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To: "php-dev" <internals@lists.php.net>, "Antony Dovgal" <antony@zend.com>,
        "Andrei Zmievski" <andrei@gravitonic.com>
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Date: Mon, 13 Nov 2006 06:46:50 -0600
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Subject: Re: [PHP-DEV] zend_u_strtod() 400% speed up
From: php_lists@realplain.com ("Matt Wilmas")

Hi Antony,

----- Original Message -----
From: "Antony Dovgal"
Sent: Friday, November 10, 2006

> On 11/10/2006 02:14 PM, Matt Wilmas wrote:
> > Hi Antony,
> >
> > ----- Original Message -----
> > From: "Antony Dovgal"
> > Sent: Friday, November 10, 2006
> >
> >> Hello all.
> >>
> >> I would like to propose a replacement for current zend_u_strtod()
> > implementation.
> >> The patch: http://tony2001.phpclub.net/dev/tmp/u_strtod.diff
> >>
> >> According to my tests, new implementation is faster in about 40 (forty)
> > times.
> >> The simple script below takes ~1 sec to run with the patch and ~40
seconds
> > without.
> >
> > Cool. :-)  I'd just been thinking about zend_u_strtod() again -- if you
see
> > my thread asking Andrei about the Unicode characters allowed as
numbers...
> > I changed the function back in the summer to be about 8x faster by
> > converting FROM Unicode and using the regular zend_strtod(), but it was
just
> > a quick hack, so maybe better that it wasn't applied!
> > http://realplain.com/php/zend_u_strtod.diff
>
> Hmm.. Actually, your version seems to be slightly faster (~15%) than mine
> and there are several advantages, like no formatter is required, avoiding
> parsing non-numeric strings and less TSRMLS_FETCH() calls, which leads to
> even better results on non-numeric strings.
>
> Also, it looks like a good idea to use zend_strtod() in both native and
> unicode modes.

Hmm, I don't understand how mine was faster if yours was 40x faster than the
current version, as when I tested mine, it was only ~8x. :-/

Well anyway, as I mentioned in my first reply, I had another idea since I
learned (from README.UNICODE and Andrei) that only ASCII digits are allowed
in Unicode.  I just put this together:
http://realplain.com/php/zend_u_strtod.c  I didn't test it (or even try to
compile), but you get the idea -- "manually" copying the relevant Unicode
chars to a char * (am I doing that right?).  I've got the "char buf[64]"
there, assuming it's more efficient than using emalloc() (?), when the
number will fit.  I didn't know what size to make it, just whatever catches
the vast majority of cases...

I'd really like to see a faster version implemented soon. :-)


Matt