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From: "federico at kircheis dot it" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/112335] New: missed optimization on reset and assign unique_ptr
Date: Wed, 01 Nov 2023 13:26:03 +0000	[thread overview]
Message-ID: <bug-112335-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112335

            Bug ID: 112335
           Summary: missed optimization on reset and assign unique_ptr
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: federico at kircheis dot it
  Target Milestone: ---

Given following snippet

----
#include <memory>

struct s{
    s();
    ~s() noexcept;
};



void bar1(std::unique_ptr<s>& ps1, std::unique_ptr<s>& ps2){
    ps1.reset();
    ps1 = std::move(ps2);
}

void bar2(std::unique_ptr<s>& ps1, std::unique_ptr<s>& ps2){
    ps1 = std::move(ps2);
}
----

If I am not mistaken, bar1 and bar2 should have exactly the same behavior, but
on https://godbolt.org/z/q4nKsPq7z it is possible to see that the generated
code differs.

             reply	other threads:[~2023-11-01 13:26 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-01 13:26 federico at kircheis dot it [this message]
2023-11-01 15:51 ` [Bug c++/112335] " pinskia at gcc dot gnu.org
2023-11-02  7:17 ` federico at kircheis dot it
2023-11-02  7:19 ` federico at kircheis dot it
2023-11-02  7:30 ` pinskia at gcc dot gnu.org
2023-11-02  8:01 ` federico at kircheis dot it
2023-11-02 17:23 ` redi at gcc dot gnu.org
2023-11-03  8:06 ` federico at kircheis dot it
2023-11-03  9:10 ` redi at gcc dot gnu.org
2023-11-03 10:23 ` federico at kircheis dot it
2023-11-03 14:23 ` redi at gcc dot gnu.org

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