This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH] Fix PR61221
- From: Jeff Law <law at redhat dot com>
- To: Richard Biener <rguenther at suse dot de>, gcc-patches at gcc dot gnu dot org
- Date: Tue, 20 May 2014 10:47:44 -0600
- Subject: Re: [PATCH] Fix PR61221
- Authentication-results: sourceware.org; auth=none
- References: <alpine dot LSU dot 2 dot 11 dot 1405191451130 dot 13304 at zhemvz dot fhfr dot qr> <537A3810 dot 7010708 at redhat dot com> <bd0f023d-08df-4739-b58a-7d61e2ffc558 at email dot android dot com> <alpine dot LSU dot 2 dot 11 dot 1405201000280 dot 13304 at zhemvz dot fhfr dot qr>
On 05/20/14 02:06, Richard Biener wrote:
We're still going to have problems if SSA names are re-used
(as even released SSA names have to remain valid lattice
entries after this). But currently nothing will create new
SSA names (fingers crossing) during eliminate. A followup
patch of mine will though, thus I'll do that two-staged
SSA name release/reuse list you thought would maybe fix this
issue.
Sounds good (the two-staged release/reuse).
The other thing I had pondered was two modes. One with immediate re-use
and one with the two-staged release/reuse.
But before doing anything my plan was to revisit the need for the
release/reuse code. That code was written when we had to go completely
out of SSA, then back into SSA in the first incarnation of the SSA jump
threading support.
With the incremental updating of the SSA graph, we may find that we
really just don't need this code anymore. I wouldn't lose any sleep if
after a bit of poking you came to that conclusion and just ripped out
the release/reuse code completely.
jeff