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Subject: Re: [PHP-DEV] Supporting object types in BCMath
In-Reply-To: <09F87F91-6538-48D2-9E34-0296E02CCC1A@sakiot.com>
Date: Mon, 18 Mar 2024 09:01:21 +0900
Cc: php internals <internals@lists.php.net>
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Message-ID: <B0C84CC1-8E07-4D90-9A76-E2BA0B483A62@sakiot.com>
References: <a1f10f65-2d44-45bf-8692-51398c168bbe@redmagic.org.uk>
 <09F87F91-6538-48D2-9E34-0296E02CCC1A@sakiot.com>
To: Barney Laurance <barney@redmagic.org.uk>
From: saki@sakiot.com (Saki Takamachi)

Hi,

I created a prototype, although it's pretty rough. It can overload =
operators and calculate not only between `BcNum` but also between =
`BcNum` and `int` or `string`.
https://github.com/php/php-src/pull/13741

I compared the execution times.

Test code:
```
<?php

$start =3D microtime(true);
$num =3D new BcNum('3.650000001', 10);
$num2 =3D new BcNum('4.2335185', 10);
for ($i =3D 0; $i < 1000000; $i++) {
$num3 =3D str_repeat('1', rand(1, 1));
$num4 =3D str_repeat('1', rand(1, 1));
$num =3D $num + $num3;
$num2 =3D $num2 - $num4;
$num =3D $num + $num2;
}
var_dump('BcNum and string: ' . microtime(true) - $start);

$start =3D microtime(true);
$num =3D new BcNum('3.650000001', 10);
$num2 =3D new BcNum('4.2335185', 10);
for ($i =3D 0; $i < 1000000; $i++) {
$num3 =3D new BcNum(str_repeat('1', rand(1, 1)), 10);
$num4 =3D new BcNum(str_repeat('1', rand(1, 1)), 10);
$num =3D $num + $num3;
$num2 =3D $num2 - $num4;
$num =3D $num + $num2;
}
var_dump('BcNum and BcNum: ' . microtime(true) - $start);

$start =3D microtime(true);
$num =3D '3.650000001';
$num2 =3D '4.2335185';
for ($i =3D 0; $i < 1000000; $i++) {
$num3 =3D str_repeat('1', rand(1, 1));
$num4 =3D str_repeat('1', rand(1, 1));
$num =3D bcadd($num, $num3, 10);
$num2 =3D bcsub($num2, $num4, 10);
$num =3D bcadd($num, $num2, 10);
}
var_dump('bcadd, bcsub: ' . microtime(true) - $start);
```

Result:
```
string(33) "BcNum and string: 3.2775790691376"
string(32) "BcNum and BcNum: 4.3857049942017"
string(29) "bcadd, bcsub: 4.2680249214172"
```

The execution speed ranking does not change even if the calculation is =
done simply by adding one time. When calculating between `BcNum`, the =
cost of creating an instance is probably high. However, since this =
difference was obtained after 1 million trials, it may be safe to assume =
that the difference is not that big.

Personally, I think the main point of this proposal is the increased =
convenience through operator overloading, not execution time.

Regards.

Saki=