On Sunday 07 August 2005 14:07, Björn Haase wrote: > I think that such kind of optimization could help very much for my > fractional numerics library where some functions tend to be lengthy but use > very few registers. I would be willing to try to implement it. > > I can imagine two possible approaches for addressing the issue. One that > only needs adaptions in the back-end and implements the optimization only > for one target and then one more generic solution. > > > 1.) target specific approach
I wouldn't do that... > 2.) generic > > One could of course try to store the information on register usage > somewhere in the tree structure. ...but I wouldn't do this either. You could add a HARD_REG_SET to cgraph_rtl_info and teach caller-save.c about it. I'm sure there are lots of other places that would require changes, but I have no idea how much, or if it is at all feasible. In any case, you should assume that it is a much bigger job than just modifying the call expander. Gr. Steven
