diff --git a/osaca/parser/parser_AArch64.py b/osaca/parser/parser_AArch64.py
index 012a6f7..f32619a 100755
--- a/osaca/parser/parser_AArch64.py
+++ b/osaca/parser/parser_AArch64.py
@@ -123,10 +123,12 @@ class ParserAArch64(BaseParser):
         vector = (
             pp.oneOf('v z', caseless=True).setResultsName('prefix')
             + pp.Word(pp.nums).setResultsName('name')
-            + pp.Literal('.')
-            + pp.Optional(pp.Word('12468')).setResultsName('lanes')
-            + pp.Word(pp.alphas, exact=1).setResultsName('shape')
-            + pp.Optional(index)
+            + pp.Optional(
+                pp.Literal('.')
+                + pp.Optional(pp.Word('12468')).setResultsName('lanes')
+                + pp.Word(pp.alphas, exact=1).setResultsName('shape')
+                + pp.Optional(index)
+            )
         )
         predicate = (
             pp.CaselessLiteral('p').setResultsName('prefix')
diff --git a/osaca/semantics/hw_model.py b/osaca/semantics/hw_model.py
index 9968e43..7e5ca3c 100755
--- a/osaca/semantics/hw_model.py
+++ b/osaca/semantics/hw_model.py
@@ -574,7 +574,10 @@ class MachineModel(object):
         if reg['prefix'] != i_reg['prefix']:
             return False
         if 'shape' in reg:
-            if 'shape' in i_reg and reg['shape'] == i_reg['shape']:
+            if 'shape' in i_reg and (
+                    reg['shape'] == i_reg['shape'] 
+                    or self.WILDCARD in (reg['shape'] + i_reg['shape'])
+            ):
                 return True
             return False
         return True