Re: Do definitions in headers still help optimization?

[LIU Hao <lh_mouse@126.com>]

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在 2024/1/13 0:01, Xi Ruoyao 写道:
> And LTO cannot cross shared library boundary.  It even cannot cross
> static library boundary if the static library is intended to be
> distributed in binary form: a static library containing LTO bitcode
> will just blow up if attempting to "link" against it using a different
> compiler or even a different version of the compiler.  So LTO-enabled
> distros build packages containing static libraries with -ffat-lto-
> objects and then strip the LTO bitcode away from the static libraries.

I don't think that's the case for me. I'm building a shared library against only system libraries. 
My observation is basically

1) Link time grows dramatically.
    [less than 2 minutes => more than 1 hour]
2) Binary size also grows dramatically.
    [1.9 MiB => 9.0 MiB]
3) The overall performance improvement is not worth the cost.
    [31382.685 seconds => 29882.761 seconds] (-4.779%)
4) Function calls use much more stack space and are more likely to cause
    stack overflows.


-- 
Best regards,
LIU Hao


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