Support for Marvell Quad-Core ARM Chips Found in Xcode

Friday September 23, 2011 9:25 AM PDT by Eric Slivka

Ars Technica reports that support for Marvell's quad-core Armada XP processor has recently been added to the version of Apple's "Clang" compiler used in its Xcode developer tools. It is unclear, however, why support for the ARM-based processor has been included.
A developer who works on low-level ARM assembly coding for security products was the first to alert Ars that support had been added for Armada's Cortex A9-compatible processors in the latest version of Xcode (a claim that we later confirmed first-hand). The source code for a part of Clang that interprets what CPU type is being targeted for optimization includes a definition for an architecture type of "armv7k" and CPU type "pj4b". PJ4B is a specially optimized CPU design used in Marvell's quad-core Armada XP embedded processors.
The reports suggests that while the inclusion of Armada XP support could point toward potential adoption of the processor in a future iOS device or even a MacBook Air, it is more likely that Apple is using the processor in prototypes simply for testing purposes as it continues work on its own ARM-based chips.

Several reports have indicated that Apple's next-generation A6 system-on-a-chip will offer a quad-core processor, although Ars Technica's report suggests that the A6 is primarily being designed as die shrink of the existing dual-core A5 design.

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Posted: 41 months ago
I still find it hard to believe that we're talking about a quad-core processor inside a phone! Just a few years ago, I was stunned that one was possible inside a desktop computer.
Rating: 8 Votes
Posted: 41 months ago
I wouldn't guess anything but prototyping. Their internal team has proven themselves more than capable with the A4 and A5.

I also agree with Ars' prediction that A6 will simply be a 28nm die shrink of the A5. Have to save all the power they can to squeeze in a new LTE chip from Qualcomm.
Rating: 4 Votes
Posted: 41 months ago
A4 and A5 are just modified Samsung ARM CPU's. maybe for A6 Apple is going with another reference design?
Rating: 3 Votes
Posted: 41 months ago

it's just multiple execution units that share a cache. it's not like real multiple CPU's on a single die


Mobile quad cores follow the same philosophy as desktop ones. I don't see a distinction. They both share caches too.
Rating: 3 Votes
Posted: 41 months ago
Clang is an open source project, that Apple is heavily invested in. But It could be that the support is included by someone else. Since it is an open source project, one could probably dig into the project and find out who included the support.

The Armada cores are ARMv7 compliant but they are not derived directly from ARM's own core design (Coretex A8 and A9) as are the A4 and A5. I have no clear idea of what this means for iOS development though.
I think it's unlikely that Apple will use Armada XP processors in any product since they are not designed for cellphones of portable devices. It's plausible though that Apple is using them for simulating stuff for future designs.
Rating: 2 Votes
Posted: 41 months ago

[obligatory] But will it play Crysis? [/obligatory]


Crysis?

Pffft . . .

Infinity Blade is the new benchmark. :p
Rating: 2 Votes
Posted: 41 months ago
http://www.appleinsider.com/articles/08/03/06/teardown_a_look_inside_apples_time_capsule_backup_appliance.html&page=2

Apple currently uses Marvell SoC in the Time Capsule and Airport Extreme. Perhaps Apple wants to expand the Time Capsule to become a mini-server and needs a quad core, but wants to stick with Marvell? This would certainly fit with those rumours before of the Time Capsule gaining the ability to store and stream both media and OS updates to connected devices.
Rating: 2 Votes
Posted: 41 months ago
It might very well be a testing lab thing. If someone wants to optimize addressing 4 cores just to see if the load spread is working properly, it is the right way to use an existing chip which is a close as it can get to the ones used right now. That does not mean it will be used in iDevices. When I use my 6 core processor, I see that even brand new software is not optimized for multicore systems beyond 2 cores. Early implementation in software design would help to save battery life down the line if programmers can test quadcores early on.
Rating: 1 Votes
Posted: 41 months ago
Not sure about the iPhone but a quad-core ipad 3 sure why not, blow everyone out of the water and humiliate them in the same sentence. ;)
Rating: 1 Votes
Posted: 41 months ago

obligatory "no". not all quad-cores are created equal.


Looks like someone needs to realize what sarcasm is…
Rating: 1 Votes

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