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/* ===-- ashrti3.c - Implement __ashrti3 -----------------------------------===
*
* The LLVM Compiler Infrastructure
*
* This file is dual licensed under the MIT and the University of Illinois Open
* Source Licenses. See LICENSE.TXT for details.
*
* ===----------------------------------------------------------------------===
*
* This file implements __ashrti3 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "int_lib.h"
#ifdef CRT_HAS_128BIT
/* Returns: arithmetic a >> b */
/* Precondition: 0 <= b < bits_in_tword */
COMPILER_RT_ABI ti_int
__ashrti3(ti_int a, si_int b)
{
const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT);
twords input;
twords result;
input.all = a;
if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */
{
/* result.s.high = input.s.high < 0 ? -1 : 0 */
result.s.high = input.s.high >> (bits_in_dword - 1);
result.s.low = input.s.high >> (b - bits_in_dword);
}
else /* 0 <= b < bits_in_dword */
{
if (b == 0)
return a;
result.s.high = input.s.high >> b;
result.s.low = (input.s.high << (bits_in_dword - b)) | (input.s.low >> b);
}
return result.all;
}
#endif /* CRT_HAS_128BIT */
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