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  • lefty2 - Tuesday, November 10, 2015 - link

    I didn't even know you could have 32-bit ARMv8.
    ARMv8 normally has a disadvantage for mobile because the 64-bit uses up more memory and mobile devices don't have more than 4GB of memory - so the 64-bit addressing is useless. However, the extra registers provide a preformance boost. So 32 bit ARMv8 has the benefit of the extra registers without the crutch of the 64-bit ness.
  • sprockkets - Tuesday, November 10, 2015 - link

    You can also have 32bit memory space with 64 bit code. Fun huh? Supposedly android went that route to avoid the problems apple suffered when they went 64 bit (safari anyone?). Though one person said that wasn't the case.
  • Daniel Egger - Tuesday, November 10, 2015 - link

    I thought that AArch32 was covered in an AT article some time ago. AArch64 has more advantages than simply more registers and 64bit address space allows a lot more than just addressing more than 4GB of memory at once. The memory overhead is actually negligible as really the only thing which is always 64bit wide are addresses however in a load-store-architecture there're actually rather few OPs operating directly on addresses so even if the kernel (and only the kernel) was AArch64 to optionally allow for 64bit applications the overhead is probably not even noticeable.

    However people love looking for arbitrary reasons to mask their inability to write decent software and most Android applications are real pigs in that regard.
  • lefty2 - Tuesday, November 10, 2015 - link

    > AArch64 has more advantages than simply more registers and 64bit address space allows
    No, but those are the main advantages
    > The memory overhead is actually negligible
    Not true and there are benchmarks that actually prove this.
  • loa - Wednesday, November 11, 2015 - link

    There is a significant disadvantage to using 64-bit pointers if you don't need more than 4gb of adress space.
    Just google for "intel x32". This is Intels attempt at having the advantages of x86-64 (mainly more registers) with the smaller pointer size of 32-bit applications.
    You get an integer performance in average application of about 5-10%, and a memory reduction of about 10-15%. In pointer-intensive applications, like JavaScript, the advantage is higher.
  • r3loaded - Tuesday, November 10, 2015 - link

    ARMv8 was more than just about going 64-bit. It gave ARM a chance to clean up the ISA, removing features such as conditional execution that aren't really necessary nowadays. With v8-M now official and a new release of ARM Compiler 6 due shortly with v8-M support, our general advice to partners in all sectors working on a new project is to target v8, even if they're not interested in 64-bit addressing. There's no reason not to at this point.
  • Mr Perfect - Tuesday, November 10, 2015 - link

    I'm not really sure what these new M parts affect. Phones and tablets have the A series and in-car looks to be R, so what are these Ms used in?
  • Ryan Smith - Tuesday, November 10, 2015 - link

    Everything else. Sensors, wearables, etc. Anything where a very basic processor would fit the bill.
  • Anato - Wednesday, November 11, 2015 - link

    Payment terminals, burglar alarm, industrial monitor & control, I think there will be 2-10 times more applications and use cases for M series than there is A+R combined. You just don't think it as its hidden...
  • flgt - Wednesday, November 11, 2015 - link

    Things like Xbox One controller for another example...

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