always transform integer abs, even in GRAPH_STATE_KEEP_MUX

[libfirm] / scripts / ir_spec.py

from spec_util import abstract, setnodedefaults

class Op(object):
        """Base class for firm nodes"""
abstract(Op)

class Unop(Op):
        """Unary nodes have exactly 1 input"""
        name     = "unop"
        ins      = [
                ("op",  "operand"),
        ]
        op_index = 0
        pinned   = "no"
abstract(Unop)

class Binop(Op):
        """Binary nodes have exactly 2 inputs"""
        name     = "binop"
        ins      = [
                ( "left",   "first operand" ),
                ( "right", "second operand" ),
        ]
        op_index = 0
        pinned   = "no"
abstract(Binop)

class Add(Binop):
        """returns the sum of its operands"""
        flags = [ "commutative" ]

class Alloc(Op):
        """allocates a block of memory.
        It can be specified whether the variable should be allocated to the stack
        or to the heap."""
        ins   = [
                ("mem",   "memory dependency" ),
                ("count", "number of objects to allocate" ),
        ]
        outs  = [
                ("M",         "memory result"),
                ("X_regular", "control flow when no exception occurs"),
                ("X_except",  "control flow when exception occured"),
                ("res",       "pointer to newly allocated memory"),
        ]
        attrs = [
                dict(
                        name    = "type",
                        type    = "ir_type*",
                        comment = "type of the allocated variable",
                ),
                dict(
                        name    = "where",
                        type    = "ir_where_alloc",
                        comment = "whether to allocate the variable on the stack or heap",
                )
        ]
        flags       = [ "fragile", "uses_memory" ]
        pinned      = "exception"
        pinned_init = "op_pin_state_pinned"
        attr_struct = "alloc_attr"

class Anchor(Op):
        """utiliy node used to "hold" nodes in a graph that might possibly not be
        reachable by other means or which should be reachable immediately without
        searching through the graph.
        Each firm-graph contains exactly one anchor node whose address is always
        known. All other well-known graph-nodes like Start, End, NoMem, Bad, ...
        are found by looking at the respective Anchor operand."""
        mode             = "mode_ANY"
        arity            = "variable"
        flags            = [ "dump_noblock" ]
        pinned           = "yes"
        attr_struct      = "irg_attr"
        knownBlock       = True
        singleton        = True
        noconstructor    = True
        customSerializer = True

class And(Binop):
        """returns the result of a bitwise and operation of its operands"""
        flags    = [ "commutative" ]

class ASM(Op):
        """executes assembler fragments of the target machine"""
        mode             = "mode_T"
        arity            = "variable"
        flags            = [ "keep", "uses_memory" ]
        pinned           = "memory"
        pinned_init      = "op_pin_state_pinned"
        attr_struct      = "asm_attr"
        attrs_name       = "assem"
        customSerializer = True
        attrs = [
                dict(
                        name    = "input_constraints",
                        type    = "ir_asm_constraint*",
                        comment = "input constraints",
                ),
                dict(
                        name    = "n_output_constraints",
                        type    = "int",
                        noprop  = True,
                        comment = "number of output constraints",
                ),
                dict(
                        name    = "output_constraints",
                        type    = "ir_asm_constraint*",
                        comment = "output constraints",
                ),
                dict(
                        name    = "n_clobbers",
                        type    = "int",
                        noprop  = True,
                        comment = "number of clobbered registers/memory",
                ),
                dict(
                        name    = "clobbers",
                        type    = "ident**",
                        comment = "list of clobbered registers/memory",
                ),
                dict(
                        name    = "text",
                        type    = "ident*",
                        comment = "assembler text",
                ),
        ]
        # constructor is written manually at the moment, because of the clobbers+
        # constraints arrays needing special handling (2 arguments for 1 attribute)
        noconstructor = True

class Bad(Op):
        """Bad nodes indicate invalid input, which is values which should never be
        computed.

        The typical use case for the Bad node is removing unreachable code.
        Frontends should set the current_block to Bad when it is clear that
        following code must be unreachable (ie. after a goto or return statement).
        Optimisations also set block predecessors to Bad when it becomes clear,
        that a control flow edge can never be executed.

