source: mainline/uspace/lib/softfloat/generic/comparison.c@ 98e4507

/*
 * Copyright (c) 2005 Josef Cejka
 * All rights reserved.
 *
 * 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/** @addtogroup softfloat
 * @{
 */
/** @file
 */

#include <sftypes.h>
#include <comparison.h>

/* NaN : exp = 0xff and nonzero fraction */
int isFloat32NaN(float32 f)
{
        return ((f.parts.exp == 0xFF) && (f.parts.fraction));
}

/* NaN : exp = 0x7ff and nonzero fraction */
int isFloat64NaN(float64 d)
{
        return ((d.parts.exp == 0x7FF) && (d.parts.fraction));
}

/* SigNaN : exp = 0xff fraction = 0xxxxx..x (binary), where at least one x is nonzero */
int isFloat32SigNaN(float32 f)
{
        return ((f.parts.exp == 0xFF) && (f.parts.fraction < 0x400000) && (f.parts.fraction));
}

/* SigNaN : exp = 0x7ff fraction = 0xxxxx..x (binary), where at least one x is nonzero */
int isFloat64SigNaN(float64 d)
{
        return ((d.parts.exp == 0x7FF) && (d.parts.fraction) && (d.parts.fraction < 0x8000000000000ll));
}

int isFloat32Infinity(float32 f)
{
        return ((f.parts.exp == 0xFF) && (f.parts.fraction == 0x0));
}

int isFloat64Infinity(float64 d) 
{
        return ((d.parts.exp == 0x7FF) && (d.parts.fraction == 0x0));
}

int isFloat32Zero(float32 f)
{
        return (((f.binary) & 0x7FFFFFFF) == 0);
}

int isFloat64Zero(float64 d)
{
        return (((d.binary) & 0x7FFFFFFFFFFFFFFFll) == 0);
}

/**
 * @return 1 if both floats are equal - but NaNs are not recognized
 */
int isFloat32eq(float32 a, float32 b)
{
        /* a equals to b or both are zeros (with any sign) */
        return ((a.binary==b.binary) || (((a.binary | b.binary) & 0x7FFFFFFF) == 0));
}

/**
 * @return 1 if a < b - but NaNs are not recognized 
 */
int isFloat32lt(float32 a, float32 b) 
{
        if (((a.binary | b.binary) & 0x7FFFFFFF) == 0)
                return 0; /* +- zeroes */
        
        if ((a.parts.sign) && (b.parts.sign))
                /* if both are negative, smaller is that with greater binary value */
                return (a.binary > b.binary);
        
        /* lets negate signs - now will be positive numbers allways bigger than negative (first bit will be set for unsigned integer comparison) */
        a.parts.sign = !a.parts.sign;
        b.parts.sign = !b.parts.sign;
        return (a.binary < b.binary);
}

/**
 * @return 1 if a > b - but NaNs are not recognized 
 */
int isFloat32gt(float32 a, float32 b) 
{
        if (((a.binary | b.binary) & 0x7FFFFFFF) == 0)
                return 0; /* zeroes are equal with any sign */
        
        if ((a.parts.sign) && (b.parts.sign))
                /* if both are negative, greater is that with smaller binary value */
                return (a.binary < b.binary);
        
        /* lets negate signs - now will be positive numbers allways bigger than negative (first bit will be set for unsigned integer comparison) */
        a.parts.sign = !a.parts.sign;
        b.parts.sign = !b.parts.sign;
        return (a.binary > b.binary);
}

/** @}
 */