[Mlir-commits] [mlir] Add more ZA modes (PR #77361)

[Benjamin Maxwell]

================
@@ -28,13 +28,15 @@ def ArmStreamingMode : I32EnumAttr<"ArmStreamingMode", "Armv9 Streaming SVE mode
   let genSpecializedAttr = 0;
 }
 
-// TODO: Add other ZA modes.
-// https://arm-software.github.io/acle/main/acle.html#sme-attributes-relating-to-za
 def ArmZaMode : I32EnumAttr<"ArmZaMode", "Armv9 ZA storage mode",
     [
       I32EnumAttrCase<"Disabled", 0, "disabled">,
       // A function's ZA state is created on entry and destroyed on exit.
       I32EnumAttrCase<"NewZA", 1, "arm_new_za">,
+      // A function that preserves ZA state.
+      I32EnumAttrCase<"PreservesZA", 2, "arm_preserves_za">,
----------------
MacDue wrote:

It's a little odd to have 'PreservesZA' as a ZA mode, as it's an attribute that can be used alongside `arm_new_za` or `arm_shared_za`, not an independent mode. 

https://github.com/llvm/llvm-project/pull/77361