1/* ===-- ashlti3.c - Implement __ashlti3 -----------------------------------===
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 __ashlti3 for the compiler_rt library.
11 *
12 * ===----------------------------------------------------------------------===
13 */
14
15#include "int_lib.h"
16
17#ifdef CRT_HAS_128BIT
18
19/* Returns: a << b */
20
21/* Precondition: 0 <= b < bits_in_tword */
22
23COMPILER_RT_ABI ti_int
24__ashlti3(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.low = 0;
33 result.s.high = input.s.low << (b - bits_in_dword);
34 }
35 else /* 0 <= b < bits_in_dword */
36 {
37 if (b == 0)
38 return a;
39 result.s.low = input.s.low << b;
40 result.s.high = (input.s.high << b) | (input.s.low >> (bits_in_dword - b));
41 }
42 return result.all;
43}
44
45#endif /* CRT_HAS_128BIT */
46