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

[BALATON Zoltan <balaton@eik.bme.hu>]

Hello,

Sorry to comment on this without really knowing what is it about but maybe 
my view is not completely useless if this is to be understood by people 
who don't know anything about it. If it is not useful just ignore.

On Tue, 20 Aug 2019, Richard Henderson wrote:
> Would it be clearer to use the x86 instruction name: SHRD (SHift Right Doubleword)?

Not unless you name it shr32 or something like that. SHRD does not look 
meaningful without knowing the instruction and elsewhere you use bit 
numbers instead of b, w, d letters. (I don't know if shr32 is actually a 
good name for this op, just commenting on the naming itself.)

> What if we use the AArch64 mnemonics: zxt (zero-extend) and sxt (sign-extend)?
> This would give us
>
>    tcg_gen_zxt8_i32
>    tcg_gen_sxt8_i32
>    (etc)
>    tcg_gen_zxt_i32_i64
>    tcg_gen_sxt_i32_i64

Again this might look familiar to those knowing AArch64 but not to someone 
who does not know that. Maybe zext sext is a bit more decypherable.

In general I think it would be best to name these to describe what they do 
not necessarily following any other ISA naming because that's only useful 
for those who know those particular instructions so maybe it should be 
consistent within TCG and does not have to match what CPUs call it.

Regards,
BALATON Zoltan