        The gigo optimisations ensures that nodes with Bad as their block, get
        replaced by Bad themselfes. Nodes with at least 1 Bad input get exchanged
        with Bad too. Exception to this rule are Block, Phi, Tuple and End node;
        This is because removing inputs from a Block is hairy operation (requiring,
        Phis to be shortened too for example). So instead of removing block inputs
        they are set to Bad, and the actual removal is left to the control flow
        optimisation phase. Block, Phi, Tuple with only Bad inputs however are
        replaced by Bad right away."""
        flags         = [ "start_block", "dump_noblock" ]
        pinned        = "yes"
        knownBlock    = True
        block         = "get_irg_start_block(irg)"
        attr_struct   = "bad_attr"
        init = '''
        res->attr.bad.irg.irg = irg;
        '''

class Deleted(Op):
        """Internal node which is temporary set to nodes which are already removed
        from the graph."""
        mode             = "mode_Bad"
        flags            = [ ]
        pinned           = "yes"
        noconstructor    = True
        customSerializer = True

class Block(Op):
        """A basic block"""
        mode             = "mode_BB"
        knownBlock       = True
        block            = "NULL"
        pinned           = "yes"
        arity            = "variable"
        flags            = [ "labeled" ]
        attr_struct      = "block_attr"
        customSerializer = True

        init = '''
        res->attr.block.irg.irg     = irg;
        res->attr.block.backedge    = new_backedge_arr(irg->obst, arity);
        set_Block_matured(res, 1);

        /* Create and initialize array for Phi-node construction. */
        if (get_irg_phase_state(irg) == phase_building) {
                res->attr.block.graph_arr = NEW_ARR_D(ir_node *, irg->obst, irg->n_loc);
                memset(res->attr.block.graph_arr, 0, irg->n_loc * sizeof(ir_node*));
        }
        '''

class Borrow(Binop):
        """Returns the borrow bit from and implied subtractions of its 2 operands"""
        flags = []

class Bound(Op):
        """Performs a bounds-check: if lower <= index < upper then return index,
        otherwise throw an exception."""
        ins    = [
                ("mem",    "memory dependency"),
                ("index",  "value to test"),
                ("lower",  "lower bound (inclusive)"),
                ("upper",  "upper bound (exclusive)"),
        ]
        outs  = [
                ("M",         "memory result"),
                ("X_regular", "control flow when no exception occurs"),
                ("X_except",  "control flow when exception occured"),
                ("res",       "the checked index"),
        ]
        flags  = [ "fragile", "highlevel" ]
        pinned = "exception"
        pinned_init = "op_pin_state_pinned"
        attr_struct = "bound_attr"
        attrs_name  = "bound"

class Builtin(Op):
        """performs a backend-specific builtin."""
        ins      = [
                ("mem", "memory dependency"),
        ]
        arity    = "variable"
        outs     = [
                ("M",        "memory result"),
                ("1_result", "first result"),
        ]
        flags    = [ "uses_memory" ]
        attrs    = [
                dict(
                        type    = "ir_builtin_kind",
                        name    = "kind",
                        comment = "kind of builtin",
                ),
                dict(
                        type    = "ir_type*",
                        name    = "type",
                        comment = "method type for the builtin call",
                )
        ]
        pinned      = "memory"
        pinned_init = "op_pin_state_pinned"
        attr_struct = "builtin_attr"
        init   = '''
        assert((get_unknown_type() == type) || is_Method_type(type));
        '''

class Call(Op):
        """Calls other code. Control flow is transfered to ptr, additional
        operands are passed to the called code. Called code usually performs a
        return operation. The operands of this return operation are the result
        of the Call node."""
        ins      = [
                ("mem",   "memory dependency"),
                ("ptr",   "pointer to called code"),
        ]
        arity    = "variable"
        outs     = [
                ("M",                "memory result"),
                ("X_regular",        "control flow when no exception occurs"),
                ("X_except",         "control flow when exception occured"),
                ("T_result",         "tuple containing all results"),
        ]
        flags    = [ "fragile", "uses_memory" ]
        attrs    = [
                dict(
                        type    = "ir_type*",
                        name    = "type",
                        comment = "type of the call (usually type of the called procedure)",
                ),
                dict(
                        type = "unsigned",
                        name = "tail_call",
                        # the tail call attribute can only be set by analysis
                        init = "0",
                )
        ]
        attr_struct = "call_attr"
        pinned      = "memory"
        pinned_init = "op_pin_state_pinned"
        init = '''
        assert((get_unknown_type() == type) || is_Method_type(type));
        '''

class Carry(Binop):
        """Computes the value of the carry-bit that would result when adding the 2
        operands"""
        flags = [ "commutative" ]

class Cast(Unop):
        """perform a high-level type cast"""
        mode     = "get_irn_mode(irn_op)"
        flags    = [ "highlevel" ]
        attrs    = [
                dict(
                        type    = "ir_type*",
                        name    = "type",
                        comment = "target type of the case",
                )
        ]
        attr_struct = "cast_attr"
        init     = "assert(is_atomic_type(type));"

class Cmp(Binop):
        """Compares its two operands and checks whether a specified
           relation (like less or equal) is fulfilled."""
        flags = []
        mode  = "mode_b"
        attrs = [
                dict(
                        type    = "ir_relation",
                        name    = "relation",
                        comment = "Comparison relation"
                )
        ]
        attr_struct = "cmp_attr"

class Cond(Op):
        """Conditionally change control flow. There are two versions of this node:

        Boolean Cond:
        Input:  A value of mode_b
        Output: A tuple of two control flows. The first is taken if the input is
                false, the second if it is true.

        Switch Cond:
        Input:  A value of mode_Iu
        Output: A tuple of n control flows. If the Cond's input is i, control flow
        will proceed along output i. If the input is >= n control flow proceeds
        along output def_proj.
        """
        ins      = [
                ("selector",  "condition parameter"),
        ]
        outs     = [
                ("false", "control flow if operand is \"false\""),
                ("true",  "control flow if operand is \"true\""),
        ]
        flags    = [ "cfopcode", "forking" ]
        pinned   = "yes"
        attrs    = [
                dict(
                        name    = "default_proj",
                        type    = "long",
                        init    = "0",
                        comment = "Proj-number of default case for switch-Cond",
                ),
                dict(
                        name    = "jmp_pred",
                        type    = "cond_jmp_predicate",
                        init    = "COND_JMP_PRED_NONE",
                        comment = "can indicate the most likely jump",
                )
        ]
        attr_struct = "cond_attr"

class Confirm(Op):
        """Specifies constraints for a value. This allows explicit representation
        of path-sensitive properties. (Example: This value is always >= 0 on 1
        if-branch then all users within that branch are rerouted to a confirm-node
        specifying this property).

        A constraint is specified for the relation between value and bound.
        value is always returned.
        Note that this node does NOT check or assert the constraint, it merely
        specifies it."""
        ins      = [
                ("value",  "value to express a constraint for"),
                ("bound",  "value to compare against"),
        ]
        mode     = "get_irn_mode(irn_value)"
        flags    = [ "highlevel" ]
        pinned   = "yes"
        attrs    = [
                dict(
                        name    = "relation",
                        type    = "ir_relation",
                        comment = "relation of value to bound",
                ),
        ]
        attr_struct = "confirm_attr"
        attrs_name  = "confirm"

class Const(Op):
        """Returns a constant value."""
        flags      = [ "constlike", "start_block" ]
        block      = "get_irg_start_block(irg)"
        mode       = "get_tarval_mode(tarval)"
        knownBlock = True
        pinned     = "no"
        attrs      = [
                dict(
                        type    = "ir_tarval*",
                        name    = "tarval",
                        comment = "constant value (a tarval object)",
                )
        ]
        attr_struct = "const_attr"
        attrs_name  = "con"

class Conv(Unop):
        """Converts values between modes"""
        flags = []
        attrs = [
                dict(
                        name    = "strict",
                        type    = "int",
                        init    = "0",
                        comment = "force floating point to restrict precision even if backend computes in higher precision (deprecated)",
                )
        ]
        attr_struct = "conv_attr"
        attrs_name  = "conv"

