[clang] [CIR] Implement 'loop hint' lowering (PR #232975)

[Erich Keane via cfe-commits]

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@@ -953,6 +953,140 @@ def CIR_FenvAttr : CIR_Attr<"Fenv", "fenv"> {
   let canHaveIllegalCXXABIType = 0;
 }
 
+//===----------------------------------------------------------------------===//
+// CIR_FlagParam
+//===----------------------------------------------------------------------===//
+
+/// A simple UnitAttr wrapper so that an attributes parameter can print JUST its
+/// name and be used with the ($keyword^)? syntax in assemblyFormat.
+class CIR_FlagParam<string keyword> : OptionalParameter<"mlir::UnitAttr"> {
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erichkeane wrote:

Yes, exactly that.  The printers for operations don't seem available in attributes.  I tried to use OILIST and it has that problem too.

https://github.com/llvm/llvm-project/pull/232975