mem_dump: add summary of inferred memory usage

Signed-off-by: Nishanth <ndszz306@gmail.com>

Author: NishDs-06

flow/scripts/mem_dump.py

@@ -4,8 +4,6 @@
 
 
 def find_top_modules(data):
-    # There can be some cruft in the modules list so that
-    # we have multiple top level candidates.
     top_module = []
     instantiations = set(
         [
@@ -14,7 +12,7 @@ def find_top_modules(data):
             for cell in minfo2["cells"].values()
         ]
     )
-    for mname, minfo in data["modules"].items():
+    for mname in data["modules"].keys():
         if mname not in instantiations:
             top_module.append(mname)
     return top_module
@@ -23,16 +21,6 @@ def find_top_modules(data):
 def find_cells_by_type_in_module(
     module_name, data, target_type, current_path, matching_cells
 ):
-    """
-    Searches through hierarchy starting at module_name to find all instances of
-    the given module/type in the hierarchy.
-
-    Returns list of cell paths, which are constructed as:
-
-        <top_module_name>.(<child_inst_name>.<child_module_name>+).<memory_inst_name>
-
-    where the child_inst_name/child_module_name pairs are repeated for each level of the hierarchy.
-    """
     for cell_name, cell in data["modules"][module_name]["cells"].items():
         cell_path = (
             f"{current_path}.{module_name}.{cell_name}"
@@ -42,18 +30,15 @@ def find_cells_by_type_in_module(
         if cell["type"] == target_type:
             matching_cells.append(cell_path)
         elif cell["type"] in data["modules"]:
-            # Recursively search within the module
             matching_cells.extend(
                 find_cells_by_type_in_module(
                     cell["type"], data, target_type, cell_path, []
                 )
             )
-
     return matching_cells
 
 
 def find_cells_by_type(top_modules, data, module_name, current_path=""):
-    # first find top module, the module without any submodules
     names = []
     for top_module in top_modules:
         names.extend(
@@ -69,13 +54,12 @@ def format_ram_table_from_json(data, max_bits=None):
     formatting = "{:>5} | {:>5} | {:>6} | {:<20} | {:<80}\n"
     table = formatting.format("Rows", "Width", "Bits", "Module", "Instances")
     table += "-" * len(table) + "\n"
+
     max_ok = True
     entries = []
 
-    # Collect the entries in a list
     for module_name, module_info in data["modules"].items():
-        cells = module_info["cells"]
-        for cell in cells.values():
+        for cell in module_info["cells"].values():
             if not cell["type"].startswith("$mem"):
                 continue
             parameters = cell["parameters"]
@@ -84,18 +68,38 @@ def format_ram_table_from_json(data, max_bits=None):
             instances = find_cells_by_type(top_modules, data, module_name)
             instance_bits = size * width
             bits = instance_bits * len(instances)
+
             entries.append((size, width, bits, module_name, ", ".join(instances)))
+
             if max_bits is not None and instance_bits > max_bits:
                 max_ok = False
 
-    # Sort the entries by descending bits
     entries.sort(key=lambda x: x[2], reverse=True)
 
-    # Format the sorted entries into the table
     for entry in entries:
         table += formatting.format(*entry)
 
-    return table, max_ok
+    # ---- Summary statistics ----
+    total_bits = sum(e[2] for e in entries)
+
+    largest_instance_bits = 0
+    largest_instance_module = None
+
+    for size, width, _, module, _ in entries:
+        instance_bits = size * width
+        if instance_bits > largest_instance_bits:
+            largest_instance_bits = instance_bits
+            largest_instance_module = module
+
+    summary = {
+        "memory_count": len(entries),
+        "largest_instance_bits": largest_instance_bits,
+        "largest_instance_module": largest_instance_module,
+        "largest_total_bits": entries[0][2] if entries else 0,
+        "total_bits": total_bits,
+    }
+
+    return table, max_ok, summary
 
 
 if __name__ == "__main__":
@@ -119,9 +123,27 @@ def format_ram_table_from_json(data, max_bits=None):
     print(" " + "\n ".join(src_files))
 
     print("Memories found in the design:")
-    formatted_table, max_ok = format_ram_table_from_json(json_data, args.max_bits)
+    formatted_table, max_ok, summary = format_ram_table_from_json(
+        json_data, args.max_bits
+    )
+
     print(formatted_table)
-    if not max_ok:
-        sys.exit(
-            f"Error: Synthesized memory size {args.max_bits} exceeds SYNTH_MEMORY_MAX_BITS"
-        )
+
+    print("Summary:")
+    print(f"- Total inferred memories: {summary['memory_count']}")
+    print(
+        f"- Largest single memory instance: "
+        f"{summary['largest_instance_bits']} bits "
+        f"(module {summary['largest_instance_module']})"
+    )
+    print(f"- Total inferred memory bits (all instances): {summary['total_bits']}")
+
+    if args.max_bits is not None:
+        status = "OK" if max_ok else "FAIL"
+        print(f"- SYNTH_MEMORY_MAX_BITS: {args.max_bits}")
+        print(f"- Status: {status}")
+
+        if not max_ok:
+            sys.exit(
+                f"Error: Synthesized memory size {args.max_bits} exceeds SYNTH_MEMORY_MAX_BITS"
+            )