1//===-- ashrdi3.c - Implement __ashrdi3 -----------------------------------===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// 9// This file implements __ashrdi3 for the compiler_rt library. 10// 11//===----------------------------------------------------------------------===// 12 13#include "int_lib.h" 14 15// Returns: arithmetic a >> b 16 17// Precondition: 0 <= b < bits_in_dword 18 19COMPILER_RT_ABI di_int __ashrdi3(di_int a, int b) { 20 const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT); 21 dwords input; 22 dwords result; 23 input.all = a; 24 if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */ { 25 // result.s.high = input.s.high < 0 ? -1 : 0 26 result.s.high = input.s.high >> (bits_in_word - 1); 27 result.s.low = input.s.high >> (b - bits_in_word); 28 } else /* 0 <= b < bits_in_word */ { 29 if (b == 0) 30 return a; 31 result.s.high = input.s.high >> b; 32 result.s.low = 33 ((su_int)input.s.high << (bits_in_word - b)) | (input.s.low >> b); 34 } 35 return result.all; 36} 37 38#if defined(__ARM_EABI__) 39COMPILER_RT_ALIAS(__ashrdi3, __aeabi_lasr) 40#endif 41