On 06/22/16 20:49, Jeff Law wrote: > On 06/21/2016 11:12 PM, Bernd Edlinger wrote: > >> >> What I wanted to say here, is that lra goes thru several iterations, >> changes something in the register allocation that has an impact on the >> frame layout, typically 4-5 times, and calls INITIAL_ELIMINATION_OFFSET >> 3-4 times in a row, and in the results must be consistent in each >> iteration to be usable. >> >> So I am open to suggestions, how would you explain this idea in the doc? > I'm not sure :( The goal is still the same, you're trying to separate > the O(n) from the O(1) operations. So you want the COMPUTE_FRAME_LAYOUT > hook to be called once for things which don't vary and > INITIAL_ELIMINATION_OFFSET multiple times for things that do vary. > > Thinking more about this, which port has has a particularly expensive > INITIAL_ELIMINATION_OFFSET? >
I'd bet on mips for instance. Bernd.
