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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/114228] [14 Regression] memset/memcpy loop
 not always recognised with -Os
Date: Mon, 04 Mar 2024 13:32:20 +0000
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X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 14.0
X-Bugzilla-Keywords: missed-optimization, needs-bisection
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D114228

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
           Keywords|                            |needs-bisection
   Last reconfirmed|                            |2024-03-04
             Status|UNCONFIRMED                 |NEW
   Target Milestone|---                         |14.0
            Summary|memset/memcpy loop not      |[14 Regression]
                   |always recognised with -Os  |memset/memcpy loop not
                   |                            |always recognised with -Os

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.

The IR is the same before coming into ldist .

ldist in 13.2.0 had:
```
ldist creates useful parallel partition:
  0, 1, 2, 3, 4
Applying pattern match.pd:365, generic-match.cc:23462
distribute loop <1> into partitions:
```

But the trunk:
```
ldist asked to generate code for vertex 3
ldist creates useful parallel partition:
  0, 1, 2, 3, 4
Loop 1 not distributed.
```

But no reason why though.=