--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/python/ppci/irmach.py	Thu Dec 05 17:02:38 2013 +0100
@@ -0,0 +1,70 @@
+
+"""
+  Abstract assembly language instructions.
+
+  This is the second intermediate representation.
+  
+  Instructions are selected and scheduled at this stage.
+"""
+
+from target import Instruction
+
+
+class Frame:
+    """ 
+        Activation record abstraction. This class contains a flattened 
+        function. Instructions are selected and scheduled at this stage.
+        Frames differ per machine.
+    """
+    def __init__(self, name):
+        self.name = name
+        self.instructions = []
+        self.stacksize = 0
+
+    def __repr__(self):
+        return 'Frame {}'.format(self.name)
+
+    def lower_to(self, outs):
+        for im in self.instructions:
+            if isinstance(im.assem, Instruction):
+                outs.emit(im.assem)
+            else:
+                outs.emit(im.assem.fromim(im))
+
+
+class AbstractInstruction:
+    """ 
+        Abstract machine instruction class. This is a very simple
+        abstraction of machine instructions.
+    """
+    def __init__(self, cls, ops=(), src=(), dst=(), jumps=(), others=(), ismove=False):
+        assert type(cls) is type or isinstance(cls, Instruction)
+        self.assem = cls
+        self.ops = tuple(ops)
+        self.src = tuple(src)
+        self.dst = tuple(dst)
+        self.jumps = tuple(jumps)
+        self.others = tuple(others)
+        self.ismove = ismove
+
+    def __repr__(self):
+        return self.render()
+
+    def render(self):
+        """
+            Substitutes source, dst and labels in the string
+        """
+        x = str(self.assem)
+        for i, s in enumerate(self.src):
+            p = '%s{}'.format(i)
+            x = x.replace(p, str(s))
+        for i, d in enumerate(self.dst):
+            p = '%d{}'.format(i)
+            x = x.replace(p, str(d))
+        for i, j in enumerate(self.jumps):
+            p = '%l{}'.format(i)
+            x = x.replace(p, str(j))
+        return x
+
+
+makeIns = AbstractInstruction