Remove the number field from the PredNode union type.

Predicate numbers are available in the maps
isa.settings.predicate_number and isa.instp_number instead.

Like the name field, predicate numbers don't interact well with
unique_pred().

lib/cretonne/meta/cdsl/isa.py

@@ -103,23 +103,17 @@ class TargetISA(object):
         """
         Collect and number all predicates in use.
 
-        Sets `instp.number` for all used instruction predicates and places them
-        in `self.all_instps` in numerical order.
-
         Ensures that all ISA predicates have an assigned bit number in
         `self.settings`.
         """
-        self.all_instps = list()  # type: List[PredNode]
-        instps = set()  # type: Set[PredNode]
+        self.instp_number = OrderedDict()  # type: OrderedDict[PredNode, int]
         for cpumode in self.cpumodes:
             for enc in cpumode.encodings:
                 instp = enc.instp
-                if instp and instp not in instps:
+                if instp and instp not in self.instp_number:
                     # assign predicate number starting from 0.
-                    assert instp.number is None
-                    instp.number = len(instps)
-                    instps.add(instp)
-                    self.all_instps.append(instp)
+                    n = len(self.instp_number)
+                    self.instp_number[instp] = n
 
                 # All referenced ISA predicates must have a number in
                 # `self.settings`. This may cause some parent predicates to be

lib/cretonne/meta/cdsl/predicates.py

@@ -80,7 +80,6 @@ class Predicate(object):
 
     def __init__(self, parts):
         # type: (Sequence[PredNode]) -> None
-        self.number = None  # type: int
         self.parts = parts
         self.context = reduce(
                 _descendant,
@@ -210,7 +209,6 @@ class FieldPredicate(object):
 
     def __init__(self, field, function, args):
         # type: (FormatField, str, Sequence[Any]) -> None
-        self.number = None  # type: int
         self.field = field
         self.function = function
         self.args = args
@@ -330,7 +328,6 @@ class TypePredicate(object):
         assert value_type is not None
         self.value_arg = value_arg
         self.value_type = value_type
-        self.number = None  # type: int
 
     def __str__(self):
         # type: () -> str

lib/cretonne/meta/cdsl/settings.py

@@ -23,7 +23,6 @@ class Setting(object):
     def __init__(self, doc):
         # type: (str) -> None
         self.name = None  # type: str  # Assigned later by `extract_names()`.
-        self.number = None  # type: int
         self.__doc__ = doc
         # Offset of byte in settings vector containing this setting.
         self.byte_offset = None  # type: int