From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon-CC+yJ3UmIYqDUpFQwHEjaQ@public.gmane.org Subject: [Bug 90887] PhiMovesPass in register allocator broken Date: Mon, 29 Jun 2015 21:43:49 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1520471985==" Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: nouveau-bounces-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Sender: "Nouveau" To: nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org List-Id: nouveau.vger.kernel.org --===============1520471985== Content-Type: multipart/alternative; boundary="1435614228.fa1A382.26000"; charset="UTF-8" --1435614228.fa1A382.26000 Date: Mon, 29 Jun 2015 21:43:48 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" https://bugs.freedesktop.org/show_bug.cgi?id=90887 --- Comment #19 from jr --- I do prefer the map based approach over this last attempt. Keeping track of the relevant BB is quite obviously correct, but trying to keep track of edge reordering instead looks like some kind of thimbleriggery to me:-) AFAICT the separate loop added by commit e43a3a66 was an attempt to fix the problem. Attach() and detach() influenced the iterator ei of the loop, possibly creating crashes or endless loops. These symptoms are corrected by the patch, but the real problem - reordering of the edge linked list - is still not accounted for. Your patch shows how to do that correctly. Since my attempt doesn't change the incoming edge list, the separate loop becomes obsolete as a bonus feature. I do like that property, but I don't think it makes much of a difference in practice (since the lists in question are very short). -- You are receiving this mail because: You are the QA Contact for the bug. You are the assignee for the bug. --1435614228.fa1A382.26000 Date: Mon, 29 Jun 2015 21:43:48 +0000 MIME-Version: 1.0 Content-Type: text/html; charset="UTF-8"

Comment # 19 on bug 90887 from 
I do prefer the map based approach over this last attempt. Keeping track of the
relevant BB is quite obviously correct, but trying to keep track of edge
reordering instead looks like some kind of thimbleriggery to me:-)

AFAICT the separate loop added by commit e43a3a66 was an attempt to fix the
problem. Attach() and detach() influenced the iterator ei of the loop, possibly
creating crashes or endless loops. These symptoms are corrected by the patch,
but the real problem - reordering of the edge linked list - is still not
accounted for. Your patch shows how to do that correctly.

Since my attempt doesn't change the incoming edge list, the separate loop
becomes obsolete as a bonus feature. I do like that property, but I don't think
it makes much of a difference in practice (since the lists in question are very
short).

You are receiving this mail because:
  • You are the QA Contact for the bug.
  • You are the assignee for the bug.
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