1 /*===-- ashrdi3.c - Implement __ashrdi3 -----------------------------------=== 2 * 3 * The LLVM Compiler Infrastructure 4 * 5 * This file is distributed under the University of Illinois Open Source 6 * License. See LICENSE.TXT for details. 7 * 8 * ===----------------------------------------------------------------------=== 9 * 10 * This file implements __ashrdi3 for the compiler_rt library. 11 * 12 * ===----------------------------------------------------------------------=== 13 */ 14 15 #include "int_lib.h" 16 17 /* Returns: arithmetic a >> b */ 18 19 /* Precondition: 0 <= b < bits_in_dword */ 20 21 di_int __ashrdi3(di_int a,si_int b)22__ashrdi3(di_int a, si_int b) 23 { 24 const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT); 25 dwords input; 26 dwords result; 27 input.all = a; 28 if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */ 29 { 30 /* result.s.high = input.s.high < 0 ? -1 : 0 */ 31 result.s.high = input.s.high >> (bits_in_word - 1); 32 result.s.low = input.s.high >> (b - bits_in_word); 33 } 34 else /* 0 <= b < bits_in_word */ 35 { 36 if (b == 0) 37 return a; 38 result.s.high = input.s.high >> b; 39 result.s.low = (input.s.high << (bits_in_word - b)) | (input.s.low >> b); 40 } 41 return result.all; 42 } 43