fix(aten::instance_norm): Handle optional inputs in instance norm converter

Author: narendasan

core/conversion/converters/impl/batch_norm.cpp

@@ -134,9 +134,15 @@ auto batch_norm_registrations TORCHTRT_UNUSED =
 
               auto eps = static_cast<float>(args[7].unwrapToDouble(1e-5f));
 
-              auto scales = args[1].unwrapToTensor(at::ones(shape[1], options)).cpu().contiguous();
-              auto bias = args[2].unwrapToTensor(at::zeros(shape[1], options)).cpu().contiguous();
 
+              auto scales = at::ones(shape[1], options);
+              if (!args[1].IValue()->isNone()) {
+                scales = args[1].unwrapToTensor(at::ones(shape[1], options)).cpu().contiguous();
+              }
+              auto bias = at::zeros(shape[1], options);
+              if (!args[2].IValue()->isNone()){
+                bias = args[2].unwrapToTensor(at::zeros(shape[1], options)).cpu().contiguous();
+              }
               // track_running_stats=True
               if (!args[3].IValue()->isNone() || !args[4].IValue()->isNone()) {
                 auto running_mean = args[3].unwrapToTensor();
@@ -154,6 +160,8 @@ auto batch_norm_registrations TORCHTRT_UNUSED =
                 return true;
               }
 
+              // Not sure this actually does something since the cudnn_enabled is from the PyTorch context.
+              // We need cuDNN either way to run this converter
               auto cudnn_enabled = static_cast<bool>(args[8].unwrapToBool(false));
               if (!cudnn_enabled) {
                 LOG_DEBUG(
@@ -162,7 +170,7 @@ auto batch_norm_registrations TORCHTRT_UNUSED =
                     so for some functionalities, users need to install correct \
                     cuDNN version by themselves. Please see our support matrix \
                     here: https://docs.nvidia.com/deeplearning/tensorrt/support-matrix/index.html.");
-                return false;
+                //return false;
               }
 
               const int relu = 0;

core/util/prelude.h

@@ -2,6 +2,7 @@
 
 // A collection of headers from util that will typically get included in most
 // files
+#include <cstdint>
 #include "core/util/Exception.h"
 #include "core/util/build_info.h"
 #include "core/util/jit_util.h"

tests/core/conversion/converters/test_instance_norm.cpp

@@ -18,7 +18,7 @@ constexpr auto graph = R"IR(
             %running_mean.1 : Tensor?,
             %running_var.1 : Tensor?,
             %use_input_stats.1 : bool):
-        %cudnn_enabled.1 : bool = prim::Constant[value=0]()
+        %cudnn_enabled.1 : bool = prim::Constant[value=1]()
         %momentum.1 : float = prim::Constant[value=0.10000000000000001]()
         %eps.1 : float = prim::Constant[value=1.0000000000000001e-05]()
         %4 : Tensor = aten::instance_norm(%input.1,