cosmopolitan/third_party/compiler_rt/ctzti2.c

37 lines
987 B
C

/* clang-format off */
/* ===-- ctzti2.c - Implement __ctzti2 -------------------------------------===
*
* 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 __ctzti2 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
STATIC_YOINK("huge_compiler_rt_license");
#include "third_party/compiler_rt/int_lib.h"
#ifdef CRT_HAS_128BIT
/* Returns: the number of trailing 0-bits */
/* Precondition: a != 0 */
COMPILER_RT_ABI si_int
__ctzti2(ti_int a)
{
twords x;
x.all = a;
const di_int f = -(x.s.low == 0);
return __builtin_ctzll((x.s.high & f) | (x.s.low & ~f)) +
((si_int)f & ((si_int)(sizeof(di_int) * CHAR_BIT)));
}
#endif /* CRT_HAS_128BIT */