Re: Probably a weird question: Lua in big endian

[Ralph Hempel <rhempel@...>]

Bogdan Marinescu wrote:
>     I'm going to put a bet on a compiled code issue with the
>     compiler optimizing a copy or move incorrectly. Probably
>     in the memcpy() or memmove() operation.
>
> (*many printfs later...*)
>
> Well I'll be. You are officially my new mentor :) You are right, 
> "memcpy" is broken in their library. Probably they try to do memcpy on 
> words instead of bytes to optimize speed, and they ignore alignment. So 
> the memcpy in newlstr (lstring.c) triggered an aligment exception (I 
> don't have any way to actually verify this, but now it's my time to bet 
> that this is the problem, since one of its arguments is not aligned).
> Thank you all for your help, and Ralph, very good call!

It's really just a good/lucky guess based on past experience.

To verify this, just take Lua out of the equation and use the
printf() to supply more information.

Do a memmove() or memcpy() and force the operands to be 32, 16, and
8 bit aligned, and see what happens when you have a misaligned
value being copied.

Now if only I could find a company that needs this kind of experience
I'd be happy :-)

Ralph