[Mlir-commits] [mlir] [MLIR][DLTI] Introduce DLTIQueryInterface and impl for DLTI attrs (PR #104595)

[Adam Siemieniuk]

================
@@ -93,20 +85,63 @@ def DLTI_DataLayoutSpecAttr :
 
     /// Returns the stack alignment identifier.
     StringAttr getStackAlignmentIdentifier(MLIRContext *context) const;
+
+    /// Returns the attribute associated with the key.
+    FailureOr<Attribute> query(DataLayoutEntryKey key) {
+      return llvm::cast<mlir::DataLayoutSpecInterface>(*this).queryHelper(key);
+    }
+  }];
+}
+
+def DLTI_MapAttr : DLTIAttr<"Map", [DLTIQueryInterface]> {
+  let summary = "A mapping of DLTI-information by way of key-value pairs";
+  let description = [{
+    A Data Layout and Target Information map is a list of entries effectively
+    encoding a dictionary, mapping DLTI-related keys to DLTI-related values.
+
+    This attribute's main purpose is to facilate querying IR for arbitrary
+    DLTI-related key-value associations. Note that facility functions exist to
+    perform recursive lookups on nested DLTI map attributes.
+
+    Consider the following shallow usage of a DLTI-map
+    ```
+    #dlti.map<#dlti.dl_entry<"CPU::cache::L1::size_in_bytes", 65536 : i32>>
+    ```
+    versus nested maps, which make it possible to obtain sub-dictionaries of
+    related information (with the following example making use of other
+    attributes that also implement the `DLTIQueryInterface`):
+    ```
+    #dlti.target_system_spec<"CPU":
+      #dlti.target_device_spec<#dlti.dl_entry<"cache",
+        #dlti.map<#dlti.dl_entry<"L1",
+          #dlti.map<#dlti.dl_entry<"size_in_bytes", 65536 : i32>>,
+                  #dlti.dl_entry<"L1d",
+          #dlti.map<#dlti.dl_entry<"size_in_bytes", 32768 : i32>> >>>>
----------------
adam-smnk wrote:

```suggestion
      #dlti.target_device_spec<#dlti.dl_entry<"cache",
        #dlti.map<#dlti.dl_entry<"L1",
          #dlti.map<#dlti.dl_entry<"size_in_bytes", 65536 : i32>>>,
                  #dlti.dl_entry<"L1d",
          #dlti.map<#dlti.dl_entry<"size_in_bytes", 32768 : i32>> >>>>>
```

https://github.com/llvm/llvm-project/pull/104595