1 |
|
|
/* ===-- ashrti3.c - Implement __ashrti3 -----------------------------------=== |
2 |
|
|
* |
3 |
|
|
* The LLVM Compiler Infrastructure |
4 |
|
|
* |
5 |
|
|
* This file is dual licensed under the MIT and the University of Illinois Open |
6 |
|
|
* Source Licenses. See LICENSE.TXT for details. |
7 |
|
|
* |
8 |
|
|
* ===----------------------------------------------------------------------=== |
9 |
|
|
* |
10 |
|
|
* This file implements __ashrti3 for the compiler_rt library. |
11 |
|
|
* |
12 |
|
|
* ===----------------------------------------------------------------------=== |
13 |
|
|
*/ |
14 |
|
|
|
15 |
|
|
#include "int_lib.h" |
16 |
|
|
|
17 |
|
|
#ifdef CRT_HAS_128BIT |
18 |
|
|
|
19 |
|
|
/* Returns: arithmetic a >> b */ |
20 |
|
|
|
21 |
|
|
/* Precondition: 0 <= b < bits_in_tword */ |
22 |
|
|
|
23 |
|
|
COMPILER_RT_ABI ti_int |
24 |
|
|
__ashrti3(ti_int a, si_int b) |
25 |
|
|
{ |
26 |
|
|
const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT); |
27 |
|
|
twords input; |
28 |
|
|
twords result; |
29 |
|
|
input.all = a; |
30 |
|
|
if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ |
31 |
|
|
{ |
32 |
|
|
/* result.s.high = input.s.high < 0 ? -1 : 0 */ |
33 |
|
|
result.s.high = input.s.high >> (bits_in_dword - 1); |
34 |
|
|
result.s.low = input.s.high >> (b - bits_in_dword); |
35 |
|
|
} |
36 |
|
|
else /* 0 <= b < bits_in_dword */ |
37 |
|
|
{ |
38 |
|
|
if (b == 0) |
39 |
|
|
return a; |
40 |
|
|
result.s.high = input.s.high >> b; |
41 |
|
|
result.s.low = (input.s.high << (bits_in_dword - b)) | (input.s.low >> b); |
42 |
|
|
} |
43 |
|
|
return result.all; |
44 |
|
|
} |
45 |
|
|
|
46 |
|
|
#endif /* CRT_HAS_128BIT */ |