//*************************************************************************
// DESCRIPTION: Verilator: Large 4-state numbers
//
// Code available from: http://www.veripool.org/verilator
//
// AUTHORS: Wilson Snyder with Paul Wasson, Duane Gabli
//
//*************************************************************************
//
// Copyright 2003-2011 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 <cmath>
#include <cstdio>
#include <cstdarg>
#include <algorithm>
#include <iomanip>
#include "V3Number.h"

#define MAX_SPRINTF_DOUBLE_SIZE 100  // Maximum characters with a sprintf %e/%f/%g (probably < 30)

//######################################################################
// Read class functions
// CREATION

V3Number::V3Number(VerilogString, FileLine* fileline, const string& str) {
    // Create a number using a verilog string as the value, thus 8 bits per character.
    // cppcheck bug - doesn't see init() resets these
    // cppcheck: Member variable 'm_sized/m_width' is not initialized in the constructor
    init(fileline, str.length()*8);
    m_fromString = true;
    for (unsigned pos=0; pos<str.length(); ++pos) {
	int topos = str.length()-1-pos;
	for (int bit=0; bit<8; ++bit) {
	    if (str[pos] & (1UL<<bit)) {
		m_value[topos/4] |= (1UL<<(bit + (topos%4)*8));
	    }
	}
    }
}

V3Number::V3Number (FileLine* fileline, const char* sourcep) {
    init(fileline, 0);
    const char* value_startp = sourcep;
    for (const char* cp=sourcep; *cp; cp++) {
	if (*cp == '\'') {
	    value_startp = cp+1;
	    break;
	}
    }

    bool unbased = false;
    char base = '\0';
    if (value_startp != sourcep) {	// Has a '
	char widthn[100]; char* wp=&widthn[0];
	const char* cp=sourcep;
	for (; *cp; cp++) {
	    if (*cp == '\'') { cp++ ; break; }
	    if (*cp != '_') *wp++ = *cp;
	}
	*wp++ = '\0';
	while (*cp && *cp == '_') cp++;
	if (*cp && tolower(*cp)=='s') {
	    cp++; isSigned(true);
	}
	if (*cp) { base=*cp; cp++; }
	value_startp = cp;

	if (atoi(widthn)) {
	    width(atoi(widthn), true);
	}
    } else {
	unbased = true;
	base = 'd';
    }

    for (int i=0; i<words(); i++) m_value[i]=m_valueX[i] = 0;

    // Special SystemVerilog unsized constructs
    if (base == '0') {
	setBit(0, 0); width(1, false);	// So we extend it
	m_autoExtend = true;
    } else if (base == '1') {
	setBit(0, 1); width(1, false);	// So we extend it
	m_autoExtend = true;
    } else if (tolower(base) == 'z') {
	setBit(0, 'z'); width(1, false);	// So we extend it
	m_autoExtend = true;
    } else if (tolower(base) == 'x') {
	setBit(0, 'x'); width(1, false);	// So we extend it
	m_autoExtend = true;
    }
    // Otherwise...
    else if (!m_sized) {
	width(32, false); // Says the spec.
	if (unbased) isSigned(true); // Also says the spec.
    }

    // Ignore leading blanks
    while (*value_startp=='_' || isspace(*value_startp)) value_startp++;

    int obit = 0;  // Start at LSB
    if (tolower(base) == 'd') {
	// Ignore leading zeros so we don't issue too many digit errors when lots of leading 0's
	while (*value_startp=='_' || *value_startp=='0') value_startp++;
	// Convert decimal number to hex
	int olen = 0;
	uint32_t val = 0;
	int got_x = 0;
	int got_z = 0;
	int got_01 = 0;
	for (const char* cp=value_startp; *cp; cp++) {
	    switch (tolower(*cp)) {
	    case '0': case '1': case '2': case '3': case '4':
	    case '5': case '6': case '7': case '8': case '9': {
		if (olen<=7) {  // 10000000 fits in 32 bits, so ok
		    // Constants are common, so for speed avoid wide math until we need it
		    val = val*10 + (*cp-'0');
		    m_value[0] = val;
		} else { // Wide; all previous digits are already in m_value[0]
		    // this = (this * 10)/*product*/ + (*cp-'0')/*addend*/
		    // Assumed rare; lots of optimizations are possible here
		    V3Number product (fileline, width()+4);  // +4 for overflow detection
		    V3Number ten (fileline, width()+4, 10);
		    V3Number addend (fileline, width(), (*cp-'0'));
		    product.opMul(*this,ten);
		    this->opAdd(product,addend);
		    if (product.bitsValue(width(), 4)) {  // Overflowed
			m_fileline->v3error("Too many digits for "<<width()<<" bit number: "<<sourcep);
			while (*(cp+1)) cp++;  // Skip ahead so don't get multiple warnings
		    }
		}
		olen++;
		got_01 = 1;
		break;
	    }
	    case 'z': case '?': {
		if (!m_sized)  m_fileline->v3error("Unsized X/Z/? not legal in decimal constant: "<<*cp);
		setAllBitsZ();
		got_z = 1;
		break;
	    }
	    case 'x': {
		if (!m_sized)  m_fileline->v3error("Unsized X/Z/? not legal in decimal constant: "<<*cp);
		got_x = 1;
		setAllBitsX();
		break;
	    }
	    case '_': break;
	    default: {
		m_fileline->v3error("Illegal character in decimal constant: "<<*cp);
		break;
	    }
	    }
	}
	obit = width();
	if ((got_01+got_x+got_z)>1) m_fileline->v3error("Mixing X/Z/? with digits not legal in decimal constant: "<<value_startp);
    }
    else {
	// Convert bin/octal number to hex
	for (const char* cp=value_startp+strlen(value_startp)-1;
	     (cp>=value_startp
	      && obit<=width());
	     cp--) {
	    if (*cp!='_' && *cp!='0' && obit>=width()) {
		m_fileline->v3error("Too many digits for "<<width()<<" bit number: "<<sourcep);
		break;
	    }
	    switch(tolower(base)) {
	    case 'b': {
		switch(tolower(*cp)) {
		case '0': setBit(obit++, 0); break;
		case '1': setBit(obit++, 1); break;
		case 'z': case '?': setBit(obit++, 'z'); break;
		case 'x': setBit(obit++, 'x'); break;
		case '_': break;
		default:
		    m_fileline->v3error("Illegal character in binary constant: "<<*cp);
		}
	    break;
	    }

	    case 'o':
	    case 'c': {
		switch(tolower(*cp)) {
		case '0': setBit(obit++, 0); setBit(obit++, 0);  setBit(obit++, 0);  break;
		case '1': setBit(obit++, 1); setBit(obit++, 0);  setBit(obit++, 0);  break;
		case '2': setBit(obit++, 0); setBit(obit++, 1);  setBit(obit++, 0);  break;
		case '3': setBit(obit++, 1); setBit(obit++, 1);  setBit(obit++, 0);  break;
		case '4': setBit(obit++, 0); setBit(obit++, 0);  setBit(obit++, 1);  break;
		case '5': setBit(obit++, 1); setBit(obit++, 0);  setBit(obit++, 1);  break;
		case '6': setBit(obit++, 0); setBit(obit++, 1);  setBit(obit++, 1);  break;
		case '7': setBit(obit++, 1); setBit(obit++, 1);  setBit(obit++, 1);  break;
		case 'z': case '?':
		    setBit(obit++, 'z'); setBit(obit++, 'z');  setBit(obit++, 'z');  break;
		case 'x':
		    setBit(obit++, 'x'); setBit(obit++, 'x');  setBit(obit++, 'x');  break;
		case '_': break;
		default:
		    m_fileline->v3error("Illegal character in octal constant");
		}
		break;
	    }

