[Mlir-commits] [mlir] [mlir][linalg] Extend elementwise (PR #124661)

[Rolf Morel]

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@@ -55,6 +55,50 @@ def TernaryFn : I32EnumAttr<"TernaryFn", "", [
   let genSpecializedAttr = 0;
   let cppNamespace = "::mlir::linalg";
 }
+
+// Join two I32EnumAttrCase lists. This joining takes care that the
+// 'int enum values' in the combined list do not overlap. It does this
+// by adding to each element of second list the offset '!size(a)'.
+class JoinTwoI32EnumAttrCaseList< list<I32EnumAttrCase> a,
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rolfmorel wrote:

Thanks for the alternative join-based approach, @javedabsar1 - It's quite impressive what can done with TableGen! (For better or worse, TableGen is a programming language on its own.)

I would still think an approach like @rengolin's would lead to simpler C++. The scheme I have in mind is to just shift the arity 30 bits, e.g.   `I32EnumAttrCase<"abs", 2>` becomes `I32EnumAttrCase<"abs", 2 + (1 << 30)>`, 
`I32EnumAttrCase<"div", 3 + (2 << 30)>`
`I32EnumAttrCase<"select", 0 + (3 << 30)>`. This way the arity can be retrieved by just shifting right 30 bits (e.g. `derivedEnumVal >> 30`) and to obtain the original op code you just do `derivedEnumVal & ((1 << 30) - 1)`.

Three nested `!lfold`s should now suffice to derive all the derived enum cases and `ElementwiseFnLimits` could go.

https://github.com/llvm/llvm-project/pull/124661