[llvm] [RISCV] Add extension information to RISCVFeatures.td. NFC (PR #89326)

[Pengcheng Wang via llvm-commits]

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@@ -146,28 +164,28 @@ def HasStdExtMOrZmmul
 // Atomic Extensions
 
 def FeatureStdExtA
-    : SubtargetFeature<"a", "HasStdExtA", "true",
-                       "'A' (Atomic Instructions)">;
+    : RISCVExtension<"a", 2, 1, "HasStdExtA", "true",
+                     "'A' (Atomic Instructions)">;
 def HasStdExtA : Predicate<"Subtarget->hasStdExtA()">,
                  AssemblerPredicate<(all_of FeatureStdExtA),
                                     "'A' (Atomic Instructions)">;
 
 def FeatureStdExtZtso
-    : SubtargetFeature<"experimental-ztso", "HasStdExtZtso", "true",
-                       "'Ztso' (Memory Model - Total Store Order)">;
+    : RISCVExperimentalExtension<"ztso", 0, 1, "HasStdExtZtso", "true",
+                                 "'Ztso' (Memory Model - Total Store Order)">;
 def HasStdExtZtso : Predicate<"Subtarget->hasStdExtZtso()">,
                     AssemblerPredicate<(all_of FeatureStdExtZtso),
                         "'Ztso' (Memory Model - Total Store Order)">;
 def NotHasStdExtZtso : Predicate<"!Subtarget->hasStdExtZtso()">;
 
-def FeatureStdExtZa64rs : SubtargetFeature<"za64rs", "HasStdExtZa64rs", "true",
-                                           "'Za64rs' (Reservation Set Size of at Most 64 Bytes)">;
+def FeatureStdExtZa64rs : RISCVExtension<"za64rs", 1, 0, "HasStdExtZa64rs", "true",
+                                         "'Za64rs' (Reservation Set Size of at Most 64 Bytes)">;
 
-def FeatureStdExtZa128rs : SubtargetFeature<"za128rs", "HasStdExtZa128rs", "true",
-                                            "'Za128rs' (Reservation Set Size of at Most 128 Bytes)">;
+def FeatureStdExtZa128rs : RISCVExtension<"za128rs", 1, 0, "HasStdExtZa128rs", "true",
+                                          "'Za128rs' (Reservation Set Size of at Most 128 Bytes)">;
 
 def FeatureStdExtZaamo
-    : SubtargetFeature<"experimental-zaamo", "HasStdExtZaamo", "true",
+    : RISCVExperimentalExtension<"zaamo", 0, 2, "HasStdExtZaamo", "true",
                        "'Zaamo' (Atomic Memory Operations)">;
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wangpc-pp wrote:

ditto.

https://github.com/llvm/llvm-project/pull/89326