On Sun, Oct 16, 2016 at 05:05:17PM -0500, Daniel Santos wrote:
> >>The insn that's getting deleted is 75, where RCX is set. I'm starting
> >>to think that maybe df_analyze() presumes that my call (to the stub) is
> >>invalidating RCX, although it does not.
> >It looks like you don't use add_function_usage_to on the call insn?
> Oddly enough, I had forgotten to call add_function_usage_to() on my save
> stub (which I didn't post), but not the restore stub. So thanks for that
> psychic intervention. :) But if you look carefully, it's there, although
> it's hard to read because of all the line wrapping:
> (expr_list (use (reg:DI 4 si))
But shouldn't it be marked as using RCX as well?
> So the bright side is that I'm learning a lot more about
> gcc internals! Which is probably my main goal of this exercise.