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.
changed: renamed macro CONSTANTSGENERATOR to TTMATH_CONSTANTSGENERATOR
git-svn-id: svn://ttmath.org/publicrep/ttmath/trunk@152 e52654a7-88a9-db11-a3e9-0013d4bc506e
void UInt::Mul3Big(const UInt<value_size> & ss2, UInt<value_size*2> & result)
a new multiplication algorithm: Karatsuba multiplication,
on a vector UInt<100> with all items different from zero this algorithm is faster
about 3 times than Mul2Big(), and on a vector UInt<1000> with all items different from
zero this algorithm is faster more than 5 times than Mul2Big()
(measured on 32bit platform with GCC 4.3.3 with -O3 and -DTTMATH_RELEASE)
added: uint MulFastest(const UInt<value_size> & ss2)
void MulFastestBig(const UInt<value_size> & ss2, UInt<value_size*2> & result)
those methods are trying to select the fastest multiplication algorithm
changed: uint Mul(const UInt<value_size> & ss2, uint algorithm = 100)
void MulBig(const UInt<value_size> & ss2, UInt<value_size*2> & result, uint algorithm = 100)
those methods by default use MulFastest() and MulFastestBig()
changed: changed a little Mul2Big() to cooperate with Mul3Big()
changed: names of methods in macros TTMATH_LOG()
added: uint AddVector(const uint * ss1, const uint * ss2, uint ss1_size, uint ss2_size, uint * result)
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
git-svn-id: svn://ttmath.org/publicrep/ttmath/trunk@148 e52654a7-88a9-db11-a3e9-0013d4bc506e
changed: UInt::SubInt() in no-asm code is a little faster now
changed: small cosmetic changes in commentaries
deleted: some debug #ifdef's from UInt::Div() (in no-asm code)
git-svn-id: svn://ttmath.org/publicrep/ttmath/trunk@136 e52654a7-88a9-db11-a3e9-0013d4bc506e
all the methods which are using assembler code have been
rewritten to no-asm forms, now we have:
1. asm for x86 file: ttmathuint_x86.h
2. asm for x86_64 file: ttmathuint_x86_64.h
3. no asm file: ttmathuint_noasm.h
(it's used when macro TTMATH_NOASM is defined)
The third form can be used on x86 and x86_64 as well and
on other platforms with a little effort.
(Temporarily I left there some '#ifdef's for debugging.)
git-svn-id: svn://ttmath.org/publicrep/ttmath/trunk@126 e52654a7-88a9-db11-a3e9-0013d4bc506e
Tomasz Sowa