Allow dot syntax notation for enumerated immediate operands.

The meta language patterns sometimes need to refer to specific values of
enumerated immediate operands. The dot syntax provides a namespaced,
typed way of doing that: icmp(intcc.ult, a, x).

Add an ast.Enumerator class for representing this kind of AST leaf node.

Add value definitions for the intcc and floatcc immediate operand kinds.

lib/cretonne/meta/base/immediates.py

@@ -34,7 +34,19 @@ ieee64 = ImmediateKind('ieee64', 'A 64-bit immediate floating point number.')
 intcc = ImmediateKind(
         'intcc',
         'An integer comparison condition code.',
-        default_member='cond', rust_type='IntCC')
+        default_member='cond', rust_type='IntCC',
+        values={
+            'eq':  'Equal',
+            'ne':  'NotEqual',
+            'sge': 'SignedGreaterThanOrEqual',
+            'sgt': 'SignedGreaterThan',
+            'sle': 'SignedLessThanOrEqual',
+            'slt': 'SignedLessThan',
+            'uge': 'UnsignedGreaterThanOrEqual',
+            'ugt': 'UnsignedGreaterThan',
+            'ule': 'UnsignedLessThanOrEqual',
+            'ult': 'UnsignedLessThan',
+        })
 
 #: A condition code for comparing floating point values.
 #:
@@ -43,4 +55,20 @@ intcc = ImmediateKind(
 floatcc = ImmediateKind(
         'floatcc',
         'A floating point comparison condition code.',
-        default_member='cond', rust_type='FloatCC')
+        default_member='cond', rust_type='FloatCC',
+        values={
+            'ord': 'Ordered',
+            'uno': 'Unordered',
+            'eq':  'Equal',
+            'ne':  'NotEqual',
+            'one': 'OrderedNotEqual',
+            'ueq': 'UnorderedOrEqual',
+            'lt':  'LessThan',
+            'le':  'LessThanOrEqual',
+            'gt':  'GreaterThan',
+            'ge':  'GreaterThanOrEqual',
+            'ult': 'UnorderedOrLessThan',
+            'ule': 'UnorderedOrLessThanOrEqual',
+            'ugt': 'UnorderedOrGreaterThan',
+            'uge': 'UnorderedOrGreaterThanOrEqual',
+        })

lib/cretonne/meta/base/legalize.py

@@ -7,6 +7,7 @@ patterns that describe how base instructions can be transformed to other base
 instructions that are legal.
 """
 from __future__ import absolute_import
+from .immediates import intcc
 from .instructions import iadd, iadd_cout, iadd_cin, iadd_carry, iadd_imm
 from .instructions import isub, isub_bin, isub_bout, isub_borrow
 from .instructions import band, bor, bxor, isplit, iconcat
@@ -90,14 +91,14 @@ expand.legalize(
         (a, c) << iadd_cout(x, y),
         Rtl(
             a << iadd(x, y),
-            c << icmp('IntCC::UnsignedLessThan', a, x)
+            c << icmp(intcc.ult, a, x)
         ))
 
 expand.legalize(
         (a, b) << isub_bout(x, y),
         Rtl(
             a << isub(x, y),
-            b << icmp('IntCC::UnsignedGreaterThan', a, x)
+            b << icmp(intcc.ugt, a, x)
         ))
 
 expand.legalize(