	    case 'h': {
		switch(tolower(*cp)) {
		case '0': setBit(obit++,0); setBit(obit++,0); setBit(obit++,0); setBit(obit++,0); break;
		case '1': setBit(obit++,1); setBit(obit++,0); setBit(obit++,0); setBit(obit++,0); break;
		case '2': setBit(obit++,0); setBit(obit++,1); setBit(obit++,0); setBit(obit++,0); break;
		case '3': setBit(obit++,1); setBit(obit++,1); setBit(obit++,0); setBit(obit++,0); break;
		case '4': setBit(obit++,0); setBit(obit++,0); setBit(obit++,1); setBit(obit++,0); break;
		case '5': setBit(obit++,1); setBit(obit++,0); setBit(obit++,1); setBit(obit++,0); break;
		case '6': setBit(obit++,0); setBit(obit++,1); setBit(obit++,1); setBit(obit++,0); break;
		case '7': setBit(obit++,1); setBit(obit++,1); setBit(obit++,1); setBit(obit++,0); break;
		case '8': setBit(obit++,0); setBit(obit++,0); setBit(obit++,0); setBit(obit++,1); break;
		case '9': setBit(obit++,1); setBit(obit++,0); setBit(obit++,0); setBit(obit++,1); break;
		case 'a': setBit(obit++,0); setBit(obit++,1); setBit(obit++,0); setBit(obit++,1);  break;
		case 'b': setBit(obit++,1); setBit(obit++,1); setBit(obit++,0); setBit(obit++,1); break;
		case 'c': setBit(obit++,0); setBit(obit++,0); setBit(obit++,1); setBit(obit++,1); break;
		case 'd': setBit(obit++,1); setBit(obit++,0); setBit(obit++,1); setBit(obit++,1); break;
		case 'e': setBit(obit++,0); setBit(obit++,1); setBit(obit++,1); setBit(obit++,1); break;
		case 'f': setBit(obit++,1); setBit(obit++,1); setBit(obit++,1); setBit(obit++,1); break;
		case 'z': case '?':
		    setBit(obit++,'z'); setBit(obit++,'z'); setBit(obit++,'z'); setBit(obit++,'z'); break;
		case 'x':
		    setBit(obit++,'x'); setBit(obit++,'x'); setBit(obit++,'x'); setBit(obit++,'x'); break;
		case '_':  break;
		default:
		    m_fileline->v3error("Illegal character in hex constant: "<<*cp);
		}
		break;
	    }
	    default:
		m_fileline->v3error("Illegal base character: "<<base);
	    }
	}
    }

    // Z or X extend specific width values.  Spec says we don't 1 extend.
    // This fixes 2'bx to become 2'bxx.
    while (obit<=width() && obit && bitIsXZ(obit-1)) {
	setBit(obit, bitIs(obit-1));
	obit++;
    }

    //printf("Dump \"%s\"  CP \"%s\"  B '%c' %d W %d\n", sourcep, value_startp, base, width(), m_value[0]);
}

//======================================================================
// Global

int V3Number::log2b(uint32_t num) {
    // See also opCLog2
    for (int bit=31; bit>0; bit--) if (num & (VL_ULL(1)<<bit)) return(bit);
    return(0);
}

//======================================================================
// Setters

V3Number& V3Number::setZero() {
    for (int i=0; i<words(); i++) m_value[i]=m_valueX[i] = 0;
    return *this;
}
V3Number& V3Number::setQuad(vluint64_t value) {
    for (int i=0; i<words(); i++) m_value[i]=m_valueX[i] = 0;
    m_value[0] = value & VL_ULL(0xffffffff);
    m_value[1] = (value>>VL_ULL(32)) & VL_ULL(0xffffffff);
    return *this;
}
V3Number& V3Number::setLong(uint32_t value) {
    for (int i=0; i<words(); i++) m_value[i]=m_valueX[i] = 0;
    m_value[0] = value;
    return *this;
}
V3Number& V3Number::setLongS(vlsint32_t value) {
    for (int i=0; i<words(); i++) m_value[i]=m_valueX[i] = 0;
    union { uint32_t u; vlsint32_t s; } u;
    u.s = value;
    m_value[0] = u.u;
    return *this;
}
V3Number& V3Number::setDouble(double value) {
    if (VL_UNLIKELY(width()!=64)) {
	m_fileline->v3fatalSrc("Real operation on wrong sized number");
    }
    m_double = true;
    union { double d; uint32_t u[2]; } u;
    u.d = value;
    for (int i=2; i<words(); i++) m_value[i]=m_valueX[i] = 0;
    m_value[0] = u.u[0]; m_value[1] = u.u[1];
    return *this;
}
V3Number& V3Number::setSingleBits(char value) {
    for (int i=1/*upper*/; i<words(); i++) m_value[i]=m_valueX[i] = 0;
    m_value[0] = (value=='1'||value=='x'||value==1||value==3);
    m_valueX[0] = (value=='z'||value=='x'||value==2||value==3);
    return *this;
}

V3Number& V3Number::setAllBits0() {
    for (int i=0; i<words(); i++) { m_value[i] = m_valueX[i]=0; }
    return *this;
}
V3Number& V3Number::setAllBits1() {
    for (int i=0; i<words(); i++) { m_value[i]= ~0; m_valueX[i] = 0; }
    return *this;
}
V3Number& V3Number::setAllBitsX() {
    for (int i=0; i<words(); i++) { m_value[i]=m_valueX[i] = ~0; }
    return *this;
}
V3Number& V3Number::setAllBitsZ() {
    for (int i=0; i<words(); i++) { m_value[i]=0; m_valueX[i] = ~0; }
    return *this;
}
V3Number& V3Number::setMask(int nbits) {
    setZero();
    for (int bit=0; bit<nbits; bit++) { setBit(bit,1); }
    return *this;
}

//======================================================================
// ACCESSORS - as strings

string V3Number::ascii(bool prefixed, bool cleanVerilog) const {
    ostringstream out;

    if (isDouble()) {
	out.precision(17);
	out<<toDouble();
	return out.str();
    }
    if (prefixed) {
	if (sized()) {
	    out<<width()<<"'";
	} else if (autoExtend() && !sized() && width()==1) {
	    out<<"'";
	    if (bitIs0(0)) out<<'0';
	    else if (bitIs1(0)) out<<'1';
	    else if (bitIsZ(0)) out<<'z';
	    else out<<'x';
	    return out.str();
	} else {
	    if (cleanVerilog) out<<"'";
	    else out<<"?"<<width()<<"?";
	}
	if (isSigned()) out<<"s";
    }

    bool binary = (isFourState()
#ifdef V3NUMBER_ASCII_BINARY
		   || 1
#endif
	);
    //out<<"-"<<hex<<m_value[0]<<"-";

    if (binary) {
	out<<"b";
	out<<displayed("%0b");
    }
    else {
	if (prefixed) out<<"h";
	// Always deal with 4 bits at once.  Note no 4-state, it's above.
	out<<displayed("%0h");
    }
    return out.str();
}

bool V3Number::displayedFmtLegal(char format) {
    // Is this a valid format letter?
    switch (tolower(format)) {
    case 'b': return true;
    case 'c': return true;
    case 'd': return true; // Unsigned decimal
    case 'e': return true;
    case 'f': return true;
    case 'g': return true;
    case 'h': return true;
    case 'o': return true;
    case 's': return true;
    case 't': return true;
    case 'x': return true;
    case '~': return true; // Signed decimal
    default: return false;
    }
}

