Re: [PATCH 04/10] x86: "prefix_extra" can't really be "2"

[Hongtao Liu via Gcc-patches]

On Thu, Aug 3, 2023 at 4:11 PM Jan Beulich via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> In the three remaining instances separate "prefix_0f" and "prefix_rep"
> are what is wanted instead.
Ok.
>
> gcc/
>
>         * config/i386/i386.md (rd<fsgs>base<mode>): Add "prefix_0f" and
>         "prefix_rep". Drop "prefix_extra".
>         (wr<fsgs>base<mode>): Likewise.
>         (ptwrite<mode>): Likewise.
>
> --- a/gcc/config/i386/i386.md
> +++ b/gcc/config/i386/i386.md
> @@ -25914,7 +25914,8 @@
>    "TARGET_64BIT && TARGET_FSGSBASE"
>    "rd<fsgs>base\t%0"
>    [(set_attr "type" "other")
> -   (set_attr "prefix_extra" "2")])
> +   (set_attr "prefix_0f" "1")
> +   (set_attr "prefix_rep" "1")])
>
>  (define_insn "wr<fsgs>base<mode>"
>    [(unspec_volatile [(match_operand:SWI48 0 "register_operand" "r")]
> @@ -25922,7 +25923,8 @@
>    "TARGET_64BIT && TARGET_FSGSBASE"
>    "wr<fsgs>base\t%0"
>    [(set_attr "type" "other")
> -   (set_attr "prefix_extra" "2")])
> +   (set_attr "prefix_0f" "1")
> +   (set_attr "prefix_rep" "1")])
>
>  (define_insn "ptwrite<mode>"
>    [(unspec_volatile [(match_operand:SWI48 0 "nonimmediate_operand" "rm")]
> @@ -25930,7 +25932,8 @@
>    "TARGET_PTWRITE"
>    "ptwrite\t%0"
>    [(set_attr "type" "other")
> -   (set_attr "prefix_extra" "2")])
> +   (set_attr "prefix_0f" "1")
> +   (set_attr "prefix_rep" "1")])
>
>  (define_insn "@rdrand<mode>"
>    [(set (match_operand:SWI248 0 "register_operand" "=r")
>


-- 
BR,
Hongtao