Add MPS device (#1197)

* Add MPS device

* Fix device setting

Author: chmjkb

mnist_rnn/main.py

@@ -91,8 +91,10 @@ def main():
                         help='learning rate (default: 0.1)')
     parser.add_argument('--gamma', type=float, default=0.7, metavar='M',
                         help='learning rate step gamma (default: 0.7)')
-    parser.add_argument('--no-cuda', action='store_true', default=False,
-                        help='disables CUDA training')
+    parser.add_argument('--cuda', action='store_true', default=False,
+                        help='enables CUDA training')
+    parser.add_argument('--mps', action="store_true", default=False,
+                        help="enables MPS training")
     parser.add_argument('--dry-run', action='store_true', default=False,
                         help='quickly check a single pass')
     parser.add_argument('--seed', type=int, default=1, metavar='S',
@@ -102,13 +104,19 @@ def main():
     parser.add_argument('--save-model', action='store_true', default=False,
                         help='for Saving the current Model')
     args = parser.parse_args()
-    use_cuda = not args.no_cuda and torch.cuda.is_available()
 
-    torch.manual_seed(args.seed)
+    if args.cuda and not args.mps:
+        device = "cuda"
+    elif args.mps and not args.cuda:
+        device = "mps"
+    else:
+        device = "cpu"
+
+    device = torch.device(device)
 
-    device = torch.device("cuda" if use_cuda else "cpu")
+    torch.manual_seed(args.seed)
 
-    kwargs = {'num_workers': 1, 'pin_memory': True} if use_cuda else {}
+    kwargs = {'num_workers': 1, 'pin_memory': True} if args.cuda else {}
     train_loader = torch.utils.data.DataLoader(
         datasets.MNIST('../data', train=True, download=True,
                        transform=transforms.Compose([