1 /*===-- ashrdi3.c - Implement __ashrdi3 -----------------------------------=== 2 * 3 * The LLVM Compiler Infrastructure 4 * 5 * This file is dual licensed under the MIT and the University of Illinois Open 6 * Source Licenses. 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 ARM_EABI_FNALIAS(lasr, ashrdi3) 22 23 COMPILER_RT_ABI di_int 24 __ashrdi3(di_int a, si_int b) 25 { 26 const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT); 27 dwords input; 28 dwords result; 29 input.all = a; 30 if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */ 31 { 32 /* result.s.high = input.s.high < 0 ? -1 : 0 */ 33 result.s.high = input.s.high >> (bits_in_word - 1); 34 result.s.low = input.s.high >> (b - bits_in_word); 35 } 36 else /* 0 <= b < bits_in_word */ 37 { 38 if (b == 0) 39 return a; 40 result.s.high = input.s.high >> b; 41 result.s.low = (input.s.high << (bits_in_word - b)) | (input.s.low >> b); 42 } 43 return result.all; 44 } 45
