1 //===-- clzti2.c - Implement __clzti2 -------------------------------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This file implements __clzti2 for the compiler_rt library.
11 //===----------------------------------------------------------------------===//
17 // Returns: the number of leading 0-bits
19 // Precondition: a != 0
21 COMPILER_RT_ABI si_int __clzti2(ti_int a) {
24 const di_int f = -(x.s.high == 0);
25 return __builtin_clzll((x.s.high & ~f) | (x.s.low & f)) +
26 ((si_int)f & ((si_int)(sizeof(di_int) * CHAR_BIT)));
29 #endif // CRT_HAS_128BIT