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Re: C++: EGCS perf. vs GCC




  In message <199812071914.OAA06892@y.dyson.net>you write:
  > It seems that scheduling with the P6 is sometimes counter intuitive.
Scheduling in general can be counter intuitive :-)  I've spent most of the
last two weeks with my head buried in haifa pipeline dumps for a project I'm
working on.  

  > One can often gain significant performance improvements, but those
  > improvements are very sensitive to alignment and "pipeline" state.
Yes.  We've actually got most (all?) of the recommended stuff for PPro/PII
instruction alignments.   It was a small, but noticable win.  We've also made
significant improvments to data alignments, but more work needs to be done for
the data alignments, particularly stuff in the stack.


  I suggest reviewing
  > carefully:
  > 
  > 	http://www.announce.com/agner/assem
Yup.  Definitely worth the time for anyone that is interested in optimize
Pentium, PPro/PII.


jeff


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