support popcnt on armv8
authorNiklas Fiekas <niklas.fiekas@backscattering.de>
Thu, 25 Jun 2020 10:42:25 +0000 (12:42 +0200)
committerJoost VandeVondele <Joost.VandeVondele@gmail.com>
Sat, 27 Jun 2020 08:19:29 +0000 (10:19 +0200)
commitaecfca2dc2d760df257e18cd6b29d266a3c3e68a
tree7fd45568405a5f19eb82142afdf46d95ffaf6dc6
parenta84e3ac287fa2c2db5ee58faabdb31943acc78d0
support popcnt on armv8

* Supports popcnt (thanks @daylen)
* bits = 64 is now the default

Tested with g++ (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04) 7.5.0 on ThunderX CN8890,
yields about 9% speedup.

Also tested with clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final).

closes https://github.com/official-stockfish/Stockfish/pull/2770

No functional change.
src/Makefile