Add complete IR generator.

artiq/compiler/ir.py

@@ -3,6 +3,8 @@ The :mod:`ir` module contains the intermediate representation
 of the ARTIQ compiler.
 """
 
+from collections import OrderedDict
+from pythonparser import ast
 from . import types, builtins
 
 # Generic SSA IR classes
@@ -13,13 +15,13 @@ def escape_name(name):
     else:
         return "\"{}\"".format(name.replace("\"", "\\\""))
 
-class TSSABasicBlock(types.TMono):
+class TBasicBlock(types.TMono):
     def __init__(self):
-        super().__init__("ssa.basic_block")
+        super().__init__("label")
 
-class TSSAOption(types.TMono):
+class TOption(types.TMono):
     def __init__(self, inner):
-        super().__init__("ssa.option", {"inner": inner})
+        super().__init__("option", {"inner": inner})
 
 class Value:
     """
@@ -30,7 +32,7 @@ class Value:
     """
 
     def __init__(self, typ):
-        self.uses, self.type = set(), typ
+        self.uses, self.type = set(), typ.find()
 
     def replace_all_uses_with(self, value):
         for user in self.uses:
@@ -40,7 +42,7 @@ class Constant(Value):
     """
     A constant value.
 
-    :ivar value: (None, True or False) value
+    :ivar value: (Python object) value
     """
 
     def __init__(self, value, typ):
@@ -127,6 +129,8 @@ class Instruction(User):
     """
 
     def __init__(self, operands, typ, name=""):
+        assert isinstance(operands, list)
+        assert isinstance(typ, types.Type)
         super().__init__(operands, typ, name)
         self.basic_block = None
 
@@ -160,6 +164,9 @@ class Instruction(User):
         else:
             self.erase()
 
+    def _operands_as_string(self):
+        return ", ".join([operand.as_operand() for operand in self.operands])
+
     def __str__(self):
         if builtins.is_none(self.type):
             prefix = ""
@@ -168,8 +175,7 @@ class Instruction(User):
                                         types.TypePrinter().name(self.type))
 
         if any(self.operands):
-            return "{}{} {}".format(prefix, self.opcode(),
-                ", ".join([operand.as_operand() for operand in self.operands]))
+            return "{}{} {}".format(prefix, self.opcode(), self._operands_as_string())
         else:
             return "{}{}".format(prefix, self.opcode())
 
@@ -182,7 +188,7 @@ class Phi(Instruction):
     """
 
     def __init__(self, typ, name=""):
-        super().__init__(typ, name)
+        super().__init__([], typ, name)
 
     def opcode(self):
         return "phi"
@@ -217,9 +223,11 @@ class Phi(Instruction):
                                         types.TypePrinter().name(self.type))
 
         if any(self.operands):
-            operand_list = ["%{} => %{}".format(escape_name(block.name), escape_name(value.name))
-                            for operand in self.operands]
+            operand_list = ["%{} => {}".format(escape_name(block.name), value.as_operand())
+                            for value, block in self.incoming()]
             return "{}{} [{}]".format(prefix, self.opcode(), ", ".join(operand_list))
+        else:
+            return "{}{} [???]".format(prefix, self.opcode())
 
 class Terminator(Instruction):
     """
@@ -237,7 +245,7 @@ class BasicBlock(NamedValue):
     """
 
     def __init__(self, instructions, name=""):
-        super().__init__(TSSABasicBlock(), name)
+        super().__init__(TBasicBlock(), name)
         self.instructions = []
         self.set_instructions(instructions)
 
