Message-ID: <19990226143506.26990@atrey.karlin.mff.cuni.cz>
Date: Fri, 26 Feb 1999 14:35:06 +0100
From: Jan Hubicka <hubicka AT atrey DOT karlin DOT mff DOT cuni DOT cz>
To: pgcc AT delorie DOT com
Cc: johnny AT entity DOT netcologne DOT de
Subject: Re: loop unrolling
References: <199902241423 DOT JAA29290 AT envy DOT delorie DOT com> <19990225235232 DOT C20417 AT cerebro DOT laendle>
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In-Reply-To: <19990225235232.C20417@cerebro.laendle>; from Marc Lehmann on Thu, Feb 25, 1999 at 11:52:32PM +0100
Reply-To: pgcc AT delorie DOT com

> Have you made a benchmark? (I haven't). Scheduling is often unintuitive.
> 
> It might indeed be the case that gcc's scheduling constants are suboptimal
> for some cases. One of the problms is that the normal list scheduler
> isn't up to scheduling for superscalar architectures (pentiumpro), while
> the scheduling parameters aren't tuned for the haifa scheduler.
Just curious:
I still hear, that haifa scheduler is ready for superscalar CPUs and
normal not.
Why? The definitions are same, only haifa can do scheduling more agresivly.
Or I am wrong?
(except the MD_SCHED hacks. Is that the superscalar feature?)

Honza