------- Comment #21 from ebotcazou at gcc dot gnu dot org  2010-01-07 07:39 
-------
> Because at the point of propagation, propagated constant _is_ equal to
> whatever REG_EQUAL says. Removing this note at the point of propagation
> would IMO disable much more optimization opportunities.

What kind of opportunities exactly?  The insn is more precise that the note.

> BTW: This fixup happens in very rare occasions. Although the loop looks scary,
> it usually processes very small BBs (I didn't found the case where more than
> one assignment was moved at the top of the test BB.

Yes, but removing REG_EQUAL notes pointing to constants seems a bad idea.


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