audk/ArmPkg/Library/CompilerIntrinsicsLib/Arm/lshrdi3.c

84 lines
2.9 KiB
C
Raw Normal View History

/** @file
Copyright (c) 2008-2009, Apple Inc. All rights reserved.
All rights reserved. This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
/**
University of Illinois/NCSA
Open Source License
Copyright (c) 2003-2008 University of Illinois at Urbana-Champaign.
All rights reserved.
Developed by:
LLVM Team
University of Illinois at Urbana-Champaign
http://llvm.org
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal with
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:
* Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimers.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimers in the
documentation and/or other materials provided with the distribution.
* Neither the names of the LLVM Team, University of Illinois at
Urbana-Champaign, nor the names of its contributors may be used to
endorse or promote products derived from this Software without specific
prior written permission.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
SOFTWARE.
**/
#include "Llvm_int_lib.h"
// Returns: logical a >> b
// Precondition: 0 <= b < bits_in_dword
INT64
__lshrdi3(INT64 a, INT32 b)
{
const int bits_in_word = (int)(sizeof(INT32) * CHAR_BIT);
udwords input;
udwords result;
input.all = a;
if (b & bits_in_word) // bits_in_word <= b < bits_in_dword
{
result.high = 0;
result.low = input.high >> (b - bits_in_word);
}
else // 0 <= b < bits_in_word
{
if (b == 0)
return a;
result.high = input.high >> b;
result.low = (input.high << (bits_in_word - b)) | (input.low >> b);
}
return result.all;
}