JSpeed

UPDATE

I haven't had much time to work on the AST implementation of this project, so I went back to the original version, that solely used regular expressions. I've posted a pre-release in the downloads section. You can read how to implement it by heading over to the wiki;

JSpeed Implementation

News

• There are defects to be ironed out with this project, and those will begin to diminish as I get more time to work on this. If you encounter problems, please post issues, thanks!
• I uploaded a new version (0.2.0), which has the index as an interface for JSpeed. This way, you can avoid having to setup the PHP object all together.
• I haven't worked on this project lately, due to time constraints and other interests, but I plan to redirect my focus towards it.
• Thanks for your emails! I will look into applying some of the optimizations in a later release.

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The JSpeed engine analyzes different portions of your JS code for fragments which can be optimized, and substitutes them with faster code.

Optimization Example:

    for (i=0;i<1;i++) {
	j = i + 1;
	f = Math.floor(i);
	f = Math.floor(21.4);
}

for (i = 0, j = 0; i < 1000000; i++, j++) {
	if (i == 4) {
		var tmp = i / 2;
		a = Math.abs(i);
	}
	
	if ((i % 2) == 0) {
		var tmp = i / 2;
		tmp = Math.min(i,tmp);
		i++;
	}
}
var arr = new Array(1000000);
for (var i = 0; i < arr.length; i++) {}

before: ~14 ms

  for (var i=0;i<1;++i) {
	j = i + 1;
	f = i>>0;
	f = 21.4>>0;
}

for (var i = 0, j = 0; i < 1000000; ++i, ++j) {
	if (i == 4) {
		var tmp = i >> 1;
		a = i < 0 ? ~i++ : i;
	}
	
	if ((i & 1) == 0) {
		var tmp = i >> 1;
		tmp = i < tmp ? i : tmp;
		i++;
	}
}
var arr = new Array(1000000);
for (var i = 0, arr_len = arr.length; i < arr_len; ++i) {}

after: ~7 ms

Features

• Helps make your code faster!
• Specify which part of your code (e.g. for-loops, function, global, etc.) you want JSpeed to target, and select which optimizations you want performed on it.
• Optimizations can be made via a regular expression, or through a callback function, in PHP.
• Minifies JavaScript code after it has been optimized
• Can take an array of scripts, and return each one separately, or concatenate them all into one (1) file.

Current Optimizations

• Division by 2,4,8
• Multiplication by 2,4,8
• Math.min optimization
• Math.floor optimization
• Math.abs optimization
• Even/odd check, i % 2 == 0
• Change for-loop conditional variables to local
• Post-increment to pre-increment
• Store array length in a variable in for-loops
• Code minification
• Join multiple scripts into one (1) optified (optimized/minifed) script.

Contact

If you have any inquiries or even have some optimization ideas to contribute, please send me an e-mail.

Thanks for looking!