[llvm-bugs] [Bug 25335] Clang always emits a library call for unaligned atomics

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=25335

Nikita Kniazev <nok.raven at gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Product|new-bugs                    |clang
                 CC|                            |neeilans at live.com,
                   |                            |nok.raven at gmail.com,
                   |                            |richard-llvm at metafoo.co.uk
             Status|NEW                         |RESOLVED
           Assignee|unassignedbugs at nondot.org   |unassignedclangbugs at nondot.
                   |                            |org
            Summary|atomics are 20x slower      |Clang always emits a
                   |compared to gcc if          |library call for unaligned
                   |atomic<T>'s T is a packed   |atomics
                   |struct                      |
          Component|new bugs                    |Frontend
         Resolution|---                         |DUPLICATE

--- Comment #2 from Nikita Kniazev <nok.raven at gmail.com> ---
Clang always emits a library call for unaligned atomics by design 
https://github.com/llvm/llvm-project/blob/32e2729e337640e547bb6e8bd3dbe43ac36daa81/clang/lib/CodeGen/CGAtomic.cpp#L809-L810

https://godbolt.org/z/Gz4srWKqT

I am marking this as a duplicate of bug 38846 which has a discussion.

*** This bug has been marked as a duplicate of bug 38846 ***

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