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From: "amylaar at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/24814] unrolling doesn't put loop notes in right place Date: Tue, 07 Mar 2006 20:52:00 -0000 [thread overview] Message-ID: <20060307205216.9358.qmail@sourceware.org> (raw) In-Reply-To: <bug-24814-5394@http.gcc.gnu.org/bugzilla/> ------- Comment #5 from amylaar at gcc dot gnu dot org 2006-03-07 20:52 ------- (In reply to comment #4) > Actually there is nothing that uses LOOP_NOTEs other than the old RTL loop > optimizer. At least, nothing that _should_ use it. Wanna know about loops? > Find natural loops instead of depending on the notes. So you are saying I should put natural loop detection into the SH backend so that it can decide if it should save all target registers? Note that the branch probability estimation machinery does not set estimated execution counts, so the execution counts are unusable without profile data. > But the point is moot, the old RTL loop optimizer is no more. It had its weaknesses, but at least it was well-tuned for a wide range of target architectures and operated generally well together with the rest of the compiler. What we have now is a collection of passes that often work at cross-purposes. E.g. web, loop strength reduction/unrolling and auto-increment generation are completely out of sync. -- amylaar at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |UNCONFIRMED Resolution|WONTFIX | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24814
next prev parent reply other threads:[~2006-03-07 20:52 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2005-11-11 20:57 [Bug rtl-optimization/24814] New: " amylaar at gcc dot gnu dot org 2005-11-11 20:59 ` [Bug rtl-optimization/24814] " amylaar at gcc dot gnu dot org 2005-11-11 21:05 ` pinskia at gcc dot gnu dot org 2005-11-11 21:44 ` amylaar at gcc dot gnu dot org 2006-02-27 14:06 ` steven at gcc dot gnu dot org 2006-03-07 20:52 ` amylaar at gcc dot gnu dot org [this message] 2006-03-07 21:50 ` dberlin at gcc dot gnu dot org 2006-03-07 22:43 ` amylaar at gcc dot gnu dot org 2006-04-24 22:34 ` steven at gcc dot gnu dot org
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