| 1 | //===-- ashrti3.c - Implement __ashrti3 -----------------------------------===// |
|---|---|
| 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 __ashrti3 for the compiler_rt library. |
| 10 | // |
| 11 | //===----------------------------------------------------------------------===// |
| 12 | |
| 13 | #include "int_lib.h" |
| 14 | |
| 15 | #ifdef CRT_HAS_128BIT |
| 16 | |
| 17 | // Returns: arithmetic a >> b |
| 18 | |
| 19 | // Precondition: 0 <= b < bits_in_tword |
| 20 | |
| 21 | COMPILER_RT_ABI ti_int __ashrti3(ti_int a, int b) { |
| 22 | const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT); |
| 23 | twords input; |
| 24 | twords result; |
| 25 | input.all = a; |
| 26 | if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ { |
| 27 | // result.s.high = input.s.high < 0 ? -1 : 0 |
| 28 | result.s.high = input.s.high >> (bits_in_dword - 1); |
| 29 | result.s.low = input.s.high >> (b - bits_in_dword); |
| 30 | } else /* 0 <= b < bits_in_dword */ { |
| 31 | if (b == 0) |
| 32 | return a; |
| 33 | result.s.high = input.s.high >> b; |
| 34 | result.s.low = |
| 35 | ((du_int)input.s.high << (bits_in_dword - b)) | (input.s.low >> b); |
| 36 | } |
| 37 | return result.all; |
| 38 | } |
| 39 | |
| 40 | #endif // CRT_HAS_128BIT |
| 41 |