class CopyB(Op):
        """Copies a block of memory"""
        ins   = [
                ("mem",  "memory dependency"),
                ("dst",  "destination address"),
                ("src",  "source address"),
        ]
        outs  = [
                ("M",         "memory result"),
                ("X_regular", "control flow when no exception occurs"),
                ("X_except",  "control flow when exception occured"),
        ]
        flags = [ "fragile", "uses_memory" ]
        attrs = [
                dict(
                        name    = "type",
                        type    = "ir_type*",
                        comment = "type of copied data",
                )
        ]
        attr_struct = "copyb_attr"
        attrs_name  = "copyb"
        pinned      = "memory"
        pinned_init = "op_pin_state_pinned"

class Div(Op):
        """returns the quotient of its 2 operands"""
        ins   = [
                ("mem",   "memory dependency"),
                ("left",  "first operand"),
                ("right", "second operand"),
        ]
        outs  = [
                ("M",         "memory result"),
                ("X_regular", "control flow when no exception occurs"),
                ("X_except",  "control flow when exception occured"),
                ("res",       "result of computation"),
        ]
        flags = [ "fragile", "uses_memory" ]
        attrs_name = "div"
        attrs = [
                dict(
                        type    = "ir_mode*",
                        name    = "resmode",
                        comment = "mode of the result value",
                ),
                dict(
                        name = "no_remainder",
                        type = "int",
                        init = "0",
                )
        ]
        attr_struct = "div_attr"
        pinned      = "exception"
        op_index    = 1
        arity_override = "oparity_binary"

class Dummy(Op):
        """A placeholder value. This is used when constructing cyclic graphs where
        you have cases where not all predecessors of a phi-node are known. Dummy
        nodes are used for the unknown predecessors and replaced later."""
        ins        = []
        flags      = [ "cfopcode", "start_block", "constlike", "dump_noblock" ]
        knownBlock = True
        pinned     = "yes"
        block      = "get_irg_start_block(irg)"

class End(Op):
        """Last node of a graph. It references nodes in endless loops (so called
        keepalive edges)"""
        mode             = "mode_X"
        pinned           = "yes"
        arity            = "dynamic"
        flags            = [ "cfopcode" ]
        knownBlock       = True
        block            = "get_irg_end_block(irg)"
        singleton        = True
        customSerializer = True

class Eor(Binop):
        """returns the result of a bitwise exclusive or operation of its operands"""
        flags    = [ "commutative" ]

class Free(Op):
        """Frees a block of memory previously allocated by an Alloc node"""
        ins    = [
                ("mem",   "memory dependency" ),
                ("ptr",   "pointer to the object to free"),
                ("size",  "number of objects to allocate" ),
        ]
        mode   = "mode_M"
        flags  = [ "uses_memory" ]
        pinned = "yes"
        attrs  = [
                dict(
                        name    = "type",
                        type    = "ir_type*",
                        comment = "type of the allocated variable",
                ),
                dict(
                        name    = "where",
                        type    = "ir_where_alloc",
                        comment = "whether allocation was on the stack or heap",
                )
        ]
        attr_struct = "free_attr"

class Id(Op):
        """Returns its operand unchanged."""
        ins    = [
           ("pred", "the value which is returned unchanged")
        ]
        pinned = "no"
        flags  = []

class IJmp(Op):
        """Jumps to the code in its argument. The code has to be in the same
        function and the the destination must be one of the blocks reachable
        by the tuple results"""
        mode     = "mode_X"
        pinned   = "yes"
        ins      = [
           ("target", "target address of the jump"),
        ]
        flags    = [ "cfopcode", "forking", "keep", "unknown_jump" ]

class InstOf(Op):
        """Tests whether an object is an instance of a class-type"""
        ins   = [
           ("store", "memory dependency"),
           ("obj",   "pointer to object being queried")
        ]
        outs  = [
                ("M",         "memory result"),
                ("X_regular", "control flow when no exception occurs"),
                ("X_except",  "control flow when exception occured"),
                ("res",       "checked object pointer"),
        ]
        flags = [ "highlevel" ]
        attrs = [
                dict(
                        name    = "type",
                        type    = "ir_type*",
                        comment = "type to check ptr for",
                )
        ]
        attr_struct = "io_attr"
        pinned      = "memory"
        pinned_init = "op_pin_state_floats"

class Jmp(Op):
        """Jumps to the block connected through the out-value"""
        mode     = "mode_X"
        pinned   = "yes"
        ins      = []
        flags    = [ "cfopcode" ]

class Load(Op):
        """Loads a value from memory (heap or stack)."""
        ins   = [
                ("mem", "memory dependency"),
                ("ptr",  "address to load from"),
        ]
        outs  = [
                ("M",         "memory result"),
                ("X_regular", "control flow when no exception occurs"),
                ("X_except",  "control flow when exception occured"),
                ("res",       "result of load operation"),
        ]
        flags    = [ "fragile", "uses_memory" ]
        pinned   = "exception"
        attrs    = [
                dict(
                        type      = "ir_mode*",
                        name      = "mode",
                        comment   = "mode of the value to be loaded",
                ),
                dict(
                        type      = "ir_volatility",
                        name      = "volatility",
                        comment   = "volatile loads are a visible side-effect and may not be optimized",
                        init      = "flags & cons_volatile ? volatility_is_volatile : volatility_non_volatile",
                ),
                dict(
                        type      = "ir_align",
                        name      = "unaligned",
                        comment   = "pointers to unaligned loads don't need to respect the load-mode/type alignments",
                        init      = "flags & cons_unaligned ? align_non_aligned : align_is_aligned",
                ),
        ]
        attr_struct = "load_attr"
        constructor_args = [
                dict(
                        type    = "ir_cons_flags",
                        name    = "flags",
                        comment = "specifies alignment, volatility and pin state",
                ),
        ]
        pinned_init = "flags & cons_floats ? op_pin_state_floats : op_pin_state_pinned"

class Minus(Unop):
        """returns the difference between its operands"""
        flags = []

class Mod(Op):
        """returns the remainder of its operands from an implied division.

        Examples:
        * mod(5,3)   produces 2
        * mod(5,-3)  produces 2
        * mod(-5,3)  produces -2
        * mod(-5,-3) produces -2
        """
        ins   = [
                ("mem",   "memory dependency"),
                ("left",  "first operand"),
                ("right", "second operand"),
        ]
        outs  = [
                ("M",         "memory result"),
                ("X_regular", "control flow when no exception occurs"),
                ("X_except",  "control flow when exception occured"),
                ("res",       "result of computation"),
        ]
        flags = [ "fragile", "uses_memory" ]
        attrs_name = "mod"
        attrs = [
                dict(
                        type    = "ir_mode*",
                        name    = "resmode",
                        comment = "mode of the result",
                ),
        ]
        attr_struct = "mod_attr"
        pinned      = "exception"
        op_index    = 1
        arity_override = "oparity_binary"

class Mul(Binop):
        """returns the product of its operands"""
        flags = [ "commutative" ]

class Mulh(Binop):
        """returns the upper word of the product of its operands (the part which
        would not fit into the result mode of a normal Mul anymore)"""
        flags = [ "commutative" ]

class Mux(Op):
        """returns the false or true operand depending on the value of the sel
        operand"""
        ins    = [
           ("sel",   "value making the output selection"),
           ("false", "selected if sel input is false"),
           ("true",  "selected if sel input is true"),
        ]
        flags  = []
        pinned = "no"

class NoMem(Op):
        """Placeholder node for cases where you don't need any memory input"""
        mode          = "mode_M"
        flags         = [ "dump_noblock", "dump_noinput" ]
        pinned        = "yes"
        knownBlock    = True
        block         = "get_irg_start_block(irg)"
        singleton     = True

class Not(Unop):
        """returns the logical complement of a value. Works for integer values too.
        If the input is false/zero then true/one is returned, otherwise false/zero
        is returned."""
        flags = []

class Or(Binop):
        """returns the result of a bitwise or operation of its operands"""
        flags = [ "commutative" ]

