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提交 364bf2a3 编写于 作者: X xlu
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6622432: RFE: Performance improvements to java.math.BigDecimal 

Reviewed-by: darcy
上级 ae34f917
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Showing with 1471 addition and 1103 deletion
src/share/classes/java/math/BigDecimal.java
浏览文件 @ 364bf2a3
......@@ -29,6 +29,9 @@
package java.math;
import java.util.Arrays;
import static java.math.BigInteger.LONG_MASK;
/**
* Immutable, arbitrary-precision signed decimal numbers. A
* {@code BigDecimal} consists of an arbitrary precision integer
......@@ -229,7 +232,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @serial
* @see #scale
*/
private int scale = 0; // Note: this may have any value, so
private int scale; // Note: this may have any value, so
// calculations must be done in longs
/**
* The number of decimal digits in this BigDecimal, or 0 if the
......@@ -240,25 +243,25 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
*
* @since 1.5
*/
private volatile transient int precision = 0;
private transient int precision;
/**
* Used to store the canonical string representation, if computed.
*/
private volatile transient String stringCache = null;
private transient String stringCache;
/**
* Sentinel value for {@link #intCompact} indicating the
* significand information is only available from {@code intVal}.
*/
private static final long INFLATED = Long.MIN_VALUE;
static final long INFLATED = Long.MIN_VALUE;
/**
* If the absolute value of the significand of this BigDecimal is
* less than or equal to {@code Long.MAX_VALUE}, the value can be
* compactly stored in this field and used in computations.
*/
private transient long intCompact = INFLATED;
private transient long intCompact;
// All 18-digit base ten strings fit into a long; not all 19-digit
// strings will
......@@ -269,19 +272,47 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
/* Appease the serialization gods */
private static final long serialVersionUID = 6108874887143696463L;
private static final ThreadLocal<StringBuilderHelper>
threadLocalStringBuilderHelper = new ThreadLocal<StringBuilderHelper>() {
@Override
protected StringBuilderHelper initialValue() {
return new StringBuilderHelper();
}
};
// Cache of common small BigDecimal values.
private static final BigDecimal zeroThroughTen[] = {
new BigDecimal(BigInteger.ZERO, 0, 0),
new BigDecimal(BigInteger.ONE, 1, 0),
new BigDecimal(BigInteger.valueOf(2), 2, 0),
new BigDecimal(BigInteger.valueOf(3), 3, 0),
new BigDecimal(BigInteger.valueOf(4), 4, 0),
new BigDecimal(BigInteger.valueOf(5), 5, 0),
new BigDecimal(BigInteger.valueOf(6), 6, 0),
new BigDecimal(BigInteger.valueOf(7), 7, 0),
new BigDecimal(BigInteger.valueOf(8), 8, 0),
new BigDecimal(BigInteger.valueOf(9), 9, 0),
new BigDecimal(BigInteger.TEN, 10, 0),
new BigDecimal(BigInteger.ZERO, 0, 0, 1),
new BigDecimal(BigInteger.ONE, 1, 0, 1),
new BigDecimal(BigInteger.valueOf(2), 2, 0, 1),
new BigDecimal(BigInteger.valueOf(3), 3, 0, 1),
new BigDecimal(BigInteger.valueOf(4), 4, 0, 1),
new BigDecimal(BigInteger.valueOf(5), 5, 0, 1),
new BigDecimal(BigInteger.valueOf(6), 6, 0, 1),
new BigDecimal(BigInteger.valueOf(7), 7, 0, 1),
new BigDecimal(BigInteger.valueOf(8), 8, 0, 1),
new BigDecimal(BigInteger.valueOf(9), 9, 0, 1),
new BigDecimal(BigInteger.TEN, 10, 0, 2),
};
// Cache of zero scaled by 0 - 15
private static final BigDecimal[] ZERO_SCALED_BY = {
zeroThroughTen[0],
new BigDecimal(BigInteger.ZERO, 0, 1, 1),
new BigDecimal(BigInteger.ZERO, 0, 2, 1),
new BigDecimal(BigInteger.ZERO, 0, 3, 1),
new BigDecimal(BigInteger.ZERO, 0, 4, 1),
new BigDecimal(BigInteger.ZERO, 0, 5, 1),
new BigDecimal(BigInteger.ZERO, 0, 6, 1),
new BigDecimal(BigInteger.ZERO, 0, 7, 1),
new BigDecimal(BigInteger.ZERO, 0, 8, 1),
new BigDecimal(BigInteger.ZERO, 0, 9, 1),
new BigDecimal(BigInteger.ZERO, 0, 10, 1),
new BigDecimal(BigInteger.ZERO, 0, 11, 1),
new BigDecimal(BigInteger.ZERO, 0, 12, 1),
new BigDecimal(BigInteger.ZERO, 0, 13, 1),
new BigDecimal(BigInteger.ZERO, 0, 14, 1),
new BigDecimal(BigInteger.ZERO, 0, 15, 1),
};
// Constants
......@@ -311,6 +342,18 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
// Constructors
/**
* Trusted package private constructor.
