// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Collect and print statistics
//
// Code available from: http://www.veripool.org/verilator
//
//*************************************************************************
//
// Copyright 2005-2019 by Wilson Snyder.  This program is free software; you can
// redistribute it and/or modify it under the terms of either the GNU
// Lesser General Public License Version 3 or the Perl Artistic License
// Version 2.0.
//
// Verilator is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
//*************************************************************************

#include "config_build.h"
#include "verilatedos.h"

#include "V3Global.h"
#include "V3Stats.h"
#include "V3Ast.h"
#include "V3File.h"

// This visitor does not edit nodes, and is called at error-exit, so should use constant iterators
#include "V3AstConstOnly.h"

#include <cstdarg>
#include <iomanip>
#include <map>

//######################################################################
// Stats class functions

class StatsVisitor : public AstNVisitor {
private:
    // NODE STATE/TYPES

    typedef std::map<string,int> NameMap;  // Number of times a name appears

    // STATE
    string	m_stage;		// Name of the stage we are scanning
    /// m_fast = true:  Counting only critical branch of fastpath
    /// m_fast = false:  Counting every node, ignoring structure of program
    bool	m_fast;

    AstCFunc*	m_cfuncp;		// Current CFUNC
    V3Double0	m_statInstrLong;	// Instruction count
    bool	m_counting;		// Currently counting
    double	m_instrs;		// Current instr count (for determining branch direction)
    bool	m_tracingCall;          // Iterating into a CCall to a CFunc

    std::vector<V3Double0> m_statTypeCount;     // Nodes of given type
    V3Double0		m_statAbove[AstType::_ENUM_END][AstType::_ENUM_END];	// Nodes of given type
    V3Double0		m_statPred[AstBranchPred::_ENUM_END];	// Nodes of given type
    V3Double0		m_statInstr;		// Instruction count
    V3Double0		m_statInstrFast;	// Instruction count, non-slow() eval functions only
    std::vector<V3Double0> m_statVarWidths;     // Variables of given width
    std::vector<NameMap>   m_statVarWidthNames; // Var names of given width
    V3Double0		m_statVarArray;		// Statistic tracking
    V3Double0		m_statVarBytes;		// Statistic tracking
    V3Double0		m_statVarClock;		// Statistic tracking
    V3Double0		m_statVarScpBytes;	// Statistic tracking

    // METHODS
    VL_DEBUG_FUNC;  // Declare debug()

    void allNodes(AstNode* nodep) {
	m_instrs += nodep->instrCount();
	if (m_counting) {
	    ++m_statTypeCount[nodep->type()];
	    if (nodep->firstAbovep()) { // Grab only those above, not those "back"
		++m_statAbove[nodep->firstAbovep()->type()][nodep->type()];
	    }
	    m_statInstr += nodep->instrCount();
	    if (m_cfuncp && !m_cfuncp->slow()) m_statInstrFast += nodep->instrCount();
	}
    }

    // VISITORS
    virtual void visit(AstNodeModule* nodep) {
	allNodes(nodep);
	if (!m_fast) {
            // Count all CFuncs below this module
            iterateChildrenConst(nodep);
	}
        // Else we recursively trace fast CFuncs from the top _eval
        // func, see visit(AstNetlist*)
    }
    virtual void visit(AstVar* nodep) {
	allNodes(nodep);
        iterateChildrenConst(nodep);
	if (m_counting && nodep->dtypep()) {
	    if (nodep->isUsedClock()) ++m_statVarClock;
            if (VN_IS(nodep->dtypeSkipRefp(), UnpackArrayDType)) ++m_statVarArray;
	    else m_statVarBytes += nodep->dtypeSkipRefp()->widthTotalBytes();
	    if (int(m_statVarWidths.size()) <= nodep->width()) {
		m_statVarWidths.resize(nodep->width()+5);
		if (v3Global.opt.statsVars()) m_statVarWidthNames.resize(nodep->width()+5);
	    }
	    ++ m_statVarWidths.at(nodep->width());
	    string pn = nodep->prettyName();
	    if (v3Global.opt.statsVars()) {
		NameMap& nameMapr = m_statVarWidthNames.at(nodep->width());
		if (nameMapr.find(pn) != nameMapr.end()) {
		    nameMapr[pn]++;
		} else {
		    nameMapr[pn]=1;
		}
	    }
	}
    }
    virtual void visit(AstVarScope* nodep) {
	allNodes(nodep);
        iterateChildrenConst(nodep);
	if (m_counting) {
            if (VN_IS(nodep->varp()->dtypeSkipRefp(), BasicDType)) {
		m_statVarScpBytes += nodep->varp()->dtypeSkipRefp()->widthTotalBytes();
	    }
	}
    }
    virtual void visit(AstNodeIf* nodep) {
	UINFO(4,"   IF i="<<m_instrs<<" "<<nodep<<endl);
	allNodes(nodep);
	// Condition is part of cost allocated to PREVIOUS block
        iterateAndNextConstNull(nodep->condp());
	// Track prediction
	if (m_counting) {
	    ++m_statPred[nodep->branchPred()];
	}
	if (!m_fast) {
	    // Count everything
            iterateChildrenConst(nodep);
	} else {
	    // See which path we want to take
	    // Need to do even if !m_counting because maybe determining upstream if/else
	    double ifInstrs = 0.0;
	    double elseInstrs = 0.0;
	    if (nodep->branchPred() != AstBranchPred::BP_UNLIKELY) { // Check if
		double prevInstr = m_instrs;
		bool prevCounting = m_counting;
		{
		    m_counting = false;
		    m_instrs = 0.0;
                    iterateAndNextConstNull(nodep->ifsp());
		    ifInstrs = m_instrs;
		}
		m_instrs = prevInstr;
		m_counting = prevCounting;
	    }
	    if (nodep->branchPred() != AstBranchPred::BP_LIKELY) { // Check else
		double prevInstr = m_instrs;
		bool prevCounting = m_counting;
		{
		    m_counting = false;
		    m_instrs = 0.0;
                    iterateAndNextConstNull(nodep->elsesp());
		    elseInstrs = m_instrs;
		}
		m_instrs = prevInstr;
		m_counting = prevCounting;
	    }
	    // Now collect the stats
	    if (m_counting) {
		if (ifInstrs >= elseInstrs) {
                    iterateAndNextConstNull(nodep->ifsp());
		} else {
                    iterateAndNextConstNull(nodep->elsesp());
		}
	    }
	}
    }
    // While's we assume evaluate once.
    //virtual void visit(AstWhile* nodep) {

