177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao/* ===-- clzdi2.c - Implement __clzdi2 -------------------------------------=== 277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * The LLVM Compiler Infrastructure 477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * This file is distributed under the University of Illinois Open Source 677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * License. See LICENSE.TXT for details. 777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * ===----------------------------------------------------------------------=== 977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 1077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * This file implements __clzdi2 for the compiler_rt library. 1177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 1277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * ===----------------------------------------------------------------------=== 1377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao */ 1477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 1577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao#include "int_lib.h" 1677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 1777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao/* Returns: the number of leading 0-bits */ 1877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 1977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao/* Precondition: a != 0 */ 2077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 2177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liaosi_int 2277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao__clzdi2(di_int a) 2377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao{ 2477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao dwords x; 2577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao x.all = a; 2677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao const si_int f = -(x.s.high == 0); 2777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao return __builtin_clz((x.s.high & ~f) | (x.s.low & f)) + 2877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao (f & ((si_int)(sizeof(si_int) * CHAR_BIT))); 2977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao} 30