string V3Number::displayed(const string& vformat) const {
    string::const_iterator pos = vformat.begin();
    UASSERT(pos != vformat.end() && pos[0]=='%', "display with non format argument "<<*this);
    ++pos;
    string fmtsize;
    for (; pos != vformat.end() && (isdigit(pos[0]) || pos[0]=='.'); ++pos) {
	fmtsize += pos[0];
    }
    string str;
    char code = tolower(pos[0]);
    switch (code) {
    case 'b': {
	int bit = width()-1;
	if (fmtsize == "0") while (bit && bitIs0(bit)) bit--;
	for (; bit>=0; bit--) {
	    if (bitIs0(bit)) str+='0';
	    else if (bitIs1(bit)) str+='1';
	    else if (bitIsZ(bit)) str+='z';
	    else str+='x';
	}
	return str;
    }
    case 'o': {
	int bit = width()-1;
	if (fmtsize == "0") while (bit && bitIs0(bit)) bit--;
	while ((bit%3)!=2) bit++;
	for (; bit>0; bit -= 3) {
	    int v = bitsValue(bit-2, 3);
	    str += (char)('0'+v);
	}
	return str;
    }
    case 'h':
    case 'x': {
	int bit = width()-1;
	if (fmtsize == "0") while (bit && bitIs0(bit)) bit--;
	while ((bit%4)!=3) bit++;
	for (; bit>0; bit -= 4) {
	    int v = bitsValue(bit-3, 4);
	    if (v>=10) str += (char)('a'+v-10);
	    else str += (char)('0'+v);
	}
	return str;
    }
    case 'c': {
	if (this->width()>8) m_fileline->v3error("$display of char format of > 8 bit value");
	int v = bitsValue(0, 8);
	str += (char)(v);
	return str;
    }
    case 's': {
	// Spec says always drop leading zeros, this isn't quite right, we space pad.
	int bit=this->width()-1;
	bool start=true;
	while ((bit%8)!=7) bit++;
	for (; bit>=0; bit -= 8) {
	    int v = bitsValue(bit-7, 8);
	    if (!start || v) {
		str += (char)((v==0)?' ':v);
		start = false;	// Drop leading 0s
	    } else {
		if (fmtsize != "0") str += ' ';
	    }
	}
	return str;
    }
    case '~': // Signed decimal
    case 't': // Time
    case 'd': { // Unsigned decimal
	bool issigned = (code == '~');
	if (fmtsize == "") {
	    double mantissabits = this->width() - (issigned?1:0);
	    double maxval = pow(2.0, mantissabits);
	    double dchars = log10(maxval)+1.0;
	    if (issigned) dchars++;  // space for sign
	    fmtsize = cvtToStr(int(dchars));
	}
	if (width() > 64) {
	    m_fileline->v3error("Unsupported: $display of dec format of > 64 bit results (use hex format instead)");
	    return "ERR";
	}
	if (issigned) {
	    str = cvtToStr(toSQuad());
	} else {
	    str = cvtToStr(toUQuad());
	}
	int intfmtsize = atoi(fmtsize.c_str());
	bool zeropad = fmtsize.length()>0 && fmtsize[0]=='0';
	while ((int)(str.length()) < intfmtsize) {
	    if (zeropad) str = "0"+str;
	    else str = " "+str;
	}
	return str;
    }
    case 'e':
    case 'f':
    case 'g': {
	char tmp[MAX_SPRINTF_DOUBLE_SIZE];
	sprintf(tmp, vformat.c_str(), toDouble());
	return tmp;
    }
    default:
	m_fileline->v3fatalSrc("Unknown $display format code for number: %"<<pos[0]);
	return "ERR";
    }
}

//======================================================================
// ACCESSORS - as numbers

uint32_t V3Number::toUInt() const {
    UASSERT(!isFourState(),"toUInt with 4-state "<<*this);
    UASSERT((width()<33 || (width()<65 && m_value[1]==0)), "Value too wide "<<*this);
    return m_value[0];
}

double V3Number::toDouble() const {
    if (VL_UNLIKELY(!isDouble())) {
	m_fileline->v3fatalSrc("Real conversion on non real number");
    }
    if (VL_UNLIKELY(width()!=64)) {
	m_fileline->v3fatalSrc("Real operation on wrong sized number");
    }
    union { double d; uint32_t u[2]; } u;
    u.u[0] = m_value[0]; u.u[1] = m_value[1];
    return u.d;
}

vlsint32_t V3Number::toSInt() const {
    if (isSigned()) {
	uint32_t v = toUInt();
	uint32_t signExtend = (-(v & (1UL<<(width()-1))));
	uint32_t extended = v | signExtend;
	return (vlsint32_t)(extended);
    } else {
	// Where we use this (widths, etc) and care about signedness,
	// we can reasonably assume the MSB isn't set on unsigned numbers.
	return (vlsint32_t)toUInt();
    }
}

vluint64_t V3Number::toUQuad() const {
    UASSERT(!isFourState(),"toUQuad with 4-state "<<*this);
    UASSERT(width()<65, "Value too wide "<<*this);
    if (width()<=32) return ((vluint64_t)(toUInt()));
    return ((vluint64_t)m_value[1]<<VL_ULL(32)) | ((vluint64_t)m_value[0]);
}

vlsint64_t V3Number::toSQuad() const {
    vluint64_t v = toUQuad();
    vluint64_t signExtend = (-(v & (VL_ULL(1)<<(width()-1))));
    vluint64_t extended = v | signExtend;
    return (vlsint64_t)(extended);
}

string V3Number::toString() const {
    UASSERT(!isFourState(),"toString with 4-state "<<*this);
    // Spec says always drop leading zeros, this isn't quite right, we space pad.
    int bit=this->width()-1;
    bool start=true;
    while ((bit%8)!=7) bit++;
    string str;
    for (; bit>=0; bit -= 8) {
	int v = bitsValue(bit-7, 8);
	if (!start || v) {
	    str += (char)((v==0)?' ':v);
	    start = false;	// Drop leading 0s
	}
    }
    return str;
}

uint32_t V3Number::toHash() const {
    return m_value[0];
}

uint32_t V3Number::dataWord(int word) const {
    UASSERT(!isFourState(),"dataWord with 4-state "<<*this);
    return m_value[word];
}

bool V3Number::isEqZero() const {
    for (int i=0; i<words(); i++) {
	if (m_value[i] || m_valueX[i]) return false;
    }
    return true;
}
bool V3Number::isNeqZero() const {
    for (int i=0; i<words(); i++) {
	if (m_value[i] & ~m_valueX[i]) return true;
    }
    return false;
}
bool V3Number::isBitsZero(int msb, int lsb) const {
    for (int i=lsb; i<=msb; i++) {
	if (VL_UNLIKELY(!bitIs0(i))) return false;
    }
    return true;
}
bool V3Number::isEqOne() const {
    if (m_value[0]!=1 || m_valueX[0]) return false;
    for (int i=1; i<words(); i++) {
	if (m_value[i] || m_valueX[i]) return false;
    }
    return true;
}
bool V3Number::isEqAllOnes(int optwidth) const {
    if (!optwidth) optwidth = width();
    for(int bit=0; bit<optwidth; bit++) {
	if (!bitIs1(bit)) return false;
    }
    return true;
}
bool V3Number::isUnknown() const {
    for(int bit=0; bit<width(); bit++) {
	if (bitIsX(bit)) return true;
    }
    return false;
}
bool V3Number::isLt(const V3Number& rhs) const {
    for (int bit=0; bit<max(this->width(),rhs.width()); bit++) {
	if (this->bitIs1(bit) && rhs.bitIs0(bit)) { return 1; }
	if (rhs.bitIs1(bit) && this->bitIs0(bit)) { return 0; }
	if (this->bitIsXZ(bit)) { return 0; }
	if (rhs.bitIsXZ(bit)) { return 0; }
    }
    return 0;
}

int V3Number::minWidth() const {
    for(int bit=width()-1; bit>0; bit--) {
	if (!bitIs0(bit)) return bit+1;
    }
    return 1;	// one bit even if number is == 0
}

uint32_t V3Number::countOnes() const {
    int n=0;
    for(int bit=0; bit<this->width(); bit++) {
	if (bitIs1(bit)) n++;
    }
    return n;
}

uint32_t V3Number::mostSetBitP1() const {
    for (int bit=this->width()-1; bit>=0; bit--) {
	if (bitIs1(bit)) return bit+1;
    }
    return 0;
}
//======================================================================

