comrogue-pi/kernel/intlib.c

82 lines
2.9 KiB
C

/*
* This file is part of the COMROGUE Operating System for Raspberry Pi
*
* Copyright (c) 2013, Eric J. Bowersox / Erbosoft Enterprises
* All rights reserved.
*
* This program is free for commercial and non-commercial use as long as the following conditions are
* adhered to.
*
* Copyright in this file remains Eric J. Bowersox and/or Erbosoft, and as such any copyright notices
* in the code are not to be removed.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted
* provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this list of conditions and
* the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
* the following disclaimer in the documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* "Raspberry Pi" is a trademark of the Raspberry Pi Foundation.
*/
#include <comrogue/types.h>
#include <comrogue/intlib.h>
#include <comrogue/internals/seg.h>
#include "quad.h"
/*---------------------------
* Integer library functions
*---------------------------
*/
/* Flags used internally to IntLDiv. */
#define FLIP_QUOTIENT 0x00000001
#define FLIP_REMAINDER 0x00000002
/*
* Divides two 64-bit integers and returns a quotient and a remainder in a structure.
*
* Parameters:
* - pResult = Pointer to an LDIV structure to contain the quotient and remainder.
* - num = The numerator (dividend) for the division.
* - demom = The demoninator (divisor) for the division.
*
* Returns:
* Standard SUCCEEDED/FAILED HRESULT.
*/
SEG_LIB_CODE HRESULT IntLDiv(PLDIV pResult, INT64 num, INT64 denom)
{
UINT32 mode = 0;
if (denom == 0)
{
pResult->quot = pResult->rem = 0;
return E_INVALIDARG;
}
if (denom < 0)
{
mode ^= FLIP_QUOTIENT;
denom = -denom;
}
if (num < 0)
{
mode ^= (FLIP_QUOTIENT|FLIP_REMAINDER);
num = -num;
}
pResult->quot = __qdivrem(num, denom, (PUINT64)(&(pResult->rem)));
if (mode & FLIP_QUOTIENT)
pResult->quot = -(pResult->quot);
if (mode & FLIP_REMAINDER)
pResult->rem = -(pResult->rem);
return S_OK;
}