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Re: Forcing REG_DEAD?


Richard Hulme <peper03@yahoo.com> writes:
> Is there any way of preventing the compiler going with the indirect 
> alternative?  Can a 'parallel' match be defined in the machine 
> description that indicates the '(set (reg/f:HI...' should be discarded?

No, that wouldn't work.  The register is only dead if both combinations
take place.  Neither combine nor the target code knows when doing the
first combination whether all other uses of the register can also be
combined.

Combine just isn't designed for this kind of global optimisation.
It sounds like something that fwprop should do instead.

Thanks,
Richard


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