[LLVMdev] removing unnecessary moves with 2-address machine

[Chris Lattner]

On Wed, 5 Mar 2008, Bagel wrote:
> If the legs of the add.w were reversed, the mov.w would not be
> necessary.  I have declared the add instruction to be "commutable".
> What do I have to do to cause the optimization?

Marking it commutable and describing the move as a copy instruction should 
be enough.  Are you using llvm mainline or 2.2?  Evan implemented this in 
mainline after 2.2 was released.

-Chris

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