From: Eric Wong <normalperson@...>
Date: 2014-03-18T09:02:25+00:00
Subject: [ruby-core:61574] Re: [ruby-trunk - Feature #9425] [PATCH] st: use power-of-two sizes to avoid slow modulo ops

normalperson@yhbt.net wrote:
>  	hash_aref_sym	1.000

Lack of improvement here was disappointing since symbol keys are common,
and this showed a regression on my x86 (32-bit) VMs.

I tweaked rb_any_hash to be symbol-aware:

	http://bogomips.org/ruby.git/patch?id=497ed6355

12-30% improvement on this test from trunk depending on CPU so far \o/
(Phenom II X4 got 30%, newer/faster x86-64 CPUs show less speedup).

I'm comfortable with improvements of this series on x86 VMs running on
x86-64 (and of course native x86-64).

Can anybody with real 32-bit hardware verify this series?  Not sure I
can trust VM results; my remaining x86 hardware is on its last legs
and showing occasional HW errors.

git://80x24.org/ruby.git st-noprime-v4

      st: use power-of-two sizes to avoid slow modulo ops
      add hash benchmarks
      st.c: tweak numhash to match common Ruby use cases
      hash.c: improve symbol hash distribution