V3Number& V3Number::opBitsNonX (const V3Number& lhs) { // 0/1->1, X/Z->0
    // op i, L(lhs) bit return
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
	if (lhs.bitIs0(bit) || lhs.bitIs1(bit))  { setBit(bit,1); }
    }
    return *this;
}
V3Number& V3Number::opBitsOne (const V3Number& lhs) { // 1->1, 0/X/Z->0
    // op i, L(lhs) bit return
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
	if (lhs.bitIs1(bit))  { setBit(bit,1); }
    }
    return *this;
}
V3Number& V3Number::opBitsXZ (const V3Number& lhs) { // 0/1->1, X/Z->0
    // op i, L(lhs) bit return
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
	if (lhs.bitIsXZ(bit))  { setBit(bit,1); }
    }
    return *this;
}
V3Number& V3Number::opBitsZ (const V3Number& lhs) { // 0/1->1, X/Z->0
    // op i, L(lhs) bit return
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
      if (lhs.bitIsZ(bit))  { setBit(bit,1); }
    }
    return *this;
}
V3Number& V3Number::opBitsNonZ (const V3Number& lhs) { // 0/1->1, X/Z->0
    // op i, L(lhs) bit return
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
      if (!lhs.bitIsZ(bit)) { setBit(bit,1); }
    }
    return *this;
}

//======================================================================
// Operators - Simple per-bit logical ops

V3Number& V3Number::opRedOr (const V3Number& lhs) {
    // op i, 1 bit return
    char outc = 0;
    for(int bit=0; bit<lhs.width(); bit++) {
	if (lhs.bitIs1(bit)) return setSingleBits(1);
	else if (lhs.bitIs0(bit)) ;
	else outc = 'x';
    }
    return setSingleBits(outc);
}

V3Number& V3Number::opRedAnd (const V3Number& lhs) {
    // op i, 1 bit return
    char outc = 1;
    for(int bit=0; bit<lhs.width(); bit++) {
	if (lhs.bitIs0(bit)) return setSingleBits(0);
	else if (lhs.bitIs1(bit)) ;
	else outc = 'x';
    }
    return setSingleBits(outc);
}

V3Number& V3Number::opRedXor (const V3Number& lhs) {
    // op i, 1 bit return
    char outc = 0;
    for(int bit=0; bit<lhs.width(); bit++) {
	if (lhs.bitIs1(bit)) { if (outc==1) outc=0; else if (outc==0) outc=1; }
	else if (lhs.bitIs0(bit)) ;
	else outc = 'x';
    }
    return setSingleBits(outc);
}

V3Number& V3Number::opRedXnor (const V3Number& lhs) {
    // op i, 1 bit return
    char outc = 1;
    for(int bit=0; bit<lhs.width(); bit++) {
	if (lhs.bitIs1(bit)) { if (outc==1) outc=0; else if (outc==0) outc=1; }
	else if (lhs.bitIs0(bit)) ;
	else outc = 'x';
    }
    return setSingleBits(outc);
}

V3Number& V3Number::opCountOnes (const V3Number& lhs) {
    if (lhs.isFourState()) return setAllBitsX();
    setZero();
    m_value[0] = lhs.countOnes();
    return *this;
}
V3Number& V3Number::opIsUnknown (const V3Number& lhs) {
    return setSingleBits(lhs.isUnknown());
}
V3Number& V3Number::opOneHot (const V3Number& lhs) {
    if (lhs.isFourState()) return setAllBitsX();
    return setSingleBits(lhs.countOnes()==1);
}
V3Number& V3Number::opOneHot0 (const V3Number& lhs) {
    if (lhs.isFourState()) return setAllBitsX();
    return setSingleBits(lhs.countOnes()<=1);
}
V3Number& V3Number::opCLog2 (const V3Number& lhs) {
    if (lhs.isFourState()) return setAllBitsX();
    // IE if 4, this algorithm didn't pre-subtract 1, so we need to post-correct now
    int adjust = (lhs.countOnes()==1) ? 0 : 1;
    for (int bit=lhs.width()-1; bit>=0; bit--) {
	if (lhs.bitIs1(bit)) {
	    setLong(bit+adjust);
	    return *this;
	}
    }
    setZero();
    return *this;
}

V3Number& V3Number::opLogNot (const V3Number& lhs) {
    // op i, 1 bit return
    char outc = 1;
    for(int bit=0; bit<lhs.width(); bit++) {
	if (lhs.bitIs1(bit)) { outc=0; goto last;}
	else if (lhs.bitIs0(bit)) ;
	else outc = 'x';
    }
  last:
    return setSingleBits(outc);
}

V3Number& V3Number::opNot (const V3Number& lhs) {
    // op i, L(lhs) bit return
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
	if (lhs.bitIs0(bit))       { setBit(bit,1); }
	else if (lhs.bitIsXZ(bit)) { setBit(bit,'x'); }
    }
    return *this;
}

V3Number& V3Number::opAnd (const V3Number& lhs, const V3Number& rhs) {
    // i op j, max(L(lhs),L(rhs)) bit return, careful need to X/Z extend.
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
	if (lhs.bitIs1(bit) && rhs.bitIs1(bit))  { setBit(bit,1); }
	else if (lhs.bitIs0(bit) || rhs.bitIs0(bit)) ;  // 0
	else { setBit(bit,'x'); }
    }
    return *this;
}

V3Number& V3Number::opOr (const V3Number& lhs, const V3Number& rhs) {
    // i op j, max(L(lhs),L(rhs)) bit return, careful need to X/Z extend.
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
	if (lhs.bitIs1(bit) || rhs.bitIs1(bit))  { setBit(bit,1); }
	else if (lhs.bitIs0(bit) && rhs.bitIs0(bit)) ;  // 0
	else { setBit(bit,'x'); }
    }
    return *this;
}

V3Number& V3Number::opChangeXor (const V3Number& lhs, const V3Number& rhs) {
    // 32 bit result
    opEq(lhs,rhs);
    return *this;
}

V3Number& V3Number::opXor (const V3Number& lhs, const V3Number& rhs) {
    // i op j, max(L(lhs),L(rhs)) bit return, careful need to X/Z extend.
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
	if (lhs.bitIs1(bit) && rhs.bitIs0(bit))  { setBit(bit,1); }
	else if (lhs.bitIs0(bit) && rhs.bitIs1(bit))  { setBit(bit,1); }
	else if (lhs.bitIsXZ(bit) && rhs.bitIsXZ(bit)) { setBit(bit,'x'); }
	// else zero
    }
    return *this;
}

V3Number& V3Number::opXnor (const V3Number& lhs, const V3Number& rhs) {
    // i op j, max(L(lhs),L(rhs)) bit return, careful need to X/Z extend.
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
	if (lhs.bitIs1(bit) && rhs.bitIs1(bit))  { setBit(bit,1); }
	else if (lhs.bitIs0(bit) && rhs.bitIs0(bit))  { setBit(bit,1); }
	else if (lhs.bitIsXZ(bit) && rhs.bitIsXZ(bit)) { setBit(bit,'x'); }
	// else zero
    }
    return *this;
}

V3Number& V3Number::opConcat (const V3Number& lhs, const V3Number& rhs) {
    setZero();
    // See also error in V3Width
    if (!lhs.sized() || !rhs.sized()) {
	m_fileline->v3warn(WIDTHCONCAT,"Unsized numbers/parameters not allowed in concatenations.");
    }
    int obit = 0;
    for(int bit=0; bit<rhs.width(); bit++) {
	setBit(obit,rhs.bitIs(bit));
	obit++;
    }
    for(int bit=0; bit<lhs.width(); bit++) {
	setBit(obit,lhs.bitIs(bit));
	obit++;
    }
    return *this;
}

V3Number& V3Number::opRepl (const V3Number& lhs, const V3Number& rhs) {	// rhs is # of times to replicate
    // Hopefully the using routine has a error check too.
    // See also error in V3Width
    if (!lhs.sized()) m_fileline->v3warn(WIDTHCONCAT,"Unsized numbers/parameters not allowed in replications.");
    return opRepl(lhs, rhs.toUInt());
}

