Bug 68782 - DFG JIT Construct opcode takes a this argument even though it's not passed
Summary: DFG JIT Construct opcode takes a this argument even though it's not passed
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: 528+ (Nightly build)
Hardware: All All
: P2 Normal
Assignee: Nobody
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-09-25 16:15 PDT by Filip Pizlo
Modified: 2011-09-25 17:00 PDT (History)
4 users (show)

See Also:

Attachments
the patch (4.37 KB, patch)
2011-09-25 16:35 PDT, Filip Pizlo 		oliver: review+
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Description Filip Pizlo 2011-09-25 16:15:52 PDT 
The DFG JIT Construct implementation initially involved passing a this argument to the Construct node, and then the implementation of the Construct node would pass this argument.  This was unnecessary, since Constructors create their own this argument.  This was then half fixed: the Constructor node implementation stopped passing the this argument.  But there is still a node generated for getting the this argument, and it is still a child of Construct.  This leads to dead code, is confusing to reason about, and probably hurts performance.
Comment 1 Filip Pizlo 2011-09-25 16:35:35 PDT 
Created attachment 108617 [details]
the patch
Comment 2 Filip Pizlo 2011-09-25 17:00:41 PDT 
Landed in r95927.