base buffer handling conditions during code generation only on used buffer...

base buffer handling conditions during code generation only on used buffer entries to avoid overhead if all of them are unused

Cython/Compiler/Nodes.py

@@ -1789,9 +1789,11 @@ class FuncDefNode(StatNode, BlockNode):
                 have_object_args = True
                 break
 
+        used_buffer_entries = [entry for entry in lenv.buffer_entries if entry.used]
+
         acquire_gil_for_var_decls_only = (
                 lenv.nogil and lenv.has_with_gil_block and
-                (have_object_args or lenv.buffer_entries))
+                (have_object_args or used_buffer_entries))
 
         acquire_gil_for_refnanny_only = (
                 lenv.nogil and lenv.has_with_gil_block and not
@@ -1948,15 +1950,14 @@ class FuncDefNode(StatNode, BlockNode):
 
             # Clean up buffers -- this calls a Python function
             # so need to save and restore error state
-            buffers_present = len(lenv.buffer_entries) > 0
+            buffers_present = len(used_buffer_entries) > 0
             #memslice_entries = [e for e in lenv.entries.values() if e.type.is_memoryviewslice]
             if buffers_present:
                 code.globalstate.use_utility_code(restore_exception_utility_code)
                 code.putln("{ PyObject *__pyx_type, *__pyx_value, *__pyx_tb;")
                 code.putln("__Pyx_ErrFetch(&__pyx_type, &__pyx_value, &__pyx_tb);")
-                for entry in lenv.buffer_entries:
-                    if entry.used:
-                        Buffer.put_release_buffer_code(code, entry)
+                for entry in used_buffer_entries:
+                    Buffer.put_release_buffer_code(code, entry)
                     #code.putln("%s = 0;" % entry.cname)
                 code.putln("__Pyx_ErrRestore(__pyx_type, __pyx_value, __pyx_tb);}")
 
@@ -2003,9 +2004,8 @@ class FuncDefNode(StatNode, BlockNode):
 
         # ----- Non-error return cleanup
         code.put_label(code.return_label)
-        for entry in lenv.buffer_entries:
-            if entry.used:
-                Buffer.put_release_buffer_code(code, entry)
+        for entry in used_buffer_entries:
+            Buffer.put_release_buffer_code(code, entry)
         if is_getbuffer_slot:
             self.getbuffer_normal_cleanup(code)