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* [Bug tree-optimization/27504] x && (x & y) not optimized to x & y
[not found] <bug-27504-4@http.gcc.gnu.org/bugzilla/>
@ 2021-06-03 2:43 ` pinskia at gcc dot gnu.org
2023-05-05 8:17 ` pinskia at gcc dot gnu.org
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-06-03 2:43 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=27504
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed|2012-01-04 00:00:00 |2021-6-2
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed again.
So looking at the IR, it took until PHI-OPT4 to be able to convert it into:
<bb 2> [local count: 1073741824]:
if (x_3(D) != 0)
goto <bb 3>; [50.00%]
else
goto <bb 4>; [50.00%]
<bb 3> [local count: 536870913]:
_1 = x_3(D) & 85;
_5 = _1 != 0;
_6 = (int) _5;
<bb 4> [local count: 1073741824]:
# iftmp.0_2 = PHI <_6(3), 0(2)>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/27504] x && (x & y) not optimized to x & y
[not found] <bug-27504-4@http.gcc.gnu.org/bugzilla/>
2021-06-03 2:43 ` [Bug tree-optimization/27504] x && (x & y) not optimized to x & y pinskia at gcc dot gnu.org
@ 2023-05-05 8:17 ` pinskia at gcc dot gnu.org
2023-10-12 17:56 ` pinskia at gcc dot gnu.org
2023-10-12 18:00 ` pinskia at gcc dot gnu.org
3 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-05-05 8:17 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=27504
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #3)
> Confirmed again.
> So looking at the IR, it took until PHI-OPT4 to be able to convert it into:
> <bb 2> [local count: 1073741824]:
> if (x_3(D) != 0)
> goto <bb 3>; [50.00%]
> else
> goto <bb 4>; [50.00%]
>
> <bb 3> [local count: 536870913]:
> _1 = x_3(D) & 85;
> _5 = _1 != 0;
> _6 = (int) _5;
>
> <bb 4> [local count: 1073741824]:
> # iftmp.0_2 = PHI <_6(3), 0(2)>
In GCC 12+, phiopt2 is able to convert that into the above.
One thing that could be tried is to replace x_3 with 0 and see if _6 would
simplify down to 0 (other the phi argument). This could be part of phiopt but
would need a lot of work really.
Note VRP is able to handle the other way around already:
that is: `(x & 0x55) && x ` But that is simplier.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/27504] x && (x & y) not optimized to x & y
[not found] <bug-27504-4@http.gcc.gnu.org/bugzilla/>
2021-06-03 2:43 ` [Bug tree-optimization/27504] x && (x & y) not optimized to x & y pinskia at gcc dot gnu.org
2023-05-05 8:17 ` pinskia at gcc dot gnu.org
@ 2023-10-12 17:56 ` pinskia at gcc dot gnu.org
2023-10-12 18:00 ` pinskia at gcc dot gnu.org
3 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-10-12 17:56 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=27504
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Mine.
Bug 88280 comment #5 fixes part of the issue. The secondary issue is ifcombine
does not do the combining to get that point.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/27504] x && (x & y) not optimized to x & y
[not found] <bug-27504-4@http.gcc.gnu.org/bugzilla/>
` (2 preceding siblings ...)
2023-10-12 17:56 ` pinskia at gcc dot gnu.org
@ 2023-10-12 18:00 ` pinskia at gcc dot gnu.org
3 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-10-12 18:00 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=27504
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|unassigned at gcc dot gnu.org |pinskia at gcc dot gnu.org
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note also there are other bugs associated with similar ifcombine issue (besides
this one and PR 88280 ). I don't know if I will get to that part until next
year though.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/27504] x && (x & y) not optimized to x & y
2006-05-08 19:28 [Bug tree-optimization/27504] New: " falk at debian dot org
2006-05-09 6:20 ` [Bug tree-optimization/27504] " pinskia at gcc dot gnu dot org
@ 2006-05-09 8:36 ` rguenth at gcc dot gnu dot org
1 sibling, 0 replies; 6+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2006-05-09 8:36 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from rguenth at gcc dot gnu dot org 2006-05-09 08:36 -------
It get's a little complicated as fold gets
(xD.1520 != 0) && ((xD.1520 & 85) != 0)
from the frontend.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27504
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug tree-optimization/27504] x && (x & y) not optimized to x & y
2006-05-08 19:28 [Bug tree-optimization/27504] New: " falk at debian dot org
@ 2006-05-09 6:20 ` pinskia at gcc dot gnu dot org
2006-05-09 8:36 ` rguenth at gcc dot gnu dot org
1 sibling, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2006-05-09 6:20 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from pinskia at gcc dot gnu dot org 2006-05-09 06:20 -------
Confirmed.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |enhancement
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2006-05-09 06:20:01
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27504
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-10-12 18:00 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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[not found] <bug-27504-4@http.gcc.gnu.org/bugzilla/>
2021-06-03 2:43 ` [Bug tree-optimization/27504] x && (x & y) not optimized to x & y pinskia at gcc dot gnu.org
2023-05-05 8:17 ` pinskia at gcc dot gnu.org
2023-10-12 17:56 ` pinskia at gcc dot gnu.org
2023-10-12 18:00 ` pinskia at gcc dot gnu.org
2006-05-08 19:28 [Bug tree-optimization/27504] New: " falk at debian dot org
2006-05-09 6:20 ` [Bug tree-optimization/27504] " pinskia at gcc dot gnu dot org
2006-05-09 8:36 ` rguenth at gcc dot gnu dot org
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