When marking ops for outside compilation, use a different attribute value for each op.

These ops are later clustered by _xla_outside_compiled attribute value.  Unsupported ops marked for outside compilation
should be clustered in a separate pass.

PiperOrigin-RevId: 328200978
Change-Id: Ia3c30138ebb6a42d2e1064277c2b7461f2f53204

tensorflow/compiler/mlir/tensorflow/tests/mark_ops_for_outside_compilation.mlir

@@ -137,7 +137,7 @@ func @if_region_captured_string(%arg0: tensor<i1>, %arg1: tensor<!tf.string>) ->
     // CHECK: "tf.IfRegion"
     // CHECK: "tf.StringToNumber"
     // CHECK-NOT: _xla_outside_compilation
-    // CHECK: _xla_outside_compilation = "auto", is_stateless = true
+    // CHECK: _xla_outside_compilation = "auto1", is_stateless = true
     %1 = "tf.Const"() {value = dense<1> : tensor<i32>} : () -> tensor<i32>
     %2 = "tf.IfRegion"(%arg0) ( {
       %3 = "tf.StringToNumber"(%arg1) {out_type = f32} : (tensor<!tf.string>) -> tensor<f32>
@@ -166,7 +166,7 @@ func @if_region_string_op(%arg0: tensor<i1>, %arg1: tensor<?xi32>) -> tensor<f32
       %3 = "tf.Const"() {value = dense<1.0> : tensor<f32>} : () -> tensor<f32>
       "tf.Yield"(%3) : (tensor<f32>) -> ()
      },  {
-      // CHECK: "tf.Const"() {_xla_outside_compilation = "auto", value = dense<"1.0"> : tensor<!tf.string>}
+      // CHECK: "tf.Const"() {_xla_outside_compilation = "auto0", value = dense<"1.0"> : tensor<!tf.string>}
       // CHECK-NEXT: "tf.StringToNumber"
       // CHECK-SAME: _xla_outside_compilation
       %4 = "tf.Const"() {value = dense<"1.0"> : tensor<!tf.string>} : () -> tensor<!tf.string>
@@ -198,7 +198,7 @@ func @nested_if_region_string_op(%arg0: tensor<i1>, %arg1: tensor<?xi32>) -> ten
        // CHECK-NOT: _xla_outside_compilation
        %4 = "tf.Const"() {value = dense<true> : tensor<i1>} : () -> tensor<i1>
        %5 = "tf.IfRegion"(%4)({
-         // CHECK: "tf.Const"() {_xla_outside_compilation = "auto", value = dense<"1.0"> : tensor<!tf.string>}
+         // CHECK: "tf.Const"() {_xla_outside_compilation = "auto0", value = dense<"1.0"> : tensor<!tf.string>}
          // CHECK-NEXT: "tf.StringToNumber"
          // CHECK-SAME: _xla_outside_compilation
          %6 = "tf.Const"() {value = dense<"1.0"> : tensor<!tf.string>} : () -> tensor<!tf.string>
@@ -229,7 +229,7 @@ func @while_region_captured_string(%arg0: tensor<i32>, %arg1: tensor<!tf.string>
     // CHECK-NOT: _xla_outside_compilation
     // CHECK: "tf.WhileRegion"
     // CHECK: "tf.StringToNumber"
-    // CHECK: _xla_outside_compilation = "auto", is_stateless = true
+    // CHECK: _xla_outside_compilation = "auto1", is_stateless = true
     %1 = "tf.Const"() {value = dense<1.0> : tensor<f32>} : () -> tensor<f32>
     %2:2 = "tf.WhileRegion"(%1, %arg0) ( {
       ^bb0(%carg0: tensor<f32>, %carg1: tensor<i32>):

tensorflow/compiler/mlir/tensorflow/transforms/mark_ops_for_outside_compilation.cc

@@ -17,6 +17,7 @@ limitations under the License.
 #include <string>
 #include <utility>
 
+#include "llvm/Support/FormatVariadic.h"
 #include "mlir/IR/TypeUtilities.h"  // from @llvm-project
 #include "mlir/Pass/Pass.h"  // from @llvm-project
 #include "mlir/Pass/PassRegistry.h"  // from @llvm-project
@@ -116,15 +117,32 @@ bool HasCapturedStringOperand(Operation* op) {
 LogicalResult MarkUncompilableOps(
     const Dialect* tf_dialect, Block* block,
     llvm::DenseSet<OperationName>& supported_ops) {
+  // Automatically marked ops for outside compilation have
+  // `_xla_outside_compilation` attribute value of "auto" plus
+  // an increasing counter.  Manually marked ops for outside compilation only
+  // have an increasing counteri for the attribute value.  Therefore there is no
+  // collision in
+  // `_xla_outside_compilation` attribute between automatically and manually
+  // marking ops.
+  int outside_compiled_cluster_counter = 0;
   block->walk([&](Operation* op) {
     if (!IsSupportedOp(*op, supported_ops, tf_dialect)) {
-      op->setAttr(kXlaOutsideCompilationAttr,
-                  StringAttr::get("auto", op->getContext()));
+      op->setAttr(
+          kXlaOutsideCompilationAttr,
+          StringAttr::get(
+              llvm::formatv("auto{0}", outside_compiled_cluster_counter).str(),
+              op->getContext()));
+      outside_compiled_cluster_counter++;
     }
     if (llvm::isa<TF::IfRegionOp, TF::WhileRegionOp>(op)) {
       if (HasCapturedStringOperand(op)) {
-        op->setAttr(kXlaOutsideCompilationAttr,
-                    StringAttr::get("auto", op->getContext()));
+        op->setAttr(
+            kXlaOutsideCompilationAttr,
+            StringAttr::get(
+                llvm::formatv("auto{0}", outside_compiled_cluster_counter)
+                    .str(),
+                op->getContext()));
+        outside_compiled_cluster_counter++;
       }
     }
   });