V3Number& V3Number::opRepl (const V3Number& lhs, uint32_t rhsval) {	// rhs is # of times to replicate
    // i op repl, L(i)*value(rhs) bit return
    setZero();
    if (rhsval>8192) m_fileline->v3fatal("More than a 8k bit replication is probably wrong: "<<rhsval);
    int obit = 0;
    for (unsigned times=0; times<rhsval; times++) {
	for(int bit=0; bit<lhs.width(); bit++) {
	    setBit(obit,lhs.bitIs(bit));
	    obit++;
	}
    }
    return *this;
}

V3Number& V3Number::opLogAnd (const V3Number& lhs, const V3Number& rhs) {
    // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation
    char loutc = 0;
    char routc = 0;
    for(int bit=0; bit<lhs.width(); bit++) {
	if (lhs.bitIs1(bit)) { loutc=1; break; }
	if (lhs.bitIsXZ(bit) && loutc==0) { loutc='x'; }
    }
    for(int bit=0; bit<rhs.width(); bit++) {
	if (rhs.bitIs1(bit)) { routc=1; break; }
	if (rhs.bitIsXZ(bit) && routc==0) { routc='x'; }
    }
    char outc = 'x';
    if (routc==1 && loutc==1) outc=1;
    if (routc==0 || loutc==0) outc=0;
    return setSingleBits(outc);
}

V3Number& V3Number::opLogOr (const V3Number& lhs, const V3Number& rhs) {
    // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation, careful need to X/Z extend.
    char outc = 0;
    for(int bit=0; bit<lhs.width(); bit++) {
	if (lhs.bitIs1(bit)) { outc=1; goto last; }
	if (lhs.bitIsXZ(bit) && outc==0) { outc='x'; }
    }
    for(int bit=0; bit<rhs.width(); bit++) {
	if (rhs.bitIs1(bit)) { outc=1; goto last; }
	if (rhs.bitIsXZ(bit) && outc==0) { outc='x'; }
    }
last:
    return setSingleBits(outc);
}

V3Number& V3Number::opEq (const V3Number& lhs, const V3Number& rhs) {
    // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation, careful need to X/Z extend.
    char outc = 1;
    for (int bit=0; bit<max(lhs.width(),rhs.width()); bit++) {
	if (lhs.bitIs1(bit) && rhs.bitIs0(bit)) { outc=0; goto last; }
	if (lhs.bitIs0(bit) && rhs.bitIs1(bit)) { outc=0; goto last; }
	if (lhs.bitIsXZ(bit)) { outc='x'; }
	if (rhs.bitIsXZ(bit)) { outc='x'; }
    }
last:
    return setSingleBits(outc);
}

V3Number& V3Number::opNeq (const V3Number& lhs, const V3Number& rhs) {
    // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation, careful need to X/Z extend.
    char outc = 0;
    for (int bit=0; bit<max(lhs.width(),rhs.width()); bit++) {
	if (lhs.bitIs1(bit) && rhs.bitIs0(bit)) { outc=1; goto last; }
	if (lhs.bitIs0(bit) && rhs.bitIs1(bit)) { outc=1; goto last; }
	if (lhs.bitIsXZ(bit)) { outc='x'; }
	if (rhs.bitIsXZ(bit)) { outc='x'; }
    }
last:
    return setSingleBits(outc);
}

bool V3Number::isCaseEq (const V3Number& rhs) const {
    // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation, careful need to X/Z extend.
    if (this->width() != rhs.width()) return false;
    for (int bit=0; bit<max(this->width(),rhs.width()); bit++) {
	if (this->bitIs(bit) != rhs.bitIs(bit)) { return false; }
    }
    return true;
}

V3Number& V3Number::opCaseEq (const V3Number& lhs, const V3Number& rhs) {
    return setSingleBits(lhs.isCaseEq(rhs) ? 1:0);
}

V3Number& V3Number::opCaseNeq (const V3Number& lhs, const V3Number& rhs) {
    // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation, careful need to X/Z extend.
    char outc = 0;
    for (int bit=0; bit<max(lhs.width(),rhs.width()); bit++) {
	if (lhs.bitIs(bit) != rhs.bitIs(bit)) { outc=1; goto last; }
    }
last:
    return setSingleBits(outc);
}

V3Number& V3Number::opWildEq (const V3Number& lhs, const V3Number& rhs) {
    char outc = 1;
    for (int bit=0; bit<max(lhs.width(),rhs.width()); bit++) {
	if (!rhs.bitIsXZ(bit)
	    && lhs.bitIs(bit) != rhs.bitIs(bit)) { outc=0; goto last; }
	if (lhs.bitIsXZ(bit)) outc='x';
    }
last:
    return setSingleBits(outc);
}

V3Number& V3Number::opWildNeq (const V3Number& lhs, const V3Number& rhs) {
    char outc = 0;
    for (int bit=0; bit<max(lhs.width(),rhs.width()); bit++) {
	if (!rhs.bitIsXZ(bit)
	    && lhs.bitIs(bit) != rhs.bitIs(bit)) { outc=1; goto last; }
	if (lhs.bitIsXZ(bit)) outc='x';
    }
last:
    return setSingleBits(outc);
}

V3Number& V3Number::opGt (const V3Number& lhs, const V3Number& rhs) {
    // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation, careful need to X/Z extend.
    char outc = 0;
    for (int bit=0; bit<max(lhs.width(),rhs.width()); bit++) {
	if (lhs.bitIs1(bit) && rhs.bitIs0(bit)) { outc=1; }
	if (rhs.bitIs1(bit) && lhs.bitIs0(bit)) { outc=0; }
	if (lhs.bitIsXZ(bit)) { outc='x'; }
	if (rhs.bitIsXZ(bit)) { outc='x'; }
    }
    return setSingleBits(outc);
}

V3Number& V3Number::opGtS (const V3Number& lhs, const V3Number& rhs) {
    // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation, careful need to X/Z extend.
    char outc = 0;
    {
	int mbit=max(lhs.width()-1,rhs.width()-1);
	if (lhs.bitIsXZ(mbit)) { outc='x'; }
	else if (rhs.bitIsXZ(mbit)) { outc='x'; }
	else if (lhs.bitIs0(mbit)       && rhs.bitIs1Extend(mbit)) { outc=1; } // + > -
	else if (lhs.bitIs1Extend(mbit) && rhs.bitIs0(mbit))       { outc=0; } // - !> +
	else {
	    // both positive or negative, normal >
	    for (int bit=0; bit<max(lhs.width()-1,rhs.width()-1); bit++) {
		if (lhs.bitIs1Extend(bit) && rhs.bitIs0(bit)) { outc=1; }
		if (rhs.bitIs1Extend(bit) && lhs.bitIs0(bit)) { outc=0; }
		if (lhs.bitIsXZ(bit)) { outc='x'; }
		if (rhs.bitIsXZ(bit)) { outc='x'; }
	    }
	}
    }
    return setSingleBits(outc);
}

V3Number& V3Number::opGte (const V3Number& lhs, const V3Number& rhs) {
    // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation, careful need to X/Z extend.
    V3Number& eq = opEq (lhs,rhs);
    if (eq.isNeqZero()) return eq; // Return true
    return opGt (lhs,rhs);
}

V3Number& V3Number::opGteS (const V3Number& lhs, const V3Number& rhs) {
    // i op j, 1 bit return, max(L(lhs),L(rhs)) calculation, careful need to X/Z extend.
    V3Number& eq = opEq (lhs,rhs);
    if (eq.isNeqZero()) return eq; // Return true
    return opGtS (lhs,rhs);
}

