[Torch Dialect] Support Einsum Op (#2230)

As title, support torch.aten.einsum op

Right now only support Static Shape, because of the known issue, the
fixed solution is here: #2154

Co-authored-by: Jiawei Wu
[wujiawei.aml@bytedance.com](mailto:wujiawei.aml@bytedance.com)

include/torch-mlir/Dialect/Torch/IR/GeneratedTorchOps.td

@@ -8447,6 +8447,31 @@ def Torch_AtenOneHotOp : Torch_Op<"aten.one_hot", [
   }];
 }
 
+def Torch_AtenEinsumOp : Torch_Op<"aten.einsum", [
+    AllowsTypeRefinement,
+    HasValueSemantics,
+    ReadOnly
+  ]> {
+  let summary = "Generated op for `aten::einsum : (str, Tensor[], int[]?) -> (Tensor)`";
+  let arguments = (ins
+    Torch_StringType:$equation,
+    AnyTorchListOfTensorType:$tensors,
+    AnyTorchOptionalListOfTorchIntType:$path
+  );
+  let results = (outs
+    AnyTorchTensorType:$result
+  );
+  let hasCustomAssemblyFormat = 1;
+  let extraClassDefinition = [{
+    ParseResult AtenEinsumOp::parse(OpAsmParser &parser, OperationState &result) {
+      return parseDefaultTorchOp(parser, result, 3, 1);
+    }
+    void AtenEinsumOp::print(OpAsmPrinter &printer) {
+      printDefaultTorchOp(printer, *this, 3, 1);
+    }
+  }];
+}
+
 def Torch_AtenBucketizeTensorOp : Torch_Op<"aten.bucketize.Tensor", [
     AllowsTypeRefinement,
     HasValueSemantics,

lib/Dialect/Torch/Transforms/AbstractInterpLibrary.cpp

@@ -11321,6 +11321,33 @@ StringRef mlir::torch::Torch::getAbstractInterpLibrary() {
 "    %5 = call @__torch__.torch_mlir.jit_ir_importer.build_tools.library_generator.promote_dtypes(%0, %1) : (!torch.list<optional<int>>, !torch.list<int>) -> !torch.int\n"
 "    return %5 : !torch.int\n"
 "  }\n"
+"  func.func @\"__torch_mlir_dtype_fn.aten.einsum\"(%arg0: !torch.str, %arg1: !torch.list<tuple<int, int>>, %arg2: !torch.optional<list<int>>) -> !torch.int {\n"
+"    %true = torch.constant.bool true\n"
+"    %none = torch.constant.none\n"
+"    %str = torch.constant.str \"AssertionError: \"\n"
+"    %int0 = torch.constant.int 0\n"
+"    %0 = torch.prim.ListConstruct  : () -> !torch.list<optional<int>>\n"
+"    %1 = torch.prim.ListConstruct  : () -> !torch.list<int>\n"
+"    %2 = torch.aten.len.t %arg1 : !torch.list<tuple<int, int>> -> !torch.int\n"
+"    %3 = torch.aten.ne.int %2, %int0 : !torch.int, !torch.int -> !torch.bool\n"
+"    torch.prim.If %3 -> () {\n"
+"      torch.prim.If.yield\n"
+"    } else {\n"
+"      torch.prim.RaiseException %str, %none : !torch.str, !torch.none\n"
+"      torch.prim.If.yield\n"
+"    }\n"
+"    %4 = torch.aten.len.t %arg1 : !torch.list<tuple<int, int>> -> !torch.int\n"
+"    torch.prim.Loop %4, %true, init() {\n"
+"    ^bb0(%arg3: !torch.int):\n"
+"      %6 = torch.aten.__getitem__.t %arg1, %arg3 : !torch.list<tuple<int, int>>, !torch.int -> !torch.tuple<int, int>\n"
+"      %7:2 = torch.prim.TupleUnpack %6 : !torch.tuple<int, int> -> !torch.int, !torch.int\n"
+"      %8 = torch.aten.append.t %0, %7#0 : !torch.list<optional<int>>, !torch.int -> !torch.list<optional<int>>\n"
+"      %9 = torch.aten.append.t %1, %7#1 : !torch.list<int>, !torch.int -> !torch.list<int>\n"
+"      torch.prim.Loop.condition %true, iter()\n"
+"    } : (!torch.int, !torch.bool) -> ()\n"
+"    %5 = call @__torch__.torch_mlir.jit_ir_importer.build_tools.library_generator.promote_dtypes(%0, %1) : (!torch.list<optional<int>>, !torch.list<int>) -> !torch.int\n"
+"    return %5 : !torch.int\n"
+"  }\n"
 "  func.func @\"__torch_mlir_dtype_fn.aten._shape_as_tensor\"(%arg0: !torch.tuple<int, int>) -> !torch.int {\n"
 "    %int4 = torch.constant.int 4\n"
 "    return %int4 : !torch.int\n"