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Re: [tree-ssa-branch] Optimizing non-SIMPLE trees
> On Sun, Aug 11, 2002 at 11:06:49AM +0200, Jan Hubicka wrote:
> > I guess it is a must to constant propagate just before
> > RTL generation, that should fix the problem.
> Well, just before builtin expansion anyway. In many cases we
> would be better off expanding to trees instead of rtl. Some
> of them don't make sense to do that but...
> > Similary I think it is neccesary to put in the memories when used
> > exactly once, that should solve builtin_stdarg.
> Making the last parameter of stdarg a reference parameter might
> solve it. Alternately, is the last parameter even used other
> than for checking that it is in fact the last parameter? If not,
> then the front end could do the error check and expand that
> builtin right away.
Yes. At least with current RTL generation scheme probably propagating
memoryies is bad idea. Our current RTL generator hides memories as well
to help CSE when optimizing. I remember seeing few cases in i386
backend where knowing whether the operand is memory or not would help
but these are rare. Definitly much more rare than the builtin expansion