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≥ and ≤ are 36x slower than Texas version; ≠ is 15x slower #6357

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p6rt opened this issue Jun 22, 2017 · 8 comments
Open

≥ and ≤ are 36x slower than Texas version; ≠ is 15x slower #6357

p6rt opened this issue Jun 22, 2017 · 8 comments

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@p6rt
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@p6rt p6rt commented Jun 22, 2017

Migrated from rt.perl.org#131626 (status was 'open')

Searchable as RT131626$

@p6rt
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@p6rt p6rt commented Jun 22, 2017

From @zoffixznet

I'd expect the fancy Unicode versions of <=, >=, and != to perform equally well, instead the
� and � are 36x slower than their Texas companions and � is 15x slower.

Here's the timings for >= vs â�¥​:

m​: my $x = rand; for ^1000_000 { $ = $x >= 1_000_000_000_000 }; say now - INIT now;
rakudo-moar 43c176​: OUTPUT​: «0.74663187â�¤Â»
m​: my $x = rand; for ^1000_000 { $ = $x â�¥ 1_000_000_000_000 }; say now - INIT now;
rakudo-moar 43c176​: OUTPUT​: «(timeout)»
m​: my $x = rand; for ^1000_0 { $ = $x â�¥ 1_000_000_000_000 }; say now - INIT now;
rakudo-moar 43c176​: OUTPUT​: «0.2661272â�¤Â»
m​: say 0.2661272*100 / 0.729002
rakudo-moar 43c176​: OUTPUT​: «36.505689â�¤Â»

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@p6rt
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@p6rt p6rt commented Jun 22, 2017

From @AlexDaniel

This was discussed in rakudo/rakudo#1032 (comment)

In theory, this ticket should apply for other ops as well.

Note that I said that I will change the way unicode ops are implemented, but I didn't have much time since then. Hoping to get to it at some point.

On 2017-06-22 10​:29​:59, cpan@​zoffix.com wrote​:

I'd expect the fancy Unicode versions of <=, >=, and != to perform
equally well, instead the
≥ and ≤ are 36x slower than their Texas companions and ≠ is 15x
slower.

Here's the timings for >= vs ≥​:

m​: my $x = rand; for ^1000_000 { $ = $x >= 1_000_000_000_000 }; say
now - INIT now;
rakudo-moar 43c176​: OUTPUT​: «0.74663187â�¤»
m​: my $x = rand; for ^1000_000 { $ = $x ≥ 1_000_000_000_000 }; say now
- INIT now;
rakudo-moar 43c176​: OUTPUT​: «(timeout)»
m​: my $x = rand; for ^1000_0 { $ = $x ≥ 1_000_000_000_000 }; say now -
INIT now;
rakudo-moar 43c176​: OUTPUT​: «0.2661272â�¤»
m​: say 0.2661272*100 / 0.729002
rakudo-moar 43c176​: OUTPUT​: «36.505689â�¤»

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@p6rt
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@p6rt p6rt commented Jun 22, 2017

The RT System itself - Status changed from 'new' to 'open'

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@p6rt
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@p6rt p6rt commented Jul 10, 2017

From @zoffixznet

This bug was temporarily worked around with rakudo/rakudo@a13bad9

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@p6rt
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@p6rt p6rt commented Sep 26, 2017

From @zoffixznet

On Mon, 10 Jul 2017 02​:42​:59 -0700, cpan@​zoffix.com wrote​:

This bug was temporarily worked around with
rakudo/rakudo@a13bad9

That was reverted in rakudo/rakudo@1af2a74 as it causes problems.

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@p6rt
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@p6rt p6rt commented Sep 26, 2017

From @zoffixznet

On Thu, 22 Jun 2017 10​:29​:59 -0700, cpan@​zoffix.com wrote​:

I'd expect the fancy Unicode versions of <=, >=, and != to perform
equally well, instead the
� and � are 36x slower than their Texas companions and � is 15x
slower.

