Problems dividing 64 bits in x86 Assembly

Question

I keep getting \'Program received signal SIGFPE, Arithmetic exception\' when dividing in x86 Assembly. It\'s confusing because the answer should be smaller than a 64 bit ans

Answer 1

The arithmetic exception is "Integer overflow", from the #DE hardware divide exception! Which is normal or expected, because your result is bigger than 32-bit number.

Remember: the quotient of 64 bit / 32-bit division is only a 32 bit register (EAX). The EDX output is the remainder, not high half of the quotient. The operand-size of div %ebx is 32-bit; only the dividend is 64-bit.

Intel's datasheet has a useful table: