<filename>pyverilog/controlflow/active_analyzer.py
#-------------------------------------------------------------------------------
# active_analyzer.py
#
# Active condition list generator from Verilog Definitions
#
# Copyright (C) 2013, <NAME>
# License: Apache 2.0
#-------------------------------------------------------------------------------
from __future__ import absolute_import
from __future__ import print_function
import sys
import os

from pyverilog.dataflow.dataflow import *
import pyverilog.controlflow.splitter as splitter
import pyverilog.controlflow.transition as transition
from pyverilog.controlflow.controlflow_analyzer import VerilogControlflowAnalyzer

class VerilogActiveConditionAnalyzer(VerilogControlflowAnalyzer):
    def __init__(self, topmodule, terms, binddict, 
                 resolved_terms, resolved_binddict, constlist):
        VerilogControlflowAnalyzer.__init__(self, topmodule, terms, binddict, 
                                            resolved_terms, resolved_binddict, constlist)
        self.fsm_loops, self.fsms = self.getLoops()

    ############################################################################
    def getActiveConditions(self, termname, condition=splitter.active_constant):
        if not termname in self.resolved_binddict: return {}
        tree = self.makeTree(termname)
        funcdict = splitter.split(tree)
        funcdict = splitter.filter(funcdict, termname, condition)
        funcdict = splitter.remove_reset_condition(funcdict)

        if len(funcdict) == 1 and len(list(funcdict.keys())[0]) == 0:
            func = funcdict.values()[0]
            return {termname : ( ('any', None), )}

        active_conditions = {}
        active_conditions_size = 0
        for fsm_sig in self.fsms.keys():
            rslt = self.getActiveConditions_fsm(fsm_sig, funcdict)
            if len(rslt) > 0: active_conditions[fsm_sig] = rslt
            active_conditions_size += len(rslt)

        if active_conditions_size == 0:
            rslt = self.getActiveConditions_fsm(termname, funcdict)
            if len(rslt) > 0: active_conditions[termname] = rslt

        return active_conditions

    def getActiveConditions_fsm(self, fsm_sig, funcdict):
        # returns a list of some (state, transcond) pairs
        active_conditions = []
        fsm_sig_width = self.getWidth(fsm_sig)
        for condlist, func in sorted(funcdict.items(), key=lambda x:len(x[0])):
            node = transition.walkCondlist(condlist, fsm_sig, fsm_sig_width)
            state_node_list = []
            if isinstance(node, transition.StateNodeList):
                for n in node.nodelist: state_node_list.append(n)
            elif node:
                state_node_list.append(node)

            for state_node in state_node_list:
                #if state_node.isany:
                #    active_conditions.append( ('any', state_node.transcond) )
                for rs, re in state_node.range_pairs:
                    for state in range(rs, re+1):
                        transcond = self.optimizer.optimize(state_node.transcond)
                        if isinstance(transcond, DFEvalValue) and transcond.value == 0: continue
                        active_conditions.append( (state, transcond) )
        return tuple(active_conditions)
