Generic speed question (PHP vs.) Post: 302663993

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Top Forums Programming Generic speed question (PHP vs.) Post 302663993 by Corona688 on Thursday 28th of June 2012 05:23:27 PM

06-28-2012

Registered User

General discussion can only tell you general things. In short, not too helpful.

How to optimize also depends on the code to be optimized. A general conversation can't tell you much.

That function, for instance, can be replaced with a table lookup. You can only calculate factorials so high anyway before your integers or even your floats overflow. Just make a big array, so that instead of making 17 function calls to calculate one number, you make one array lookup.

If you insist on calculating it, there's no point recursing here, just loop.

Code:

$m=1;
while($n>1)
{
  $m *= $n;
  $n--;
}

C can make things like this much faster, yes. I think I wrote a loop to calculate fibbonaci numbers that was 2 or 3 instructions long once. But arrays beat even that. One array lookup in C can amount to one instruction.

But C isn't the best thing in the world for dealing with CGI, something PHP excels at. What you gain by using C might be lost by having to write PHP's easy features from scratch.

Corona688

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php-config

php-config(1)							Scripting Language						     php-config(1)

NAME

       php-config - get information about PHP configuration and compile options

SYNOPSIS

       php-config [options]

DESCRIPTION

       php-config is a simple shell script for obtaining information about installed PHP configuration.

OPTIONS

       --prefix       Directory prefix where PHP is installed, e.g. /usr/local
       --includes     List of -I options with all include files
       --ldflags      LD Flags which PHP was compiled with
       --libs	      Extra libraries which PHP was compiled with
       --man-dir      The directory prefix where the manpages is installed
       --extension-dir
		      Directory where extensions are searched by default
       --include-dir  Directory prefix where header files are installed by default
       --php-binary   Full path to php CLI or CGI binary
       --php-sapis    Show all SAPI modules available
       --configure-options
		      Configure options to recreate configuration of current PHP installation
       --version      PHP version
       --vernum       PHP version as integer

SEE ALSO

       php(1)

VERSION INFORMATION

       This manpage describes php, version 7.1.19.

COPYRIGHT

       Copyright (C) 1997-2018 The PHP Group

       This  source  file  is  subject to version 3.01 of the PHP license, that is bundled with this package in the file LICENSE, and is available
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       If you did not receive a copy of the PHP license and  are  unable  to  obtain  it  through  the	world-wide-web,  please  send  a  note	to
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The PHP Group							       2018							     php-config(1)