[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Emacs-diffs] master 81a1088: Tweak builtin symbol order for speed

From: Paul Eggert
Subject: [Emacs-diffs] master 81a1088: Tweak builtin symbol order for speed
Date: Sat, 13 Jul 2019 17:54:06 -0700
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2

On 7/12/19 12:12 AM, Pip Cet wrote:

I don't understand why this would improve performance this
significantly (maybe because it allows 8-bit offsets to be used rather
than 32-bit ones?).

Yes, that's my guess too. For the record, my benchmark platform was my old work desktop (AMD Phenom II X4 910e, circa 2010) running Fedora 30 x86-64, with plain 'make compile-always' (no -j). I really should get that upgraded.

Maybe it would be a good idea to make Vdead a symbol (or a tagged NULL
pointer) and treat it similarly, if this actually improves

It does speed up GC a bit. I installed the attached. Thanks for the suggestion.

+      static char const commonsym[][8]

I'm curious, why isn't this simply "static char *commonsym[]"?

Old performance habits that don't matter here. Besides, that alternative should be 'static char const *const commonsym[]" which is not obviously simpler....

Attachment: 0001-Replace-Vdead-with-tagged-pointer.patch
Description: Text Data

reply via email to

[Prev in Thread] Current Thread [Next in Thread]