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Ignore whitespace Rev 730 → Rev 731

/uspace/trunk/softfloat/generic/add.c
0,0 → 1,229
/*
* 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<add.h>
#include<comparison.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 & FLOAT32_HIDDEN_BIT_MASK ) {
/* result is not denormalized */
a.parts.exp = 1;
};
a.parts.mantisa = mant1;
return a;
};
mant1 |= FLOAT32_HIDDEN_BIT_MASK; //add hidden bit
 
if (exp2 == 0) {
/* second operand is denormalized */
--expdiff;
} else {
/* add hidden bit to second operand */
mant2 |= FLOAT32_HIDDEN_BIT_MASK;
};
/* create some space for rounding */
mant1 <<= 6;
mant2 <<= 6;
if (expdiff > 24) {
goto done;
};
mant2>>=expdiff;
mant1+=mant2;
done:
if (mant1 & (FLOAT32_HIDDEN_BIT_MASK << 6) ) {
++exp1;
mant1 >>= 1;
};
/* rounding - if first bit after mantisa is set then round up */
mant1 += (0x1 << 5);
if (mant1 & (FLOAT32_HIDDEN_BIT_MASK << 6)) {
++exp1;
mant1 >> =1;
};
a.parts.exp = exp1;
/*Clear hidden bit and shift */
a.parts.mantisa = ((mant1>>6) & (~FLOAT32_HIDDEN_BIT_MASK)) ;
return a;
}
 
 
/** Add two Float64 numbers with same signs
*/
float64 addFloat64(float64 a, float64 b)
{
int expdiff;
__u64 exp1,exp2,mant1,mant2;
expdiff=a.parts.exp - b.parts.exp;
if (expdiff<0) {
if (isFloat64NaN(b)) {
//TODO: fix SigNaN
if (isFloat64SigNaN(b)) {
};
 
return b;
};
/* b is infinity and a not */
if (b.parts.exp==0x8FF) {
return b;
}
mant1=b.parts.mantisa;
exp1=b.parts.exp;
mant2=a.parts.mantisa;
exp2=a.parts.exp;
expdiff*=-1;
} else {
if (isFloat64NaN(a)) {
//TODO: fix SigNaN
if ((isFloat64SigNaN(a))||(isFloat64SigNaN(b))) {
};
return a;
};
/* a is infinity and b not */
if (a.parts.exp == 0x8FF) {
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 & FLOAT64_HIDDEN_BIT_MASK) {
/* result is not denormalized */
a.parts.exp = 1;
};
a.parts.mantisa = mant1;
return a;
};
/* add hidden bit - mant1 is sure not denormalized */
mant1 |= FLOAT64_HIDDEN_BIT_MASK;
 
/* second operand ... */
if (exp2 == 0) {
/* ... is denormalized */
--expdiff;
} else {
/* is not denormalized */
mant2 |= FLOAT64_HIDDEN_BIT_MASK;
};
/* create some space for rounding */
mant1 <<= 6;
mant2 <<= 6;
if (expdiff > 53) {
goto done;
};
mant2 >>= expdiff;
mant1 += mant2;
done:
if (mant1 & (FLOAT64_HIDDEN_BIT_MASK << 6) ) {
++exp1;
mant1 >>= 1;
};
/* rounding - if first bit after mantisa is set then round up */
mant1 += (0x1 << 5);
if (mant1 & (FLOAT64_HIDDEN_BIT_MASK << 6)) {
++exp1;
mant1 >> =1;
};
a.parts.exp = exp1;
/*Clear hidden bit and shift */
a.parts.mantisa = ( (mant1 >>6 ) & (~ (FLOAT64_HIDDEN_BIT_MASK)));
return a;
}