import sys
from pypy.translator.simplify import join_blocks, cleanup_graph
from pypy.translator.simplify import get_graph, get_funcobj
from pypy.translator.unsimplify import copyvar
from pypy.objspace.flow.model import Variable, Constant, Block, Link
from pypy.objspace.flow.model import SpaceOperation, c_last_exception
from pypy.objspace.flow.model import FunctionGraph
from pypy.objspace.flow.model import traverse, mkentrymap, checkgraph
from pypy.annotation import model as annmodel
from pypy.rpython.lltypesystem.lltype import Bool, Signed, typeOf, Void, Ptr
from pypy.rpython.lltypesystem.lltype import normalizeptr
from pypy.rpython.ootypesystem import ootype
from pypy.rpython import rmodel
from pypy.tool.algo import sparsemat
from pypy.translator.backendopt import removenoops
from pypy.translator.backendopt.support import log, split_block_with_keepalive
from pypy.translator.unsimplify import split_block
from pypy.translator.backendopt.support import find_backedges, find_loop_blocks
from pypy.translator.backendopt.canraise import RaiseAnalyzer

class CannotInline(Exception):
    pass

def get_meth_from_oosend(op):
    method_name = op.args[0].value
    INSTANCE = op.args[1].concretetype
    _, meth = INSTANCE._lookup(op.args[0].value)
    virtual = getattr(meth, '_virtual', True)
    if virtual:
        return None
    else:
        return meth

class CanRaise:
    def __init__(self, can_raise):
        self.can_raise = can_raise

def collect_called_graphs(graph, translator, include_oosend=True):
    graphs_or_something = {}
    for block in graph.iterblocks():
        for op in block.operations:
            if op.opname == "direct_call":
                graph = get_graph(op.args[0], translator)
                if graph is not None:
                    graphs_or_something[graph] = True
                else:
                    graphs_or_something[op.args[0]] = True
            if op.opname == "indirect_call":
                graphs = op.args[-1].value
                if graphs is None:
                    graphs_or_something[op.args[0]] = True
                else:
                    for graph in graphs:
                        graphs_or_something[graph] = True
            if op.opname == 'oosend' and include_oosend:
                meth = get_meth_from_oosend(op)
                if hasattr(meth, 'graph'):
                    key = meth.graph
                elif hasattr(meth, '_can_raise'):
                    key = CanRaise(meth._can_raise)
                else:
                    key = op.args[0]
                graphs_or_something[key] = True
    return graphs_or_something

def iter_callsites(graph, calling_what):
    for block in graph.iterblocks():
        for i, op in enumerate(block.operations):
            if op.opname == "direct_call":
                funcobj = get_funcobj(op.args[0].value)
            elif op.opname == "oosend":
                funcobj = get_meth_from_oosend(op)
                if funcobj is None:
                    continue # cannot inline virtual methods
            else:
                continue

            graph = getattr(funcobj, 'graph', None)
            # accept a function or a graph as 'inline_func'
            if (calling_what is None or
                graph is calling_what or
                getattr(funcobj, '_callable', None) is calling_what):
                yield graph, block, i

def find_callsites(graph, calling_what):
    return list(iter_callsites(graph, calling_what))

def iter_first_callsites(graph, calling_what):
    # restart the iter_callsites iterator every time, since the graph might
    # have changed
    while 1:
        iterator = iter_callsites(graph, calling_what)
        yield iterator.next()

def contains_call(graph, calling_what):
    try:
        iterator = iter_callsites(graph, calling_what)
        iterator.next()
        return True
    except StopIteration:
        return False

def inline_function(translator, inline_func, graph, lltype_to_classdef,
                    raise_analyzer, call_count_pred=None, cleanup=True):
    inliner = Inliner(translator, graph, inline_func, lltype_to_classdef,
                      raise_analyzer = raise_analyzer,
                      call_count_pred=call_count_pred, cleanup=cleanup)
    return inliner.inline_all()

def simple_inline_function(translator, inline_func, graph):
    inliner = Inliner(translator, graph, inline_func,
                      translator.rtyper.lltype_to_classdef_mapping(),
                      raise_analyzer = RaiseAnalyzer(translator))
    return inliner.inline_all()


def _find_exception_type(block):
    #XXX slightly brittle: find the exception type for simple cases
    #(e.g. if you do only raise XXXError) by doing pattern matching
    currvar = block.exits[0].args[1]
    ops = block.operations
    i = len(ops)-1
    while True:
        if isinstance(currvar, Constant):
            value = currvar.value
            if isinstance(typeOf(value), ootype.Instance):
                TYPE = ootype.dynamicType(value)
            else:
                TYPE = typeOf(normalizeptr(value))
            return TYPE, block.exits[0]
        if i < 0:
            return None, None
        op = ops[i]
        i -= 1
        if op.opname in ("same_as", "cast_pointer", "ooupcast", "oodowncast") and op.result is currvar:
            currvar = op.args[0]
        elif op.opname == "malloc" and op.result is currvar:
            return Ptr(op.args[0].value), block.exits[0]
        elif op.opname == "new" and op.result is currvar:
            return op.args[0].value, block.exits[0]

def does_raise_directly(graph, raise_analyzer):
    """ this function checks, whether graph contains operations which can raise
    and which are not exception guarded """
    for block in graph.iterblocks():
        if block is graph.exceptblock:
            return True      # the except block is reachable
        if block.exitswitch == c_last_exception:
            consider_ops_to = -1
        else:
            consider_ops_to = len(block.operations)
        for op in block.operations[:consider_ops_to]:
            if raise_analyzer.can_raise(op):
                return True
    return False

def any_call_to_raising_graphs(from_graph, translator, raise_analyzer):
    for graph_or_something in collect_called_graphs(from_graph, translator):
        if isinstance(graph_or_something, FunctionGraph):
            if does_raise_directly(graph_or_something, raise_analyzer):
                return True
        elif isinstance(graph_or_something, CanRaise):
            if graph_or_something.can_raise:
                return True
        else:
            return True # conservatively
    for block in from_graph.iterblocks():
        if block.exitswitch == c_last_exception:
            consider_ops_to = -1
        else:
            consider_ops_to = len(block.operations)
        for op in block.operations[:consider_ops_to]:
            if raise_analyzer.can_raise(op):
                return True
    return False

class BaseInliner(object):
    def __init__(self, translator, graph, lltype_to_classdef, 
                 inline_guarded_calls=False,
                 inline_guarded_calls_no_matter_what=False,
                 raise_analyzer=None,
                 call_count_pred=None,
                 cleanup=True):
        self.translator = translator
        self.graph = graph
        self.do_cleanup = cleanup
        self.inline_guarded_calls = inline_guarded_calls
        # if this argument is set, the inliner will happily produce wrong code!
        # it is used by the exception transformation
        self.inline_guarded_calls_no_matter_what = inline_guarded_calls_no_matter_what
        assert raise_analyzer is not None
        self.raise_analyzer = raise_analyzer
        self.lltype_to_classdef = lltype_to_classdef
        self.call_count_pred = call_count_pred

    def inline_all(self):
        count = 0
        non_recursive = {}
        call_count_pred = self.call_count_pred
        while self.block_to_index:
            block, d = self.block_to_index.popitem()
            index_operation, subgraph = d.popitem()
            if d:
                self.block_to_index[block] = d
            if subgraph not in non_recursive and contains_call(subgraph, subgraph):
                raise CannotInline("inlining a recursive function")
            else:
                non_recursive[subgraph] = True
            if call_count_pred:
                countop = block.operations[index_operation-1]
                assert countop.opname == 'instrument_count'
                assert countop.args[0].value == 'inline'
                label = countop.args[1].value
                if not call_count_pred(label):
                    continue
            operation = block.operations[index_operation]
            self.inline_once(block, index_operation)
            count += 1
        if self.do_cleanup:
            self.cleanup()
        return count

    def get_graph_from_op(self, op):
        assert op.opname in ('direct_call', 'oosend')
        if op.opname == 'direct_call':
            return get_funcobj(self.op.args[0].value).graph
        else:
            return get_meth_from_oosend(op).graph

    def inline_once(self, block, index_operation):
        self.varmap = {}
        self._copied_blocks = {}
        self.op = block.operations[index_operation]
        self.graph_to_inline = self.get_graph_from_op(self.op)
        self.exception_guarded = False
        if (block.exitswitch == c_last_exception and
            index_operation == len(block.operations) - 1):
            self.exception_guarded = True
            if self.inline_guarded_calls:
                if (not self.inline_guarded_calls_no_matter_what and 
                    does_raise_directly(self.graph_to_inline, self.raise_analyzer)):
                    raise CannotInline("can't inline because the call is exception guarded")
            elif any_call_to_raising_graphs(self.graph_to_inline,
                                            self.translator, self.raise_analyzer):
                raise CannotInline("can't handle exceptions")
        self._passon_vars = {}
        self.entrymap = mkentrymap(self.graph_to_inline)
        self.do_inline(block, index_operation)

    def search_for_calls(self, block):
        d = {}
        for i, op in enumerate(block.operations):
            if op.opname == "direct_call":
                funcobj = get_funcobj(op.args[0].value)
            elif op.opname == "oosend":
                funcobj = get_meth_from_oosend(op)
                if funcobj is None:
                    continue
            else:
                continue
            graph = getattr(funcobj, 'graph', None)
            # accept a function or a graph as 'inline_func'
            if (graph is self.inline_func or
                getattr(funcobj, '_callable', None) is self.inline_func):
                d[i] = graph
        if d:
            self.block_to_index[block] = d
        else:
            try:
                del self.block_to_index[block]
            except KeyError:
                pass

    def get_new_name(self, var):
        if var is None:
            return None
        if isinstance(var, Constant):
            return var
        if var not in self.varmap:
            self.varmap[var] = copyvar(None, var)
        return self.varmap[var]

    def generate_keepalive(self, *args):
        from pypy.translator.backendopt.support import generate_keepalive
        if self.translator.rtyper.type_system.name == 'lltypesystem':
            return generate_keepalive(*args)
        else:
            return []

    def passon_vars(self, cache_key):
        if cache_key in self._passon_vars:
            return self._passon_vars[cache_key]
        result = [copyvar(None, var)
                      for var in self.original_passon_vars]
        self._passon_vars[cache_key] = result
        return result
        
    def copy_operation(self, op):
        args = [self.get_new_name(arg) for arg in op.args]
        result = SpaceOperation(op.opname, args, self.get_new_name(op.result))
        return result

    def copy_block(self, block):
        if block in self._copied_blocks:
            return self._copied_blocks[block]
        args = ([self.get_new_name(var) for var in block.inputargs] +
                self.passon_vars(block))
        newblock = Block(args)
        self._copied_blocks[block] = newblock
        newblock.operations = [self.copy_operation(op) for op in block.operations]
        newblock.closeblock(*[self.copy_link(link, block) for link in block.exits])
        newblock.exitswitch = self.get_new_name(block.exitswitch)
        self.search_for_calls(newblock)
        return newblock

    def copy_link(self, link, prevblock):
        newargs = [self.get_new_name(a) for a in link.args] + self.passon_vars(prevblock)
        newlink = Link(newargs, self.copy_block(link.target), link.exitcase)
        newlink.last_exception = self.get_new_name(link.last_exception)
        newlink.last_exc_value = self.get_new_name(link.last_exc_value)
        if hasattr(link, 'llexitcase'):
            newlink.llexitcase = link.llexitcase
        return newlink
        

    def find_args_in_exceptional_case(self, link, block, etype, evalue, afterblock, passon_vars):
        linkargs = []
        for arg in link.args:
            if arg == link.last_exception:
                linkargs.append(etype)
            elif arg == link.last_exc_value:
                linkargs.append(evalue)
            elif isinstance(arg, Constant):
                linkargs.append(arg)
            else:
                index = afterblock.inputargs.index(arg)
                linkargs.append(passon_vars[index - 1])
        return linkargs

    def rewire_returnblock(self, afterblock):
        copiedreturnblock = self.copy_block(self.graph_to_inline.returnblock)
        linkargs = ([copiedreturnblock.inputargs[0]] +
                    self.passon_vars(self.graph_to_inline.returnblock))
        linkfrominlined = Link(linkargs, afterblock)
        copiedreturnblock.exitswitch = None
        copiedreturnblock.recloseblock(linkfrominlined)
        assert copiedreturnblock.exits[0].target == afterblock
       
    def rewire_exceptblock(self, afterblock):
        #let links to exceptblock of the graph to inline go to graphs exceptblock
        copiedexceptblock = self.copy_block(self.graph_to_inline.exceptblock)
        if not self.exception_guarded:
            self.rewire_exceptblock_no_guard(afterblock, copiedexceptblock)
        else:
            # first try to match exceptions using a very simple heuristic
            self.rewire_exceptblock_with_guard(afterblock, copiedexceptblock)
            # generate blocks that do generic matching for cases when the
            # heuristic did not work
            self.generic_exception_matching(afterblock, copiedexceptblock)

    def rewire_exceptblock_no_guard(self, afterblock, copiedexceptblock):
         # find all copied links that go to copiedexceptblock
        for link in self.entrymap[self.graph_to_inline.exceptblock]:
            copiedblock = self.copy_block(link.prevblock)
            for copiedlink in copiedblock.exits:
                if copiedlink.target is copiedexceptblock:
                    copiedlink.args = copiedlink.args[:2]
                    copiedlink.target = self.graph.exceptblock
                    for a1, a2 in zip(copiedlink.args,
                                      self.graph.exceptblock.inputargs):
                        if hasattr(a2, 'concretetype'):
                            assert a1.concretetype == a2.concretetype
                        else:
                            # if self.graph.exceptblock was never used before
                            a2.concretetype = a1.concretetype
    
    def rewire_exceptblock_with_guard(self, afterblock, copiedexceptblock):
        # this rewiring does not always succeed. in the cases where it doesn't
        # there will be generic code inserted
        rclass = self.translator.rtyper.type_system.rclass
        excdata = self.translator.rtyper.getexceptiondata()
        exc_match = excdata.fn_exception_match
        for link in self.entrymap[self.graph_to_inline.exceptblock]:
            if link.prevblock.exits[0] is not link:
                continue
            copiedblock = self.copy_block(link.prevblock)
            VALUE, copiedlink = _find_exception_type(copiedblock)
            #print copiedblock.operations
            if VALUE is None or VALUE not in self.lltype_to_classdef:
                continue
            classdef = self.lltype_to_classdef[VALUE]
            rtyper = self.translator.rtyper
            classrepr = rclass.getclassrepr(rtyper, classdef)
            vtable = classrepr.getruntime(excdata.lltype_of_exception_type)
            var_etype = copiedlink.args[0]
            var_evalue = copiedlink.args[1]
            for exceptionlink in afterblock.exits[1:]:
                if exc_match(vtable, exceptionlink.llexitcase):
                    passon_vars = self.passon_vars(link.prevblock)
                    copiedblock.operations += self.generate_keepalive(passon_vars)
                    copiedlink.target = exceptionlink.target
                    linkargs = self.find_args_in_exceptional_case(
                        exceptionlink, link.prevblock, var_etype, var_evalue, afterblock, passon_vars)
                    copiedlink.args = linkargs
                    break

    def generic_exception_matching(self, afterblock, copiedexceptblock):
        #XXXXX don't look: insert blocks that do exception matching
        #for the cases where direct matching did not work        
        exc_match = Constant(
            self.translator.rtyper.getexceptiondata().fn_exception_match)
        exc_match.concretetype = typeOf(exc_match.value)
        blocks = []
        for i, link in enumerate(afterblock.exits[1:]):
            etype = copyvar(None, copiedexceptblock.inputargs[0])
            evalue = copyvar(None, copiedexceptblock.inputargs[1])
            passon_vars = self.passon_vars(i)
            block = Block([etype, evalue] + passon_vars)
            res = Variable()
            res.concretetype = Bool
            cexitcase = Constant(link.llexitcase)
            cexitcase.concretetype = typeOf(cexitcase.value)
            args = [exc_match, etype, cexitcase]
            block.operations.append(SpaceOperation("direct_call", args, res))
            block.exitswitch = res
            linkargs = self.find_args_in_exceptional_case(link, link.target,
                                                          etype, evalue, afterblock,
                                                          passon_vars)
            l = Link(linkargs, link.target)
            l.prevblock = block
            l.exitcase = True
            l.llexitcase = True
            block.closeblock(l)
            if i > 0:
                l = Link(blocks[-1].inputargs, block)
                l.exitcase = False
                l.llexitcase = False
                blocks[-1].recloseblock(l, *blocks[-1].exits)
            blocks.append(block)

        blocks[-1].recloseblock(*blocks[-1].exits[:1])
        blocks[-1].operations = []
        blocks[-1].exitswitch = None
        blocks[-1].exits[0].exitcase = None
        del blocks[-1].exits[0].llexitcase
        linkargs = copiedexceptblock.inputargs
        copiedexceptblock.recloseblock(Link(linkargs, blocks[0]))
        copiedexceptblock.operations += self.generate_keepalive(linkargs)

    def do_inline(self, block, index_operation):
        splitlink = split_block(None, block, index_operation)
        afterblock = splitlink.target
        # these variables have to be passed along all the links in the inlined
        # graph because the original function needs them in the blocks after
        # the inlined function
        # for every inserted block we need a new copy of these variables,
        # this copy is created with the method passon_vars
        self.original_passon_vars = [arg for arg in block.exits[0].args
                                         if isinstance(arg, Variable)]
        n = 0
        while afterblock.operations[n].opname == 'keepalive':
            n += 1
        assert afterblock.operations[n].opname == self.op.opname
        self.op = afterblock.operations.pop(n)
        #vars that need to be passed through the blocks of the inlined function
        linktoinlined = splitlink
        copiedstartblock = self.copy_block(self.graph_to_inline.startblock)
        copiedstartblock.isstartblock = False
        #find args passed to startblock of inlined function
        passon_args = []
        for arg in self.op.args[1:]:
            if isinstance(arg, Constant):
                passon_args.append(arg)
            else:
                index = afterblock.inputargs.index(arg)
                passon_args.append(linktoinlined.args[index])
        passon_args += self.original_passon_vars

        if self.op.opname == 'oosend' and not isinstance(self.op.args[1], Constant):
            # if we try to inline a graph defined in a superclass, the
            # type of 'self' on the graph differs from the current
            linkv = passon_args[0]
            inputv = copiedstartblock.inputargs[0]
            LINK_SELF = linkv.concretetype
            INPUT_SELF = inputv.concretetype
            if LINK_SELF != INPUT_SELF:
                # need to insert an upcast
                if ootype.isSubclass(LINK_SELF, INPUT_SELF):
                    opname = 'ooupcast'
                else:
                    assert ootype.isSubclass(INPUT_SELF, LINK_SELF)
                    opname = 'oodowncast'
                v = Variable()
                v.concretetype = INPUT_SELF
                upcast = SpaceOperation(opname, [linkv], v)
                block.operations.append(upcast)
                passon_args[0] = v

        #rewire blocks
        linktoinlined.target = copiedstartblock
        linktoinlined.args = passon_args
        afterblock.inputargs = [self.op.result] + afterblock.inputargs
        if self.graph_to_inline.returnblock in self.entrymap:
            self.rewire_returnblock(afterblock) 
        if self.graph_to_inline.exceptblock in self.entrymap:
            self.rewire_exceptblock(afterblock)
        if self.exception_guarded:
            assert afterblock.exits[0].exitcase is None
            afterblock.recloseblock(afterblock.exits[0])
            afterblock.exitswitch = None
        self.search_for_calls(afterblock)
        self.search_for_calls(block)

    def cleanup(self):
        """ cleaning up -- makes sense to be done after inlining, because the
        inliner inserted quite some empty blocks and blocks that can be
        joined. """
        cleanup_graph(self.graph)


class Inliner(BaseInliner):
    def __init__(self, translator, graph, inline_func, lltype_to_classdef,
                 inline_guarded_calls=False,
                 inline_guarded_calls_no_matter_what=False,
                 raise_analyzer=None,
                 call_count_pred=None,
                 cleanup=True):
        BaseInliner.__init__(self, translator, graph, lltype_to_classdef,
                             inline_guarded_calls,
                             inline_guarded_calls_no_matter_what,
                             raise_analyzer,
                             call_count_pred,
                             cleanup)
        self.inline_func = inline_func
        # to simplify exception matching
        join_blocks(graph)
        # find callsites *after* joining blocks...
        callsites = find_callsites(graph, inline_func)
        self.block_to_index = {}
        for g, block, i in callsites:
            self.block_to_index.setdefault(block, {})[i] = g

class OneShotInliner(BaseInliner):
    def search_for_calls(self, block):
        pass


