Re: [PATCH v3 4/8] target/ppc: add vmulld instruction

[Richard Henderson]

On 6/25/20 10:00 AM, Lijun Pan wrote:
> vmulld: Vector Multiply Low Doubleword.
> 
> Signed-off-by: Lijun Pan <ljp@linux.ibm.com>
> ---
> v3: use tcg_gen_gvec_mul()
> 
>  target/ppc/translate/vmx-impl.inc.c | 1 +
>  target/ppc/translate/vmx-ops.inc.c  | 4 ++++

This part looks fine.

>  tcg/ppc/tcg-target.h                | 2 ++
>  tcg/ppc/tcg-target.inc.c            | 7 +++++--

This part must be a separate patch.


> @@ -3149,6 +3150,7 @@ static void tcg_out_vec_op(TCGContext *s, TCGOpcode opc,
>      static const uint32_t
>          add_op[4] = { VADDUBM, VADDUHM, VADDUWM, VADDUDM },
>          sub_op[4] = { VSUBUBM, VSUBUHM, VSUBUWM, VSUBUDM },
> +        mul_op[4] = { 0, 0, VMULUWM, VMULLD },
>          neg_op[4] = { 0, 0, VNEGW, VNEGD },
>          eq_op[4]  = { VCMPEQUB, VCMPEQUH, VCMPEQUW, VCMPEQUD },
>          ne_op[4]  = { VCMPNEB, VCMPNEH, VCMPNEW, 0 },
> @@ -3199,8 +3201,9 @@ static void tcg_out_vec_op(TCGContext *s, TCGOpcode opc,
>          a1 = 0;
>          break;
>      case INDEX_op_mul_vec:
> -        tcg_debug_assert(vece == MO_32 && have_isa_2_07);
> -        insn = VMULUWM;
> +        tcg_debug_assert((vece == MO_32 && have_isa_2_07) ||
> +                         (vece == MO_64 && have_isa_3_10));
> +        insn = mul_op[vece];

I think it would be ok to just index mul_op here, since the real isa check is
to be done elsewhere.

Missing a change to tcg_can_emit_vec_op to do that isa check, and allow
INDEX_op_mul_vec to be used for MO_64.

Missing a change to tcg_target_init to test for PPC_FEATURE2_ARCH_3_1.


r~