[fpc-devel] FillWord, FillDWord and FillQWord are very poorly optimised on Win64 (not sure about x86-64 on Linux)

Martok listbox at martoks-place.de
Wed Nov 1 12:30:53 CET 2017

Am 01.11.2017 um 05:58 schrieb J. Gareth Moreton:
> So I've been doing some playing around recently, and noticed that while FillChar has some very fast internal 
> code for initialising a block of memory, making use of non-temporal hints and memory fences, the versions 
> for the larger types fall back to slow Pascal code.
It might be worth it to look at the Pascal versions from generic.inc first, and
see if it is possible to come up with versions that generate faster code.

I'm actually surprised "REP STOSD" should be that much faster. I remember it
being slower on modern platforms than it used to be?


Ceterum censeo b32079 esse sanandam.

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