Useful error when input dim is unused by LHS/RHS.

Differential Revision: https://reviews.llvm.org/D128925

mlir/lib/Dialect/Vector/IR/VectorOps.cpp

@@ -698,8 +698,9 @@ static LogicalResult verifyOutputShape(
           extents[pos] = getAffineConstantExpr(v.getShape()[idx], ctx);
       }
     }
-    assert(llvm::all_of(extents, [](AffineExpr e) { return e; }) &&
-           "expected extent along all dimensions.");
+    if (!llvm::all_of(extents, [](AffineExpr e) { return e; }))
+      return op.emitOpError("expected all input dimensions to be used by "
+                            "either the LHS or the RHS");
 
     AffineMap resMap = op.getIndexingMaps()[2];
     auto extentsMap = AffineMap::get(/*dimCount=*/extents.size(),

mlir/test/Dialect/Vector/invalid.mlir

@@ -874,6 +874,21 @@ func.func @contraction(%arg0: vector<2x1xf32>, %arg1: vector<1x3xf32>, %arg2: ve
 
 // -----
 
+func.func @contract_with_dim_unused_by_lhs_and_rhs(%arg0 : vector<1x2xi32>, %arg1 : vector<2xi32>, %arg2 : vector<1xi32>) -> vector<1xi32> {
+// expected-error@+1 {{'vector.contract' op expected all input dimensions to be used by either the LHS or the RHS}}
+  %result = vector.contract {
+    indexing_maps = [
+      affine_map<(d0, d1, d2) -> (d0, d2)>,
+      affine_map<(d0, d1, d2) -> (d2)>,
+      affine_map<(d0, d1, d2) -> (d1)>
+    ],
+    iterator_types = ["reduction", "parallel", "reduction"],
+    kind = #vector.kind<add>} %arg0, %arg1, %arg2 : vector<1x2xi32>, vector<2xi32> into vector<1xi32>
+  return  %result : vector<1xi32>
+}
+
+// -----
+
 func.func @create_mask_0d_no_operands() {
   %c1 = arith.constant 1 : index
   // expected-error@+1 {{must specify exactly one operand for 0-D create_mask}}