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Re: RFC: Simplify rules for ctz/clz patterns and RTL

From: "Andrew Pinski" <pinskia at gmail dot com>
To: "Zack Weinberg" <zack at codesourcery dot com>
Cc: "Segher Boessenkool" <segher at kernel dot crashing dot org>, gcc at gcc dot gnu dot org
Date: Wed, 15 Aug 2007 11:44:28 -0700
Subject: Re: RFC: Simplify rules for ctz/clz patterns and RTL
References: <46BD5B17.9080009@codesourcery.com> <62defd1ecb56eda092535c7147d5d3c6@kernel.crashing.org> <46C34786.3@codesourcery.com>

On 8/15/07, Zack Weinberg <zack@codesourcery.com> wrote:
> Is popcount really slow on PowerPC?  (Compared to clz?)
popcount is really popcount in bytes and then you do a multiple to get
the real popcount.  This is why it is slower than count leading zeros.
 Also popcount does not exist in most powerpc's while count leading
zeros exist in all.

Thanks,
Andrew Pinski

Follow-Ups:
- Re: RFC: Simplify rules for ctz/clz patterns and RTL
  - From: Zack Weinberg

References:
- RFC: Simplify rules for ctz/clz patterns and RTL
  - From: Zack Weinberg
- Re: RFC: Simplify rules for ctz/clz patterns and RTL
  - From: Segher Boessenkool
- Re: RFC: Simplify rules for ctz/clz patterns and RTL
  - From: Zack Weinberg

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