fix handling right shifts

YosysHQ · Oct 3, 2023 · 0f4eff9 · 0f4eff9
1 parent f597cc3
commit 0f4eff9
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/kernel/celledges.cc b/kernel/celledges.cc
@@ -183,13 +183,16 @@ void shift_op(AbstractCellEdgesDatabase *db, RTLIL::Cell *cell)
 			db->add_edge(cell, ID::B, k, ID::Y, i, -1);
 
 		if (cell->type.in(ID($shl), ID($sshl))) {
-			for (int k = min(i, a_width); k >= 0; k--)
+			for (int k = min(i, a_width-1); k >= 0; k--)
 				db->add_edge(cell, ID::A, k, ID::Y, i, -1);
 		}
 
 		if (cell->type.in(ID($shr), ID($sshr)))
 			for (int k = i; k < a_width; k++)
 				db->add_edge(cell, ID::A, k, ID::Y, i, -1);
+
+		if (cell->type == ID($sshr) && i >= a_width)
+			db->add_edge(cell, ID::A, a_width - 1, ID::Y, i, -1);
 
 		if (cell->type.in(ID($shift), ID($shiftx)))
 			for (int k = 0; k < a_width; k++)