21 Nov
2020
21 Nov
'20
10:57 a.m.
On Sat, Nov 21, 2020 at 10:20 AM David Edelsohn dje.gcc@gmail.com wrote:
Please don't target Power7. Please target Power9, or at least Power8.
The PPC64LE Linux ABI specifies Power8 as the minimum ISA.
Power ISA 2.07 is Power8. ISA 3.0 is Power9. ISA 3.1 is Power10.
Small nit... PowerMac G4's and G5's still have a strong following. There's a lot of activity on Debian's PowerPC list.
The G4's and G5's provide Altivec acceleration and the old gcc compiler even accepts -mcpu=power4.
ChaCha is a simple algorithm that benefits from Altivec, even when you manage the 64-bit additions/carries in a 32x4 vector arrangement.
Jeff