V3Number& V3Number::opLt (const V3Number& lhs, const V3Number& rhs) {
    return opGt(rhs,lhs);
}
V3Number& V3Number::opLte (const V3Number& lhs, const V3Number& rhs) {
    return opGte(rhs,lhs);
}
V3Number& V3Number::opLtS (const V3Number& lhs, const V3Number& rhs) {
    return opGtS(rhs,lhs);
}
V3Number& V3Number::opLteS (const V3Number& lhs, const V3Number& rhs) {
    return opGteS(rhs,lhs);
}

V3Number& V3Number::opRotR (const V3Number& lhs, const V3Number& rhs) {
    // L(lhs) bit return
    if (rhs.isFourState()) return setAllBitsX();
    setZero();
    uint32_t rhsval = rhs.toUInt();
    for (int bit=0; bit<this->width(); bit++) {
	setBit(bit,lhs.bitIs((bit + rhsval) % this->width()));
    }
    return *this;
}

V3Number& V3Number::opRotL (const V3Number& lhs, const V3Number& rhs) {
    // L(lhs) bit return
    if (rhs.isFourState()) return setAllBitsX();
    setZero();
    uint32_t rhsval = rhs.toUInt();
    for (int bit=0; bit<this->width(); bit++) {
	if (bit >= (int)rhsval) {
	    setBit(bit,lhs.bitIs((bit - rhsval) % this->width()));
	}
    }
    return *this;
}

V3Number& V3Number::opShiftR (const V3Number& lhs, const V3Number& rhs) {
    // L(lhs) bit return
    if (rhs.isFourState()) return setAllBitsX();
    setZero();
    uint32_t rhsval = rhs.toUInt();
    for (int bit=0; bit<this->width(); bit++) {
	setBit(bit,lhs.bitIs(bit + rhsval));
    }
    return *this;
}

V3Number& V3Number::opShiftRS (const V3Number& lhs, const V3Number& rhs) {
    // L(lhs) bit return
    // The spec says a unsigned >>> still acts as a normal >>.
    // We presume it is signed; as that's V3Width's job to convert to opShiftR
    if (rhs.isFourState()) return setAllBitsX();
    setZero();
    uint32_t rhsval = rhs.toUInt();
    for (int bit=0; bit<this->width(); bit++) {
	setBit(bit,lhs.bitIsExtend(bit + rhsval));
    }
    return *this;
}

V3Number& V3Number::opShiftL (const V3Number& lhs, const V3Number& rhs) {
    // L(lhs) bit return
    if (rhs.isFourState()) return setAllBitsX();
    setZero();
    uint32_t rhsval = rhs.toUInt();
    for (int bit=0; bit<this->width(); bit++) {
	if (bit >= (int)rhsval) {
	    setBit(bit,lhs.bitIs(bit - rhsval));
	}
    }
    return *this;
}

//======================================================================
// Ops - Arithmetic

V3Number& V3Number::opAbsS (const V3Number& lhs) {
    // op i, L(lhs) bit return
    if (lhs.isFourState()) return setAllBitsX();
    if (lhs.isNegative()) {
	return opNegate(lhs);
    } else {
	return opAssign(lhs);
    }
}
V3Number& V3Number::opNegate (const V3Number& lhs) {
    // op i, L(lhs) bit return
    if (lhs.isFourState()) return setAllBitsX();
    V3Number notlhs (lhs.m_fileline, width());
    notlhs.opNot(lhs);
    V3Number one (lhs.m_fileline, width(), 1);
    opAdd(notlhs,one);
    return *this;
}
V3Number& V3Number::opAdd (const V3Number& lhs, const V3Number& rhs) {
    // i op j, max(L(lhs),L(rhs)) bit return, if any 4-state, 4-state return
    if (lhs.isFourState() || rhs.isFourState()) return setAllBitsX();
    setZero();
    // Addem
    int carry=0;
    for (int bit=0; bit<this->width(); bit++) {
	int sum = ((lhs.bitIs1(bit)?1:0) + (rhs.bitIs1(bit)?1:0) + carry);
	if (sum & 1) {
	    setBit(bit,1);
	}
	carry = (sum >= 2);
    }
    return *this;
}
V3Number& V3Number::opSub (const V3Number& lhs, const V3Number& rhs) {
    // i op j, max(L(lhs),L(rhs)) bit return, if any 4-state, 4-state return
    if (lhs.isFourState() || rhs.isFourState()) return setAllBitsX();
    V3Number negrhs (rhs.m_fileline, rhs.width());
    negrhs.opNegate(rhs);
    return opAdd(lhs, negrhs);
}
V3Number& V3Number::opMul (const V3Number& lhs, const V3Number& rhs) {
    // i op j, max(L(lhs),L(rhs)) bit return, if any 4-state, 4-state return
    if (lhs.isFourState() || rhs.isFourState()) return setAllBitsX();
    setZero();
    if (width() <= 64) {
	setQuad(lhs.toUQuad() * rhs.toUQuad());
	opCleanThis();   // Mult produces extra bits in result
    } else {
	for (int lword=0; lword<lhs.words(); lword++) {
	    for (int rword=0; rword<rhs.words(); rword++) {
		vluint64_t mul = (vluint64_t)(lhs.m_value[lword]) * (vluint64_t)(rhs.m_value[rword]);
		for (int qword=lword+rword; qword<this->words(); qword++) {
		    mul += (vluint64_t)(m_value[qword]);
		    m_value[qword] = (mul & VL_ULL(0xffffffff));
		    mul = (mul >> VL_ULL(32)) & VL_ULL(0xffffffff);
		}
	    }
	}
	opCleanThis();   // Mult produces extra bits in result
    }
    return *this;
}
V3Number& V3Number::opMulS (const V3Number& lhs, const V3Number& rhs) {
    // Signed multiply
    if (lhs.isFourState() || rhs.isFourState()) return setAllBitsX();
    V3Number lhsNoSign = lhs;  if (lhs.isNegative()) lhsNoSign.opNegate(lhs);
    V3Number rhsNoSign = rhs;  if (rhs.isNegative()) rhsNoSign.opNegate(rhs);
    V3Number qNoSign = opMul(lhsNoSign,rhsNoSign);
    if ((lhs.isNegative() && !rhs.isNegative())
	|| (!lhs.isNegative() && rhs.isNegative())) {
	opNegate(qNoSign);
    } else {
	opAssign(qNoSign);
    }
    return *this;
}
V3Number& V3Number::opDiv (const V3Number& lhs, const V3Number& rhs) {
    UINFO(9, "opdiv "<<lhs<<" "<<rhs<<endl);
    // i op j, max(L(lhs),L(rhs)) bit return, if any 4-state, 4-state return
    if (lhs.isFourState() || rhs.isFourState()) return setAllBitsX();
    if (rhs.isEqZero()) return setAllBitsX();
    if (lhs.width()<=64) {
	setQuad(lhs.toUQuad() / rhs.toUQuad());
	return *this;
    } else {
	// Wide division
	return opModDivGuts(lhs,rhs,false);
    }
}
V3Number& V3Number::opDivS (const V3Number& lhs, const V3Number& rhs) {
    // Signed divide
    //UINFO(9, ">>divs-start "<<lhs<<" "<<rhs<<endl);
    if (lhs.isFourState() || rhs.isFourState()) return setAllBitsX();
    if (rhs.isEqZero()) return setAllBitsX();
    V3Number lhsNoSign = lhs;  if (lhs.isNegative()) lhsNoSign.opNegate(lhs);
    V3Number rhsNoSign = rhs;  if (rhs.isNegative()) rhsNoSign.opNegate(rhs);
    V3Number qNoSign = opDiv(lhsNoSign,rhsNoSign);
    //UINFO(9, " >divs-mid "<<lhs<<" "<<rhs<<" "<<qNoSign<<endl);
    if ((lhs.isNegative() && !rhs.isNegative())
	|| (!lhs.isNegative() && rhs.isNegative())) {
	opNegate(qNoSign);
    } else {
	opAssign(qNoSign);
    }
    UINFO(9, " <divs-out "<<lhs<<" "<<rhs<<" ="<<*this<<endl);
    return *this;
}
V3Number& V3Number::opModDiv (const V3Number& lhs, const V3Number& rhs) {
    // i op j, max(L(lhs),L(rhs)) bit return, if any 4-state, 4-state return
    if (lhs.isFourState() || rhs.isFourState()) return setAllBitsX();
    if (rhs.isEqZero()) return setAllBitsX();
    if (lhs.width()<=64) {
	setQuad(lhs.toUQuad() % rhs.toUQuad());
	return *this;
    } else {
	// Wide modulus
	return opModDivGuts(lhs,rhs,true);
    }
}
V3Number& V3Number::opModDivS (const V3Number& lhs, const V3Number& rhs) {
    // Signed moddiv
    if (lhs.isFourState() || rhs.isFourState()) return setAllBitsX();
    if (rhs.isEqZero()) return setAllBitsX();
    V3Number lhsNoSign = lhs;  if (lhs.isNegative()) lhsNoSign.opNegate(lhs);
    V3Number rhsNoSign = rhs;  if (rhs.isNegative()) rhsNoSign.opNegate(rhs);
    V3Number qNoSign = opModDiv(lhsNoSign,rhsNoSign);
    if (lhs.isNegative()) {	// Just lhs' sign  (*DIFFERENT FROM PERL, which uses rhs sign*)
	opNegate(qNoSign);
    } else {
	opAssign(qNoSign);
    }
    return *this;
}
V3Number& V3Number::opModDivGuts(const V3Number& lhs, const V3Number& rhs, bool is_modulus) {
    // See Knuth Algorithm D.  Computes u/v = q.r
    // This isn't massively tuned, as wide division is rare
    setZero();
    // Find MSB and check for zero.
    int words = lhs.words();
    int umsbp1 = lhs.mostSetBitP1(); // dividend
    int vmsbp1 = rhs.mostSetBitP1(); // divisor
    if (VL_UNLIKELY(vmsbp1==0)  // rwp==0 so division by zero.  Return 0.
	|| VL_UNLIKELY(umsbp1==0)) {	// 0/x so short circuit and return 0
	UINFO(9, "  opmoddiv-zero "<<lhs<<" "<<rhs<<" now="<<*this<<endl);
	return *this;
    }

