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/* ===-- lshrti3.c - Implement __lshrti3 -----------------------------------===
*
* 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 __lshrti3 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
/* Returns: logical a >> b */
/* Precondition: 0 <= b < bits_in_tword */
#include <sys/limits.h>
#include <sys/endian.h>
typedef int si_int;
typedef unsigned int su_int;
typedef long long di_int;
typedef unsigned long long du_int;
typedef int ti_int __attribute__ ((mode (TI)));
typedef int tu_int __attribute__ ((mode (TI)));
#if BYTE_ORDER == LITTLE_ENDIAN
#define _YUGA_LITTLE_ENDIAN 0
#else
#define _YUGA_LITTLE_ENDIAN 1
#endif
typedef union
{
tu_int all;
struct
{
#if _YUGA_LITTLE_ENDIAN
du_int low;
du_int high;
#else
du_int high;
du_int low;
#endif /* _YUGA_LITTLE_ENDIAN */
}s;
} utwords;
ti_int
__lshrti3(ti_int a, si_int b)
{
const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT);
utwords input;
utwords result;
input.all = a;
if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */
{
result.s.high = 0;
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;
}
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