Here's the timings for >= vs â�¥​:

m​: my $x = rand; for ^1000_000 { $ = $x >= 1_000_000_000_000 }; say
now - INIT now;
rakudo-moar 43c176​: OUTPUT​: «0.74663187â�¤Â»
m​: my $x = rand; for ^1000_000 { $ = $x â�¥ 1_000_000_000_000 }; say now
- INIT now;
rakudo-moar 43c176​: OUTPUT​: «(timeout)»
m​: my $x = rand; for ^1000_0 { $ = $x â�¥ 1_000_000_000_000 }; say now -
INIT now;
rakudo-moar 43c176​: OUTPUT​: «0.2661272â�¤Â»
m​: say 0.2661272*100 / 0.729002
rakudo-moar 43c176​: OUTPUT​: «36.505689â�¤Â»

So I made the static optimizer change Mexico ops to Texas versions, so this problem no longer exist. So, should the ticket be closed?

Fixed in rakudo/rakudo@6ec21cb

I tried writing a test, but couldn't get anything usable. My attempt was this​:

  use Test;
  subtest 'performance of â�¤, â�¥, â�  compared to Texas versions' => {
  sub measure (&code) { code for ^300; with now { code for ^100_000; now - $_ } }
 
  is-approx { rand â�¤ rand }.&measure, { rand <= rand }.&measure, 'â�¤', :rel-tol<.5>;
  is-approx { rand â�¥ rand }.&measure, { rand >= rand }.&measure, 'â�¥', :rel-tol<.5>;
  is-approx { rand â�  rand }.&measure, { rand != rand }.&measure, 'â� ', :rel-tol<.5>;
  }

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@p6rt
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@p6rt p6rt commented Oct 22, 2017

From @zoffixznet

On Tue, 26 Sep 2017 11​:03​:11 -0700, cpan@​zoffix.com wrote​:

On Thu, 22 Jun 2017 10​:29​:59 -0700, cpan@​zoffix.com wrote​:

I'd expect the fancy Unicode versions of <=, >=, and != to perform
equally well, instead the
� and � are 36x slower than their Texas companions and � is 15x
slower.

Here's the timings for >= vs â�¥​:

m​: my $x = rand; for ^1000_000 { $ = $x >= 1_000_000_000_000 }; say
now - INIT now;
rakudo-moar 43c176​: OUTPUT​: «0.74663187â�¤Â»
m​: my $x = rand; for ^1000_000 { $ = $x â�¥ 1_000_000_000_000 }; say
now
- INIT now;
rakudo-moar 43c176​: OUTPUT​: «(timeout)»
m​: my $x = rand; for ^1000_0 { $ = $x â�¥ 1_000_000_000_000 }; say now
-
INIT now;
rakudo-moar 43c176​: OUTPUT​: «0.2661272â�¤Â»
m​: say 0.2661272*100 / 0.729002
rakudo-moar 43c176​: OUTPUT​: «36.505689â�¤Â»

So I made the static optimizer change Mexico ops to Texas versions, so
this problem no longer exist. So, should the ticket be closed?

Fixed in rakudo/rakudo@6ec21cb

I tried writing a test, but couldn't get anything usable. My attempt
was this​:

use Test;
subtest 'performance of �, �, � compared to Texas versions' => {
sub measure (&code) { code for ^300; with now { code for ^100_000;
now - $_ } }

is-approx { rand � rand }.&measure, { rand <= rand }.&measure, '�',
:rel-tol<.5>;
is-approx { rand � rand }.&measure, { rand >= rand }.&measure, '�',
:rel-tol<.5>;
is-approx { rand � rand }.&measure, { rand != rand }.&measure, '�',
:rel-tol<.5>;
}

So the optimizer fix didn't do a full job. There were still cases that ended up 86x slower​:

When chained​:

  <Zoffix__> m​: $ = rand â�¤ rand â�¤ rand for ^100_000; say now - INIT now
  <camelia> rakudo-moar a042fd927​: OUTPUT​: «2.91023964â�¤Â»
  <Zoffix__> m​: $ = rand <= rand <= rand for ^100_000; say now - INIT now
  <camelia> rakudo-moar a042fd927​: OUTPUT​: «0.094577â�¤Â»

Or when user defines their own version of the ASCII op​:

  <Zoffix__> m​: $ = rand â�¤ rand for ^100_000; say now - INIT now
  <camelia> rakudo-moar a042fd927​: OUTPUT​: «0.0474443â�¤Â»
  <Zoffix__> m​: class Foo {}; sub infix​:«<=» (Foo, Foo) {}; $ = rand â�¤ rand for ^100_000; say now - INIT now
  <camelia> rakudo-moar a042fd927​: OUTPUT​: «1.94282032â�¤Â»

Some proposed to substitute Unicode versions for Texas ones during parsing and codegen, but the only way I
know how to do that would make user's use of `�` use a custom `!=` op, if one exists.

