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From "Shazron Abdullah (JIRA)" <>
Subject [jira] [Commented] (CB-4863) Drop iOS 5.0 support
Date Thu, 19 Dec 2013 18:29:07 GMT


Shazron Abdullah commented on CB-4863:

>From :
Perf gains for 64 bit:

The 64-bit isa pointer for an Objective-C object only uses 31 bits, the
rest of the 33 bits are used for an inline reference count. Previously,
reference counting was in an external table. The old way was slower, thus
the new way results in performance gains for object alloc/dealloc.

"My casual benchmarking indicates that basic object creation and
destruction takes about 380ns on a 5S running in 32-bit mode, while it's
only about 200ns when running in 64-bit mode. If any instance of the class
has ever had a weak reference and an associated object set, the 32-bit time
rises to about 480ns, while the 64-bit time remains around 200ns for any
instances that were not themselves the target.

In short, the improvements to Apple's runtime make it so that *object
allocation in 64-bit mode costs only 40-50% of what it does in 32-bit mode*.
If your app creates and destroys a lot of objects, that's a big deal."

> Drop iOS 5.0 support
> --------------------
>                 Key: CB-4863
>                 URL:
>             Project: Apache Cordova
>          Issue Type: Improvement
>          Components: iOS
>    Affects Versions: 3.0.0
>            Reporter: Shazron Abdullah
>            Assignee: Shazron Abdullah
>            Priority: Minor
>              Labels: ios7
> Adding this issue for discussion.
> We still support iOS 5.0 in the Deployment Target.
> iOS 6.0 and greater support enables arm64 support (64-bit) but not sure of any advantages
there, really. 
> Also, this is consistent with our previous support where we only support the current
iOS version and one version back. Also, finding a device with iOS 5 support (besides the iPad
1, which cannot have iOS 6 support) is becoming problematic.
> iOS 6 API diffs from 5:
> Apple's note regarding 64-bit support:
> {quote}
> If you wish to continue to support iOS 6 then you will need to build for 32-bit only.
Next month we will be making changes that will allow you to create a single app binary that
supports 32-bit on iOS 6, as well as 32-bit and 64-bit on iOS 7. 
> {quote}
> So, based on that I think if we go ahead and support arm64 we wait for this 64-bit iOS
fat binary functionality coming "next month". This probably will coincide with their Mavericks
10.9 OS and SDK release with the new accompanying Xcode bump.

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