[PATCH 8/9] x86: drop/replace IgnoreSize

[H.J. Lu]

On Wed, Mar 4, 2020 at 2:03 AM Jan Beulich <jbeulich@suse.com> wrote:
>
> Even after commit dc2be329b950 ("i386: Only check suffix in instruction
> mnemonic"), by which many of its uses have become unnecessary (some were
> unnecessary even before), IgnoreSize is still used for various slightly
> different purposes:
> - to suppress emission of an operand size prefix,
> - in Intel syntax mode to zap "derived" suffixes in certain cases and to
>   skip certain checks of remaining "derived" suffixes,
> - to suppress ambiguous operand size / missing suffix diagnostics,
> - for prefixes to suppress the "stand-alone ... prefix" warning.
> Drop entirely unnecessary ones and where possible also replace instances
> by the more focused (because of having just a single purpose) NoRex64.
>
> To further restrict when IgnoreSize is needed, also generalize the logic
> when to skip a template because of a present or derived L or Q suffix,
> by skipping immediate operands. Additionally consider mask registers and
> VecSIB there.
>
> Note that for the time being the attribute needs to be kept in place on
> MMX/SSE/etc insns (but not on VEX/EVEX encoded ones unless an operand
> template of them allows for only non-SIMD-register actuals) allowing for
> Dword operands - the logic when to emit a data size prefix would need
> further adjustment first.
>
> Note also that the memory forms of {,v}pinsrw get their permission for
> an L or Q suffix dropped. I can only assume that it being this way was a
> cut-and-paste mistake from the register forms, as the latter
> specifically have NoRex64 set, and the {,v}pextrw counterparts don't
> allow these suffixes either.
>
> Convert VexW= again to their respective VexW* on lines touched anyway.
>
> gas/
> 2020-03-XX  Jan Beulich  <jbeulich@suse.com>
>
>         * config/tc-i386.c (match_template): Extend code in logic
>         rejecting certain suffixes in certain modes to also cover mask
>         register use and VecSIB. Drop special casing of broadcast. Skip
>         immediates in the check.
>
> opcodes/
> 2020-03-XX  Jan Beulich  <jbeulich@suse.com>
>
>         * i386-opc.tbl: Drop IgnoreSize from various SIMD insns. Replace
>         VexW= by VexW* and VexVVVV=1 by just VexVVVV where applicable.
>         * i386-tbl.h: Re-generate.
>

OK.

Thanks.


-- 
H.J.