It's possible we *do* want to declare that we do such aliasing​: a Unicode op is just a grammatical alias
to the ASCII op and gets rewritten to it. If there's a consensus to do that, it should be done for all the ops,
even ones that don't have this performance issue (which is due to capture slipping).

For now, I basically restored lizmat++'s original fix adding whatever datish ops that were
originally missing as well​: rakudo/rakudo@6ad06fa

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@p6rt
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@p6rt p6rt commented Mar 1, 2018

From @AlexDaniel

It seems like it is fixed properly now. See this discussion​: https://irclog.perlgeek.de/perl6-dev/2018-03-01#i_15872426

On 2017-10-22 08​:28​:20, cpan@​zoffix.com wrote​:

On Tue, 26 Sep 2017 11​:03​:11 -0700, cpan@​zoffix.com wrote​:

On Thu, 22 Jun 2017 10​:29​:59 -0700, cpan@​zoffix.com wrote​:

I'd expect the fancy Unicode versions of <=, >=, and != to perform
equally well, instead the
≥ and ≤ are 36x slower than their Texas companions and ≠ is 15x
slower.

Here's the timings for >= vs ≥​:

m​: my $x = rand; for ^1000_000 { $ = $x >= 1_000_000_000_000 }; say
now - INIT now;
rakudo-moar 43c176​: OUTPUT​: «0.74663187â�¤»
m​: my $x = rand; for ^1000_000 { $ = $x ≥ 1_000_000_000_000 }; say
now
- INIT now;
rakudo-moar 43c176​: OUTPUT​: «(timeout)»
m​: my $x = rand; for ^1000_0 { $ = $x ≥ 1_000_000_000_000 }; say
now
-
INIT now;
rakudo-moar 43c176​: OUTPUT​: «0.2661272â�¤»
m​: say 0.2661272*100 / 0.729002
rakudo-moar 43c176​: OUTPUT​: «36.505689â�¤»

So I made the static optimizer change Mexico ops to Texas versions,
so
this problem no longer exist. So, should the ticket be closed?

Fixed in rakudo/rakudo@6ec21cb

I tried writing a test, but couldn't get anything usable. My attempt
was this​:

use Test;
subtest 'performance of ≤, ≥, ≠ compared to Texas versions' => {
sub measure (&code) { code for ^300; with now { code for
^100_000;
now - $_ } }

is-approx { rand ≤ rand }.&measure, { rand <= rand }.&measure, '≤',
:rel-tol<.5>;
is-approx { rand ≥ rand }.&measure, { rand >= rand }.&measure, '≥',
:rel-tol<.5>;
is-approx { rand ≠ rand }.&measure, { rand != rand }.&measure, '≠',
:rel-tol<.5>;
}

So the optimizer fix didn't do a full job. There were still cases that
ended up 86x slower​:

When chained​:

<Zoffix__> m​: $ = rand ≤ rand ≤ rand for ^100_000; say now - INIT now
<camelia> rakudo-moar a042fd927​: OUTPUT​: «2.91023964â�¤»
<Zoffix__> m​: $ = rand <= rand <= rand for ^100_000; say now - INIT
now
<camelia> rakudo-moar a042fd927​: OUTPUT​: «0.094577â�¤»

Or when user defines their own version of the ASCII op​:

<Zoffix__> m​: $ = rand ≤ rand for ^100_000; say now - INIT now
<camelia> rakudo-moar a042fd927​: OUTPUT​: «0.0474443â�¤»
<Zoffix__> m​: class Foo {}; sub infix​:«<=» (Foo, Foo) {}; $ = rand ≤
rand for ^100_000; say now - INIT now
<camelia> rakudo-moar a042fd927​: OUTPUT​: «1.94282032â�¤»

Some proposed to substitute Unicode versions for Texas ones during
parsing and codegen, but the only way I
know how to do that would make user's use of `≠` use a custom `!=` op,
if one exists.

It's possible we *do* want to declare that we do such aliasing​: a
Unicode op is just a grammatical alias
to the ASCII op and gets rewritten to it. If there's a consensus to do
that, it should be done for all the ops,
even ones that don't have this performance issue (which is due to
capture slipping).

For now, I basically restored lizmat++'s original fix adding whatever
datish ops that were
originally missing as well​:
rakudo/rakudo@6ad06fa

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