[LLVMdev] Unaligned vector memory access for ARM/NEON.

Bob Wilson bob.wilson at apple.com
Sun Sep 9 22:44:35 PDT 2012

On Sep 7, 2012, at 4:46 PM, David Peixotto <dpeixott at codeaurora.org> wrote:
>> Note that this won't work on big-endian targets where changing the
>> vld1/vst1 element size actually changes the behavior of the instructions.
> Ok, so would it be best to put an explicit test for endianess in the code?
> The td files already contain restrictions some for endianess for selecting
> unaligned loads/stores. Probably the safest thing would be an explicit test,
> but it sounds like there is not a real effort to support big-endian arm
> targets anyway.
> I should be able to get the patch together and submit it for review next
> week.

I don't know if anyone actually uses arm processors in big-endian mode, but it shouldn't be too hard to conditionalize it.  If it does turn out to be difficult for some reason, we should at least have comments to indicate where the endian assumptions are being made.

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