search for: pseudocopy

...ad of always adding plain copy. > > Would that work for you? You can’t legitimately copy from vector to scalar. It conceptually doesn’t work, and going through memory doesn’t help. The use instruction needs to be rewritten to (in the worst case) scalarize the operation for every workitem. A pseudocopy would still be some illegal operation which cannot exist which would need to be guaranteed to be removed, so I don’t think this would be any cleaner than allowing the illegal copies. > >> So far I’ve worked around this by lying and reporting all of the invalid source register banks as l...

Hi, Some operations on AMDGPU require operands which must be in a register bank that is impossible to copy from another. The operation needs to be rewritten in a complex way to avoid the illegal copy. Currently if I correctly report the required register banks in the operand mapping, RegBankSelect happily inserts the illegal copies, somehow concluding they are cheap (I would at least hope