Add value_opnums and imm_opnums fields to Instruction.

These two tuples contain operand indexes of the explicit value operands
and immediate operands respectively. We can no longer use the
instruction format value_operands field.

lib/cretonne/meta/cdsl/instructions.py

@@ -104,9 +104,18 @@ class Instruction(object):
         self.ins = self._to_operand_tuple(ins)
         self.outs = self._to_operand_tuple(outs)
         self.format = InstructionFormat.lookup(self.ins, self.outs)
-        # Indexes into outs for value results. Others are `variable_args`.
+
+        # Indexes into `self.outs` for value results.
+        # Other results are `variable_args`.
         self.value_results = tuple(
                 i for i, o in enumerate(self.outs) if o.is_value())
+        # Indexes into `self.ins` for value operands.
+        self.value_opnums = tuple(
+                i for i, o in enumerate(self.ins) if o.is_value())
+        # Indexes into `self.ins` for non-value operands.
+        self.imm_opnums = tuple(
+                i for i, o in enumerate(self.ins) if o.is_immediate())
+
         self._verify_polymorphic()
         for attr in Instruction.ATTRIBS:
             setattr(self, attr, not not kwargs.get(attr, False))

lib/cretonne/meta/cdsl/operands.py

@@ -157,3 +157,14 @@ class Operand(object):
         Is this an SSA value operand?
         """
         return self.kind is VALUE
+
+    def is_immediate(self):
+        # type: () -> bool
+        """
+        Is this an immediate operand?
+
+        Note that this includes both `ImmediateKind` operands *and* entity
+        references. It is any operand that doesn't represent a value
+        dependency.
+        """
+        return self.kind is not VALUE and self.kind is not VARIABLE_ARGS