Re: [Qemu-devel] [EXTERNAL]Re: Proposal for amending TCG interface naming scheme

[David Hildenbrand <david@redhat.com>]

On 20.08.19 17:37, Richard Henderson wrote:
> On 8/20/19 6:49 AM, Aleksandar Markovic wrote:
>>> From: Peter Maydell <peter.maydell@linaro.org>
>>> On Tue, 20 Aug 2019 at 13:50, Aleksandar Markovic
>>> <amarkovic@wavecomp.com> wrote:
>>>> The idea is to provide significant "lexicographic" distance between those > groups of functions, rather than having the similar name (wiht common root > "ext) for all of them.
>>>
>>> The current naming of the extract/sextract TCG ops is intended to keep
>>> them in line with the extract32/sextract32/extract64/sextract64 utility
>>> functions in bitops.h. I think those ones are reasonably named. The
>>> other ops are a bit more ad-hoc in naming, admittedly...
>>>
>>
>> How about
>>
>> tcg_gen_extract2_i32
>> tcg_gen_extract2_i64
>> tcg_gen_extract2_tl
>> tcg_gen_extrl_i64_i32
>> tcg_gen_extrh_i64_i32
>> tcg_gen_ext_i32_i64
>> tcg_gen_extu_i32_i64
>>
>> to
>>
>> tcg_gen_gather_i32
>> tcg_gen_gather_i64
>> tcg_gen_gather_tl
> 
> I'm not sure how "gather" applies.  To me this sounds like a vector
> scatter/gather operation, where N different addresses are used to load the N
> elements of the vector.
> 
> When extract2 was named, I was only thinking "extract" because of how the
> AArch64 instruction that implements this operation is named (EXTR), and "extr"
> itself was already taken.  We did ask for naming suggestions at the time, but
> no better ideas were floated...
> 
> Would it be clearer to use the x86 instruction name: SHRD (SHift Right Doubleword)?
> 

I still think your proposal back then made sense - extract2. Extract a
64bit value from a 128bit value.

-- 

Thanks,

David / dhildenb