Bug 6167

Summary:

RenderStyle default constructor should initialize its members for speed

Product:

WebKit

Reporter:

Darin Adler <darin>

Component:

CSS

Assignee:

Darin Adler <darin>

Status:

RESOLVED FIXED

Severity:

Enhancement

CC:

hyatt, mjs

Priority:

Version:

420+

Hardware:

Mac

OS:

OS X 10.4

Attachments:

Description	Flags
both performance improvements described in the bug text	none
both performance improvements described in the bug text	eric: review+

Description Darin Adler 2005-12-20 09:24:32 PST

The default constructor for RenderStyle doesn't initialize its members. Instead it lets them all get default 
initialized and then uses assignment to set their initial values. This results in extra code because of the 
DataRef operator= implementation.

Also, DataRef's operator= should have the "==" check removed since that extra branch makes things a 
little slower.

Comment 1 Darin Adler 2005-12-21 22:47:47 PST

Created attachment 5215 [details]
both performance improvements described in the bug text

Comment 2 Darin Adler 2005-12-21 22:51:25 PST

Created attachment 5216 [details]
both performance improvements described in the bug text

Comment 3 Eric Seidel (no email) 2005-12-22 01:32:00 PST

Comment on attachment 5215 [details]
both performance improvements described in the bug text

Another great looking patch.  I assume this is a performance win?  r=me.

Comment 4 Eric Seidel (no email) 2005-12-22 01:38:39 PST

Comment on attachment 5215 [details]
both performance improvements described in the bug text

oops, wrong one.

Comment 5 Eric Seidel (no email) 2005-12-22 01:39:01 PST

Comment on attachment 5216 [details]
both performance improvements described in the bug text

r=me.

It looks like
 void RenderStyle::cleanup()
could just be killed entirely now.

Comment 6 Darin Adler 2005-12-22 08:32:22 PST

I left the cleanup function in there because Maciej has the commented-out counts in it. I would have 
removed it entirely if that wasn't there.