# ____________________________________________________________
#
# Automatic inlining

OP_WEIGHTS = {'same_as': 0,
              'cast_pointer': 0,
              'keepalive': 0,
              'malloc': 2,
              'yield_current_frame_to_caller': sys.maxint, # XXX bit extreme
              'resume_point': sys.maxint, # XXX bit extreme
              'instrument_count': 0,
              'debug_assert': -1,
              }

def block_weight(block, weights=OP_WEIGHTS):
    total = 0
    for op in block.operations:
        if op.opname == "direct_call":
            total += 1.5 + len(op.args) / 2
        elif op.opname == "indirect_call":
            total += 2 + len(op.args) / 2
        elif op.opname == "oosend":
            total += 2 + len(op.args) / 2
        total += weights.get(op.opname, 1)
    if block.exitswitch is not None:
        total += 1
    return max(0, total)


def measure_median_execution_cost(graph):
    blocks = []
    blockmap = {}
    for block in graph.iterblocks():
        blockmap[block] = len(blocks)
        blocks.append(block)
    loops = find_loop_blocks(graph)
    M = sparsemat.SparseMatrix(len(blocks))
    vector = []
    for i, block in enumerate(blocks):
        vector.append(block_weight(block))
        M[i, i] = 1
        if block.exits:
            if block not in loops:
                current_loop_start = None
            else:
                current_loop_start = loops[block]
            loop_exits = []
            for link in block.exits:
                if (link.target in loops and
                    loops[link.target] is current_loop_start):
                    loop_exits.append(link)
            if len(loop_exits) and len(loop_exits) < len(block.exits):
                f = 0.3 / (len(block.exits) - len(loop_exits))
                b = 0.7 / len(loop_exits)
            else:
                b = f = 1.0 / len(block.exits)
            for link in block.exits:
                if (link.target in loops and
                    loops[link.target] is current_loop_start):
                    M[i, blockmap[link.target]] -= b
                else:
                    M[i, blockmap[link.target]] -= f
    try:
        Solution = M.solve(vector)
    except ValueError:
        return sys.maxint
    else:
        res = Solution[blockmap[graph.startblock]]
        assert res >= 0
        return res

def static_instruction_count(graph):
    count = 0
    for block in graph.iterblocks():
        count += block_weight(block)
    return count

def inlining_heuristic(graph):
    # XXX ponderation factors?
    count = static_instruction_count(graph)
    if count >= 200:
        return count, True
    return (0.9999 * measure_median_execution_cost(graph) +
            count), True

def inlinable_static_callers(graphs):
    ok_to_call = set(graphs)
    result = []
    for parentgraph in graphs:
        for block in parentgraph.iterblocks():
            for op in block.operations:
                if op.opname == "direct_call":
                    funcobj = get_funcobj(op.args[0].value)
                    graph = getattr(funcobj, 'graph', None)
                    if graph is not None and graph in ok_to_call:
                        if getattr(getattr(funcobj, '_callable', None),
                                   '_dont_inline_', False):
                            continue
                        result.append((parentgraph, graph))
                if op.opname == "oosend":
                    meth = get_meth_from_oosend(op)
                    graph = getattr(meth, 'graph', None)
                    if graph is not None and graph in ok_to_call:
                        result.append((parentgraph, graph))
    return result
    
def instrument_inline_candidates(graphs, threshold):
    cache = {None: False}
    def candidate(graph):
        try:
            return cache[graph]
        except KeyError:
            res = static_instruction_count(graph) <= threshold
            cache[graph] = res
            return res
    n = 0
    for parentgraph in graphs:
        for block in parentgraph.iterblocks():
            ops = block.operations
            i = len(ops)-1
            while i >= 0:
                op = ops[i]
                i -= 1
                if op.opname == "direct_call":
                    funcobj = get_funcobj(op.args[0].value)
                    graph = getattr(funcobj, 'graph', None)
                    if graph is not None:
                        if getattr(getattr(funcobj, '_callable', None),
                                   '_dont_inline_', False):
                            continue
                    if candidate(graph):
                        tag = Constant('inline', Void)
                        label = Constant(n, Signed)
                        dummy = Variable()
                        dummy.concretetype = Void
                        count = SpaceOperation('instrument_count',
                                               [tag, label], dummy)
                        ops.insert(i+1, count)
                        n += 1
    log.inlining("%d call sites instrumented" % n)

