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74 lines
2.4 KiB
C
74 lines
2.4 KiB
C
/* Math functions for i387.
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Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by John C. Bowman <bowman@ipp-garching.mpg.de>, 1995.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
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Boston, MA 02110-1301, USA.
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*/
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#include <w32k.h>
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/*
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* FIXME! Is there a better algorithm. like FT_MulDiv
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*
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* @implemented
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*/
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INT APIENTRY EngMulDiv(
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INT nMultiplicand,
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INT nMultiplier,
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INT nDivisor)
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{
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#if SIZEOF_LONG_LONG >= 8
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long long ret;
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if (!nDivisor) return -1;
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/* We want to deal with a positive divisor to simplify the logic. */
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if (nDivisor < 0)
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{
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nMultiplicand = - nMultiplicand;
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nDivisor = -nDivisor;
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}
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/* If the result is positive, we "add" to round. else, we subtract to round. */
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if ( ( (nMultiplicand < 0) && (nMultiplier < 0) ) ||
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( (nMultiplicand >= 0) && (nMultiplier >= 0) ) )
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ret = (((long long)nMultiplicand * nMultiplier) + (nDivisor/2)) / nDivisor;
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else
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ret = (((long long)nMultiplicand * nMultiplier) - (nDivisor/2)) / nDivisor;
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if ((ret > 2147483647) || (ret < -2147483647)) return -1;
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return ret;
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#else
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if (!nDivisor) return -1;
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/* We want to deal with a positive divisor to simplify the logic. */
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if (nDivisor < 0)
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{
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nMultiplicand = - nMultiplicand;
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nDivisor = -nDivisor;
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}
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/* If the result is positive, we "add" to round. else, we subtract to round. */
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if ( ( (nMultiplicand < 0) && (nMultiplier < 0) ) ||
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( (nMultiplicand >= 0) && (nMultiplier >= 0) ) )
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return ((nMultiplicand * nMultiplier) + (nDivisor/2)) / nDivisor;
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return ((nMultiplicand * nMultiplier) - (nDivisor/2)) / nDivisor;
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#endif
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}
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