[Mlir-commits] [mlir] [MLIR][LLVMIR] Add support for intrinsics with metadata arguments (PR #200308)

[Tobias Gysi]

================
@@ -2502,6 +2502,68 @@ def LLVM_InlineAsmOp : LLVM_Op<"inline_asm", [DeclareOpInterfaceMethods<MemoryEf
   let hasVerifier = 1;
 }
 
+//===--------------------------------------------------------------------===//
+// MetadataAsValueOp
+//===--------------------------------------------------------------------===//
+
+def LLVM_MetadataAsValueOp : LLVM_Op<"mlir.metadata_as_value", [Pure]> {
+  let summary =
+      "Wraps an LLVM `metadata` constant so it can be used as an SSA value.";
+  let description = [{
+    Materializes an `!llvm.metadata` SSA value that mirrors LLVM IR's
+    `llvm::MetadataAsValue`: a wrapper that lifts an arbitrary
+    `llvm::Metadata` node into the value domain so it can be used as an
+    operand to instructions that take `metadata` arguments (for example the
+    constrained floating-point intrinsics or `llvm.read_register`).
+
+    The wrapped metadata is described by the `metadata` attribute, which
+    must be one of the LLVM dialect's metadata-attribute classes:
+
+    * `#llvm.md_string<"...">` — `llvm::MDString`.
+    * `#llvm.md_const<...>` — `llvm::ConstantAsMetadata`.
+    * `#llvm.md_func<@symbol>` — `llvm::ValueAsMetadata` of a function.
+    * `#llvm.md_node<...>` — `llvm::MDNode` over any of the above.
----------------
gysit wrote:

```suggestion
    * `#llvm.md_string<"...">` -> `llvm::MDString`.
    * `#llvm.md_const<...>` ->`llvm::ConstantAsMetadata`.
    * `#llvm.md_func<@symbol>` -> `llvm::ValueAsMetadata` of a function.
    * `#llvm.md_node<...>` -> `llvm::MDNode` over any of the above.
```
nit:

https://github.com/llvm/llvm-project/pull/200308