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* [Bug tree-optimization/61110] New: Simplify value_replacement in phiopt
@ 2014-05-08 13:40 glisse at gcc dot gnu.org
2014-05-17 12:48 ` [Bug tree-optimization/61110] " glisse at gcc dot gnu.org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: glisse at gcc dot gnu.org @ 2014-05-08 13:40 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61110
Bug ID: 61110
Summary: Simplify value_replacement in phiopt
Product: gcc
Version: 4.10.0
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: glisse at gcc dot gnu.org
The patch for PR 59100 introduced 2 functions neutral_element_p and
absorbing_element_p. I don't know why I did that. When we see:
(x != 0) ? x + y : y
instead of asking if 0 is a neutral element of + on the left, it is easier to
try to fold "0 + y" (I replaced x with the rhs of the comparison) and check if
that matches "y". This handles neutral and absorbing as a single case and is
even more general (we could also do it for the non-constant case: (x!=y) ? x|y
: x). We could even imagine generalizing it to the case where middle_bb has 2
or 3 statements (but the cost analysis may need to be refined then).
I probably won't do it immediately (the current code works) but I didn't want
this idea to be forgotten.
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug tree-optimization/61110] Simplify value_replacement in phiopt 2014-05-08 13:40 [Bug tree-optimization/61110] New: Simplify value_replacement in phiopt glisse at gcc dot gnu.org @ 2014-05-17 12:48 ` glisse at gcc dot gnu.org 2014-11-05 16:11 ` pinskia at gcc dot gnu.org ` (3 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: glisse at gcc dot gnu.org @ 2014-05-17 12:48 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61110 --- Comment #1 from Marc Glisse <glisse at gcc dot gnu.org> --- Another extension is discussed here: https://gcc.gnu.org/ml/gcc-patches/2014-05/msg00704.html (also transform if there is a second phi but it could be turned into a cmove) ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/61110] Simplify value_replacement in phiopt 2014-05-08 13:40 [Bug tree-optimization/61110] New: Simplify value_replacement in phiopt glisse at gcc dot gnu.org 2014-05-17 12:48 ` [Bug tree-optimization/61110] " glisse at gcc dot gnu.org @ 2014-11-05 16:11 ` pinskia at gcc dot gnu.org 2023-10-31 5:08 ` pinskia at gcc dot gnu.org ` (2 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu.org @ 2014-11-05 16:11 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61110 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Depends on| |25290 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- I think some of this should really be moved to match.pd and phi-opt use it instead. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/61110] Simplify value_replacement in phiopt 2014-05-08 13:40 [Bug tree-optimization/61110] New: Simplify value_replacement in phiopt glisse at gcc dot gnu.org 2014-05-17 12:48 ` [Bug tree-optimization/61110] " glisse at gcc dot gnu.org 2014-11-05 16:11 ` pinskia at gcc dot gnu.org @ 2023-10-31 5:08 ` pinskia at gcc dot gnu.org 2024-05-02 21:47 ` pinskia at gcc dot gnu.org 2024-05-07 21:43 ` pinskia at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-10-31 5:08 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61110 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |pinskia at gcc dot gnu.org --- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Mine working on this. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/61110] Simplify value_replacement in phiopt 2014-05-08 13:40 [Bug tree-optimization/61110] New: Simplify value_replacement in phiopt glisse at gcc dot gnu.org ` (2 preceding siblings ...) 2023-10-31 5:08 ` pinskia at gcc dot gnu.org @ 2024-05-02 21:47 ` pinskia at gcc dot gnu.org 2024-05-07 21:43 ` pinskia at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu.org @ 2024-05-02 21:47 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61110 --- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Created attachment 58089 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58089&action=edit Start of rewriting value_replacement to use match-and-simplify This is a start and does not remove the old code. It has a few small regressions due to not being able to merge the bb when doing the replacement. this is something which I am working on but I am posting it here as I stopping to work on this for a month or so but will come back to it. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/61110] Simplify value_replacement in phiopt 2014-05-08 13:40 [Bug tree-optimization/61110] New: Simplify value_replacement in phiopt glisse at gcc dot gnu.org ` (3 preceding siblings ...) 2024-05-02 21:47 ` pinskia at gcc dot gnu.org @ 2024-05-07 21:43 ` pinskia at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu.org @ 2024-05-07 21:43 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61110 Bug 61110 depends on bug 114894, which changed state. Bug 114894 Summary: `a == 0 ? 0 : a * b` -> `a * b` likewise for `a & b` https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114894 What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |RESOLVED Resolution|--- |FIXED ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2024-05-07 21:43 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2014-05-08 13:40 [Bug tree-optimization/61110] New: Simplify value_replacement in phiopt glisse at gcc dot gnu.org 2014-05-17 12:48 ` [Bug tree-optimization/61110] " glisse at gcc dot gnu.org 2014-11-05 16:11 ` pinskia at gcc dot gnu.org 2023-10-31 5:08 ` pinskia at gcc dot gnu.org 2024-05-02 21:47 ` pinskia at gcc dot gnu.org 2024-05-07 21:43 ` pinskia at gcc dot gnu.org
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