26,8 → 26,9 |
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
*/ |
|
#include "sftypes.h" |
#include "sub.h" |
#include<sftypes.h> |
#include<sub.h> |
#include<comparison.h> |
|
/** Subtract two float32 numbers with same signs |
*/ |
48,7 → 49,7 |
return b; |
}; |
|
if (b.parts.exp==0xFF) { |
if (b.parts.exp == FLOAT32_MAX_EXPONENT) { |
b.parts.sign=!b.parts.sign; /* num -(+-inf) = -+inf */ |
return b; |
} |
63,13 → 64,13 |
} else { |
if (isFloat32NaN(a)) { |
//TODO: fix SigNaN |
if ((isFloat32SigNaN(a))||(isFloat32SigNaN(b))) { |
if (isFloat32SigNaN(a) || isFloat32SigNaN(b)) { |
}; |
return a; |
}; |
|
if (a.parts.exp==0xFF) { |
if (b.parts.exp==0xFF) { |
if (a.parts.exp == FLOAT32_MAX_EXPONENT) { |
if (b.parts.exp == FLOAT32_MAX_EXPONENT) { |
/* inf - inf => nan */ |
//TODO: fix exception |
result.binary = FLOAT32_NAN; |
97,20 → 98,134 |
return result; |
}; |
|
// create some space for rounding |
/* add hidden bit */ |
mant1 |= FLOAT32_HIDDEN_BIT_MASK; |
|
if (exp2 == 0) { |
/* denormalized */ |
--expdiff; |
} else { |
/* normalized */ |
mant2 |= FLOAT32_HIDDEN_BIT_MASK; |
}; |
|
/* create some space for rounding */ |
mant1<<=6; |
mant2<<=6; |
|
mant1|=0x20000000; //add hidden bit |
if (expdiff > FLOAT32_MANTISA_SIZE + 1) { |
goto done; |
}; |
|
mant1 = mant1 - (mant2 >> expdiff); |
done: |
//TODO: find first nonzero digit and shift result and detect possibly underflow |
while ((exp1 > 0) && (!(mant1 & (FLOAT32_HIDDEN_BIT_MASK << 6 )))) { |
--exp1; |
mant1 <<= 1; |
/* TODO: fix underflow - mant1 == 0 does not necessary means underflow... */ |
}; |
|
/* rounding - if first bit after mantisa is set then round up */ |
mant1 += 0x20; |
|
if (mant1 & (FLOAT32_HIDDEN_BIT_MASK << 7)) { |
++exp1; |
mant1 >>= 1; |
}; |
|
/*Clear hidden bit and shift */ |
result.parts.mantisa = ((mant1 >> 6) & (~FLOAT32_HIDDEN_BIT_MASK)); |
result.parts.exp = exp1; |
|
return result; |
} |
|
/** Subtract two float64 numbers with same signs |
*/ |
float64 subFloat64(float64 a, float64 b) |
{ |
int expdiff; |
__u32 exp1, exp2; |
__u64 mant1, mant2; |
float64 result; |
|
result.d = 0; |
|
expdiff = a.parts.exp - b.parts.exp; |
if ((expdiff < 0 ) || ((expdiff == 0) && (a.parts.mantisa < b.parts.mantisa))) { |
if (isFloat64NaN(b)) { |
//TODO: fix SigNaN |
if (isFloat64SigNaN(b)) { |
}; |
return b; |
}; |
|
if (b.parts.exp == FLOAT64_MAX_EXPONENT) { |
b.parts.sign = !b.parts.sign; /* num -(+-inf) = -+inf */ |
return b; |
} |
|
result.parts.sign = !a.parts.sign; |
|
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; |
}; |
|
if (a.parts.exp == FLOAT64_MAX_EXPONENT) { |
if (b.parts.exp == FLOAT64_MAX_EXPONENT) { |
/* inf - inf => nan */ |
//TODO: fix exception |
result.binary = FLOAT64_NAN; |
return result; |
}; |
return a; |
} |
|
result.parts.sign = a.parts.sign; |
|
mant1 = a.parts.mantisa; |
exp1 = a.parts.exp; |
mant2 = b.parts.mantisa; |
exp2 = b.parts.exp; |
}; |
|
if (exp1 == 0) { |
//both are denormalized |
result.parts.mantisa = mant1 - mant2; |
if (result.parts.mantisa > mant1) { |
//TODO: underflow exception |
return result; |
}; |
result.parts.exp = 0; |
return result; |
}; |
|
/* add hidden bit */ |
mant1 |= FLOAT64_HIDDEN_BIT_MASK; |
|
if (exp2==0) { |
/* denormalized */ |
--expdiff; |
} else { |
mant2|=0x20000000; //hidden bit |
/* normalized */ |
mant2 |= FLOAT64_HIDDEN_BIT_MASK; |
}; |
|
if (expdiff>24) { |
/* create some space for rounding */ |
mant1 <<= 6; |
mant2 <<= 6; |
|
if (expdiff > FLOAT64_MANTISA_SIZE + 1) { |
goto done; |
}; |
|
117,23 → 232,24 |
mant1 = mant1-(mant2>>expdiff); |
done: |
//TODO: find first nonzero digit and shift result and detect possibly underflow |
while ((exp1>0)&&(!(mant1&0x20000000))) { |
exp1--; |
while ((exp1 > 0) && (!(mant1 & (FLOAT64_HIDDEN_BIT_MASK << 6 )))) { |
--exp1; |
mant1 <<= 1; |
/* TODO: fix underflow - mant1 == 0 does not necessary means underflow... */ |
}; |
|
//rounding - if first bit after mantisa is set then round up |
/* rounding - if first bit after mantisa is set then round up */ |
mant1 += 0x20; |
|
if (mant1&0x40000000) { |
if (mant1 & (FLOAT64_HIDDEN_BIT_MASK << 7)) { |
++exp1; |
mant1>>=1; |
}; |
|
result.parts.mantisa = ((mant1&(~0x20000000))>>6); /*Clear hidden bit and shift */ |
/*Clear hidden bit and shift */ |
result.parts.mantisa = ((mant1 >> 6) & (~FLOAT64_HIDDEN_BIT_MASK)); |
result.parts.exp = exp1; |
|
return result; |
}; |
} |
|