public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug tree-optimization/112814] New: `Plus <PHI <a,b>, PHI<b,a>>` is not optimized to just PLUS<a,b>
@ 2023-12-01 20:39 pinskia at gcc dot gnu.org
  2023-12-01 20:42 ` [Bug tree-optimization/112814] " pinskia at gcc dot gnu.org
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-12-01 20:39 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112814

            Bug ID: 112814
           Summary: `Plus <PHI <a,b>, PHI<b,a>>` is not optimized to just
                    PLUS<a,b>
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Take:
```
int f(int a, int b, int c)
{
        int d, e;
        if (c) d = a, e = b;
        else   d = b, e = a;
        return d+e;
}
```
This should just be optimized to `return a+b` but it is currently not.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [Bug tree-optimization/112814] `Plus <PHI <a,b>, PHI<b,a>>` is not optimized to just PLUS<a,b>
  2023-12-01 20:39 [Bug tree-optimization/112814] New: `Plus <PHI <a,b>, PHI<b,a>>` is not optimized to just PLUS<a,b> pinskia at gcc dot gnu.org
@ 2023-12-01 20:42 ` pinskia at gcc dot gnu.org
  2023-12-01 20:43 ` pinskia at gcc dot gnu.org
  2023-12-04  6:50 ` rguenth at gcc dot gnu.org
  2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-12-01 20:42 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112814

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://github.com/llvm/llv
                   |                            |m-project/issues/73904

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Similarly:
```
int f(int a, int b, int c)
{
        int d, e;
        return (c ? a : b) + (c ? b : a);
}
```


Note the above could be done using a match pattern. catching it before
gimplification.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [Bug tree-optimization/112814] `Plus <PHI <a,b>, PHI<b,a>>` is not optimized to just PLUS<a,b>
  2023-12-01 20:39 [Bug tree-optimization/112814] New: `Plus <PHI <a,b>, PHI<b,a>>` is not optimized to just PLUS<a,b> pinskia at gcc dot gnu.org
  2023-12-01 20:42 ` [Bug tree-optimization/112814] " pinskia at gcc dot gnu.org
@ 2023-12-01 20:43 ` pinskia at gcc dot gnu.org
  2023-12-04  6:50 ` rguenth at gcc dot gnu.org
  2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu.org @ 2023-12-01 20:43 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112814

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [Bug tree-optimization/112814] `Plus <PHI <a,b>, PHI<b,a>>` is not optimized to just PLUS<a,b>
  2023-12-01 20:39 [Bug tree-optimization/112814] New: `Plus <PHI <a,b>, PHI<b,a>>` is not optimized to just PLUS<a,b> pinskia at gcc dot gnu.org
  2023-12-01 20:42 ` [Bug tree-optimization/112814] " pinskia at gcc dot gnu.org
  2023-12-01 20:43 ` pinskia at gcc dot gnu.org
@ 2023-12-04  6:50 ` rguenth at gcc dot gnu.org
  2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2023-12-04  6:50 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112814

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-12-04

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Interesting one - this isn't catched by PRE code hoisting because that only
hoists sth if it's available in one of the successors (but it's only antic
there).

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2023-12-04  6:50 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-12-01 20:39 [Bug tree-optimization/112814] New: `Plus <PHI <a,b>, PHI<b,a>>` is not optimized to just PLUS<a,b> pinskia at gcc dot gnu.org
2023-12-01 20:42 ` [Bug tree-optimization/112814] " pinskia at gcc dot gnu.org
2023-12-01 20:43 ` pinskia at gcc dot gnu.org
2023-12-04  6:50 ` rguenth at gcc dot gnu.org

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).