Add some missing 64-bit math functions for gcc

[mirror_edk2.git] / ArmPkg / Library / CompilerIntrinsicsLib / Arm / moddi3.c

/** @file
  Compiler intrinsic for 64-bit mod, ported from LLVM code.

  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
  
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**/


#include "Llvm_int_lib.h"

UINT64 __udivmoddi4(UINT64 a, UINT64 b, UINT64* rem);

// Returns: a % b

INT64
__moddi3(INT64 a, INT64 b)
{
    const int bits_in_dword_m1 = (int)(sizeof(INT64) * CHAR_BIT) - 1;
    INT64 s = b >> bits_in_dword_m1;  // s = b < 0 ? -1 : 0
    b = (b ^ s) - s;                   // negate if s == -1
    s = a >> bits_in_dword_m1;         // s = a < 0 ? -1 : 0
    a = (a ^ s) - s;                   // negate if s == -1
    INT64 r;
    __udivmoddi4(a, b, (UINT64*)&r);
    return (r ^ s) - s;                // negate if s == -1
}