1 //===-- ashrdi3.c - Implement __ashrdi3 -----------------------------------===//
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
7 //===----------------------------------------------------------------------===//
9 // This file implements __ashrdi3 for the compiler_rt library.
11 //===----------------------------------------------------------------------===//
15 // Returns: arithmetic a >> b
17 // Precondition: 0 <= b < bits_in_dword
19 COMPILER_RT_ABI di_int __ashrdi3(di_int a, si_int b) {
20 const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT);
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 */ {
31 result.s.high = input.s.high >> b;
32 result.s.low = (input.s.high << (bits_in_word - b)) | (input.s.low >> b);
37 #if defined(__ARM_EABI__)
38 COMPILER_RT_ALIAS(__ashrdi3, __aeabi_lasr)