@@ -253,10 +261,13 @@ class BasicBlock(NamedValue):
             self.function.remove(self)
 
     def prepend(self, insn):
+        assert isinstance(insn, Instruction)
         insn.set_basic_block(self)
         self.instructions.insert(0, insn)
+        return insn
 
     def append(self, insn):
+        assert isinstance(insn, Instruction)
         insn.set_basic_block(self)
         self.instructions.append(insn)
         return insn
@@ -265,11 +276,13 @@ class BasicBlock(NamedValue):
         return self.instructions.index(insn)
 
     def insert(self, before, insn):
+        assert isinstance(insn, Instruction)
         insn.set_basic_block(self)
         self.instructions.insert(self.index(before), insn)
         return insn
 
     def remove(self, insn):
+        assert insn in self.instructions
         insn._detach()
         self.instructions.remove(insn)
         return insn
@@ -290,10 +303,13 @@ class BasicBlock(NamedValue):
 
     def predecessors(self):
         assert self.function is not None
-        self.function.predecessors_of(self)
+        return self.function.predecessors_of(self)
 
     def __str__(self):
         lines = ["{}:".format(escape_name(self.name))]
+        if self.function is not None:
+            lines[0] += " ; predecessors: {}".format(
+                ", ".join([escape_name(pred.name) for pred in self.predecessors()]))
         for insn in self.instructions:
             lines.append("  " + str(insn))
         return "\n".join(lines)
@@ -312,10 +328,9 @@ class Function(Value):
     """
 
     def __init__(self, typ, name, arguments):
-        self.type, self.name = typ, name
-        self.arguments = []
-        self.basic_blocks = []
-        self.names = set()
+        super().__init__(typ)
+        self.name = name
+        self.names, self.arguments, self.basic_blocks = set(), [], []
         self.set_arguments(arguments)
 
     def _remove_name(self, name):
@@ -325,7 +340,7 @@ class Function(Value):
         name, counter = base_name, 1
         while name in self.names or name == "":
             if base_name == "":
-                name = str(counter)
+                name = "v.{}".format(str(counter))
             else:
                 name = "{}.{}".format(name, counter)
             counter += 1
@@ -346,10 +361,11 @@ class Function(Value):
 
     def remove(self, basic_block):
         basic_block._detach()
-        self.basic_block.remove(basic_block)
+        self.basic_blocks.remove(basic_block)
 
     def predecessors_of(self, successor):
-        return [block for block in self.basic_blocks if successor in block.successors()]
+        return [block for block in self.basic_blocks
+                       if block.is_terminated() and successor in block.successors()]
 
     def as_operand(self):
         return "{} @{}".format(types.TypePrinter().name(self.type),
@@ -369,6 +385,412 @@ class Function(Value):
 
