[Bug 56867] New: dynamic_cast too slow on wine compared to windows

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56867

Bug ID: 56867
           Summary: dynamic_cast too slow on wine compared to windows
           Product: Wine
           Version: unspecified
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: msvcp
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Herb Sutter said dynamic cast was using string comparison and now it is not. So
the performance of dynamic cast becomes MUCH faster.

Same program with static link with microsoft's own library.

$ wine ./cout.exe 
coutfd:0.1162809s
u=10000000

wine DLL implementation:

$ wine ./cout.exe 
coutfd:0.4995548s
u=10000000

The overhead is 5x at least

[Bug 56867] dynamic_cast too slow on wine compared to windows

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56867

--- Comment #1 from Nikolay Sivov  ---
Becomes much faster after msvc compiler changes, or because of what?

Source code for this benchmark would be interesting, and pre-built binaries
too. What should be compared is the difference between wine and windows under
same conditions, so statically linked binary on wine vs statically linked
binary on windows, and so on. That's assuming benchmarks are measuring what
there are supposed to.

[Bug 56867] dynamic_cast too slow on wine compared to windows

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56867

--- Comment #2 from cqwrteur  ---
(In reply to Nikolay Sivov from comment #1)
> Becomes much faster after msvc compiler changes, or because of what?
>
> Source code for this benchmark would be interesting, and pre-built binaries
> too. What should be compared is the difference between wine and windows
> under same conditions, so statically linked binary on wine vs statically
> linked binary on windows, and so on. That's assuming benchmarks are
> measuring what there are supposed to.

https://github.com/trcrsired/fast_io/blob/master/benchmark/0018.get_fd/coutf...

This is to extract FILE* from C++'s std::cout

https://github.com/trcrsired/windows-msvc-sysroot

/*
I am working on adding --sysroot toggle to clang
*/
Compile with clang --target=x86_64-windows
-Iwindows-msvc-sysroot/include/c++/stl -Iwindows-msvc-sysroot/include
-Lwindows-msvc-sysroot/x86_64-windows-msvc -Ofast

[Bug 56867] dynamic_cast too slow on wine compared to windows

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56867

--- Comment #3 from cqwrteur  ---
Compile with clang --target=x86_64-windows
-Iwindows-msvc-sysroot/include/c++/stl -Iwindows-msvc-sysroot/include
-Lwindows-msvc-sysroot/x86_64-unknown-windows-msvc -Ofas

[Bug 56867] dynamic_cast too slow on wine compared to windows

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56867

--- Comment #4 from cqwrteur  ---
dynamic cast is here

https://github.com/trcrsired/fast_io/blob/742950421eedc149585122059cd8196545...

Wine source shows it does strcmp which is slow. Microsoft has changed the
implementation to not be strcmp-ed. Though i do not know how they've done it.

https://github.com/wine-mirror/wine/blob/f9af971bd7d6799d54436ba9f7fa327b7ed...

[Bug 56867] dynamic_cast too slow on wine compared to windows

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56867

--- Comment #5 from cqwrteur  ---
(In reply to cqwrteur from comment #4)
> dynamic cast is here
>
> https://github.com/trcrsired/fast_io/blob/
> 742950421eedc149585122059cd8196545e28dac/include/fast_io_legacy_impl/filebuf/
> fp_hack/msvc_stl.h#L84
>
> Wine source shows it does strcmp which is slow. Microsoft has changed the
> implementation to not be strcmp-ed. Though i do not know how they've done it.
>
> https://github.com/wine-mirror/wine/blob/
> f9af971bd7d6799d54436ba9f7fa327b7edfbc77/dlls/msvcrt/cpp.c#L819

https://youtu.be/ARYP83yNAWk?si=D0GjCDbYwLeEXW_1&t=4473

Herb Sutter (Microsoft VC Team Lead) said, "We know Microsoft did string
comparison; we are fixing that."

[Bug 56867] dynamic_cast too slow on wine compared to windows

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56867

cqwrteur  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #6 from cqwrteur  ---
I got the same result on windows. so it is my fault.

[Bug 56867] dynamic_cast too slow on wine compared to windows

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56867

--- Comment #7 from Austin English  ---
Closing.

[Bug 56867] dynamic_cast too slow on wine compared to windows

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=56867

Austin English  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |CLOSED

--- Comment #8 from Austin English  ---
Actually closing.