[OE-core] [PATCH 1/3] Add ARM tune file overhaul based largely on work from Mark Hatle

[Khem Raj]

On 07/27/2011 08:25 AM, Phil Blundell wrote:
> On Wed, 2011-07-27 at 09:58 -0500, Mark Hatle wrote:
>> For the tune names..  armv5 means I want classic ARM instructions, while armv5t
>> means I was thumb instructions.
>>
>> So armv5 and armv5t are distinct in the contents of the tunings.
>
> Ah, I see.  Does that go for v4t too?  I can imagine cases where you
> would want to say "select the v4T ISA but generate ARM code not Thumb".
>
>> Yes, the mention of DSP should be using the 'e'.  What I'm not sure of is does
>> the "dsp" capabilities actually change any of the code or support generated.  If
>> not then we can ignore it.
>
> Yes.  PLD, for example, is only available in ARMv5E (not ARMv5) and this
> will affect any code which uses __builtin_prefetch().  I don't think GCC
> will ever open-code the saturating arithmetic instructions, but it does
> expose the v5/v5e distinction through preprocessor macros and source
> code might use that to select asm() statements which use those opcodes.

LDRD/STRD which are armv5e only are used by gcc IIRC

>
>> For armv5 this gives us:
>>
>> armv5, armv5t, armv5e, armv5te... add in their VFP variants and the hard float
>> EABI...
>
> Does anybody really want the hardfloat abi on armv5?  I guess it doesn't
> hurt all that much to offer it, but anything that makes that monstrous
> set of .inc files bigger seems like a bad thing.
>
> p.
>
>
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