Bug #79353 [Com]: bad optimizing "Null Coalescing Assignment"
Edit report at https://bugs.php.net/bug.php?id=79353&edit=1
ID: 79353
Comment by: melindaetinw81 at gmail dot com
Reported by: bugreports at gmail dot com
Summary: bad optimizing "Null Coalescing Assignment"
Status: Assigned
Type: Bug
Package: opcache
PHP Version: 7.4Git-2020-03-08 (Git)
Assigned To: nikic
Block user comment: N
Private report: N
New Comment:
I'll be sure to keep an eye on this thread.
(https://www.myiclubonline.biz/)github.com
Previous Comments:
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[2020-03-10 10:44:11] nikic@php.net
Yes, this is only for master, as the change is non-trivial.
I'm also keeping this issue open, because we should still try to remove the COALESCE itself.
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[2020-03-10 10:29:40] bugreports at gmail dot com
as i understand that it will be part of PHP8 and not optimized for 7.4?
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[2020-03-09 15:21:19] nikic@php.net
https://github.com/php/php-src/commit/d9c45d86f9cd3d20f66ebf38384a9f53113415e5
Pi node placement turned out to be more complicated than anticipated, because it did not pass our
existing profitability heuristic.
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[2020-03-09 14:34:50] nikic@php.net
I think we mainly need to add pi node placement for coalesce.
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[2020-03-08 02:46:53] bugreports at gmail dot com
Description:
------------
with opcache other than "Null coalescing operator" the "Null Coalescing
Assignment" is not completly optimized out
function a()
{
$test = $test ?? TRUE;
return $test;
}
function b()
{
$test ??= TRUE;
return $test;
}
runtime difference with 50000000 calls:
a(): 3.1884
b(): 3.3666
function name: a
number of ops: 2
----------------------------------------------------------------------------------
5 0* COALESCE ~1 !0
6 1* RETURN <true>
function name: b
number of ops: 3
----------------------------------------------------------------------------------
11 0* COALESCE ~1 !0
1* ASSIGN $2 !0, <true>
12 2* RETURN !0
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Edit this bug report at https://bugs.php.net/bug.php?id=79353&edit=1
Thread (7 messages)