* Trusted simply means if val is INFLATED, intVal could not be null and
* if intVal is null, val could not be INFLATED.
*/
BigDecimal(BigInteger intVal, long val, int scale, int prec) {
this.scale = scale;
this.precision = prec;
this.intCompact = val;
this.intVal = intVal;
}
/**
* Translates a character array representation of a
* {@code BigDecimal} into a {@code BigDecimal}, accepting the
......@@ -331,10 +374,19 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @since 1.5
*/
public BigDecimal(char[] in, int offset, int len) {
// protect against huge length.
if (offset+len > in.length || offset < 0)
throw new NumberFormatException();
// This is the primary string to BigDecimal constructor; all
// incoming strings end up here; it uses explicit (inline)
// parsing for speed and generates at most one intermediate
// (temporary) object (a char[] array).
// (temporary) object (a char[] array) for non-compact case.
// Use locals for all fields values until completion
int prec = 0; // record precision value
int scl = 0; // record scale value
long rs = 0; // the compact value in long
BigInteger rb = null; // the inflated value in BigInteger
// use array bounds checking to handle too-long, len == 0,
// bad offset, etc.
......@@ -351,27 +403,62 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
}
// should now be at numeric part of the significand
int dotoff = -1; // '.' offset, -1 if none
boolean dot = false; // true when there is a '.'
int cfirst = offset; // record start of integer
long exp = 0; // exponent
if (len > in.length) // protect against huge length
throw new NumberFormatException();
char coeff[] = new char[len]; // integer significand array
char c; // work
char c; // current character
boolean isCompact = (len <= MAX_COMPACT_DIGITS);
// integer significand array & idx is the index to it. The array
// is ONLY used when we can't use a compact representation.
char coeff[] = isCompact ? null : new char[len];
int idx = 0;
for (; len > 0; offset++, len--) {
c = in[offset];
if ((c >= '0' && c <= '9') || Character.isDigit(c)) {
// have digit
coeff[precision] = c;
precision++; // count of digits
if ((c >= '0' && c <= '9') || Character.isDigit(c)) {
// First compact case, we need not to preserve the character
// and we can just compute the value in place.
if (isCompact) {
int digit = Character.digit(c, 10);
if (digit == 0) {
if (prec == 0)
prec = 1;
else if (rs != 0) {
rs *= 10;
++prec;
} // else digit is a redundant leading zero
} else {
if (prec != 1 || rs != 0)
++prec; // prec unchanged if preceded by 0s
rs = rs * 10 + digit;
}
} else { // the unscaled value is likely a BigInteger object.