    virtual void visit(AstCCall* nodep) {
	allNodes(nodep);
        iterateChildrenConst(nodep);
        if (m_fast && !nodep->funcp()->entryPoint()) {
	    // Enter the function and trace it
            m_tracingCall = true;
            iterate(nodep->funcp());
        }
    }
    virtual void visit(AstCFunc* nodep) {
        if (m_fast) {
            if (!m_tracingCall && !nodep->entryPoint()) return;
            m_tracingCall = false;
        }
	m_cfuncp = nodep;
	allNodes(nodep);
        iterateChildrenConst(nodep);
	m_cfuncp = NULL;
    }
    virtual void visit(AstNode* nodep) {
	allNodes(nodep);
        iterateChildrenConst(nodep);
    }
    virtual void visit(AstNetlist* nodep) {
        if (m_fast && nodep->evalp()) {
            m_instrs = 0;
            m_counting = true;
            if (nodep->evalp()) iterateChildrenConst(nodep->evalp());
            m_counting = false;
        }
        allNodes(nodep);
        iterateChildrenConst(nodep);
    }
public:
    // CONSTRUCTORS
    StatsVisitor(AstNetlist* nodep, const string& stage, bool fast)
	: m_stage(stage), m_fast(fast) {
	UINFO(9,"Starting stats, fast="<<fast<<endl);
	m_cfuncp = NULL;
	m_counting = !m_fast;
	m_instrs = 0;
        m_tracingCall = false;
	// Initialize arrays
	m_statTypeCount.resize(AstType::_ENUM_END);
	// Process
        iterate(nodep);
    }
    virtual ~StatsVisitor() {
	// Done. Publish statistics
	V3Stats::addStat(m_stage, "Instruction count, TOTAL", m_statInstr);
	V3Stats::addStat(m_stage, "Instruction count, fast critical",  m_statInstrFast);
	// Vars
	V3Stats::addStat(m_stage, "Vars, unpacked arrayed", m_statVarArray);
	V3Stats::addStat(m_stage, "Vars, clock attribute", m_statVarClock);
	V3Stats::addStat(m_stage, "Var space, non-arrays, bytes", m_statVarBytes);
	if (m_statVarScpBytes!=0.0) {
	    V3Stats::addStat(m_stage, "Var space, scoped, bytes", m_statVarScpBytes);
	}
	for (unsigned i=0; i<m_statVarWidths.size(); i++) {
	    double count = double(m_statVarWidths.at(i));
	    if (count != 0.0) {
		if (v3Global.opt.statsVars()) {
		    NameMap& nameMapr = m_statVarWidthNames.at(i);
		    for (NameMap::iterator it=nameMapr.begin(); it!=nameMapr.end(); ++it) {
                        std::ostringstream os; os<<"Vars, width "<<std::setw(5)<<std::dec<<i<<" "<<it->first;
			V3Stats::addStat(m_stage, os.str(), it->second);
		    }
		} else {
                    std::ostringstream os; os<<"Vars, width "<<std::setw(5)<<std::dec<<i;
		    V3Stats::addStat(m_stage, os.str(), count);
		}
	    }
	}
	// Node types
	for (int type=0; type<AstType::_ENUM_END; type++) {
	    double count = double(m_statTypeCount.at(type));
	    if (count != 0.0) {
		V3Stats::addStat(m_stage, string("Node count, ")+AstType(type).ascii(), count);
	    }
	}
	for (int type=0; type<AstType::_ENUM_END; type++) {
	    for (int type2=0; type2<AstType::_ENUM_END; type2++) {
		double count = double(m_statAbove[type][type2]);
		if (count != 0.0) {
		    V3Stats::addStat(m_stage, string("Node pairs, ")+AstType(type).ascii()+"_"+AstType(type2).ascii(), count);
		}
	    }
	}
	// Branch pred
	for (int type=0; type<AstBranchPred::_ENUM_END; type++) {
	    double count = double(m_statPred[type]);
	    if (count != 0.0) {
		V3Stats::addStat(m_stage, string("Branch prediction, ")+AstBranchPred(type).ascii(), count);
	    }
	}
    }
};

//######################################################################
// Top Stats class

void V3Stats::statsStageAll(AstNetlist* nodep, const string& stage, bool fast) {
    StatsVisitor visitor (nodep, stage, fast);
}

void V3Stats::statsFinalAll(AstNetlist* nodep) {
    statsStageAll(nodep, "Final");
    statsStageAll(nodep, "Final_Fast", true);
}
