Added MAD operation to core_operations.py and function definition for replacing operations

b_asic/core_operations.py

@@ -229,3 +229,18 @@ class Butterfly(AbstractOperation):
 
     def evaluate(self, a, b):
         return a + b, a - b
+
+class MAD(AbstractOperation):
+    """Multiply-and-add operation.
+    TODO: More info.
+    """
+
+    def __init__(self, src0: Optional[SignalSourceProvider] = None, src1: Optional[SignalSourceProvider] = None, name: Name = ""):
+        super().__init__(input_count = 3, output_count = 1, name = name, input_sources = [src0, src1])
+
+    @property
+    def type_name(self) -> TypeName:
+        return "mad"
+
+    def evaluate(self, a, b, c):
+        return a * b + c

b_asic/signal_flow_graph.py

@@ -405,6 +405,16 @@ class SFG(AbstractOperation):
         # The old SFG will be deleted by Python GC
         return self()
 
+    def replace_operations(self, inputs: Sequence[Input], outputs: Sequence[Output], operation: Operation):
+        """Replace one or more operations in the sfg with a operation that have same number of inputs and outputs.
+        Then return a new deepcopy of the sfg.
+
+        Arguments:
+        inputs: The inputs for the operations we are replacing.
+        outputs: The outputs for the operations we are replacing.
+        operation: The replacing operation.
+        """
+
     def _evaluate_source(self, src: OutputPort, results: MutableResultMap, registers: MutableRegisterMap, prefix: str) -> Number:
         src_prefix = prefix
         if src_prefix: