[FRONTEND] check that tensors have power-of-two number of elements (#499)

python/triton/language/core.py

@@ -380,6 +380,9 @@ class tensor:
         self.numel = 1
         for s in self.shape:
             self.numel *= s
+        is_pow2 = (self.numel and (not(self.numel & (self.numel - 1))))
+        if not is_pow2:
+            raise ValueError("Triton tensors must have a power-of-two number of elements")
         self.numel = constexpr(self.numel)
         self.type = type  # Tensor type (can be block_type)
         # Following the practice in pytorch, dtype is scalar type