x86 -mno-push-args buglet?

[Jan Hubicka]

> > In case you want constant stack pointer (and no such artefacts) use
> > -maccumulate-outgong-args.  The -mpush-args isn't particulary usefull for
> > normal use IMO, but is usefull for me to test behaviour fo calls.c with
> > various settings.
> 
> Thanks for the clarification.  I jumped to the conclusion that
> -mno-push-args meant constant stack pointer and completely missed
> the existence of -maccumulate-outgoing-args.

Perhaps we can do something against that confusion, since you are most
probably not the last person falling to the trap.  I am not sure if it is
clear to omit documentation of that flag or something like that.

I doubt that it will be usefull (it brings speedups over normal settings
in some cases, but in most cases it is slower and longer than
-maccumulate-outgoing-args).
I would like to combine strengths of those two laters.  Basically 
teach -maccumulate-outgoing-args to make stack pointer non-constant
when it shortens register lifetimes or avoid copying of structures...

But I have too much thinks to do in calls.c before this one.

Honza
> 
> -- John
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