[Mlir-commits] [mlir] [MLIR][LLVM] Attach kernel metadata representation to `llvm.func` (PR #101314)

[Tobias Gysi]

================
@@ -226,6 +241,129 @@ static LogicalResult setNoaliasScopesAttr(const llvm::MDNode *node,
   return success();
 }
 
+/// Extract constant integer value from metadata if this is constant. Return
+/// `std::nullopt` otherwise.
+static std::optional<int32_t> parseIntegerMD(llvm::Metadata *md) {
+  auto *c = llvm::dyn_cast_or_null<llvm::ConstantAsMetadata>(md);
+  if (!c)
+    return {};
+
+  auto *ci = dyn_cast<llvm::ConstantInt>(c->getValue());
+  if (!ci)
+    return {};
+
+  return ci->getValue().getSExtValue();
+}
+
+/// Convert an `MDNode` to an LLVM dialect `VecTypeHintAttr` if possible.
+static VecTypeHintAttr convertVecTypeHint(Builder builder, llvm::MDNode *md,
+                                          ModuleImport &moduleImport) {
+  if (!md || md->getNumOperands() != 2)
+    return {};
+
+  auto *hintMD = dyn_cast<llvm::ValueAsMetadata>(md->getOperand(0).get());
+  if (!hintMD)
+    return {};
+  TypeAttr hint = TypeAttr::get(moduleImport.convertType(hintMD->getType()));
+
+  std::optional<int32_t> optIsSigned = parseIntegerMD(md->getOperand(1).get());
+  if (!optIsSigned)
+    return {};
+  bool isSigned = *optIsSigned != 0;
+
+  return builder.getAttr<VecTypeHintAttr>(hint, isSigned);
+}
+
+/// Convert an `MDNode` to an MLIR `DenseI32ArrayAttr` if possible.
+static DenseI32ArrayAttr convertDenseI32Array(Builder builder,
+                                              llvm::MDNode *md) {
+  if (!md)
+    return {};
+  SmallVector<int32_t> vals;
+  for (const llvm::MDOperand &op : md->operands()) {
+    std::optional<int32_t> mdValue = parseIntegerMD(op.get());
+    if (!mdValue)
+      return {};
+    vals.push_back(*mdValue);
+  }
+  return builder.getDenseI32ArrayAttr(vals);
+}
+
+/// Convert an `MDNode` to an MLIR `IntegerAttr` if possible.
+static IntegerAttr convertIntegerMD(Builder builder, llvm::MDNode *md) {
+  if (!md || md->getNumOperands() != 1)
+    return {};
+  std::optional<int32_t> val = parseIntegerMD(md->getOperand(0));
+  if (!val)
+    return {};
+  return builder.getI32IntegerAttr(*val);
+}
+
+template <typename Encoder, typename Setter>
----------------
gysit wrote:

Could we have one template argument for the attribute type here and then use function_ref to replace the Setter / Encoder ? E.g. the encoder would be function_ref<AttrTy(llvm::MDNode*)>

https://github.com/llvm/llvm-project/pull/101314