YOLOv5 Export Benchmarks for GPU (#6963)

* Add benchmarks.py GPU support

* Updates

* Updates

* Updates

* Updates

* Add --half

* Add TRT requirements

* Cleanup

* Add TF to warmup types

* Update export.py

* Update export.py

* Update benchmarks.py

models/common.py

@@ -464,10 +464,11 @@ class DetectMultiBackend(nn.Module):
 
     def warmup(self, imgsz=(1, 3, 640, 640)):
         # Warmup model by running inference once
-        if self.pt or self.jit or self.onnx or self.engine:  # warmup types
-            if isinstance(self.device, torch.device) and self.device.type != 'cpu':  # only warmup GPU models
+        if any((self.pt, self.jit, self.onnx, self.engine, self.saved_model, self.pb)):  # warmup types
+            if self.device.type != 'cpu':  # only warmup GPU models
                 im = torch.zeros(*imgsz, dtype=torch.half if self.fp16 else torch.float, device=self.device)  # input
-                self.forward(im)  # warmup
+                for _ in range(2 if self.jit else 1):  #
+                    self.forward(im)  # warmup
 
     @staticmethod
     def model_type(p='path/to/model.pt'):