Using the VFU?

turkeyman · Post by **turkeyman** » Sat Jun 25, 2005 12:55 pm

Does anyone know anything about accessing the VFU?

From what i know, its a similar coprocessor to the PS2's VU0, but way better. It supposedly has less latency, can perform operations from the general registers (saves on loads of qmtc2/qmfc2 instructions), and has a dot product!! :P

Does the inline assembler know aything about the coprocessor instructions? (i'm not really sure how GCC is put together, or how it knows about its architectures assembly.. sorry, i'm not really a linux dude :/)

ReKleSS · Post by **ReKleSS** » Sat Jun 25, 2005 12:58 pm

The opcodes and stuff to control the vfu are in the toolchain. Take a look at the diffs for binutils/binutils-psp/opcodes/mips-opc.c.diff if you want to see them. The problem is, the compiler chokes on them and nobody knows how to initialise the vfu just yet. So... you can't do anything with it yet.
-ReK
(this is my understanding of the current situation, anyway)

Post by **mrbrown** » Sat Jun 25, 2005 3:25 pm

Although the VFPU opcodes are listed in mips-opc.c, they aren't supported by the assembler yet (and are only partially supported by the disassembler). I'm still working on getting them supported, but it's a lot of work.