llvm-project/compiler-rt/lib/builtins/clzti2.c

30 lines
884 B
C

//===-- clzti2.c - Implement __clzti2 -------------------------------------===//
//
// 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 __clzti2 for the compiler_rt library.
//
//===----------------------------------------------------------------------===//
#include "int_lib.h"
#ifdef CRT_HAS_128BIT
// Returns: the number of leading 0-bits
// Precondition: a != 0
COMPILER_RT_ABI int __clzti2(ti_int a) {
twords x;
x.all = a;
const di_int f = -(x.s.high == 0);
return __builtin_clzll((x.s.high & ~f) | (x.s.low & f)) +
((si_int)f & ((si_int)(sizeof(di_int) * CHAR_BIT)));
}
#endif // CRT_HAS_128BIT