Is it possible, then how to?
I see in Beyond3D they bench using 5-way mad so off course the performance improved 20 percent
Compiler tries to use all 5-units as much as possible. One main problem with code generation in Brook+ IL is that a mad instruction in Brook+ doesn't generate mad in ISA.
One way to resolve this problem is to change all mul_ieee instructions to mul in IL generated by brcc. Of course, if you want to tune your code further to maximize 5-way usage, you can hand-tune the IL.
Can you provide an example?
It is a fine topic btw
I have a question regard this. If I change MUL_IEEE to a MUL instruction the compiler generates MAD instructions. However acording to the RV770 ISA there are two MAD instructions, one for MULADD and one for MULADD_IEEE. Why doesn't the IL compiler generates MULADD_IEEE instructions when MUL_IEEE is used?
Also, using double precision Brook+ generates DMUL and DADD instructions, but then the IL compiler doesn't fuse them into MULADD_64. Is this normal? Is there any workaround?
You could always edit the generated IL, I changed the HLSL library to do it, I have to go now, but if you search in this forum you will find a better description of how to do it.
Retrieving data ...