Re: target/ppc: Move VMX int add/sub saturate insns to decodetree.

[Richard Henderson <richard.henderson@linaro.org>]

On 5/12/24 11:38, Chinmay Rath wrote:
> 1. vsubsbs and bcdtrunc :
> 
> In this pair, bcdtrunc has the insn flag check PPC2_ISA300 in the
> vmx-impl file, within the GEN_VXFORM_DUAL macro, which does this flag
> check.
> However it also has this flag check in the vmx-ops file.
> Hence I have retained the same in the new entry in the vmx-ops file.
> This is consistent with the behaviour in done in the following commit :
> https://github.com/qemu/qemu/commit/b132be53a4ba6a0a40d5643d791822f958a36e53
> So even though the flag check is removed from the vmx-impl file, it is
> retained in the vmx-ops file. All good here.
> 
> 2. vadduhs and vmul10euq :
> 
> In this pair, vmul10euq has the insn flag check PPC2_ISA300 in the
> vmx-impl file, check done within the GEN_VXFORM_DUAL macro.
> However the same flag was NOT originally present in the
> vmx-ops file, so I have NOT included in its new entry in the vmx-ops
> file. I have done this, following the behaviour done in the following
> commit :
> https://github.com/qemu/qemu/commit/c85929b2ddf6bbad737635c9b85213007ec043af
> So this flag check for vmul10euq is excluded now. Is this not a problem ?
> I feel that this leads to the flag check being skipped now, however this
> behaviour was followed in the above mentioned commit.

This second link is for VAVG* and VABSD*.

Yes you are correct that this second case was done incorrectly. Thankfully the mistake was 
fixed in the very next commit, when VABSD* was converted to decodetree as well.


r~