1/* ===-- lshrti3.c - Implement __lshrti3 -----------------------------------===
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 __lshrti3 for the compiler_rt library.
11 *
12 * ===----------------------------------------------------------------------===
13 */
14
15#include "int_lib.h"
16
17#ifdef CRT_HAS_128BIT
18
19/* Returns: logical a >> b */
20
21/* Precondition:  0 <= b < bits_in_tword */
22
23COMPILER_RT_ABI ti_int
24__lshrti3(ti_int a, si_int b)
25{
26    const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT);
27    utwords input;
28    utwords result;
29    input.all = a;
30    if (b & bits_in_dword)  /* bits_in_dword <= b < bits_in_tword */
31    {
32        result.s.high = 0;
33        result.s.low = input.s.high >> (b - bits_in_dword);
34    }
35    else  /* 0 <= b < bits_in_dword */
36    {
37        if (b == 0)
38            return a;
39        result.s.high  = input.s.high >> b;
40        result.s.low = (input.s.high << (bits_in_dword - b)) | (input.s.low >> b);
41    }
42    return result.all;
43}
44
45#endif /* CRT_HAS_128BIT */
46