Activations LeakyReLU / PReLU / Softplus / Mish (#109)

* Leaky_relu / prelu / softplus / mish

* added tests

* updated bench

* remove torch refs, add init to PReLU

* added arvix reference to mish

* added missing docs

benchmarks/python/comparative/bench_torch.py

@@ -163,6 +163,22 @@ def log_sigmoid(x):
     sync_if_needed(x)
 
 
+@torch.no_grad()
+def prelu(x: torch.Tensor) -> torch.Tensor:
+    y = x
+    for _ in range(100):
+        y = torch.nn.functional.prelu(y, torch.ones(1).to(y.device))
+    sync_if_needed(x)
+
+
+@torch.no_grad()
+def mish(x: torch.Tensor) -> torch.Tensor:
+    y = x
+    for _ in range(100):
+        return torch.nn.functional.mish(y)
+    sync_if_needed(x)
+
+
 @torch.no_grad()
 def scalar_mult(x):
     y = x
@@ -376,6 +392,10 @@ if __name__ == "__main__":
     elif args.benchmark == "log_sigmoid":
         print(bench(log_sigmoid, x))
 
+    elif args.benchmark == "prelu":
+        print(bench(prelu, x))
+    elif args.benchmark == "mish":
+        print(bench(mish, x))
     elif args.benchmark == "scalar_mul":
         print(bench(scalar_mult, x))