class Phi(Op):
        """Choose a value based on control flow. A phi node has 1 input for each
        predecessor of its block. If a block is entered from its nth predecessor
        all phi nodes produce their nth input as result."""
        pinned        = "yes"
        arity         = "variable"
        flags         = []
        attr_struct   = "phi_attr"
        init          = '''
        res->attr.phi.u.backedge = new_backedge_arr(irg->obst, arity);'''
        init_after_opt = '''
        /* Memory Phis in endless loops must be kept alive.
           As we can't distinguish these easily we keep all of them alive. */
        if (is_Phi(res) && mode == mode_M)
                add_End_keepalive(get_irg_end(irg), res);'''

class Pin(Op):
        """Pin the value of the node node in the current block. No users of the Pin
        node can float above the Block of the Pin. The node cannot float behind
        this block. Often used to Pin the NoMem node."""
        ins      = [
                ("op", "value which is pinned"),
        ]
        mode     = "get_irn_mode(irn_op)"
        flags    = [ "highlevel" ]
        pinned   = "yes"

class Proj(Op):
        """returns an entry of a tuple value"""
        ins              = [
                ("pred", "the tuple value from which a part is extracted"),
        ]
        flags            = []
        pinned           = "no"
        knownBlock       = True
        knownGraph       = True
        block            = "get_nodes_block(irn_pred)"
        graph            = "get_irn_irg(irn_pred)"
        customSerializer = True
        attrs      = [
                dict(
                        type    = "long",
                        name    = "proj",
                        comment = "number of tuple component to be extracted",
                ),
        ]
        attr_struct = "proj_attr"

class Raise(Op):
        """Raises an exception. Unconditional change of control flow. Writes an
        explicit Except variable to memory to pass it to the exception handler.
        Must be lowered to a Call to a runtime check function."""
        ins    = [
                ("mem",     "memory dependency"),
                ("exo_ptr", "pointer to exception object to be thrown"),
        ]
        outs  = [
                ("M", "memory result"),
                ("X", "control flow to exception handler"),
        ]
        flags  = [ "highlevel", "cfopcode" ]
        pinned = "yes"

class Return(Op):
        """Returns from the current function. Takes memory and return values as
        operands."""
        ins      = [
                ("mem", "memory dependency"),
        ]
        arity    = "variable"
        mode     = "mode_X"
        flags    = [ "cfopcode" ]
        pinned   = "yes"

class Rotl(Binop):
        """Returns its first operand bits rotated left by the amount in the 2nd
        operand"""
        flags    = []

class Sel(Op):
        """Computes the address of a entity of a compound type given the base
        address of an instance of the compound type."""
        ins    = [
                ("mem", "memory dependency"),
                ("ptr", "pointer to object to select from"),
        ]
        arity  = "variable"
        flags  = []
        mode   = "is_Method_type(get_entity_type(entity)) ? mode_P_code : mode_P_data"
        pinned = "no"
        attrs  = [
                dict(
                        type    = "ir_entity*",
                        name    = "entity",
                        comment = "entity which is selected",
                )
        ]
        attr_struct = "sel_attr"

class Shl(Binop):
        """Returns its first operands bits shifted left by the amount of the 2nd
        operand"""
        flags = []

class Shr(Binop):
        """Returns its first operands bits shifted right by the amount of the 2nd
        operand. No special handling for the sign bit (zero extension)"""
        flags = []

class Shrs(Binop):
        """Returns its first operands bits shifted right by the amount of the 2nd
        operand. The leftmost bit (usually the sign bit) stays the same
        (sign extension)"""
        flags = []

class Start(Op):
        """The first node of a graph. Execution starts with this node."""
        outs       = [
                ("X_initial_exec", "control flow"),
                ("M",              "initial memory"),
                ("P_frame_base",   "frame base pointer"),
                ("T_args",         "function arguments")
        ]
        mode             = "mode_T"
        pinned           = "yes"
        flags            = [ "cfopcode" ]
        singleton        = True
        knownBlock       = True
        customSerializer = True
        block            = "get_irg_start_block(irg)"

