/* * Copyright (C) 2010-2016 JPEXS, All rights reserved. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 3.0 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library. * * ----------------- Original copyright -------------------------- * * Copyright 1996-2004 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Sun designates this * particular file as subject to the "Classpath" exception as provided * by Sun in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. */ package com.jpexs.decompiler.flash.ecma; import java.util.regex.Pattern; public class EcmaFloatingDecimal { boolean isExceptional; boolean isNegative; int decExponent; char digits[]; int nDigits; int bigIntExp; int bigIntNBits; boolean mustSetRoundDir = false; boolean fromHex = false; int roundDir = 0; // set by doubleValue private EcmaFloatingDecimal(boolean negSign, int decExponent, char[] digits, int n, boolean e) { isNegative = negSign; isExceptional = e; this.decExponent = decExponent; this.digits = digits; this.nDigits = n; } /* * Constants of the implementation * Most are IEEE-754 related. * (There are more really boring constants at the end.) */ static final long signMask = 0x8000000000000000L; static final long expMask = 0x7ff0000000000000L; static final long fractMask = ~(signMask | expMask); static final int expShift = 52; static final int expBias = 1023; static final long fractHOB = (1L << expShift); // assumed High-Order bit static final long expOne = ((long) expBias) << expShift; // exponent of 1.0 static final int maxSmallBinExp = 62; static final int minSmallBinExp = -(63 / 3); static final int maxDecimalDigits = 15; static final int maxDecimalExponent = 308; static final int minDecimalExponent = -324; static final int bigDecimalExponent = 324; // i.e. abs(minDecimalExponent) static final long highbyte = 0xff00000000000000L; static final long highbit = 0x8000000000000000L; static final long lowbytes = ~highbyte; static final int singleSignMask = 0x80000000; static final int singleExpMask = 0x7f800000; static final int singleFractMask = ~(singleSignMask | singleExpMask); static final int singleExpShift = 23; static final int singleFractHOB = 1 << singleExpShift; static final int singleExpBias = 127; static final int singleMaxDecimalDigits = 7; static final int singleMaxDecimalExponent = 38; static final int singleMinDecimalExponent = -45; static final int intDecimalDigits = 9; /* * count number of bits from high-order 1 bit to low-order 1 bit, * inclusive. */ private static int countBits(long v) { // // the strategy is to shift until we get a non-zero sign bit // then shift until we have no bits left, counting the difference. // we do byte shifting as a hack. Hope it helps. // if (v == 0L) { return 0; } while ((v & highbyte) == 0L) { v <<= 8; } while (v > 0L) { // i.e. while ((v&highbit) == 0L ) v <<= 1; } int n = 0; while ((v & lowbytes) != 0L) { v <<= 8; n += 8; } while (v != 0L) { v <<= 1; n += 1; } return n; } /* * Keep big powers of 5 handy for future reference. */ private static FDBigInt b5p[]; private static synchronized FDBigInt big5pow(int p) { assert p >= 0 : p; // negative power of 5 if (b5p == null) { b5p = new FDBigInt[p + 1]; } else if (b5p.length <= p) { FDBigInt t[] = new FDBigInt[p + 1]; System.arraycopy(b5p, 0, t, 0, b5p.length); b5p = t; } if (b5p[p] != null) { return b5p[p]; } else if (p < small5pow.length) { return b5p[p] = new FDBigInt(small5pow[p]); } else if (p < long5pow.length) { return b5p[p] = new FDBigInt(long5pow[p]); } else { // construct the value. // recursively. int q, r; // in order to compute 5^p, // compute its square root, 5^(p/2) and square. // or, let q = p / 2, r = p -q, then // 5^p = 5^(q+r) = 5^q * 5^r q = p >> 1; r = p - q; FDBigInt bigq = b5p[q]; if (bigq == null) { bigq = big5pow(q); } if (r < small5pow.length) { return (b5p[p] = bigq.mult(small5pow[r])); } else { FDBigInt bigr = b5p[r]; if (bigr == null) { bigr = big5pow(r); } return (b5p[p] = bigq.mult(bigr)); } } } // // a common operation // private static FDBigInt multPow52(FDBigInt v, int p5, int p2) { if (p5 != 0) { if (p5 < small5pow.length) { v = v.mult(small5pow[p5]); } else { v = v.mult(big5pow(p5)); } } if (p2 != 0) { v.lshiftMe(p2); } return v; } // // another common operation // private static FDBigInt constructPow52(int p5, int p2) { FDBigInt v = new FDBigInt(big5pow(p5)); if (p2 != 0) { v.lshiftMe(p2); } return v; } /* * Make a floating double into a FDBigInt. * This could also be structured as a FDBigInt * constructor, but we'd have to build a lot of knowledge * about floating-point representation into it, and we don't want to. * * AS A SIDE EFFECT, THIS METHOD WILL SET THE INSTANCE VARIABLES * bigIntExp and bigIntNBits * */ private FDBigInt doubleToBigInt(double dval) { long lbits = Double.doubleToLongBits(dval) & ~signMask; int binexp = (int) (lbits >>> expShift); lbits &= fractMask; if (binexp > 0) { lbits |= fractHOB; } else { assert lbits != 0L : lbits; // doubleToBigInt(0.0) binexp += 1; while ((lbits & fractHOB) == 0L) { lbits <<= 1; binexp -= 1; } } binexp -= expBias; int nbits = countBits(lbits); /* * We now know where the high-order 1 bit is, * and we know how many there are. */ int lowOrderZeros = expShift + 1 - nbits; lbits >>>= lowOrderZeros; bigIntExp = binexp + 1 - nbits; bigIntNBits = nbits; return new FDBigInt(lbits); } /* * Compute a number that is the ULP of the given value, * for purposes of addition/subtraction. Generally easy. * More difficult if subtracting and the argument * is a normalized a power of 2, as the ULP changes at these points. */ private static double ulp(double dval, boolean subtracting) { long lbits = Double.doubleToLongBits(dval) & ~signMask; int binexp = (int) (lbits >>> expShift); double ulpval; if (subtracting && (binexp >= expShift) && ((lbits & fractMask) == 0L)) { // for subtraction from normalized, powers of 2, // use next-smaller exponent binexp -= 1; } if (binexp > expShift) { ulpval = Double.longBitsToDouble(((long) (binexp - expShift)) << expShift); } else if (binexp == 0) { ulpval = Double.MIN_VALUE; } else { ulpval = Double.longBitsToDouble(1L << (binexp - 1)); } if (subtracting) { ulpval = -ulpval; } return ulpval; } /* * Round a double to a float. * In addition to the fraction bits of the double, * look at the class instance variable roundDir, * which should help us avoid double-rounding error. * roundDir was set in hardValueOf if the estimate was * close enough, but not exact. It tells us which direction * of rounding is preferred. */ float stickyRound(double dval) { long lbits = Double.doubleToLongBits(dval); long binexp = lbits & expMask; if (binexp == 0L || binexp == expMask) { // what we have here is special. // don't worry, the right thing will happen. return (float) dval; } lbits += (long) roundDir; // hack-o-matic. return (float) Double.longBitsToDouble(lbits); } /* * This is the easy subcase -- * all the significant bits, after scaling, are held in lvalue. * negSign and decExponent tell us what processing and scaling * has already been done. Exceptional cases have already been * stripped out. * In particular: * lvalue is a finite number (not Inf, nor NaN) * lvalue > 0L (not zero, nor negative). * * The only reason that we develop the digits here, rather than * calling on Long.toString() is that we can do it a little faster, * and besides want to treat trailing 0s specially. If Long.toString * changes, we should re-evaluate this strategy! */ private void developLongDigits(int decExponent, long lvalue, long insignificant) { char digits[]; int ndigits; int digitno; int c; // // Discard non-significant low-order bits, while rounding, // up to insignificant value. int i; for (i = 0; insignificant >= 10L; i++) { insignificant /= 10L; } if (i != 0) { long pow10 = long5pow[i] << i; // 10^i == 5^i * 2^i; long residue = lvalue % pow10; lvalue /= pow10; decExponent += i; if (residue >= (pow10 >> 1)) { // round up based on the low-order bits we're discarding lvalue++; } } if (lvalue <= Integer.MAX_VALUE) { assert lvalue > 0L : lvalue; // lvalue <= 0 // even easier subcase! // can do int arithmetic rather than long! int ivalue = (int) lvalue; ndigits = 10; digits = (char[]) (perThreadBuffer.get()); digitno = ndigits - 1; c = ivalue % 10; ivalue /= 10; while (c == 0) { decExponent++; c = ivalue % 10; ivalue /= 10; } while (ivalue != 0) { digits[digitno--] = (char) (c + '0'); decExponent++; c = ivalue % 10; ivalue /= 10; } digits[digitno] = (char) (c + '0'); } else { // same algorithm as above (same bugs, too ) // but using long arithmetic. ndigits = 20; digits = (char[]) (perThreadBuffer.get()); digitno = ndigits - 1; c = (int) (lvalue % 10L); lvalue /= 10L; while (c == 0) { decExponent++; c = (int) (lvalue % 10L); lvalue /= 10L; } while (lvalue != 0L) { digits[digitno--] = (char) (c + '0'); decExponent++; c = (int) (lvalue % 10L); lvalue /= 10; } digits[digitno] = (char) (c + '0'); } char result[]; ndigits -= digitno; result = new char[ndigits]; System.arraycopy(digits, digitno, result, 0, ndigits); this.digits = result; this.decExponent = decExponent + 1; this.nDigits = ndigits; } // // add one to the least significant digit. // in the unlikely event there is a carry out, // deal with it. // assert that this will only happen where there // is only one digit, e.g. (float)1e-44 seems to do it. // private void roundup() { int i; int q = digits[i = (nDigits - 1)]; if (q == '9') { while (q == '9' && i > 0) { digits[i] = '0'; q = digits[--i]; } if (q == '9') { // carryout! High-order 1, rest 0s, larger exp. decExponent += 1; digits[0] = '1'; return; } // else fall through. } digits[i] = (char) (q + 1); } /* * FIRST IMPORTANT CONSTRUCTOR: DOUBLE */ public EcmaFloatingDecimal(double d, boolean maxPrecision) { long dBits = Double.doubleToLongBits(d); long fractBits; int binExp; int nSignificantBits; // discover and delete sign if ((dBits & signMask) != 0) { isNegative = true; dBits ^= signMask; } else { isNegative = false; } // Begin to unpack // Discover obvious special cases of NaN and Infinity. binExp = (int) ((dBits & expMask) >> expShift); fractBits = dBits & fractMask; if (binExp == (int) (expMask >> expShift)) { isExceptional = true; if (fractBits == 0L) { digits = infinity; } else { digits = notANumber; isNegative = false; // NaN has no sign! } nDigits = digits.length; return; } isExceptional = false; // Finish unpacking // Normalize denormalized numbers. // Insert assumed high-order bit for normalized numbers. // Subtract exponent bias. if (binExp == 0) { if (fractBits == 0L) { // not a denorm, just a 0! decExponent = 0; digits = zero; nDigits = 1; return; } while ((fractBits & fractHOB) == 0L) { fractBits <<= 1; binExp -= 1; } nSignificantBits = expShift + binExp + 1; // recall binExp is - shift count. binExp += 1; } else { fractBits |= fractHOB; nSignificantBits = expShift + 1; } binExp -= expBias; // call the routine that actually does all the hard work. dtoa(binExp, fractBits, nSignificantBits); if (!maxPrecision) { if (nDigits > 15) { nDigits = 15; if (digits[15] >= '5') { roundup(); } while (nDigits > 0 && digits[nDigits - 1] == '0') { nDigits--; } } } } /* * SECOND IMPORTANT CONSTRUCTOR: SINGLE */ public EcmaFloatingDecimal(float f) { int fBits = Float.floatToIntBits(f); int fractBits; int binExp; int nSignificantBits; // discover and delete sign if ((fBits & singleSignMask) != 0) { isNegative = true; fBits ^= singleSignMask; } else { isNegative = false; } // Begin to unpack // Discover obvious special cases of NaN and Infinity. binExp = (int) ((fBits & singleExpMask) >> singleExpShift); fractBits = fBits & singleFractMask; if (binExp == (int) (singleExpMask >> singleExpShift)) { isExceptional = true; if (fractBits == 0L) { digits = infinity; } else { digits = notANumber; isNegative = false; // NaN has no sign! } nDigits = digits.length; return; } isExceptional = false; // Finish unpacking // Normalize denormalized numbers. // Insert assumed high-order bit for normalized numbers. // Subtract exponent bias. if (binExp == 0) { if (fractBits == 0) { // not a denorm, just a 0! decExponent = 0; digits = zero; nDigits = 1; return; } while ((fractBits & singleFractHOB) == 0) { fractBits <<= 1; binExp -= 1; } nSignificantBits = singleExpShift + binExp + 1; // recall binExp is - shift count. binExp += 1; } else { fractBits |= singleFractHOB; nSignificantBits = singleExpShift + 1; } binExp -= singleExpBias; // call the routine that actually does all the hard work. dtoa(binExp, ((long) fractBits) << (expShift - singleExpShift), nSignificantBits); } private void dtoa(int binExp, long fractBits, int nSignificantBits) { int nFractBits; // number of significant bits of fractBits; int nTinyBits; // number of these to the right of the point. int decExp; // Examine number. Determine if it is an easy case, // which we can do pretty trivially using float/long conversion, // or whether we must do real work. nFractBits = countBits(fractBits); nTinyBits = Math.max(0, nFractBits - binExp - 1); if (binExp <= maxSmallBinExp && binExp >= minSmallBinExp) { // Look more closely at the number to decide if, // with scaling by 10^nTinyBits, the result will fit in // a long. if ((nTinyBits < long5pow.length) && ((nFractBits + n5bits[nTinyBits]) < 64)) { /* * We can do this: * take the fraction bits, which are normalized. * (a) nTinyBits == 0: Shift left or right appropriately * to align the binary point at the extreme right, i.e. * where a long int point is expected to be. The integer * result is easily converted to a string. * (b) nTinyBits > 0: Shift right by expShift-nFractBits, * which effectively converts to long and scales by * 2^nTinyBits. Then multiply by 5^nTinyBits to * complete the scaling. We know this won't overflow * because we just counted the number of bits necessary * in the result. The integer you get from this can * then be converted to a string pretty easily. */ long halfULP; if (nTinyBits == 0) { if (binExp > nSignificantBits) { halfULP = 1L << (binExp - nSignificantBits - 1); } else { halfULP = 0L; } if (binExp >= expShift) { fractBits <<= (binExp - expShift); } else { fractBits >>>= (expShift - binExp); } developLongDigits(0, fractBits, halfULP); return; } /* * The following causes excess digits to be printed * out in the single-float case. Our manipulation of * halfULP here is apparently not correct. If we * better understand how this works, perhaps we can * use this special case again. But for the time being, * we do not. * else { * fractBits >>>= expShift+1-nFractBits; * fractBits *= long5pow[ nTinyBits ]; * halfULP = long5pow[ nTinyBits ] >> (1+nSignificantBits-nFractBits); * developLongDigits( -nTinyBits, fractBits, halfULP ); * return; * } */ } } /* * This is the hard case. We are going to compute large positive * integers B and S and integer decExp, s.t. * d = ( B / S ) * 10^decExp * 1 <= B / S < 10 * Obvious choices are: * decExp = floor( log10(d) ) * B = d * 2^nTinyBits * 10^max( 0, -decExp ) * S = 10^max( 0, decExp) * 2^nTinyBits * (noting that nTinyBits has already been forced to non-negative) * I am also going to compute a large positive integer * M = (1/2^nSignificantBits) * 2^nTinyBits * 10^max( 0, -decExp ) * i.e. M is (1/2) of the ULP of d, scaled like B. * When we iterate through dividing B/S and picking off the * quotient bits, we will know when to stop when the remainder * is <= M. * * We keep track of powers of 2 and powers of 5. */ /* * Estimate decimal exponent. (If it is small-ish, * we could double-check.) * * First, scale the mantissa bits such that 1 <= d2 < 2. * We are then going to estimate * log10(d2) ~=~ (d2-1.5)/1.5 + log(1.5) * and so we can estimate * log10(d) ~=~ log10(d2) + binExp * log10(2) * take the floor and call it decExp. * FIXME -- use more precise constants here. It costs no more. */ double d2 = Double.longBitsToDouble( expOne | (fractBits & ~fractHOB)); decExp = (int) Math.floor( (d2 - 1.5D) * 0.289529654D + 0.176091259 + (double) binExp * 0.301029995663981); int B2, B5; // powers of 2 and powers of 5, respectively, in B int S2, S5; // powers of 2 and powers of 5, respectively, in S int M2, M5; // powers of 2 and powers of 5, respectively, in M int Bbits; // binary digits needed to represent B, approx. int tenSbits; // binary digits needed to represent 10*S, approx. FDBigInt Sval, Bval, Mval; B5 = Math.max(0, -decExp); B2 = B5 + nTinyBits + binExp; S5 = Math.max(0, decExp); S2 = S5 + nTinyBits; M5 = B5; M2 = B2 - nSignificantBits; /* * the long integer fractBits contains the (nFractBits) interesting * bits from the mantissa of d ( hidden 1 added if necessary) followed * by (expShift+1-nFractBits) zeros. In the interest of compactness, * I will shift out those zeros before turning fractBits into a * FDBigInt. The resulting whole number will be * d * 2^(nFractBits-1-binExp). */ fractBits >>>= (expShift + 1 - nFractBits); B2 -= nFractBits - 1; int common2factor = Math.min(B2, S2); B2 -= common2factor; S2 -= common2factor; M2 -= common2factor; /* * HACK!! For exact powers of two, the next smallest number * is only half as far away as we think (because the meaning of * ULP changes at power-of-two bounds) for this reason, we * hack M2. Hope this works. */ if (nFractBits == 1) { M2 -= 1; } if (M2 < 0) { // oops. // since we cannot scale M down far enough, // we must scale the other values up. B2 -= M2; S2 -= M2; M2 = 0; } /* * Construct, Scale, iterate. * Some day, we'll write a stopping test that takes * account of the asymmetry of the spacing of floating-point * numbers below perfect powers of 2 * 26 Sept 96 is not that day. * So we use a symmetric test. */ char digits[] = this.digits = new char[18]; int ndigit = 0; boolean low, high; long lowDigitDifference; int q; /* * Detect the special cases where all the numbers we are about * to compute will fit in int or long integers. * In these cases, we will avoid doing FDBigInt arithmetic. * We use the same algorithms, except that we "normalize" * our FDBigInts before iterating. This is to make division easier, * as it makes our fist guess (quotient of high-order words) * more accurate! * * Some day, we'll write a stopping test that takes * account of the asymmetry of the spacing of floating-point * numbers below perfect powers of 2 * 26 Sept 96 is not that day. * So we use a symmetric test. */ Bbits = nFractBits + B2 + ((B5 < n5bits.length) ? n5bits[B5] : (B5 * 3)); tenSbits = S2 + 1 + (((S5 + 1) < n5bits.length) ? n5bits[(S5 + 1)] : ((S5 + 1) * 3)); if (Bbits < 64 && tenSbits < 64) { if (Bbits < 32 && tenSbits < 32) { // wa-hoo! They're all ints! int b = ((int) fractBits * small5pow[B5]) << B2; int s = small5pow[S5] << S2; int m = small5pow[M5] << M2; int tens = s * 10; /* * Unroll the first iteration. If our decExp estimate * was too high, our first quotient will be zero. In this * case, we discard it and decrement decExp. */ ndigit = 0; q = b / s; b = 10 * (b % s); m *= 10; low = (b < m); high = (b + m > tens); assert q < 10 : q; // excessively large digit if ((q == 0) && !high) { // oops. Usually ignore leading zero. decExp--; } else { digits[ndigit++] = (char) ('0' + q); } /* * HACK! Java spec sez that we always have at least * one digit after the . in either F- or E-form output. * Thus we will need more than one digit if we're using * E-form */ if (decExp <= -6 || decExp >= 8) { high = low = false; } while (!low && !high) { q = b / s; b = 10 * (b % s); m *= 10; assert q < 10 : q; // excessively large digit