uefi/linaro-edk2/ArmPkg/Library/CompilerIntrinsicsLib/Arm/ashldi3.c

/** @file

  Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>

  This program and the accompanying materials
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  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.

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      LLVM Team

      University of Illinois at Urbana-Champaign

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**/

#include "Llvm_int_lib.h"

// Returns: a << b

// Precondition:  0 <= b < bits_in_dword

INT64
__ashldi3(INT64 a, INT32 b)
{
    const int bits_in_word = (int)(sizeof(INT32) * CHAR_BIT);
    dwords input;
    dwords result;
    input.all = a;
    if (b & bits_in_word)  // bits_in_word <= b < bits_in_dword
    {
        result.low = 0;
        result.high = input.low << (b - bits_in_word);
    }
    else  // 0 <= b < bits_in_word
    {
        if (b == 0)
            return a;
        result.low  = input.low << b;
        result.high = (input.high << b) | (input.low >> (bits_in_word - b));
    }
    return result.all;
}