Re: 1.25.0: aarch64-unknown-linux-gnu with neon support

Re: 1.25.0: aarch64-unknown-linux-gnu with neon support

[Chris Packham]

On Mon, Jun 13, 2022 at 2:29 PM Zvi Vered via crossgcc
<crossgcc@sourceware.org> wrote:
>
> Hello,
>
> I ran:
> ct-ng aarch64-unknown-linux-gnu
> but with this configuration, under "Target options" I can't set FPU.
>
>  How can I create gcc for armv8 (coretex A53), 64bit  with the option:
> -mfpu=neon

The aarch64 configs don't use the FPU option (I think because the FPU
is required by the ARMv8 spec). Instead you probably want to use the
-mcpu/-mtune options as per
https://gcc.gnu.org/onlinedocs/gcc-12.1.0/gcc/AArch64-Options.html#AArch64-Options

>
> Thank you,
> Zvika
> --
> For unsubscribe information see http://sourceware.org/lists.html#faq

1.25.0: aarch64-unknown-linux-gnu with neon support

[Zvi Vered]

Hello,

I ran:
ct-ng aarch64-unknown-linux-gnu
but with this configuration, under "Target options" I can't set FPU.

 How can I create gcc for armv8 (coretex A53), 64bit  with the option:
-mfpu=neon

Thank you,
Zvika

Re: 1.25.0: aarch64-unknown-linux-gnu with neon support

[Zvi Vered]

Hi Chris,

Thank you very much for your reply.
According to:
https://developer.arm.com/Processors/Cortex-A53

The architecture of Cortex-A53 is ARMv8.
Is has "Neon advanced SIMD"

I wonder how to configure crosstool 1.25.0 to fit exactly this CPU for
linux, 64bits.

Best regards,
Zvika


On Mon, Jun 13, 2022 at 12:24 PM Chris Packham <judge.packham@gmail.com>
wrote:

> On Mon, Jun 13, 2022 at 2:29 PM Zvi Vered via crossgcc
> <crossgcc@sourceware.org> wrote:
> >
> > Hello,
> >
> > I ran:
> > ct-ng aarch64-unknown-linux-gnu
> > but with this configuration, under "Target options" I can't set FPU.
> >
> >  How can I create gcc for armv8 (coretex A53), 64bit  with the option:
> > -mfpu=neon
>
> The aarch64 configs don't use the FPU option (I think because the FPU
> is required by the ARMv8 spec). Instead you probably want to use the
> -mcpu/-mtune options as per
>
> https://gcc.gnu.org/onlinedocs/gcc-12.1.0/gcc/AArch64-Options.html#AArch64-Options
>
> >
> > Thank you,
> > Zvika
> > --
> > For unsubscribe information see http://sourceware.org/lists.html#faq
>

Re: 1.25.0: aarch64-unknown-linux-gnu with neon support

[Chris Packham]

On Tue, Jun 14, 2022 at 3:21 PM Zvi Vered <veredz72@gmail.com> wrote:
>
> Hi Chris,
>
> Thank you very much for your reply.
> According to:
> https://developer.arm.com/Processors/Cortex-A53
>
> The architecture of Cortex-A53 is ARMv8.
> Is has "Neon advanced SIMD"
>
> I wonder how to configure crosstool 1.25.0 to fit exactly this CPU for linux, 64bits.
cortex-a53

Just the normal "aarch64-unknown-linux-gnu" sample should be fine.
There is also "aarch64-rpi3-linux-gnu" which targets cortex-a53
specifically but the only thing that really does is set the default
-mcpu value.

>
> Best regards,
> Zvika
>
>
> On Mon, Jun 13, 2022 at 12:24 PM Chris Packham <judge.packham@gmail.com> wrote:
>>
>> On Mon, Jun 13, 2022 at 2:29 PM Zvi Vered via crossgcc
>> <crossgcc@sourceware.org> wrote:
>> >
>> > Hello,
>> >
>> > I ran:
>> > ct-ng aarch64-unknown-linux-gnu
>> > but with this configuration, under "Target options" I can't set FPU.
>> >
>> >  How can I create gcc for armv8 (coretex A53), 64bit  with the option:
>> > -mfpu=neon
>>
>> The aarch64 configs don't use the FPU option (I think because the FPU
>> is required by the ARMv8 spec). Instead you probably want to use the
>> -mcpu/-mtune options as per
>> https://gcc.gnu.org/onlinedocs/gcc-12.1.0/gcc/AArch64-Options.html#AArch64-Options
>>
>> >
>> > Thank you,
>> > Zvika
>> > --
>> > For unsubscribe information see http://sourceware.org/lists.html#faq