Bug 126550

Summary: CStack Branch: Disable JIT stack alignment check for ARM64
Product: WebKit Reporter: Michael Saboff <msaboff>
Component: JavaScriptCoreAssignee: Michael Saboff <msaboff>
Status: RESOLVED FIXED    
Severity: Normal    
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: All   
OS: All   
Attachments:
Description Flags
Patch mark.lam: review+

Description Michael Saboff 2014-01-06 17:01:08 PST 
Since ARM64 enforces strict stack alignment, the need for checkStackPointerAlignment() is not needed.  Also, the implementation of checkStackPointerAlignment() would need to be reworked given the limits on the operations that can be done with the stack pointer register in ARM64.  Therefore checkStackPointerAlignment() should be conditionally disabled for ARM64.
Comment 1 Michael Saboff 2014-01-06 17:20:57 PST 
Created attachment 220474 [details]
Patch
Comment 2 Mark Lam 2014-01-06 17:39:06 PST 
Comment on attachment 220474 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=220474&action=review

r=me with comment fix.

> Source/JavaScriptCore/ChangeLog:8
> +        Disabled the compilation of the body of checkStackPointerAlignment for ARM64.

Can you put your bug comment here instead?  The bug comment said, "Since ARM64 enforces strict stack alignment, the need for checkStackPointerAlignment() is not needed.  Also, the implementation of checkStackPointerAlignment() would need to be reworked given the limits on the operations that can be done with the stack pointer register in ARM64.  Therefore checkStackPointerAlignment() should be conditionally disabled for ARM64."  I think your bug comment does a good job of explaining why we needed this change.
Comment 3 Michael Saboff 2014-01-06 17:53:41 PST 
Committed r161390: <http://trac.webkit.org/changeset/161390>