 # Python-specific SSA IR classes
 
+class TEnvironment(types.TMono):
+    def __init__(self, vars, outer=None):
+        if outer is not None:
+            assert isinstance(outer, TEnvironment)
+            env = OrderedDict({".outer": outer})
+            env.update(vars)
+        else:
+            env = OrderedDict(vars)
+
+        super().__init__("environment", env)
+
+    def type_of(self, name):
+        if name in self.params:
+            return self.params[name].find()
+        elif ".outer" in self.params:
+            return self.params[".outer"].type_of(name)
+        else:
+            assert False
+
+    """
+    Add a new binding, ensuring hygiene.
+
+    :returns: (string) mangled name
+    """
+    def add(self, base_name, typ):
+        name, counter = base_name, 1
+        while name in self.params or name == "":
+            if base_name == "":
+                name = str(counter)
+            else:
+                name = "{}.{}".format(name, counter)
+            counter += 1
+
+        self.params[name] = typ.find()
+        return name
+
+def is_environment(typ):
+    return isinstance(typ, TEnvironment)
+
+class EnvironmentArgument(NamedValue):
+    """
+    A function argument specifying an outer environment.
+    """
+
+    def as_operand(self):
+        return "environment(...) %{}".format(escape_name(self.name))
+
+class Alloc(Instruction):
+    """
+    An instruction that allocates an object specified by
+    the type of the intsruction.
+    """
+
+    def __init__(self, operands, typ, name=""):
+        for operand in operands: assert isinstance(operand, Value)
+        super().__init__(operands, typ, name)
+
+    def opcode(self):
+        return "alloc"
+
+    def as_operand(self):
+        if is_environment(self.type):
+            # Only show full environment in the instruction itself
+            return "%{}".format(escape_name(self.name))
+        else:
+            return super().as_operand()
+
+class GetLocal(Instruction):
+    """
+    An intruction that loads a local variable from an environment,
+    possibly going through multiple levels of indirection.
+
+    :ivar var_name: (string) variable name
+    """
+
+    """
+    :param env: (:class:`Value`) local environment
+    :param var_name: (string) local variable name
+    """
+    def __init__(self, env, var_name, name=""):
+        assert isinstance(env, Alloc)
+        assert isinstance(env.type, TEnvironment)
+        assert isinstance(var_name, str)
+        super().__init__([env], env.type.type_of(var_name), name)
+        self.var_name = var_name
+
+    def opcode(self):
+        return "getlocal({})".format(self.var_name)
+
+    def get_env(self):
+        return self.operands[0]
+
+class SetLocal(Instruction):
+    """
+    An intruction that stores a local variable into an environment,
+    possibly going through multiple levels of indirection.
+
+    :ivar var_name: (string) variable name
+    """
+
+    """
+    :param env: (:class:`Value`) local environment
+    :param var_name: (string) local variable name
+    :param value: (:class:`Value`) value to assign
+    """
+    def __init__(self, env, var_name, value, name=""):
+        assert isinstance(env, Alloc)
+        assert isinstance(env.type, TEnvironment)
+        assert isinstance(var_name, str)
+        assert env.type.type_of(var_name) == value.type
+        assert isinstance(value, Value)
+        super().__init__([env, value], builtins.TNone(), name)
+        self.var_name = var_name
+
+    def opcode(self):
+        return "setlocal({})".format(self.var_name)
+
+    def get_env(self):
+        return self.operands[0]
+
+    def get_value(self):
+        return self.operands[1]
+
+class GetAttr(Instruction):
+    """
+    An intruction that loads an attribute from an object,
+    or extracts a tuple element.
+
+    :ivar attr: (string) variable name
+    """
+
+    """
+    :param obj: (:class:`Value`) object or tuple
+    :param attr: (string or integer) attribute or index
+    """
+    def __init__(self, obj, attr, name=""):
+        assert isinstance(obj, Value)
+        assert isinstance(attr, (str, int))
+        if isinstance(attr, int):
+            assert isinstance(obj.type, types.TTuple)
+            typ = obj.type.elts[attr]
+        else:
+            typ = obj.type.attributes[attr]
+        super().__init__([obj], typ, name)
+        self.attr = attr
+
+    def opcode(self):
+        return "getattr({})".format(repr(self.attr))
+
+    def get_env(self):
+        return self.operands[0]
+
+class SetAttr(Instruction):
+    """
+    An intruction that stores an attribute to an object.
+
+    :ivar attr: (string) variable name
+    """
+
+    """
+    :param obj: (:class:`Value`) object or tuple
+    :param attr: (string or integer) attribute
+    :param value: (:class:`Value`) value to store
+    """
+    def __init__(self, obj, attr, value, name=""):
+        assert isinstance(obj, Value)
+        assert isinstance(attr, (str, int))
+        assert isinstance(value, Value)
+        if isinstance(attr, int):
+            assert value.type == obj.type.elts[attr]
+        else:
+            assert value.type == obj.type.attributes[attr]
+        super().__init__([obj, value], typ, name)
+        self.attr = attr
+
+    def opcode(self):
+        return "setattr({})".format(repr(self.attr))
+
+    def get_env(self):
+        return self.operands[0]
+
+    def get_value(self):
+        return self.operands[1]
+
+class GetElem(Instruction):
+    """
+    An intruction that loads an element from a list.
+    """
+
+    """
+    :param lst: (:class:`Value`) list
+    :param index: (:class:`Value`) index
+    """
+    def __init__(self, lst, index, name=""):
+        assert isinstance(lst, Value)
+        assert isinstance(index, Value)
+        super().__init__([lst, index], builtins.get_iterable_elt(lst.type), name)
+
+    def opcode(self):
+        return "getelem"
