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Switching entersub ops from "XS" to "Perl" and back likely won't help.
authorNicholas Clark <nick@ccl4.org>
Fri, 30 Mar 2012 19:23:25 +0000 (21:23 +0200)
committerNicholas Clark <nick@ccl4.org>
Tue, 24 Apr 2012 08:51:55 +0000 (10:51 +0200)
commitdb1070bec96fc0ff63cd42e3675f6f102d66afd0
treebe3697ec0e7d0ec1c048dbe3705f5c0b48b7ae62
parente12cb30b0275e9b3bbf93f5bd609730d429cddca
Switching entersub ops from "XS" to "Perl" and back likely won't help.

Switching OPs goes against the grain of immutable optrees under ithreads -
it could probably be made to work, but the amount of extra effort would be
non-trivial.

Secondly, cache misses are the overriding speed hit on modern CPUs.
The code switching proposed would add complexity but only be able to change
the number of branch instructions encountered, which come a distant second
to cache misses as a speed hit. The code switching would not change the data
lookups needed, and hence not the cache misses they cause.
Porting/todo.pod