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Re: Multiplications on Pentium 4
- To: dewar at gnat dot com
- Subject: Re: Multiplications on Pentium 4
- From: Jan Hubicka <jh at suse dot cz>
- Date: Sat, 8 Sep 2001 18:17:01 +0200
- Cc: jh at suse dot cz, pfk at fuchs dot offl dot uni-jena dot de, gcc at gcc dot gnu dot org
- References: <20010908153112.8DAF1F2B62@nile.gnat.com>
> It's amazing how poor the scaling lea's are on the Pentium 4, probably they
> should never be generated.
They are no worse than shifts - actually LEA is simply translated to trivial
operations.
It is amazing how bad shifts are :) but replacing them by ADDs is not always
solution due to trace cache misses.
Honza
>
> (at least you could take care of this by simply removing them :-)