[PATCH, rs6000 V2] Update "prefix" attribute for Power10 [PR99133]

[Pat Haugen]

On 3/18/21 11:33 AM, will schmidt wrote:
> Per this change:
> 
> +;; Whether an insn is a prefixed insn.  A prefixed instruction has a prefix
> +;; instruction word that conveys additional information such as a larger
> +;; immediate, additional operands, etc., in addition to the normal instruction
> +;; word.  The default "length" attribute will also be adjusted by default to
> +;; be 12 bytes.
> +(define_attr "prefixed" "no,yes"
> +  (if_then_else (eq_attr "prepend_prefixed_insn" "yes")
> +		(const_string "yes")
> +		(const_string "no")))
> 
> 
> .. it looks like at least most of the users of the "prefixed" attribute have
> been switched over to use "prepend_prefixed_insn" instead.   Are there still
> users of the "prefixed" attribute remaining ?  I'm guessing so, given context,
> but can't tell for certain.
> 
> (Just a question, not a specific request for a change)

Yes, there are still a couple uses of get_attr_prefixed() in rs6000.c, plus the Power10 scheduling description makes use of it.

-Pat