[ODE] ODE on x86_64 machine

[Jon Watte (ODE)]

The standard guarantees that longs are always >= ints. Int is "the 
natural integer machine word" which may or may not be the same size as a 
pointer. Up until recently, it has always been true that long can fit a 
pointer; that was formalized in the lp64 programming model where long 
and pointer are 64 bits; int are 32; short are 16 and char are 8 (else, 
how could you get one type per natural alignment size?)

Unfortunately, Microsoft decided to make "long" and "int" be 32 bits, 
and "long long" be 64 bits in their 64-bit compiler. This means that the 
only standard types you can depend on are now not built-in, but come 
from the system includes. size_t (unsigned) and ssize_t/ptrdiff_t (signed).

Cheers,

			/ h+


Alex Brown wrote:
> I thought longs were supposed to always be 32 bit and the ints were the 
> ones that changed based on the architecture
> 
> On 2/21/06, *Jon Watte (ODE)* < hplus-ode at mindcontrol.org 
> <mailto:hplus-ode at mindcontrol.org>> wrote:
> 
> 
> 
>     Simon Su wrote:
> 
>      > ODE source code will compile on x86_64 with just
>      > editing the file ode/test/test_space.cpp, in line 127
>      > and 128, by changing int to long.
> 
>     If you're making 64-bit edits, I suggest using a specific ptr_int type
>     (such as size_t or ssize_t) rather than "long". Microsoft, in their
>     infinite wisdom, decided that "long" is 32 bits even on 64-bit
>     platforms, breaking all existing lp64 code :-(
> 
>      > Is there a type that I can change udword to for x86_64
>      > to compile just like the int to long change?
> 
>     Someone looked at this a while back, and got reasonable results, IIRC.
>     You may want to search the list archives for "udword" and "opcode".
> 
>     Cheers,
> 
>                             / h+
> 
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