https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
Aldy Hernandez changed:
What|Removed |Added
Resolution|--- |FIXED
Status|NEW
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
--- Comment #15 from CVS Commits ---
The master branch has been updated by Aldy Hernandez :
https://gcc.gnu.org/g:eb5ee6464809e051e0292471597931a660485658
commit r12-6787-geb5ee6464809e051e0292471597931a660485658
Author: Aldy Hernandez
Date:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
--- Comment #14 from Andrew Macleod ---
(In reply to Aldy Hernandez from comment #11)
> [local count: 1063004409]:
> # j_17 = PHI
> # q_18 = PHI
>
>[local count: 1063004409]:
> # j_2 = PHI
> # prephitmp_16 = PHI <_14(4), &a(3)>
>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
Aldy Hernandez changed:
What|Removed |Added
CC||bonzini at gnu dot org
--- Comment #13
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
--- Comment #12 from Aldy Hernandez ---
Created attachment 52240
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52240&action=edit
proposed untested patch
This is a proposed patch that fixes both PRs. Perhaps we can tweak the
dominance ch
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
--- Comment #11 from Aldy Hernandez ---
The testcase for PR104067 shows an example where the dominance matters,
irregardless of if we reset relations at the backedge point. There we have a
path that looks like 9->3->5->...:
[local count: 106
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
--- Comment #10 from Andrew Macleod ---
(In reply to Jeffrey A. Law from comment #9)
>
>
>
>1 2 3
>| \ /
>|4
>| / \
>+->5 6
> / \
> 7 8
>
>
> Note how BB4 does not dominate BB5. If we try to thr
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
--- Comment #9 from Jeffrey A. Law ---
I think Andrew has raised a really interesting issue. If the relation code is
designed around seeing things in dominator order, then don't we have to stop
using it once we traverse any edge where the edge
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
--- Comment #8 from Andrew Macleod ---
No probably about it :-)
As soon as the path crosses a back edge, we can encounter definitions of
SSA_NAMEs that may have had a use in the path already, so this will then be a
new definition. The relati
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
--- Comment #7 from Aldy Hernandez ---
After chatting with Andrew about this, it seems the problem is we are starting
a path mid-loop and crossing a backedge. This causes us to use relations we
had on one iteration in another iteration.
[lo
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
--- Comment #6 from Aldy Hernandez ---
Please bear with me, as I'm coming up to speed, and my head hurts from all
these equivalences.
The problem seems to be what Jeff mentioned in comment #4.
We think _5 == _6, which makes the conditional in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
--- Comment #5 from Andrew Macleod ---
> How does equivalence handling in the Ranger world work once you traverse the
> backedge of a loop?
There are 2 aspects. Ranger itself registers equivalence sets by basic block,
not by name. All looku
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
Jeffrey A. Law changed:
What|Removed |Added
CC||law at gcc dot gnu.org
--- Comment #4
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
Andrew Macleod changed:
What|Removed |Added
CC||jeffreyalaw at gmail dot com
--- Comme
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
Richard Biener changed:
What|Removed |Added
Priority|P3 |P1
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103721
Martin Liška changed:
What|Removed |Added
Summary|[12 regression] wrong code |[12 regression] wrong code
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