    int uw = VL_WORDS_I(umsbp1);  // aka "m" in the algorithm
    int vw = VL_WORDS_I(vmsbp1);  // aka "n" in the algorithm

    if (vw == 1) {  // Single divisor word breaks rest of algorithm
	vluint64_t k = 0;
	for (int j = uw-1; j >= 0; j--) {
	    vluint64_t unw64 = ((k<<VL_ULL(32)) + (vluint64_t)(lhs.m_value[j]));
	    m_value[j] = unw64 / (vluint64_t)(rhs.m_value[0]);
	    k          = unw64 - (vluint64_t)(m_value[j])*(vluint64_t)(rhs.m_value[0]);
	}
	UINFO(9, "  opmoddiv-1w  "<<lhs<<" "<<rhs<<" q="<<*this<<" rem=0x"<<hex<<k<<dec<<endl);
	if (is_modulus) { setZero(); m_value[0] = k; }
	return *this;
    }

    // +1 word as we may shift during normalization
    uint32_t un[VL_MULS_MAX_WORDS+1]; // Fixed size, as MSVC++ doesn't allow [words] here
    uint32_t vn[VL_MULS_MAX_WORDS+1]; // v normalized

    // Zero for ease of debugging and to save having to zero for shifts
    for (int i=0; i<words; i++) { m_value[i]=0; }
    for (int i=0; i<words+1; i++) { un[i]=vn[i]=0; }  // +1 as vn may get extra word

    // Algorithm requires divisor MSB to be set
    // Copy and shift to normalize divisor so MSB of vn[vw-1] is set
    int s = 31-VL_BITBIT_I(vmsbp1-1);  // shift amount (0...31)
    uint32_t shift_mask = s ? 0xffffffff : 0;  // otherwise >> 32 won't mask the value
    for (int i = vw-1; i>0; i--) {
	vn[i] = (rhs.m_value[i] << s) | (shift_mask & (rhs.m_value[i-1] >> (32-s)));
    }
    vn[0] = rhs.m_value[0] << s;

    // Copy and shift dividend by same amount; may set new upper word
    if (s) un[uw] = lhs.m_value[uw-1] >> (32-s);
    else   un[uw] = 0;
    for (int i=uw-1; i>0; i--) {
	un[i] = (lhs.m_value[i] << s) | (shift_mask & (lhs.m_value[i-1] >> (32-s)));
    }
    un[0] = lhs.m_value[0] << s;

    //printf("  un="); for(int i=5; i>=0; i--) printf(" %08x",un[i]); printf("\n");
    //printf("  vn="); for(int i=5; i>=0; i--) printf(" %08x",vn[i]); printf("\n");
    //printf("  mv="); for(int i=5; i>=0; i--) printf(" %08x",m_value[i]); printf("\n");

    // Main loop
    for (int j = uw - vw; j >= 0; j--) {
	// Estimate
	vluint64_t unw64 = ((vluint64_t)(un[j+vw])<<VL_ULL(32) | (vluint64_t)(un[j+vw-1]));
	vluint64_t qhat = unw64 / (vluint64_t)(vn[vw-1]);
	vluint64_t rhat = unw64 - qhat*(vluint64_t)(vn[vw-1]);

      again:
	if (qhat >= VL_ULL(0x100000000)
	    || ((qhat*vn[vw-2]) > ((rhat<<VL_ULL(32)) + un[j+vw-2]))) {
	    qhat = qhat - 1;
	    rhat = rhat + vn[vw-1];
	    if (rhat < VL_ULL(0x100000000)) goto again;
	}

	vlsint64_t t = 0;  // Must be signed
	vluint64_t k = 0;
	for (int i=0; i<vw; i++) {
	    vluint64_t p = qhat*vn[i];  // Multiply by estimate
	    t = un[i+j] - k - (p & VL_ULL(0xFFFFFFFF));  // Subtract
	    un[i+j] = t;
	    k = (p >> VL_ULL(32)) - (t >> VL_ULL(32));
	}
	t = un[j+vw] - k;
	un[j+vw] = t;
	this->m_value[j] = qhat; // Save quotient digit

	if (t < 0) {
	    // Over subtracted; correct by adding back
	    this->m_value[j]--;
	    k = 0;
	    for (int i=0; i<vw; i++) {
		t = (vluint64_t)(un[i+j]) + (vluint64_t)(vn[i]) + k;
		un[i+j] = t;
		k = t >> VL_ULL(32);
	    }
	    un[j+vw] = un[j+vw] + k;
	}
    }

    //printf("  un="); for(int i=5; i>=0; i--) printf(" %08x",un[i]); printf("\n");
    //printf("  vn="); for(int i=5; i>=0; i--) printf(" %08x",vn[i]); printf("\n");
    //printf("  mv="); for(int i=5; i>=0; i--) printf(" %08x",m_value[i]); printf("\n");

    if (is_modulus) { // modulus
	// Need to reverse normalization on copy to output
	for (int i=0; i<vw; i++) {
	    m_value[i] = (un[i] >> s) | (shift_mask & (un[i+1] << (32-s)));
	}
	for (int i=vw; i<words; i++) m_value[i] = 0;
	UINFO(9, "  opmoddiv-mod "<<lhs<<" "<<rhs<<" now="<<*this<<endl);
	return *this;
    } else { // division
	UINFO(9, "  opmoddiv-div "<<lhs<<" "<<rhs<<" now="<<*this<<endl);
	return *this;
    }
}

