forums.ps2dev.org

[Shazz]

Hello,

I'm looking for VU bitwise logic operations instructions, I understood that the VU has an iALU which is accessible thru the lower instructions, and as a standard integer ALU I hoped to find instructions like right and left bit shifting, XOR, bit rotating... And it seems there is only add, sub, and & or.... is it a really limited ALU ????

Or simply the VU is really not a good way to handle bitwise operations... as the MIPS can be...

Is by nature the VU1 only dedicated to work on objects values (vertices, faces, lightsourcing...) and not for example on texture data/pixel values like a bumpmap for example ? (assuming the data can be stored in the VU1 memory of course)
_________________
- TiTAN Art Division -
http://www.titandemo.org

[blackdroid]

The VU's are vector ALU's ( lets expand VU to Vector Unit ) wich where made to perfom 4x floats vector calculations well, so yes emphasis is on vector operations.

you can generate 32bit data/textures pretty nicely with the vu's. but I would not say its something they where design for. Also you have to remember that the iALU only handles 16bit integers, making it less usable for basically anything else than loop counters ( ok that might be abit harsh, but probably in lieu with design decisions ).
_________________
Kung VU

[Shazz]