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
21COMPILER_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

source code of compiler-rt/lib/builtins/ashrti3.c