Re: Altivec in baseline for ppc64?
On 7/13/21, John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> wrote:
> I wasn't really a fan of that change but my stance is that we should use
> AltiVec
> in packages where it makes sense as the majority of the ppc64 port users
> will
> have a machine that suppport AltiVec.
please *do not* do this.
we are designing a modern Libre/Open CPU which will not punish
developers or ourselves, stabbing ourselves in the head with 950
instructions.
Power ISA is supposed to be RISC.
the only reason SIMD was made mandatory in EABI v2 was because there
was nobody making hardware other than IBM to object to what is
becoming recognised as an extremely serious and costly mistake for the
future of the OpenPOWER ecosystem.
if people continue to assume that SIMD is acceptable just because the
only current hardware is from IBM it only makes it harder and more and
more costly to unravel the f***up and widens and already yawning
barrier to entry for new implementations of OpenPOWER.
PLEASE, really, for god's sake, please do NOT recommend people
propagate the SIMD paradigm.
https://www.sigarch.org/simd-instructions-considered-harmful/
l.
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