1/* ===-- lshrdi3.c - Implement __lshrdi3 -----------------------------------===
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 __lshrdi3 for the compiler_rt library.
11 *
12 * ===----------------------------------------------------------------------===
13 */
14
15#include "int_lib.h"
16
17/* Returns: logical a >> b */
18
19/* Precondition: 0 <= b < bits_in_dword */
20
21ARM_EABI_FNALIAS(llsr, lshrdi3)
22
23COMPILER_RT_ABI di_int
24__lshrdi3(di_int a, si_int b)
25{
26 const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT);
27 udwords input;
28 udwords result;
29 input.all = a;
30 if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */
31 {
32 result.s.high = 0;
33 result.s.low = input.s.high >> (b - bits_in_word);
34 }
35 else /* 0 <= b < bits_in_word */
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_word - b)) | (input.s.low >> b);
41 }
42 return result.all;
43}
44