Re: [Qemu-devel] [PATCH v1 15/41] s390x/tcg: Implement VECTOR GALOIS FIELD MULTIPLY SUM (AND ACCUMULATE)

[Richard Henderson]

On 4/11/19 12:08 AM, David Hildenbrand wrote:
> A galois field multiplication in field 2 is like binary multiplication,
> however instead of doing ordinary binary additions, xor's are performed.
> So no carries are considered.
> 
> Implement all variants via helpers. s390_vec_sar() and s390_vec_shr()
> will be reused later on.
> 
> Signed-off-by: David Hildenbrand <address@hidden>
> ---
>  target/s390x/helper.h           |   8 ++
>  target/s390x/insn-data.def      |   4 +
>  target/s390x/translate_vx.inc.c |  38 ++++++++
>  target/s390x/vec_int_helper.c   | 168 ++++++++++++++++++++++++++++++++
>  4 files changed, 218 insertions(+)

FYI, this is now the 4th copy of this operation.

  arm: pmull
  x86: pclmulqdq
  ppc: vpmsum[bhwd]

We really should promote this to generic.  But that can come later,

Reviewed-by: Richard Henderson <address@hidden>


r~