llvm-project/compiler-rt/lib/builtins/ctzti2.c

30 lines
884 B
C

//===-- ctzti2.c - Implement __ctzti2 -------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements __ctzti2 for the compiler_rt library.
//
//===----------------------------------------------------------------------===//
#include "int_lib.h"
#ifdef CRT_HAS_128BIT
// Returns: the number of trailing 0-bits
// Precondition: a != 0
COMPILER_RT_ABI 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