[PATCH] Avoid useless REG_EQUAL notes

[Kaveh R. Ghazi]

 > From: Roger Sayle <roger@www.eyesopen.com>
 > 
 > On Thu, 20 Feb 2003, Kaveh R. Ghazi wrote:
 > >  > 2003-02-20  Roger Sayle  <roger at eyesopen dot com>
 > >  >
 > >  > 	    * explow.c (force_reg): Avoid useless REG_EQUAL notes.
 > >  >
 > >
 > > Were you able to measure any significant differences in memory usage
 > > and/or speed?
 > >
 > > Is this appropriate/useful for 3.3?
 > 
 > I must admit that I have neither timed the code nor even counted the
 > number of times we save a REG_EQUAL note.  I just consider this a
 > code hygiene clean-up, and not worthy of 3.3 unless we discover it
 > makes an observable improvement.
 > Roger

And just how would we "discover" that unless you measure it? :-)

IHMO, a one-liner like that which gives us even just 0.5% is worth
backporting.  It adds up little by little.  But you certainly wouldn't
notice it by casual observation.

--
Kaveh R. Ghazi			ghazi@caip.rutgers.edu