if (m > 0L) { low = (b < m); high = (b + m > tens); } else { // hack -- m might overflow! // in this case, it is certainly > b, // which won't // and b+m > tens, too, since that has overflowed // either! low = true; high = true; } digits[ndigit++] = (char) ('0' + q); } lowDigitDifference = (b << 1) - tens; } else { // still good! they're all longs! long b = (fractBits * long5pow[B5]) << B2; long s = long5pow[S5] << S2; long m = long5pow[M5] << M2; long tens = s * 10L; /* * Unroll the first iteration. If our decExp estimate * was too high, our first quotient will be zero. In this * case, we discard it and decrement decExp. */ ndigit = 0; q = (int) (b / s); b = 10L * (b % s); m *= 10L; low = (b < m); high = (b + m > tens); assert q < 10 : q; // excessively large digit if ((q == 0) && !high) { // oops. Usually ignore leading zero. decExp--; } else { digits[ndigit++] = (char) ('0' + q); } /* * HACK! Java spec sez that we always have at least * one digit after the . in either F- or E-form output. * Thus we will need more than one digit if we're using * E-form */ if (decExp <= -6 || decExp >= 8) { high = low = false; } while (!low && !high) { q = (int) (b / s); b = 10 * (b % s); m *= 10; assert q < 10 : q; // excessively large digit if (m > 0L) { low = (b < m); high = (b + m > tens); } else { // hack -- m might overflow! // in this case, it is certainly > b, // which won't // and b+m > tens, too, since that has overflowed // either! low = true; high = true; } digits[ndigit++] = (char) ('0' + q); } lowDigitDifference = (b << 1) - tens; } } else { FDBigInt tenSval; int shiftBias; /* * We really must do FDBigInt arithmetic. * Fist, construct our FDBigInt initial values. */ Bval = multPow52(new FDBigInt(fractBits), B5, B2); Sval = constructPow52(S5, S2); Mval = constructPow52(M5, M2); // normalize so that division works better Bval.lshiftMe(shiftBias = Sval.normalizeMe()); Mval.lshiftMe(shiftBias); tenSval = Sval.mult(10); /* * Unroll the first iteration. If our decExp estimate * was too high, our first quotient will be zero. In this * case, we discard it and decrement decExp. */ ndigit = 0; q = Bval.quoRemIteration(Sval); Mval = Mval.mult(10); low = (Bval.cmp(Mval) < 0); high = (Bval.add(Mval).cmp(tenSval) > 0); assert q < 10 : q; // excessively large digit if ((q == 0) && !high) { // oops. Usually ignore leading zero. decExp--; } else { digits[ndigit++] = (char) ('0' + q); } /* * HACK! Java spec sez that we always have at least * one digit after the . in either F- or E-form output. * Thus we will need more than one digit if we're using * E-form */ if (decExp <= -6 || decExp >= 8) { high = low = false; } while (!low && !high) { q = Bval.quoRemIteration(Sval); Mval = Mval.mult(10); assert q < 10 : q; // excessively large digit low = (Bval.cmp(Mval) < 0); high = (Bval.add(Mval).cmp(tenSval) > 0); digits[ndigit++] = (char) ('0' + q); } if (high && low) { Bval.lshiftMe(1); lowDigitDifference = Bval.cmp(tenSval); } else { lowDigitDifference = 0L; // this here only for flow analysis! } } this.decExponent = decExp + 1; this.digits = digits; this.nDigits = ndigit; /* * Last digit gets rounded based on stopping condition. */ if (high) { if (low) { if (lowDigitDifference == 0L) { // it's a tie! // choose based on which digits we like. if ((digits[nDigits - 1] & 1) != 0) { roundup(); } } else if (lowDigitDifference > 0) { roundup(); } } else { roundup(); } } } @Override public String toString() { // most brain-dead version StringBuffer result = new StringBuffer(nDigits + 8); if (isNegative) { result.append('-'); } if (isExceptional) { result.append(digits, 0, nDigits); } else { result.append("0."); result.append(digits, 0, nDigits); result.append('e'); result.append(decExponent); } return new String(result); } public String toJavaFormatString() { char result[] = (char[]) (perThreadBuffer.get()); int i = getChars(result); return new String(result, 0, i); } private int getChars(char[] result) { assert nDigits <= 19 : nDigits; // generous bound on size of nDigits int i = 0; if (isNegative && (decExponent != 0 || digits != zero)) { result[0] = '-'; i = 1; } if (isExceptional) { System.arraycopy(digits, 0, result, i, nDigits); i += nDigits; } else if (decExponent > 0 && decExponent < 22) { // print digits.digits. int charLength = Math.min(nDigits, decExponent); System.arraycopy(digits, 0, result, i, charLength); i += charLength; if (charLength < decExponent) { charLength = decExponent - charLength; System.arraycopy(zero, 0, result, i, charLength); i += charLength; } else if (charLength < nDigits) { result[i++] = '.'; int t = nDigits - charLength; System.arraycopy(digits, charLength, result, i, t); i += t; } } else if (decExponent <= 0 && decExponent > -5) { result[i++] = '0'; if (digits != zero) { result[i++] = '.'; if (decExponent != 0) { System.arraycopy(zero, 0, result, i, -decExponent); i -= decExponent; } System.arraycopy(digits, 0, result, i, nDigits); i += nDigits; } } else { result[i++] = digits[0]; result[i++] = '.'; if (nDigits > 1) { System.arraycopy(digits, 1, result, i, nDigits - 1); i += nDigits - 1; } else { result[i++] = '0'; } result[i++] = 'e'; int e; if (decExponent <= 0) { result[i++] = '-'; e = -decExponent + 1; } else { e = decExponent - 1; } // decExponent has 1, 2, or 3, digits if (e <= 9) { result[i++] = (char) (e + '0'); } else if (e <= 99) { result[i++] = (char) (e / 10 + '0'); result[i++] = (char) (e % 10 + '0'); } else { result[i++] = (char) (e / 100 + '0'); e %= 100; result[i++] = (char) (e / 10 + '0'); result[i++] = (char) (e % 10 + '0'); } } return i; } // Per-thread buffer for string/stringbuffer conversion private static ThreadLocal perThreadBuffer = new ThreadLocal() { @Override protected synchronized Object initialValue() { return new char[26]; } }; public void appendTo(Appendable buf) { char result[] = (char[]) (perThreadBuffer.get()); int i = getChars(result); if (buf instanceof StringBuilder) { ((StringBuilder) buf).append(result, 0, i); } else if (buf instanceof StringBuffer) { ((StringBuffer) buf).append(result, 0, i); } else { assert false; } } /* * All the positive powers of 10 that can be * represented exactly in double/float. */ private static final double small10pow[] = { 1.0e0, 1.0e1, 1.0e2, 1.0e3, 1.0e4, 1.0e5, 1.0e6, 1.0e7, 1.0e8, 1.0e9, 1.0e10, 1.0e11, 1.0e12, 1.0e13, 1.0e14, 1.0e15, 1.0e16, 1.0e17, 1.0e18, 1.0e19, 1.0e20, 1.0e21, 1.0e22 }; private static final float singleSmall10pow[] = { 1.0e0f, 1.0e1f, 1.0e2f, 1.0e3f, 1.0e4f, 1.0e5f, 1.0e6f, 1.0e7f, 1.0e8f, 1.0e9f, 1.0e10f }; private static final double big10pow[] = { 1e16, 1e32, 1e64, 1e128, 1e256}; private static final double tiny10pow[] = { 1e-16, 1e-32, 1e-64, 1e-128, 1e-256}; private static final int maxSmallTen = small10pow.length - 1; private static final int singleMaxSmallTen = singleSmall10pow.length - 1; private static final int small5pow[] = { 1, 5, 5 * 5, 5 * 5 * 5, 5 * 5 * 5 * 5, 5 * 5 * 5 * 5 * 5, 5 * 5 * 5 * 5 * 5 * 5, 5 * 5 * 5 * 5 * 5 * 5 * 5, 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 }; private static final long long5pow[] = { 1L, 5L, 5L * 5, 5L * 5 * 5, 5L * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5, 5L * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5,}; // approximately ceil( log2( long5pow[i] ) ) private static final int n5bits[] = { 0, 3, 5, 7, 10, 12, 14, 17, 19, 21, 24, 26, 28, 31, 33, 35, 38, 40, 42, 45, 47, 49, 52, 54, 56, 59, 61,}; private static final char infinity[] = {'I', 'n', 'f', 'i', 'n', 'i', 't', 'y'}; private static final char notANumber[] = {'N', 'a', 'N'}; private static final char zero[] = {'0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0', '0'}; /* * Grammar is compatible with hexadecimal floating-point constants * described in section 6.4.4.2 of the C99 specification. */ private static Pattern hexFloatPattern = Pattern.compile( //1 234 56 7 8 9 "([-+])?0[xX](((\\p{XDigit}+)\\.?)|((\\p{XDigit}*)\\.(\\p{XDigit}+)))[pP]([-+])?(\\p{Digit}+)[fFdD]?" ); /** * Return <code>s</code> with any leading zeros removed. */ static String stripLeadingZeros(String s) { return s.replaceFirst("^0+", ""); } /** * Extract a hexadecimal digit from position <code>position</code> of string * <code>s</code>. */ static int getHexDigit(String s, int position) { int value = Character.digit(s.charAt(position), 16); if (value <= -1 || value >= 16) { throw new AssertionError("Unexpected failure of digit conversion of " + s.charAt(position)); } return value; } } /* * A really, really simple bigint package * tailored to the needs of floating base conversion. */ class FDBigInt { int nWords; // number of words used int data[]; // value: data[0] is least significant public FDBigInt(int v) { nWords = 1; data = new int[1]; data[0] = v; } public FDBigInt(long v) { data = new int[2]; data[0] = (int) v; data[1] = (int) (v >>> 32); nWords = (data[1] == 0) ? 1 : 2; } public FDBigInt(FDBigInt other) { data = new int[nWords = other.nWords]; System.arraycopy(other.data, 0, data, 0, nWords); } private FDBigInt(int[] d, int n) { data = d; nWords = n; } public FDBigInt(long seed, char digit[], int nd0, int nd) { int n = (nd + 8) / 9; // estimate size needed. if (n < 2) { n = 2; } data = new int[n]; // allocate enough space data[0] = (int) seed; // starting value data[1] = (int) (seed >>> 32); nWords = (data[1] == 0) ? 