[debbugs-tracker] bug#35562: closed ("varset" bytecode inline path is never taken)

[GNU bug Tracking System]

Your message dated Sat, 4 May 2019 11:16:23 -0700
with message-id <address@hidden>
and subject line "varset" bytecode inline path is never taken
has caused the debbugs.gnu.org bug report #35562,
regarding "varset" bytecode inline path is never taken
to be marked as done.

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35562: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=35562
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--- Begin Message --- Subject: "varset" bytecode inline path is never taken Date: Sat, 4 May 2019 14:27:23 +0100

While reading the source, I noticed in bytecode.c that:

    /* Inline the most common case.  */

    if (SYMBOLP (sym)

&& !EQ (val, Qunbound)

&& !XSYMBOL (sym)->u.s.redirect

&& !SYMBOL_TRAPPED_WRITE_P (sym))

      SET_SYMBOL_VAL (XSYMBOL (sym), val);

should be:

    /* Inline the most common case.  */

    if (SYMBOLP (sym)

&& !EQ (val, Qunbound)

&& XSYMBOL (sym)->u.s.redirect == SYMBOL_PLAINVAL

&& !SYMBOL_TRAPPED_WRITE_P (sym))

      SET_SYMBOL_VAL (XSYMBOL (sym), val);

As it is, the inline case is never run, since "redirect" is always non-zero.

Since I'm new to emacs internals, I don't know how to benchmark to work out if this makes a noticable performance difference. :)

Thanks,

Simon.

--- End Message ---

> --- Begin Message ---
>
>
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> Subject: 
>
> "varset" bytecode inline path is never taken
>
>
>
>
> Date: 
>
> Sat, 4 May 2019 11:16:23 -0700
>
>
>
>
> User-agent: 
>
> Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1
>
>
>
>
> Thanks for reporting that typo. I verified that the patch improves performance 
> significantly (50% speedup) on Noam's benchmark, and installed the patch into 
> the Emacs master branch.
>
>
> --- End Message ---