/* ===-- clzti2.c - Implement __clzti2 -------------------------------------=== * * 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 __clzti2 for the compiler_rt library. * * ===----------------------------------------------------------------------=== */ #include "int_lib.h" #if __x86_64 /* Returns: the number of leading 0-bits */ /* Precondition: a != 0 */ si_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 /* __x86_64 */