+
+    def get_list(self):
+        return self.operands[0]
+
+    def get_index(self):
+        return self.operands[1]
+
+class SetElem(Instruction):
+    """
+    An intruction that stores an element into a list.
+    """
+
+    """
+    :param lst: (:class:`Value`) list
+    :param index: (:class:`Value`) index
+    :param value: (:class:`Value`) value to store
+    """
+    def __init__(self, lst, index, value, name=""):
+        assert isinstance(lst, Value)
+        assert isinstance(index, Value)
+        assert isinstance(value, Value)
+        assert builtins.get_iterable_elt(lst.type) == value.type.find()
+        super().__init__([lst, index, value], builtins.TNone(), name)
+
+    def opcode(self):
+        return "setelem"
+
+    def get_list(self):
+        return self.operands[0]
+
+    def get_index(self):
+        return self.operands[1]
+
+    def get_value(self):
+        return self.operands[2]
+
+class UnaryOp(Instruction):
+    """
+    An unary operation on numbers.
+
+    :ivar op: (:class:`pythonparser.ast.unaryop`) operation
+    """
+
+    """
+    :param op: (:class:`pythonparser.ast.unaryop`) operation
+    :param operand: (:class:`Value`) operand
+    """
+    def __init__(self, op, operand, name=""):
+        assert isinstance(op, ast.unaryop)
+        assert isinstance(operand, Value)
+        super().__init__([operand], operand.type, name)
+        self.op = op
+
+    def opcode(self):
+        return "unaryop({})".format(type(self.op).__name__)
+
+    def get_operand(self):
+        return self.operands[0]
+
+class Coerce(Instruction):
+    """
+    A coercion operation for numbers.
+    """
+
+    def __init__(self, value, typ, name=""):
+        assert isinstance(value, Value)
+        assert isinstance(typ, types.Type)
+        super().__init__([value], typ, name)
+
+    def opcode(self):
+        return "coerce"
+
+    def get_value(self):
+        return self.operands[0]
+
+class BinaryOp(Instruction):
+    """
+    A binary operation on numbers.
+
+    :ivar op: (:class:`pythonparser.ast.unaryop`) operation
+    """
+
+    """
+    :param op: (:class:`pythonparser.ast.operator`) operation
+    :param lhs: (:class:`Value`) left-hand operand
+    :param rhs: (:class:`Value`) right-hand operand
+    """
+    def __init__(self, op, lhs, rhs, name=""):
+        assert isinstance(op, ast.operator)
+        assert isinstance(lhs, Value)
+        assert isinstance(rhs, Value)
+        assert lhs.type == rhs.type
+        super().__init__([lhs, rhs], lhs.type, name)
+        self.op = op
+
+    def opcode(self):
+        return "binaryop({})".format(type(self.op).__name__)
+
+    def get_lhs(self):
+        return self.operands[0]
+
+    def get_rhs(self):
+        return self.operands[1]
+
+class Compare(Instruction):
+    """
+    A comparison operation on numbers.
+
+    :ivar op: (:class:`pythonparser.ast.cmpop`) operation
+    """
+
+    """
+    :param op: (:class:`pythonparser.ast.cmpop`) operation
+    :param lhs: (:class:`Value`) left-hand operand
+    :param rhs: (:class:`Value`) right-hand operand
+    """
+    def __init__(self, op, lhs, rhs, name=""):
+        assert isinstance(op, ast.cmpop)
+        assert isinstance(lhs, Value)
+        assert isinstance(rhs, Value)
+        assert lhs.type == rhs.type
+        super().__init__([lhs, rhs], builtins.TBool(), name)
+        self.op = op
+
+    def opcode(self):
+        return "compare({})".format(type(self.op).__name__)
+
+    def get_lhs(self):
+        return self.operands[0]
+
+    def get_rhs(self):
+        return self.operands[1]
+
+class Builtin(Instruction):
+    """
+    A builtin operation. Similar to a function call that
+    never raises.
+
+    :ivar op: (string) operation name
+    """
+
+    """
+    :param op: (string) operation name
+    """
+    def __init__(self, op, operands, typ, name=""):
+        assert isinstance(op, str)
+        for operand in operands: assert isinstance(operand, Value)
+        super().__init__(operands, typ, name)
+        self.op = op
+
+    def opcode(self):
+        return "builtin({})".format(self.op)
+
+class Call(Instruction):
+    """
+    A function call operation.
+    """
+
+    """
+    :param func: (:class:`Value`) function to call
+    :param args: (list of :class:`Value`) function arguments
+    """
+    def __init__(self, func, args, name=""):
+        print(func)
+        assert isinstance(func, Value)
+        for arg in args: assert isinstance(arg, Value)
+        super().__init__([func] + args, func.type.ret, name)
+
+    def opcode(self):
+        return "call"
+
+    def get_function(self):
+        return self.operands[0]
+
+    def get_arguments(self):
+        return self.operands[1:]
+
+class Select(Instruction):
+    """
+    A conditional select instruction.
+    """
+
+    """
+    :param cond: (:class:`Value`) select condition
+    :param if_true: (:class:`Value`) value of select if condition is truthful
+    :param if_false: (:class:`Value`) value of select if condition is falseful
+    """
+    def __init__(self, cond, if_true, if_false, name=""):
+        assert isinstance(cond, Value)
+        assert isinstance(if_true, Value)
+        assert isinstance(if_false, Value)
+        assert if_true.type == if_false.type
+        super().__init__([cond, if_true, if_false], if_true.type, name)
+
+    def opcode(self):
+        return "select"
+
+    def get_condition(self):
+        return self.operands[0]
+
+    def get_if_true(self):
+        return self.operands[1]
+
+    def get_if_false(self):
+        return self.operands[2]
+
 class Branch(Terminator):
     """
     An unconditional branch instruction.
@@ -378,12 +800,13 @@ class Branch(Terminator):
     :param target: (:class:`BasicBlock`) branch target
     """
     def __init__(self, target, name=""):
+        assert isinstance(target, BasicBlock)
         super().__init__([target], builtins.TNone(), name)
 
