Subject: Re: [PATCH 1/2] powerpc/64s: Fix GENERIC_CPU build flags for PPC970 / G5

From: Segher Boessenkool <[email-masked]>
Date: Wed, 21 Sep 2022 13:50:31 -0500

On Wed, Sep 21, 2022 at 11:41:02AM +1000, Nicholas Piggin wrote:
> Big-endian GENERIC_CPU supports 970, but builds with -mcpu=power5.
> POWER5 is ISA v2.02 whereas 970 is v2.01 plus Altivec. 2.02 added
> the popcntb instruction which a compiler might use.
> 
> Use -mcpu=power4.
> 
> Fixes: 471d7ff8b51b ("powerpc/64s: Remove POWER4 support")
> Signed-off-by: Nicholas Piggin <[email-masked]>

Reviewed-by: Segher Boessenkool <[email-masked]>

Thank you!

Maybe superfluous, but some more context: GCC's -mcpu=power4 means
POWER4+, ISA 2.01, according to our documentation.  There is no
difference with ISA 2.00 (what plain POWER4 implements) for anything
GCC does.

Segher