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From: Richard Guenther <rguenther@suse.de>
To: Paolo Carlini <paolo.carlini@oracle.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] Decrease integer-share-limit
Date: Thu, 16 Aug 2012 14:46:00 -0000	[thread overview]
Message-ID: <alpine.LNX.2.00.1208161643190.28649@zhemvz.fhfr.qr> (raw)
In-Reply-To: <502D057A.9080302@oracle.com>

On Thu, 16 Aug 2012, Paolo Carlini wrote:

> Hi,
> 
> On 08/16/2012 03:39 PM, Richard Guenther wrote:
> > This decreases the integer-share-limit to make sure the TREE_VEC we
> > allocate for the small cached integers has a reasonable size for
> > our GC memory allocator.
> Out of curiosity (just in case you hav two spare minutes) do you have any idea
> why this is so? I mean, naively one would think that allowing for any 8 bit
> constant would be a nice idea; puzzlingly, however the comment in the code
> says just "experimentation". I'm wondering if tweaking a bit the memory
> allocator itself could allow for the full 8 bit range without a big memory
> waste...

The GC memory allocator works on "pages", there are not pages of
arbitrary size but only power-of-two sizes.  It's hard to improve
the allocator here.

Richard.

  reply	other threads:[~2012-08-16 14:46 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-16 13:41 Richard Guenther
2012-08-16 14:37 ` Paolo Carlini
2012-08-16 14:46   ` Richard Guenther [this message]
2012-08-16 14:59     ` Jakub Jelinek
2012-08-17  7:52       ` Richard Guenther

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