Currently I'm working on a C/C++ code-base which is fairly portable, it can compile on most Unix like systems as well as MS-Windows (MSVC), using various popular compilers.

Previously I've found testing on different OS's and architectures can help find obscure bugs or bad assumptions.

I worry with the dominance of X86/IA64 our code-base may unknowingly become less portable.

Besides testing on a big-endian system (to find obvious errors with big/little endian), are there some architectures which have characteristics making them better for stress-testing software portability.

Examples of possible differences.

• different endian.
• different behavior when threading.
• behavior of stack memory.
• size of primitive types (char, short, int, long, float... etc).
• alignment/padding of structs (which might hide errors).
• difference in optimizations made by the compiler.

Are there some architectures which have more significant differences to X86/IA64, making them better candidates for exposing code portability issues? (and have C/C++ compilers and libraries - libc, libstdc++).

Asking because its a sizable time-investment to setup a new system, even if its emulated.

in case its not clear what I mean by processor-architectures, eg (x86, ia64, mips, risc, arm, m68k, ppc, itanium)