def auto_inlining(translator, threshold=None,
                  callgraph=None,
                  call_count_pred=None,
                  heuristic=inlining_heuristic):
    
    assert threshold is not None and threshold != 1
    to_cleanup = {}
    from heapq import heappush, heappop, heapreplace, heapify
    callers = {}     # {graph: {graphs-that-call-it}}
    callees = {}     # {graph: {graphs-that-it-calls}}
    if callgraph is None:
        callgraph = inlinable_static_callers(translator.graphs)
    for graph1, graph2 in callgraph:
        callers.setdefault(graph2, {})[graph1] = True
        callees.setdefault(graph1, {})[graph2] = True
    # the -len(callers) change is OK
    heap = [(0.0, -len(callers[graph]), graph) for graph in callers]
    valid_weight = {}
    try_again = {}
    lltype_to_classdef = translator.rtyper.lltype_to_classdef_mapping()
    raise_analyzer = RaiseAnalyzer(translator)
    count = 0
    while heap:
        weight, _, graph = heap[0]
        if not valid_weight.get(graph):
            if hasattr(graph, 'func') and \
                   getattr(graph.func, '_always_inline_', None):
                weight, fixed = 0.0, True
            else:
                weight, fixed = heuristic(graph)
            #print '  + cost %7.2f %50s' % (weight, graph.name)
            heapreplace(heap, (weight, -len(callers[graph]), graph))
            valid_weight[graph] = True
            if not fixed:
                try_again[graph] = True
            continue

        if weight >= threshold:
            # finished... unless some graphs not in valid_weight would now
            # have a weight below the threshold.  Re-insert such graphs
            # at the start of the heap
            finished = True
            for i in range(len(heap)):
                graph = heap[i][2]
                if not valid_weight.get(graph):
                    heap[i] = (0.0, heap[i][1], graph)
                    finished = False
            if finished:
                break
            else:
                heapify(heap)
                continue

        heappop(heap)
        if callers[graph]:
            if translator.config.translation.verbose:
                log.inlining('%7.2f %50s' % (weight, graph.name))
            else:
                log.dot()
        for parentgraph in callers[graph]:
            if parentgraph == graph:
                continue
            subcount = 0
            try:
                subcount = inline_function(translator, graph, parentgraph,
                                           lltype_to_classdef, raise_analyzer,
                                           call_count_pred, cleanup=False)
                to_cleanup[parentgraph] = True
                res = bool(subcount)
            except CannotInline:
                try_again[graph] = True
                res = CannotInline
            if res is True:
                count += subcount
                # the parentgraph should now contain all calls that were
                # done by 'graph'
                for graph2 in callees.get(graph, {}):
                    callees[parentgraph][graph2] = True
                    callers[graph2][parentgraph] = True
                if parentgraph in try_again:
                    # the parentgraph was previously uninlinable, but it has
                    # been modified.  Maybe now we can inline it into further
                    # parents?
                    del try_again[parentgraph]
                    heappush(heap, (0.0, -len(callers[parentgraph]), parentgraph))
                valid_weight[parentgraph] = False
    for graph in to_cleanup:
        cleanup_graph(graph)
    return count

def auto_inline_graphs(translator, graphs, threshold, call_count_pred=None,
                       heuristic=inlining_heuristic):
        callgraph = inlinable_static_callers(graphs)
        count = auto_inlining(translator, threshold, callgraph=callgraph,
                              heuristic=heuristic,
                              call_count_pred=call_count_pred)
        log.inlining('inlined %d callsites.'% (count,))
        for graph in graphs:
            removenoops.remove_superfluous_keep_alive(graph)
            removenoops.remove_duplicate_casts(graph, translator)

