Paolo
I placed extra fwprop before local-alloc as this was just before NOP
got created and after splitting.
Putting fwprop after combine is no problem - but is too early - none of
the patterns would be split at that time - preventing byte level
propagations.
As register usage as well as code size is clearly relevant here,
effective propagation before reload is the most desirable.
(PS I was impressed by fwprop code, I actually stand a chance of
understanding some of it)
best regards
-----Original Message-----
From: Paolo Bonzini <[EMAIL PROTECTED]>
To: Andy H <[EMAIL PROTECTED]>; GCC Development <gcc@gcc.gnu.org>
Sent: Thu, 21 Feb 2008 1:06 am
Subject: Re: Redundant logical operations left after early splitting
This would indicate that simplify-rtx inside fwprop is removing OR
Rx,0
but not picking up the the additionally revealed forward propagation
oppertunities
This would seem to be an avoidable limitation.
Yes, can you send me your MD patch and a simple testcase? fwprop is
supposed to be "cascading", and some bugs in cascading were already
revealed by the AVR port.
It might be even more worthwhile to try *moving* fwprop2 after combine,
then.
Paolo
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