| //===-- ashrdi3.c - Implement __ashrdi3 -----------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements __ashrdi3 for the compiler_rt library. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "int_lib.h" |
| |
| // Returns: arithmetic a >> b |
| |
| // Precondition: 0 <= b < bits_in_dword |
| |
| COMPILER_RT_ABI di_int __ashrdi3(di_int a, int b) { |
| const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT); |
| dwords input; |
| dwords result; |
| input.all = a; |
| if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */ { |
| // result.s.high = input.s.high < 0 ? -1 : 0 |
| result.s.high = input.s.high >> (bits_in_word - 1); |
| result.s.low = input.s.high >> (b - bits_in_word); |
| } else /* 0 <= b < bits_in_word */ { |
| if (b == 0) |
| return a; |
| result.s.high = input.s.high >> b; |
| result.s.low = |
| ((su_int)input.s.high << (bits_in_word - b)) | (input.s.low >> b); |
| } |
| return result.all; |
| } |
| |
| #if defined(__ARM_EABI__) |
| COMPILER_RT_ALIAS(__ashrdi3, __aeabi_lasr) |
| #endif |