[gcc r14-3020] x86: "prefix_extra" can't really be "2"

[gcc r14-3020] x86: "prefix_extra" can't really be "2"

[Jan Beulich]

https://gcc.gnu.org/g:0e877fd1b64626bca77395b481f00d65dc442ec3

commit r14-3020-g0e877fd1b64626bca77395b481f00d65dc442ec3
Author: Jan Beulich <jbeulich@suse.com>
Date:   Mon Aug 7 11:46:44 2023 +0200

    x86: "prefix_extra" can't really be "2"
    
    In the three remaining instances separate "prefix_0f" and "prefix_rep"
    are what is wanted instead.
    
    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.

Diff:
---
 gcc/config/i386/i386.md | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 9446ec35841..3a1973de13d 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -25920,7 +25920,8 @@
   "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")]
@@ -25928,7 +25929,8 @@
   "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")]
@@ -25936,7 +25938,8 @@
   "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")