freebsd-dev/contrib/compiler-rt/lib/builtins/clzdi2.c
Dimitry Andric f4341a5a66 Update compiler-rt to trunk r224034. This brings a number of new
builtins, and also the various sanitizers.  Support for these will be
added in a later commit.
2015-01-08 19:47:10 +00:00

30 lines
826 B
C

/* ===-- clzdi2.c - Implement __clzdi2 -------------------------------------===
*
* 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 __clzdi2 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "int_lib.h"
/* Returns: the number of leading 0-bits */
/* Precondition: a != 0 */
COMPILER_RT_ABI si_int
__clzdi2(di_int a)
{
dwords x;
x.all = a;
const si_int f = -(x.s.high == 0);
return __builtin_clz((x.s.high & ~f) | (x.s.low & f)) +
(f & ((si_int)(sizeof(si_int) * CHAR_BIT)));
}