Re: [PATCH] arch-armv7a.inc: default to Thumb2 instruction set for armv7a and above

[Khem Raj <raj.khem@gmail.com>]

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On Fri, May 18, 2018 at 3:50 PM Andre McCurdy <armccurdy@gmail.com> wrote:

> Although there may still be specific cases which can benefit from the
> ARM instruction set, the Thumb2 instruction set is generally a better
> default for armv7a class CPUs. Distros such as Debian and Fedora have
> been targeting Thumb2 by default for some time.
>
> Note that setting ARM_INSTRUCTION_SET has no effect unless
> TUNE_FEATURES contains "thumb" (which is controlled by the "t" suffix
> in DEFAULTTUNE, e.g. armv7vehf-neon -vs- armv7vethf-neon, etc) so out
> of tree machine configs may need to update their DEFAULTTUNE to take
> advantage of this change.



I think this is a good change and we shoudl take it in thumb2 is default
ISA
for other major distros as well

Oe based distros who ship feeds might be affected

>
>
> Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
> ---
>  meta/conf/machine/include/arm/arch-armv7a.inc | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/meta/conf/machine/include/arm/arch-armv7a.inc
> b/meta/conf/machine/include/arm/arch-armv7a.inc
> index bad1c27..a2663d8 100644
> --- a/meta/conf/machine/include/arm/arch-armv7a.inc
> +++ b/meta/conf/machine/include/arm/arch-armv7a.inc
> @@ -1,4 +1,5 @@
>  DEFAULTTUNE ?= "armv7athf"
> +ARM_INSTRUCTION_SET ?= "thumb"
>
>  TUNEVALID[armv7a] = "Enable instructions for ARMv7-a"
>  TUNECONFLICTS[armv7a] = "armv4 armv5 armv6 armv7"
> --
> 1.9.1
>
> --
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