V3Number& V3Number::opPow (const V3Number& lhs, const V3Number& rhs) {
    // L(i) bit return, if any 4-state, 4-state return
    if (lhs.isFourState() || rhs.isFourState()) return setAllBitsX();
    if (lhs.isEqZero()) return setZero();
    // We may want to special case when the lhs is 2, so we can get larger outputs
    if (lhs.width()>64) m_fileline->v3fatalSrc("Unsupported: Large >64bit ** math not implemented yet: "<<*this);
    if (rhs.width()>64) m_fileline->v3fatalSrc("Unsupported: Large >64bit ** math not implemented yet: "<<*this);
    setZero();
    m_value[0] = 1;
    V3Number power (lhs.m_fileline, width());  power.opAssign(lhs);
    for (int bit=0; bit<rhs.width(); bit++) {
	if (bit>0) {  // power = power*power
	    V3Number lastPower (lhs.m_fileline, width());  lastPower.opAssign(power);
	    power.opMul(lastPower, lastPower);
	}
	if (rhs.bitIs1(bit)) {  // out *= power
	    V3Number lastOut (lhs.m_fileline, width()); lastOut.opAssign(*this);
	    this->opMul(lastOut, power);
	    //UINFO(0, "pow "<<lhs<<" "<<rhs<<" b"<<bit<<" pow="<<power<<" now="<<*this<<endl);
	}
    }
    return *this;
}
V3Number& V3Number::opPowS (const V3Number& lhs, const V3Number& rhs) {
    // Signed multiply
    if (lhs.isFourState() || rhs.isFourState()) return setAllBitsX();
    if (lhs.isEqZero() && rhs.isNegative()) return setAllBitsX();  // Per spec
    if (!lhs.isNegative() && !rhs.isNegative()) return opPow(lhs,rhs);
    //if (lhs.isNegative() || rhs.isNonIntegral()) return setAllBitsX();  // Illegal pow() call
    m_fileline->v3fatalSrc("Unsupported: Power (**) operator with negative numbers: "<<*this);
    return setAllBitsX();
}

V3Number& V3Number::opBufIf1  (const V3Number& ens, const V3Number& if1s) {
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
	if (ens.bitIs1(bit))  { setBit(bit, if1s.bitIs(bit)); }
	else setBit(bit,'z');
    }
    return *this;
}

V3Number& V3Number::opAssign (const V3Number& lhs) {
    // Note may be a width change during the assign
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
	setBit(bit,lhs.bitIs(bit));
    }
    return *this;
}

V3Number& V3Number::opExtendS (const V3Number& lhs) {
    // Note may be a width change during the sign extension
    setZero();
    for(int bit=0; bit<this->width(); bit++) {
	setBit(bit,lhs.bitIsExtend(bit));
    }
    return *this;
}

V3Number& V3Number::opClean (const V3Number& lhs, uint32_t bits) {
    return opSel(lhs, bits-1, 0);
}

void V3Number::opCleanThis() {
    // Clean in place number
    if (uint32_t okbits = (width() & 31)) {
	m_value[words()-1] &= ((1UL<<okbits)-1);
    }
}

V3Number& V3Number::opSel (const V3Number& lhs, const V3Number& msb, const V3Number& lsb) {
    if (lsb.isFourState() || msb.isFourState()) return setAllBitsX();
    return opSel(lhs, msb.toUInt(), lsb.toUInt());
}

V3Number& V3Number::opSel (const V3Number& lhs, uint32_t msbval, uint32_t lsbval) {
    setZero();
    int ibit=lsbval;
    for(int bit=0; bit<this->width(); bit++) {
	if (ibit>=0 && ibit<lhs.width()
	    && ibit<=(int)msbval) {
	    setBit(bit,lhs.bitIs(ibit));
	} else {
	    setBit(bit,'x');
	}
	ibit++;
    }
    //UINFO(0,"RANGE "<<lhs<<" "<<msb<<" "<<lsb<<" = "<<*this<<endl);
    return *this;
}

V3Number& V3Number::opCond  (const V3Number& lhs, const V3Number& if1s, const V3Number& if0s) {
    V3Number lhstrue (lhs.m_fileline);  lhstrue.opRedOr(lhs);
    if (lhstrue.bitIs0(0)) {
	this->opAssign(if0s);
    }
    else if (lhstrue.bitIs1(0)) {
	this->opAssign(if1s);
    }
    else { // select is "X/Z"
	setZero();
	for(int bit=0; bit<this->width(); bit++) {
	    if (if0s.bitIs1(bit) && if1s.bitIs1(bit))  { setBit(bit,1); }
	    else if (if0s.bitIs0(bit) && if1s.bitIs0(bit))  { setBit(bit,0); }
	    else setBit(bit,'x');
	}
    }
    return *this;
}

//======================================================================
// Ops - Floating point

V3Number& V3Number::opIToRD (const V3Number& lhs) {
    return setDouble(lhs.toSInt());
}
V3Number& V3Number::opRToIS (const V3Number& lhs) {
    double v = VL_TRUNC(lhs.toDouble());
    vlsint32_t i = (vlsint32_t)v; // C converts from double to vlsint32
    return setLongS(i);
}
V3Number& V3Number::opRToIRoundS (const V3Number& lhs) {
    double v = VL_ROUND(lhs.toDouble());
    vlsint32_t i = (vlsint32_t)v; // C converts from double to vlsint32
    return setLongS(i);
}
V3Number& V3Number::opRealToBits (const V3Number& lhs) {
    // Conveniently our internal format is identical so we can copy bits...
    if (lhs.width()!=64 || this->width()!=64) {
	m_fileline->v3fatalSrc("Real operation on wrong sized number");
    }
    return opAssign(lhs);
}
V3Number& V3Number::opBitsToRealD (const V3Number& lhs) {
    // Conveniently our internal format is identical so we can copy bits...
    if (lhs.width()!=64 || this->width()!=64) {
	m_fileline->v3fatalSrc("Real operation on wrong sized number");
    }
    return opAssign(lhs);
}
V3Number& V3Number::opNegateD (const V3Number& lhs) {
    return setDouble(- lhs.toDouble());
}
V3Number& V3Number::opAddD (const V3Number& lhs, const V3Number& rhs) {
    return setDouble(lhs.toDouble() + rhs.toDouble());
}
V3Number& V3Number::opSubD (const V3Number& lhs, const V3Number& rhs) {
    return setDouble(lhs.toDouble() - rhs.toDouble());
}
V3Number& V3Number::opMulD (const V3Number& lhs, const V3Number& rhs) {
    return setDouble(lhs.toDouble() * rhs.toDouble());
}
V3Number& V3Number::opDivD (const V3Number& lhs, const V3Number& rhs) {
    // On exceptions, we just generate 'inf' through floating point
    // IEEE says it's implementation defined what happens
    return setDouble(lhs.toDouble() / rhs.toDouble());
}
V3Number& V3Number::opPowD (const V3Number& lhs, const V3Number& rhs) {
    // On exceptions, we just generate 'inf' through floating point
    // IEEE says it's implementation defined what happens
    return setDouble(pow(lhs.toDouble(), rhs.toDouble()));
}
V3Number& V3Number::opEqD (const V3Number& lhs, const V3Number& rhs) {
    return setSingleBits(lhs.toDouble() == rhs.toDouble());
}
V3Number& V3Number::opNeqD (const V3Number& lhs, const V3Number& rhs) {
    return setSingleBits(lhs.toDouble() != rhs.toDouble());
}
V3Number& V3Number::opGtD (const V3Number& lhs, const V3Number& rhs) {
    return setSingleBits(lhs.toDouble() > rhs.toDouble());
}
V3Number& V3Number::opGteD (const V3Number& lhs, const V3Number& rhs) {
    return setSingleBits(lhs.toDouble() >= rhs.toDouble());
}
V3Number& V3Number::opLtD (const V3Number& lhs, const V3Number& rhs) {
    return setSingleBits(lhs.toDouble() < rhs.toDouble());
}
V3Number& V3Number::opLteD (const V3Number& lhs, const V3Number& rhs) {
    return setSingleBits(lhs.toDouble() <= rhs.toDouble());
}