[LLVMdev] Mips -> DLX Modifications as Target

[Anton Korobeynikov]

Hello, Sean

> Mainly the problem is if the constant is specified as negative,  and
> when 0-constant can fit in 16-bits unsigned, wish it to use the SUBui
> instruction.
sub reg, imm is canonicalized in LLVM into add imm, -imm. You need to
"replay" this back via some "pipehole" pattern.

You might find ARM target useful as an example.

-- 
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University