| //===-- ashrti3.c - Implement __ashrti3 -----------------------------------===// |
| // |
| // 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 __ashrti3 for the compiler_rt library. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "int_lib.h" |
| |
| #ifdef CRT_HAS_128BIT |
| |
| // Returns: arithmetic a >> b |
| |
| // Precondition: 0 <= b < bits_in_tword |
| |
| COMPILER_RT_ABI ti_int __ashrti3(ti_int a, si_int b) { |
| const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT); |
| twords input; |
| twords result; |
| input.all = a; |
| if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ { |
| // result.s.high = input.s.high < 0 ? -1 : 0 |
| result.s.high = input.s.high >> (bits_in_dword - 1); |
| result.s.low = input.s.high >> (b - bits_in_dword); |
| } else /* 0 <= b < bits_in_dword */ { |
| if (b == 0) |
| return a; |
| result.s.high = input.s.high >> b; |
| result.s.low = (input.s.high << (bits_in_dword - b)) | (input.s.low >> b); |
| } |
| return result.all; |
| } |
| |
| #endif // CRT_HAS_128BIT |
