Subversion Repositories HelenOS

Compare Revisions

Ignore whitespace Rev 646 → Rev 647

/uspace/trunk/softfloat/generic/arithmetic.c
0,0 → 1,125
/*
* 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.
*/
 
#include<sftypes.h>
#include<arithmetic.h>
 
/** Add two Float32 numbers with same signs
*/
float32 addFloat32(float32 a, float32 b)
{
int expdiff;
__u32 exp1,exp2,mant1,mant2;
expdiff=a.parts.exp - b.parts.exp;
if (expdiff<0) {
if (isFloat32NaN(b)) {
//TODO: fix SigNaN
if (isFloat32SigNaN(b)) {
};
return b;
};
if (b.parts.exp==0xFF) {
return b;
}
mant1=b.parts.mantisa;
exp1=b.parts.exp;
mant2=a.parts.mantisa;
exp2=a.parts.exp;
expdiff*=-1;
} else {
if (isFloat32NaN(a)) {
//TODO: fix SigNaN
if ((isFloat32SigNaN(a))||(isFloat32SigNaN(b))) {
};
return a;
};
if (a.parts.exp==0xFF) {
return a;
}
mant1=a.parts.mantisa;
exp1=a.parts.exp;
mant2=b.parts.mantisa;
exp2=b.parts.exp;
};
if (exp1==0) {
//both are denormalized
mant1+=mant2;
if (mant1&0xF00000) {
a.parts.exp=1;
};
a.parts.mantisa=mant1;
return a;
};
// create some space for rounding
mant1<<=6;
mant2<<=6;
mant1|=0x20000000; //add hidden bit
if (exp2==0) {
--expdiff;
} else {
mant2|=0x20000000; //hidden bit
};
if (expdiff>24) {
goto done;
};
mant2>>=expdiff;
mant1+=mant2;
done:
if (mant1&0x40000000) {
++exp1;
mant1>>=1;
};
//rounding - if first bit after mantisa is set then round up
mant1+=0x20;
a.parts.exp=exp1;
a.parts.mantisa=mant1>>6;
return a;
};
 
/** Substract two float32 numbers with same signs
*/
float32 subFloat32(float32 a, float32 b)
{
};