Re: Lua5 / poor performance

["Russell Y. Webb" <rw20@...>]

> > That worked.  Performance is MUCH better now.  Thanks.
> The real problem is how portable that code is.
Hashing a block of memory that contains an IEEE 64bit floats should 
always give the same result.  Of course compiling lua with IEEE 32bit 
floats or integer number types will give a different hash for the same 
number.
Is this a problem?  Where are these hash values stored?  Only in memory 
in active tables as far as I know.  So the only real danger is if you 
somehow manage to pass a live lua_table in memory between lua instances 
with different number types.  If you do that, you're already in trouble 
since you just hosed the garbage collector and the string interring 
system.
Is there another case where it matters?  Does compiled lua bytecode 
contain pre-calculated hash values?  Isn't that case already broken if 
the number formats are assumed to change between compiling instance and 
loading instance of lua?
Russ