Question

Has anyone here used GMP? http://gmplib.org/ Would you recommend it if I am writing C programs to work with big numbers?

Answer 1

I looked at the source and all of the number-crunching parts are in some arcane assembly language

Answer 2

assembly language?

Answer 3

do { \
if (__builtin_constant_p (bh) && (bh) == 0) \
__asm__ ("{a%I4|add%I4c} %1,%3,%4\n\t{aze|addze} %0,%2" \
: "=r" (sh), "=&r" (sl) : "r" (ah), "%r" (al), "rI" (bl));\
else if (__builtin_constant_p (bh) && (bh) == ~(UDItype) 0) \
__asm__ ("{a%I4|add%I4c} %1,%3,%4\n\t{ame|addme} %0,%2" \
: "=r" (sh), "=&r" (sl) : "r" (ah), "%r" (al), "rI" (bl));\
else \
__asm__ ("{a%I5|add%I5c} %1,%4,%5\n\t{ae|adde} %0,%2,%3" \
: "=r" (sh), "=&r" (sl) \
: "r" (ah), "r" (bh), "%r" (al), "rI" (bl)); \
} while (0)

Answer 4

ah, bh, al, bl are byte register

Answer 5

will they help me multiply two big numbers together?

Answer 6

ah, bh, al, bl are only 8 bit registers.. They can only hold a number from 0 to 256

Answer 7

You need maybe 32 bit registers like EAX ,EBX, ECX, EDX.. there are even 64 bit registers but i dont know what they are.

Answer 8

I just want to multiply two large numbers

Answer 9

how large are these numbers?

Answer 10

If its in C, cant you use a Unsigned Long Long or something like that??

Answer 11

64 bit registers are called RAX, RBX RCX RDX.. that should make some big numbers.

Answer 12

18446744073709551617