class Store(Op):
        """Stores a value into memory (heap or stack)."""
        ins   = [
           ("mem",   "memory dependency"),
           ("ptr",   "address to store to"),
           ("value", "value to store"),
        ]
        outs  = [
                ("M",         "memory result"),
                ("X_regular", "control flow when no exception occurs"),
                ("X_except",  "control flow when exception occured"),
        ]
        flags    = [ "fragile", "uses_memory" ]
        pinned   = "exception"
        attr_struct = "store_attr"
        pinned_init = "flags & cons_floats ? op_pin_state_floats : op_pin_state_pinned"
        attrs = [
                dict(
                        type      = "ir_volatility",
                        name      = "volatility",
                        comment   = "volatile stores are a visible side-effect and may not be optimized",
                        init      = "flags & cons_volatile ? volatility_is_volatile : volatility_non_volatile",
                ),
                dict(
                        type      = "ir_align",
                        name      = "unaligned",
                        comment   = "pointers to unaligned stores don't need to respect the load-mode/type alignments",
                        init      = "flags & cons_unaligned ? align_non_aligned : align_is_aligned",
                ),
        ]
        constructor_args = [
                dict(
                        type    = "ir_cons_flags",
                        name    = "flags",
                        comment = "specifies alignment, volatility and pin state",
                ),
        ]

class Sub(Binop):
        """returns the difference of its operands"""
        flags = []

class SymConst(Op):
        """A symbolic constant.

         - symconst_type_tag   The symbolic constant represents a type tag.  The
                               type the tag stands for is given explicitly.
         - symconst_type_size  The symbolic constant represents the size of a type.
                               The type of which the constant represents the size
                               is given explicitly.
         - symconst_type_align The symbolic constant represents the alignment of a
                               type.  The type of which the constant represents the
                               size is given explicitly.
         - symconst_addr_ent   The symbolic constant represents the address of an
                               entity (variable or method).  The variable is given
                               explicitly by a firm entity.
         - symconst_ofs_ent    The symbolic constant represents the offset of an
                               entity in its owner type.
         - symconst_enum_const The symbolic constant is a enumeration constant of
                               an enumeration type."""
        mode       = "mode_P"
        flags      = [ "constlike", "start_block" ]
        knownBlock = True
        pinned     = "no"
        attrs      = [
                dict(
                        type    = "ir_entity*",
                        name    = "entity",
                        noprop  = True,
                        comment = "entity whose address is returned",
                )
        ]
        attr_struct = "symconst_attr"
        customSerializer = True
        # constructor is written manually at the moment, because of the strange
        # union argument
        noconstructor = True

class Sync(Op):
        """The Sync operation unifies several partial memory blocks. These blocks
        have to be pairwise disjunct or the values in common locations have to
        be identical.  This operation allows to specify all operations that
        eventually need several partial memory blocks as input with a single
        entrance by unifying the memories with a preceding Sync operation."""
        mode     = "mode_M"
        flags    = []
        pinned   = "no"
        arity    = "dynamic"

class Tuple(Op):
        """Builds a Tuple from single values.

        This is needed to implement optimizations that remove a node that produced
        a tuple.  The node can be replaced by the Tuple operation so that the
        following Proj nodes have not to be changed. (They are hard to find due to
        the implementation with pointers in only one direction.) The Tuple node is
        smaller than any other node, so that a node can be changed into a Tuple by
        just changing its opcode and giving it a new in array."""
        arity  = "variable"
        mode   = "mode_T"
        pinned = "no"
        flags  = [ "labeled" ]

class Unknown(Op):
        """Returns an unknown (at compile- and runtime) value. It is a valid
        optimisation to replace an Unknown by any other constant value."""
        knownBlock = True
        pinned     = "yes"
        block      = "get_irg_start_block(irg)"
        flags      = [ "start_block", "constlike", "dump_noblock" ]

# Prepare node list

def getOpList(namespace):
        nodes = []
        for t in namespace.values():
                if type(t) != type:
                        continue

                if issubclass(t, Op):
                        setnodedefaults(t)
                        nodes.append(t)
        return nodes

nodes = getOpList(globals())
nodes = sorted(nodes, lambda x,y: cmp(x.name, y.name))