Why doesn't my processor have built-in BigInt support?

Question

As far as I understood it, BigInts are usually implemented in most programming languages as arrays containing digits, where, eg.: when adding two of them, each digit is added on

Answer 1

BigInt: the fundamental function required is: Unsigned Integer Multiplication, add previous high order I wrote one in Intel 16bit assembler, then 32 bit... C code is usually fast enough .. ie for BigInt you use a software library. CPUs (and GPUs) are not designed with unsigned Integer as top priority.

If you want to write your own BigInt...

Division is done via Knuths Vol 2 (its a bunch of multiply and subtract, with some tricky add-backs)

Add with carry and subtract are easier. etc etc

I just posted this in Intel: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx SSE4 is there a BigInt LIbrary?

i5 2410M processor I suppose can NOT use AVX [AVX is only on very recent Intel CPUs] but can use SSE4.2

Is there a BigInt Library for SSE? I Guess I am looking for something that implements unsigned integer

PMULUDQ (with 128-Bit operands) PMULUDQ __m128i _mm_mul_epu32 ( __m128i a, __m128i b)

and does the carries.

Its a Laptop so I cant buy an NVIDIA GTX 550, which isnt so grand on unsigned Ints, I hear. xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx