Assign in-block indices to CFG definitions

kernel/modelverse_jit/cfg_ir.py

@@ -21,18 +21,22 @@ class BasicBlock(object):
         self.definitions = []
         self.counter = counter
         self.index = counter.next_value()
+        self.definition_counter = SharedCounter()
         self.flow = UnreachableFlow()
 
     def append_parameter(self, parameter):
         """Appends a parameter to this basic block."""
         result = self.create_definition(parameter)
         self.parameters.append(result)
+        if len(self.definitions) > 0:
+            self.renumber_definitions()
         return result
 
     def prepend_definition(self, value):
         """Defines the given value in this basic block."""
         result = self.create_definition(value)
         self.definitions.insert(0, result)
+        self.renumber_definitions()
         return result
 
     def append_definition(self, value):
@@ -47,12 +51,23 @@ class BasicBlock(object):
             return value
         else:
             assert isinstance(value, Value) or value is None
-            return Definition(self.counter.next_value(), value)
+            return Definition(
+                self.counter.next_value(),
+                self.definition_counter.next_value(),
+                value)
 
     def remove_definition(self, definition):
         """Removes the given definition from this basic block."""
         return self.definitions.remove(definition)
 
+    def renumber_definitions(self):
+        """Re-numbers all definitions in this basic block."""
+        self.definition_counter = SharedCounter()
+        for definition in self.parameters:
+            definition.renumber(self.definition_counter.next_value())
+        for definition in self.definitions:
+            definition.renumber(self.definition_counter.next_value())
+
     def __str__(self):
         prefix = '!%d(%s):' % (self.index, ', '.join(map(str, self.parameters)))
         return '\n'.join(
@@ -61,8 +76,9 @@ class BasicBlock(object):
 
 class Definition(object):
     """Maps a value to a variable."""
-    def __init__(self, index, value):
+    def __init__(self, index, definition_index, value):
         self.index = index
+        self.definition_index = definition_index
         self.value = value
         if value is not None:
             assert isinstance(value, Value)
@@ -73,6 +89,10 @@ class Definition(object):
         if new_value is not None:
             assert isinstance(new_value, Value)
 
+    def renumber(self, new_definition_index):
+        """Updates this definition's index in the block that defines it."""
+        self.definition_index = new_definition_index
+
     def ref_str(self):
         """Gets a string that represents a reference to this definition."""
         return '$%d' % self.index