[Python-Dev] Re: [Patches] PC\config.[hc] changes for Win64

Neil Hodgson nhodgson@bigpond.net.au
Tue, 9 May 2000 13:35:16 +1000

> To help me understand the significance of win64 vs. win32, can you
> list the major differences?  I thought that the main thing was that
> pointers are 64 bits, and that otherwise the APIs are the same.  In
> fact, I don't know if WIN64 refers to Windows running on 64-bit
> machines (e.g. Alphas) only, or that it is possible to have win64 on a
> 32-bit machine (e.g. Pentium).

   The 64 bit pointer change propagates to related types like size_t and
window procedure parameters. Running the 64 bit checker over Scintilla found
one real problem and a large number of strlen returning 64 bit size_ts where
only ints were expected.

   64 bit machines will continue to run Win32 code but it is unlikely that
32 bit machines will be taught to run Win64 code.

   Mixed operations, calling between 32 bit and 64 bit code and vice-versa
will be fun. Microsoft (unlike IBM with OS/2) never really did the right
thing for the 16->32 bit conversion. Is there any information yet on mixed
size applications?