
|
if (x.s.low == 0)
|
|
{
|
|
if (x.s.high == 0)
|
|
return 0;
|
|
return __builtin_ctz(x.s.high) + (1 + sizeof(si_int) * CHAR_BIT);
|
|
}
|
|
return __builtin_ctz(x.s.low) + 1;
|
|
}
|