1 : 2; int i = nd0; int limit = nd - 5; // slurp digits 5 at a time. int v; while (i < limit) { int ilim = i + 5; v = (int) digit[i++] - (int) '0'; while (i < ilim) { v = 10 * v + (int) digit[i++] - (int) '0'; } multaddMe(100000, v); // ... where 100000 is 10^5. } int factor = 1; v = 0; while (i < nd) { v = 10 * v + (int) digit[i++] - (int) '0'; factor *= 10; } if (factor != 1) { multaddMe(factor, v); } } /* * Left shift by c bits. * Shifts this in place. */ public void lshiftMe(int c) throws IllegalArgumentException { if (c <= 0) { if (c == 0) { return; // silly. } else { throw new IllegalArgumentException("negative shift count"); } } int wordcount = c >> 5; int bitcount = c & 0x1f; int anticount = 32 - bitcount; int t[] = data; int s[] = data; if (nWords + wordcount + 1 > t.length) { // reallocate. t = new int[nWords + wordcount + 1]; } int target = nWords + wordcount; int src = nWords - 1; if (bitcount == 0) { // special hack, since an anticount of 32 won't go! System.arraycopy(s, 0, t, wordcount, nWords); target = wordcount - 1; } else { t[target--] = s[src] >>> anticount; while (src >= 1) { t[target--] = (s[src] << bitcount) | (s[--src] >>> anticount); } t[target--] = s[src] << bitcount; } while (target >= 0) { t[target--] = 0; } data = t; nWords += wordcount + 1; // may have constructed high-order word of 0. // if so, trim it while (nWords > 1 && data[nWords - 1] == 0) { nWords--; } } /* * normalize this number by shifting until * the MSB of the number is at 0x08000000. * This is in preparation for quoRemIteration, below. * The idea is that, to make division easier, we want the * divisor to be "normalized" -- usually this means shifting * the MSB into the high words sign bit. But because we know that * the quotient will be 0 < q < 10, we would like to arrange that * the dividend not span up into another word of precision. * (This needs to be explained more clearly!) */ public int normalizeMe() throws IllegalArgumentException { int src; int wordcount = 0; int bitcount = 0; int v = 0; for (src = nWords - 1; src >= 0 && (v = data[src]) == 0; src--) { wordcount += 1; } if (src < 0) { // oops. Value is zero. Cannot normalize it! throw new IllegalArgumentException("zero value"); } /* * In most cases, we assume that wordcount is zero. This only * makes sense, as we try not to maintain any high-order * words full of zeros. In fact, if there are zeros, we will * simply SHORTEN our number at this point. Watch closely... */ nWords -= wordcount; /* * Compute how far left we have to shift v s.t. its highest- * order bit is in the right place. Then call lshiftMe to * do the work. */ if ((v & 0xf0000000) != 0) { // will have to shift up into the next word. // too bad. for (bitcount = 32; (v & 0xf0000000) != 0; bitcount--) { v >>>= 1; } } else { while (v <= 0x000fffff) { // hack: byte-at-a-time shifting v <<= 8; bitcount += 8; } while (v <= 0x07ffffff) { v <<= 1; bitcount += 1; } } if (bitcount != 0) { lshiftMe(bitcount); } return bitcount; } /* * Multiply a FDBigInt by an int. * Result is a new FDBigInt. */ public FDBigInt mult(int iv) { long v = iv; int r[]; long p; // guess adequate size of r. r = new int[(v * ((long) data[nWords - 1] & 0xffffffffL) > 0xfffffffL) ? nWords + 1 : nWords]; p = 0L; for (int i = 0; i < nWords; i++) { p += v * ((long) data[i] & 0xffffffffL); r[i] = (int) p; p >>>= 32; } if (p == 0L) { return new FDBigInt(r, nWords); } else { r[nWords] = (int) p; return new FDBigInt(r, nWords + 1); } } /* * Multiply a FDBigInt by an int and add another int. * Result is computed in place. * Hope it fits! */ public void multaddMe(int iv, int addend) { long v = iv; long p; // unroll 0th iteration, doing addition. p = v * ((long) data[0] & 0xffffffffL) + ((long) addend & 0xffffffffL); data[0] = (int) p; p >>>= 32; for (int i = 1; i < nWords; i++) { p += v * ((long) data[i] & 0xffffffffL); data[i] = (int) p; p >>>= 32; } if (p != 0L) { data[nWords] = (int) p; // will fail noisily if illegal! nWords++; } } /* * Multiply a FDBigInt by another FDBigInt. * Result is a new FDBigInt. */ public FDBigInt mult(FDBigInt other) { // crudely guess adequate size for r int r[] = new int[nWords + other.nWords]; int i; // I think I am promised zeros... for (i = 0; i < this.nWords; i++) { long v = (long) this.data[i] & 0xffffffffL; // UNSIGNED CONVERSION long p = 0L; int j; for (j = 0; j < other.nWords; j++) { p += ((long) r[i + j] & 0xffffffffL) + v * ((long) other.data[j] & 0xffffffffL); // UNSIGNED CONVERSIONS ALL 'ROUND. r[i + j] = (int) p; p >>>= 32; } r[i + j] = (int) p; } // compute how much of r we actually needed for all that. for (i = r.length - 1; i > 0; i--) { if (r[i] != 0) { break; } } return new FDBigInt(r, i + 1); } /* * Add one FDBigInt to another. Return a FDBigInt */ public FDBigInt add(FDBigInt other) { int i; int a[], b[]; int n, m; long c = 0L; // arrange such that a.nWords >= b.nWords; // n = a.nWords, m = b.nWords if (this.nWords >= other.nWords) { a = this.data; n = this.nWords; b = other.data; m = other.nWords; } else { a = other.data; n = other.nWords; b = this.data; m = this.nWords; } int r[] = new int[n]; for (i = 0; i < n; i++) { c += (long) a[i] & 0xffffffffL; if (i < m) { c += (long) b[i] & 0xffffffffL; } r[i] = (int) c; c >>= 32; // signed