MAMEWorld Forums - Programming - Re: mame 0.163 on ARM32

> does the r2dx_v33_r2 set work properly? it has entirely different protection.
>
> you're probably on your own for debugging the main set tho.. it really sounds like an
> endian issue, but like RB said, I thought the endian on the ARM chips was the same as
> a PC.

Adding to that, I'm quite sure raiden2.c does work on PowerPC, which is opposite-endian to Intel. I distinctly remember fixing it for MacBox360 (and the problems were in the ROM loading and sprite decryption, the protection code was just fine)

Maybe the ARM compiler does int-float casting in a different way and it's causing an integer overflow to occur somewhere that doesn't occur on Intel (e.g. by doing a float conversion after a multiplication instead of before it) Remember that signed integer overflow is undefined behaviour in C/C++; it's quite legal for one compiler to do the conversion before multiplication and another to do the conversion after, depending on which is faster on a given architecture.

On a related note one of the Yamaha FM chips doesn't work properly on PowerPC builds, and it's probably not endian-related per se because the code never casts between different integer sizes. It does, however, cast back and forth between ints and doubles all over the place just like raiden2cop.c does.