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

[Tobias Gysi]

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@@ -149,6 +150,72 @@ static LogicalResult convertInstructionImpl(OpBuilder &odsBuilder,
   return failure();
 }
 
+/// Depth-first conversion of the metadata node `md` to the matching LLVM
+/// dialect metadata attribute. Returns a null attribute for shapes that the
+/// dialect's metadata-attribute hierarchy does not currently model. `path`
+/// holds the metadata nodes on the current depth-first search path. Cyclic
+/// metadata graphs are valid in LLVM IR, but they cannot be expressed by the
+/// immutable, structurally-uniqued metadata attributes built here. The `path`
+/// set lets the traversal recognize such a back-edge and bail out. `attrMap`
+/// caches the attributes of fully converted nodes so that shared subgraphs
+/// are visited only once.
+static Attribute
+convertMetadataToAttrImpl(MLIRContext *ctx, const llvm::Metadata *md,
+                          SmallPtrSetImpl<const llvm::Metadata *> &path,
+                          DenseMap<const llvm::Metadata *, Attribute> &attrMap) {
+  if (!md)
+    return {};
+  if (auto *mdStr = dyn_cast<llvm::MDString>(md))
+    return MDStringAttr::get(ctx, StringAttr::get(ctx, mdStr->getString()));
+  if (auto *cam = dyn_cast<llvm::ConstantAsMetadata>(md)) {
+    auto *ci = dyn_cast<llvm::ConstantInt>(cam->getValue());
+    if (!ci)
+      return {};
+    auto intType = IntegerType::get(ctx, ci->getBitWidth());
+    return MDConstantAttr::get(ctx, IntegerAttr::get(intType, ci->getValue()));
+  }
+  if (auto *vam = dyn_cast<llvm::ValueAsMetadata>(md)) {
+    auto *fn = dyn_cast<llvm::Function>(vam->getValue());
+    if (!fn)
+      return {};
+    return MDFuncAttr::get(ctx, FlatSymbolRefAttr::get(ctx, fn->getName()));
+  }
+  if (auto *node = dyn_cast<llvm::MDNode>(md)) {
+    if (Attribute cached = attrMap.lookup(node))
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gysit wrote:

I wonder if it would make sense to move that at the beginning of the function the cache the leaf nodes as well? Feel free to ignore this comment if it is too messy.

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