     def opcode(self):
         return "branch"
 
-    def target(self):
+    def get_target(self):
         return self.operands[0]
 
 class BranchIf(Terminator):
@@ -393,24 +816,57 @@ class BranchIf(Terminator):
 
     """
     :param cond: (:class:`Value`) branch condition
-    :param if_true: (:class:`BasicBlock`) branch target if expression is truthful
-    :param if_false: (:class:`BasicBlock`) branch target if expression is falseful
+    :param if_true: (:class:`BasicBlock`) branch target if condition is truthful
+    :param if_false: (:class:`BasicBlock`) branch target if condition is falseful
     """
     def __init__(self, cond, if_true, if_false, name=""):
+        assert isinstance(cond, Value)
+        assert isinstance(if_true, BasicBlock)
+        assert isinstance(if_false, BasicBlock)
         super().__init__([cond, if_true, if_false], builtins.TNone(), name)
 
     def opcode(self):
-        return "branch_if"
+        return "branchif"
 
-    def condition(self):
+    def get_condition(self):
         return self.operands[0]
 
-    def if_true(self):
+    def get_if_true(self):
         return self.operands[1]
 
-    def if_false(self):
+    def get_if_false(self):
         return self.operands[2]
 
+class IndirectBranch(Terminator):
+    """
+    An indirect branch instruction.
+    """
+
+    """
+    :param target: (:class:`Value`) branch target
+    :param destinations: (list of :class:`BasicBlock`) all possible values of `target`
+    """
+    def __init__(self, target, destinations, name=""):
+        assert isinstance(target, Value)
+        assert all([isinstance(dest, BasicBlock) for dest in destinations])
+        super().__init__([target] + destinations, builtins.TNone(), name)
+
+    def opcode(self):
+        return "indirectbranch"
+
+    def get_target(self):
+        return self.operands[0]
+
+    def get_destinations(self):
+        return self.operands[1:]
+
+    def add_destination(self, destination):
+        self.operands.append(destination)
+
+    def _operands_as_string(self):
+        return "{}, [{}]".format(self.operands[0].as_operand(),
+                                 ", ".join([dest.as_operand() for dest in self.operands[1:]]))
+
 class Return(Terminator):
     """
     A return instruction.
@@ -420,28 +876,113 @@ class Return(Terminator):
     :param value: (:class:`Value`) return value
     """
     def __init__(self, value, name=""):
+        assert isinstance(value, Value)
         super().__init__([value], builtins.TNone(), name)
 
