[otbn] Represent updates to PC more nicely in operation docs
Signed-off-by: Rupert Swarbrick <rswarbrick@lowrisc.org>
diff --git a/hw/ip/otbn/util/docs/get_impl.py b/hw/ip/otbn/util/docs/get_impl.py
index 3d96062..46f9698 100644
--- a/hw/ip/otbn/util/docs/get_impl.py
+++ b/hw/ip/otbn/util/docs/get_impl.py
@@ -267,6 +267,25 @@
return NBAssign.make(reg_ref, rhs)
+ def leave_Assign(self,
+ orig: cst.Assign,
+ updated: cst.Assign) -> cst.BaseSmallStatement:
+ # Handle assignments to state.pc_next and replace them with delayed
+ # assignments to PC.
+
+ # We don't handle things like "(foo, state.pc_next) = some_fun()"
+ if len(updated.targets) != 1:
+ return updated
+
+ tgt = updated.targets[0].target
+ if ((isinstance(tgt, cst.Attribute) and
+ isinstance(tgt.value, cst.Name) and
+ tgt.value.value == 'state' and
+ tgt.attr.value == 'pc_next')):
+ return NBAssign.make(cst.Name(value='PC'), updated.value)
+
+ return updated
+
def read_implementation(path: str) -> Dict[str, str]:
'''Read the implementation at path (probably insn.py)
