Update `_make_grid()` (#7346)

models/yolo.py

@@ -77,13 +77,15 @@ class Detect(nn.Module):
 
     def _make_grid(self, nx=20, ny=20, i=0):
         d = self.anchors[i].device
+        t = self.anchors[i].dtype
         shape = 1, self.na, ny, nx, 2  # grid shape
+        y, x = torch.arange(ny, device=d, dtype=t), torch.arange(nx, device=d, dtype=t)
         if check_version(torch.__version__, '1.10.0'):  # torch>=1.10.0 meshgrid workaround for torch>=0.7 compatibility
-            yv, xv = torch.meshgrid(torch.arange(ny, device=d), torch.arange(nx, device=d), indexing='ij')
+            yv, xv = torch.meshgrid(y, x, indexing='ij')
         else:
-            yv, xv = torch.meshgrid(torch.arange(ny, device=d), torch.arange(nx, device=d))
-        grid = torch.stack((xv, yv), 2).expand(shape).float() - 0.5  # add grid offset, i.e. y = 2.0 * x - 0.5
-        anchor_grid = (self.anchors[i] * self.stride[i]).view((1, self.na, 1, 1, 2)).expand(shape).float()
+            yv, xv = torch.meshgrid(y, x)
+        grid = torch.stack((xv, yv), 2).expand(shape) - 0.5  # add grid offset, i.e. y = 2.0 * x - 0.5
+        anchor_grid = (self.anchors[i] * self.stride[i]).view((1, self.na, 1, 1, 2)).expand(shape)
         return grid, anchor_grid