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Re: [RFC] Builtin infrastructure change
- From: Michael Meissner <meissner at linux dot vnet dot ibm dot com>
- To: "Joseph S. Myers" <joseph at codesourcery dot com>
- Cc: Michael Meissner <meissner at linux dot vnet dot ibm dot com>, Richard Guenther <richard dot guenther at gmail dot com>, gcc-patches at gcc dot gnu dot org, dje dot gcc at gmail dot com, Richard Henderson <rth at redhat dot com>
- Date: Mon, 3 Oct 2011 20:07:21 -0400
- Subject: Re: [RFC] Builtin infrastructure change
- References: <20110913232752.GA17828@hungry-tiger.westford.ibm.com> <4E7110AE.5030400@redhat.com> <CAFiYyc1XG=q8zLjVZjaz7qNSAjTyu8V7zaq1wwa0Wwa8s1=X5Q@mail.gmail.com> <20111001000142.GA5759@hungry-tiger.westford.ibm.com> <Pine.LNX.4.64.1110011409250.2494@digraph.polyomino.org.uk>
On Sat, Oct 01, 2011 at 02:11:27PM +0000, Joseph S. Myers wrote:
> On Fri, 30 Sep 2011, Michael Meissner wrote:
>
> > Is this enough of a savings to continue on? I'm of two minds about it, one is
>
> The thing to measure is not so much memory as startup time (how long it
> takes to compile an empty source file), which is important for libraries
> and programs using a coding style with lots of small source files.
With my current changes which has modified the standard builtins to be lazy,
but I haven't yet done the machine dependent builtins, I saw a difference of
0.0022 seconds (0.0170 vs. 0.0148) on my 3 year old Intel core 2 laptop. I did
14 runs in total, and skipped the fastest 2 runs and slowest 2 runs, and then
averaged the 10 runs in the middle. I built boostrap builds with release
checking with the top of subversion head without changes and with my changes.
So at this point, I'm wondering whether it is worth it to finish the
optimization for lazy builtins.
--
Michael Meissner, IBM
5 Technology Place Drive, M/S 2757, Westford, MA 01886-3141, USA
meissner@linux.vnet.ibm.com fax +1 (978) 399-6899