Add clarifying comments based on code review feedback

compiler/src/iree/compiler/Codegen/Common/MaterializeTuningSpecsPass.cpp

@@ -132,6 +132,12 @@ struct MaterializeTuningSpecsPass final
         transform::TransformDialect::kWithNamedSequenceAttrName,
         UnitAttr::get(ctx));
     linkedTuningSpec->insert(linkedTuningSpec->begin(), userTuningSpec.clone());
+
+    // TODO(https://github.com/iree-org/iree/issues/19214): Add linked tuning
+    // spec memoization to IREECodegenDialect. We should be able to provide a
+    // list of input libraries that may have already been linked and ask the
+    // dialect to return it to us, or invoke a callback that will insert it if
+    // not found.
     FailureOr<transform::NamedSequenceOp> newEntrypoint =
         linkTuningSpecs(linkedTuningSpec.get());
     if (failed(newEntrypoint)) {

compiler/src/iree/compiler/Codegen/Common/Passes.td

@@ -439,6 +439,16 @@ def MaterializeEncodingIntoNopPass :
 def MaterializeTuningSpecsPass : Pass<"iree-codegen-materialize-tuning-specs", "ModuleOp"> {
   let summary =
       "Load tuning spec transform dialect libraries and encode them in the module";
+  let description = [{
+    Links all available tuning spec transform dialect modules into a single
+    tuning spec. Next, serializes this tuning spec to bytecode and attaches it
+    as a module attribute. We do this so that the full tuning spec is always
+    encoded in the program IR and can be checked with `--mlir-print-ir-after-all`
+    (or equivalent).
+
+    This attribute is expected to be short-lived and removed by
+    `iree-codegen-materialize-user-configs`.
+  }];
 }
 
 def MaterializeUserConfigsPass : Pass<"iree-codegen-materialize-user-configs", "ModuleOp"> {