[Mlir-commits] [mlir] [MLIR][XeGPU] XeVM lowering support for load_matrix/store_matrix (PR #162780)

[Charitha Saumya]

================
@@ -237,19 +237,73 @@ def XeGPU_MemDesc: XeGPUTypeDef<"MemDesc", "mem_desc", [ShapedTypeInterface], "m
       return MemDescType::get(getContext(), shape.value_or(getShape()), elementType, getMemLayout());
     }
 
-    ArrayAttr getStrides() {
+    ArrayAttr getStrideAttr() {
       auto layout = getMemLayout();
       if (layout && layout.hasAttr("stride")) {
-        return layout.getStrides();
+        return layout.getStrideAttr();
       }
-
       // derive and return default strides
       SmallVector<int64_t> defaultStrides;
       llvm::append_range(defaultStrides, getShape().drop_front());
       llvm::append_values(defaultStrides, 1);
       Builder builder(getContext());
       return builder.getI64ArrayAttr(defaultStrides);
     }
+
+    ArrayAttr getBlockAttr() {
+      auto layout = getMemLayout();
+      if (layout && layout.hasAttr("block")) {
+        return layout.getBlockAttr();
+      }
+      Builder builder(getContext());
+      return builder.getI64ArrayAttr({});
+    }
+
+    /// Heuristic to determine if the MemDesc uses column-major layout,
+    /// based on the rank and the value of the first stride dimension.
+    bool isColMajor() {
+      auto dim0 = dyn_cast<IntegerAttr>(getStrideAttr()[0]);
+      return getRank() == 2 && dim0 && dim0.getInt() == 1;
+    }
+
+    // get the Blocking shape for a MemDescType, Which is represented
+    // as an attribute in MemDescType. By default it is the shape
+    // of the mdescTy
+    SmallVector<int64_t> getBlockShape() {
+      SmallVector<int64_t> size(getShape());
+      ArrayAttr blockAttr = getBlockAttr();
+      if (!blockAttr.empty()) {
+        size.clear();
+        for (auto attr : blockAttr.getValue()) {
+          size.push_back(cast<IntegerAttr>(attr).getInt());
+        }
+      }
+      return size;
+    }
+
+    // Get strides as vector of integer. 
+    // If it contains block attribute, the strides are blocked strides.
+    //
+    // The blocking is applied against the original matrix shape
+    // so that the linear offset is not impacted by the subview.
+    //
+    // It first computes the original matrix shape using the stride info,
+    // then computes the number of blocks in each dimension of original shape,
+    // then compute the outer block shape and stride,
+    // then combines the inner and outer block shape and stride
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charithaintc wrote:

nit: use code quotes for (`mem_desc`) for code examples. That way doxygen will generate more readable docs. 

https://github.com/llvm/llvm-project/pull/162780