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added: using NaN flag in method Big::ToDouble() and Big::FromDouble()

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changed: some cosmetic changes to get rid of warnings generated by 
         MS Visual 2008 when warning level is 4
changed: names of labels in asm code: p to ttmath_loop, end to ttmath_end
         p2 to ttmath_loop2
         Robert Muir reported that there was a confict with boost::end


git-svn-id: svn://ttmath.org/publicrep/ttmath/trunk@156 e52654a7-88a9-db11-a3e9-0013d4bc506e
This commit is contained in:
Tomasz Sowa
2009-06-11 02:31:41 +00:00
parent bb2583649e
commit d789ac5396
8 changed files with 127 additions and 61 deletions
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29
CHANGELOG
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@@ -1,4 +1,4 @@
Version 0.8.5 prerelease (2009.05.15):
Version 0.8.5 prerelease (2009.06.11):
* fixed: Big::Mod(x) didn't correctly return a carry
and the result was sometimes very big (even greater than x)
* fixed: global function Mod(x) didn't set an ErrorCode object
@@ -7,7 +7,7 @@ Version 0.8.5 prerelease (2009.05.15):
* changed: function Sin(x) to Sin(x, ErrorCode * err=0)
when x was very big the function returns zero
now it sets ErrorCode object to err_overflow
and the result is undefined
and the result has a NaN flag set
the same is to Cos() function
* changed: PrepareSin(x) is using Big::Mod() now when reducing 2PI period
should be a little accurate especially on a very big 'x'
@@ -29,6 +29,31 @@ Version 0.8.5 prerelease (2009.05.15):
uint SubVector(const uint * ss1, const uint * ss2, uint ss1_size, uint ss2_size, uint * result)
three forms: asm x86, asm x86_64, no-asm
those methods are used by the Karatsuba multiplication algorithm
* added: to Big<> class: support for NaN flag (Not a Number)
bool Big::IsNan() - returns true if the NaN flag is set
void Big::SetNan() - sets the NaN flag
The NaN flag is set by default after creating an object:
Big<1, 2> a; // NaN is set (it means the object has not a valid number)
std::cout << a; // cout gives "NaN"
a = 123; // now NaN is not set
std::cout << a; // cout gives "123"
The NaN is set if there was a carry during calculations
a.Mul(very_big_value); // a will have a NaN set
The NaN is set if an argument is NaN too
b.SetNan();
a.Add(b); // a will have NaN because b has NaN too
If you try to do something on a NaN object, the result is a NaN too
a.SetNan();
a.Add(2); // a is still a NaN
The NaN is set if you use incorrect arguments
a.Ln(-10); // a will have the NaN flag
The only way to clear the NaN flag is to assign a correct value or other correct object,
supposing 'a' has NaN flag, to remove the flag you can either:
a = 10;
a.FromInt(30);
a.SetOne();
a.FromBig(other_object_without_nan);
etc.
Version 0.8.4 (2009.05.08):