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[Bug tree-optimization/34708] Inlining heuristics issue
- From: "rguenther at suse dot de" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 8 Jan 2008 12:21:25 -0000
- Subject: [Bug tree-optimization/34708] Inlining heuristics issue
- References: <bug-34708-87@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #6 from rguenther at suse dot de 2008-01-08 12:21 -------
Subject: Re: Inlining heuristics issue
On Tue, 8 Jan 2008, hubicka at ucw dot cz wrote:
> ------- Comment #5 from hubicka at ucw dot cz 2008-01-08 12:15 -------
> Subject: Re: Inlining heuristics issue
>
> > I think we want to account PHI nodes as real copies instead (d->count +=
> > PHI_NUM_ARGS (...)) -- if they involve real operands (not VOPs).
>
> We ignore cost of MODIFY_EXPR in assumption that it will get quite
> likely optimized out (that is important for simple containers). So
> ignoring PHI nodes is consistent in this manner, but on the other hand
> PHIs are less often in containers and more likely to stay after
> inlining. I will add code for that.
Well, while register copies are likely to be optimized out, by definition
a PHI node copy cannot be optimized out (unless, of course, clever
optimization applies).
Richard.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34708