     def opcode(self):
         return "return"
 
-    def value(self):
+    def get_value(self):
         return self.operands[0]
 
-class Eval(Instruction):
+class Unreachable(Terminator):
     """
-    An instruction that evaluates an AST fragment.
+    An instruction used to mark unreachable branches.
     """
 
     """
-    :param ast: (:class:`.asttyped.AST`) return value
+    :param target: (:class:`BasicBlock`) branch target
     """
-    def __init__(self, ast, name=""):
-        super().__init__([], ast.type, name)
-        self.ast = ast
+    def __init__(self, name=""):
+        super().__init__([], builtins.TNone(), name)
 
     def opcode(self):
-        return "eval"
+        return "unreachable"
 
-    def __str__(self):
-        return super().__str__() + " `{}`".format(self.ast.loc.source())
+class Raise(Terminator):
+    """
+    A raise instruction.
+    """
+
+    """
+    :param value: (:class:`Value`) exception value
+    """
+    def __init__(self, value, name=""):
+        assert isinstance(value, Value)
+        super().__init__([value], builtins.TNone(), name)
+
+    def opcode(self):
+        return "raise"
+
+    def get_value(self):
+        return self.operands[0]
+
+class Invoke(Terminator):
+    """
+    A function call operation that supports exception handling.
+    """
+
+    """
+    :param func: (:class:`Value`) function to call
+    :param args: (list of :class:`Value`) function arguments
+    :param normal: (:class:`BasicBlock`) normal target
+    :param exn: (:class:`BasicBlock`) exceptional target
+    """
+    def __init__(self, func, args, normal, exn, name=""):
+        assert isinstance(func, Value)
+        for arg in args: assert isinstance(arg, Value)
+        assert isinstance(normal, BasicBlock)
+        assert isinstance(exn, BasicBlock)
+        super().__init__([func] + args + [normal, exn], func.type.ret, name)
+
+    def opcode(self):
+        return "invoke"
+
+    def get_function(self):
+        return self.operands[0]
+
+    def get_arguments(self):
+        return self.operands[1:-2]
+
+    def get_normal_target(self):
+        return self.operands[-2]
+
+    def get_exception_target(self):
+        return self.operands[-1]
+
+    def _operands_as_string(self):
+        result = ", ".join([operand.as_operand() for operand in self.operands[:-2]])
+        result += " to {} unwind {}".format(self.operands[-2].as_operand(),
+                                            self.operands[-1].as_operand())
+        return result
+
+class LandingPad(Terminator):
+    """
+    An instruction that gives an incoming exception a name and
+    dispatches it according to its type.
+
+    Once dispatched, the exception should be cast to its proper
+    type by calling the "exncast" builtin on the landing pad value.
+
+    :ivar types: (a list of :class:`builtins.TException`)
+        exception types corresponding to the basic block operands
+    """
+
+    def __init__(self, name=""):
+        super().__init__([], builtins.TException(), name)
+        self.types = []
+
+    def add_clause(self, target, typ):
+        assert isinstance(target, BasicBlock)
+        assert builtins.is_exception(typ)
+        self.operands.append(target)
+        self.types.append(typ.find())
+
+    def opcode(self):
+        return "landingpad"
+
+    def _operands_as_string(self):
+        table = []
+        for typ, target in zip(self.types, self.operands):
+            table.append("{} => {}".format(types.TypePrinter().name(typ), target.as_operand()))
+        return "[{}]".format(", ".join(table))