shift. } if (c != 0L) { // oops -- carry out -- need longer result. int s[] = new int[r.length + 1]; System.arraycopy(r, 0, s, 0, r.length); s[i++] = (int) c; return new FDBigInt(s, i); } return new FDBigInt(r, i); } /* * Subtract one FDBigInt from another. Return a FDBigInt * Assert that the result is positive. */ public FDBigInt sub(FDBigInt other) { int r[] = new int[this.nWords]; int i; int n = this.nWords; int m = other.nWords; int nzeros = 0; long c = 0L; for (i = 0; i < n; i++) { c += (long) this.data[i] & 0xffffffffL; if (i < m) { c -= (long) other.data[i] & 0xffffffffL; } if ((r[i] = (int) c) == 0) { nzeros++; } else { nzeros = 0; } c >>= 32; // signed shift } assert c == 0L : c; // borrow out of subtract assert dataInRangeIsZero(i, m, other); // negative result of subtract return new FDBigInt(r, n - nzeros); } private static boolean dataInRangeIsZero(int i, int m, FDBigInt other) { while (i < m) { if (other.data[i++] != 0) { return false; } } return true; } /* * Compare FDBigInt with another FDBigInt. Return an integer * >0: this > other * 0: this == other * <0: this < other */ public int cmp(FDBigInt other) { int i; if (this.nWords > other.nWords) { // if any of my high-order words is non-zero, // then the answer is evident int j = other.nWords - 1; for (i = this.nWords - 1; i > j; i--) { if (this.data[i] != 0) { return 1; } } } else if (this.nWords < other.nWords) { // if any of other's high-order words is non-zero, // then the answer is evident int j = this.nWords - 1; for (i = other.nWords - 1; i > j; i--) { if (other.data[i] != 0) { return -1; } } } else { i = this.nWords - 1; } for (; i > 0; i--) { if (this.data[i] != other.data[i]) { break; } } // careful! want unsigned compare! // use brute force here. int a = this.data[i]; int b = other.data[i]; if (a < 0) { // a is really big, unsigned if (b < 0) { return a - b; // both big, negative } else { return 1; // b not big, answer is obvious; } } else // a is not really big { if (b < 0) { // but b is really big return -1; } else { return a - b; } } } /* * Compute * q = (int)( this / S ) * this = 10 * ( this mod S ) * Return q. * This is the iteration step of digit development for output. * We assume that S has been normalized, as above, and that * "this" has been lshift'ed accordingly. * Also assume, of course, that the result, q, can be expressed * as an integer, 0 <= q < 10. */ public int quoRemIteration(FDBigInt S) throws IllegalArgumentException { // ensure that this and S have the same number of // digits. If S is properly normalized and q < 10 then // this must be so. if (nWords != S.nWords) { throw new IllegalArgumentException("disparate values"); } // estimate q the obvious way. We will usually be // right. If not, then we're only off by a little and // will re-add. int n = nWords - 1; long q = ((long) data[n] & 0xffffffffL) / (long) S.data[n]; long diff = 0L; for (int i = 0; i <= n; i++) { diff += ((long) data[i] & 0xffffffffL) - q * ((long) S.data[i] & 0xffffffffL); data[i] = (int) diff; diff >>= 32; // N.B. SIGNED shift. } if (diff != 0L) { // damn, damn, damn. q is too big. // add S back in until this turns +. This should // not be very many times! long sum = 0L; while (sum == 0L) { sum = 0L; for (int i = 0; i <= n; i++) { sum += ((long) data[i] & 0xffffffffL) + ((long) S.data[i] & 0xffffffffL); data[i] = (int) sum; sum >>= 32; // Signed or unsigned, answer is 0 or 1 } /* * Originally the following line read * "if ( sum !=0 && sum != -1 )" * but that would be wrong, because of the * treatment of the two values as entirely unsigned, * it would be impossible for a carry-out to be interpreted * as -1 -- it would have to be a single-bit carry-out, or * +1. */ assert sum == 0 || sum == 1 : sum; // carry out of division correction q -= 1; } } // finally, we can multiply this by 10. // it cannot overflow, right, as the high-order word has // at least 4 high-order zeros! long p = 0L; for (int i = 0; i <= n; i++) { p += 10 * ((long) data[i] & 0xffffffffL); data[i] = (int) p; p >>= 32; // SIGNED shift. } assert p == 0L : p; // Carry out of *10 return (int) q; } public long longValue() { // if this can be represented as a long, return the value assert this.nWords > 0 : this.nWords; // longValue confused if (this.nWords == 1) { return ((long) data[0] & 0xffffffffL); } assert dataInRangeIsZero(2, this.nWords, this); // value too big assert data[1] >= 0; // value too big return ((long) (data[1]) << 32) | ((long) data[0] & 0xffffffffL); } @Override public String toString() { StringBuffer r = new StringBuffer(30); r.append('['); int i = Math.min(nWords - 1, data.length - 1); if (nWords > data.length) { r.append("(" + data.length + "<" + nWords + "!)"); } for (; i > 0; i--) { r.append(Integer.toHexString(data[i])); r.append(' '); } r.append(Integer.toHexString(data[0])); r.append(']'); return new String(r); } }