if (c == '0' || Character.digit(c, 10) == 0) {
if (prec == 0) {
coeff[idx] = c;
prec = 1;
} else if (idx != 0) {
coeff[idx++] = c;
++prec;
} // else c must be a redundant leading zero
} else {
if (prec != 1 || idx != 0)
++prec; // prec unchanged if preceded by 0s
coeff[idx++] = c;
}
}
if (dot)
++scl;
continue;
}
// have dot
if (c == '.') {
// have dot
if (dotoff >= 0) // two dots
if (dot) // two dots
throw new NumberFormatException();
dotoff = offset;
dot = true;
continue;
}
// exponent expected
......@@ -380,10 +467,9 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
offset++;
c = in[offset];
len--;
boolean negexp = false;
boolean negexp = (c == '-');
// optional sign
if (c == '-' || c == '+') {
negexp = (c == '-');
if (negexp || c == '+') {
offset++;
c = in[offset];
len--;
......@@ -422,53 +508,44 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
break; // [saves a test]
}
// here when no characters left
if (precision == 0) // no digits found
if (prec == 0) // no digits found
throw new NumberFormatException();
if (dotoff >= 0) { // had dot; set scale
scale = precision - (dotoff - cfirst);
// [cannot overflow]
}
// Adjust scale if exp is not zero.
if (exp != 0) { // had significant exponent
try {
scale = checkScale(-exp + scale); // adjust
} catch (ArithmeticException e) {
// Can't call checkScale which relies on proper fields value
long adjustedScale = scl - exp;
if (adjustedScale > Integer.MAX_VALUE ||
adjustedScale < Integer.MIN_VALUE)
throw new NumberFormatException("Scale out of range.");
}
scl = (int)adjustedScale;
}
// Remove leading zeros from precision (digits count)
int first = 0;
for (; (coeff[first] == '0' || Character.digit(coeff[first], 10) == 0) &&
precision > 1;
first++)
precision--;
// Set the significand ..
// Copy significand to exact-sized array, with sign if
// negative
// Later use: BigInteger(coeff, first, precision) for
// both cases, by allowing an extra char at the front of
// coeff.
if (isCompact) {
rs = isneg ? -rs : rs;
} else {
char quick[];
if (!isneg) {
quick = new char[precision];
System.arraycopy(coeff, first, quick, 0, precision);
quick = (coeff.length != prec) ?
Arrays.copyOf(coeff, prec) : coeff;
} else {
quick = new char[precision+1];
quick = new char[prec + 1];
quick[0] = '-';
System.arraycopy(coeff, first, quick, 1, precision);
System.arraycopy(coeff, 0, quick, 1, prec);
}
rb = new BigInteger(quick);
rs = compactValFor(rb);
}
if (precision <= MAX_COMPACT_DIGITS)
intCompact = Long.parseLong(new String(quick));
else
intVal = new BigInteger(quick);
// System.out.println(" new: " +intVal+" ["+scale+"] "+precision);
} catch (ArrayIndexOutOfBoundsException e) {
throw new NumberFormatException();
} catch (NegativeArraySizeException e) {
throw new NumberFormatException();
}
this.scale = scl;
this.precision = prec;
this.intCompact = rs;
this.intVal = (rs != INFLATED) ? null : rb;
}
/**
......@@ -754,16 +831,18 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
}
// Calculate intVal and scale
intVal = BigInteger.valueOf(sign*significand);
long s = sign * significand;
BigInteger b;
if (exponent < 0) {
intVal = intVal.multiply(BigInteger.valueOf(5).pow(-exponent));
b = BigInteger.valueOf(5).pow(-exponent).multiply(s);
scale = -exponent;
} else if (exponent > 0) {
intVal = intVal.multiply(BigInteger.valueOf(2).pow(exponent));
}
if (intVal.bitLength() <= MAX_BIGINT_BITS) {
intCompact = intVal.longValue();
b = BigInteger.valueOf(2).pow(exponent).multiply(s);
} else {
b = BigInteger.valueOf(s);
}
intCompact = compactValFor(b);
intVal = (intCompact != INFLATED) ? null : b;
}
/**
......@@ -798,10 +877,8 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* {@code BigDecimal}.
*/
public BigDecimal(BigInteger val) {
intVal = val;
if (val.bitLength() <= MAX_BIGINT_BITS) {
intCompact = val.longValue();
}
intCompact = compactValFor(val);
intVal = (intCompact != INFLATED) ? null : val;
}
/**
......@@ -817,7 +894,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @since 1.5
*/
public BigDecimal(BigInteger val, MathContext mc) {
intVal = val;
this(val);
if (mc.precision > 0)
roundThis(mc);
}
......@@ -833,11 +910,8 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
*/
public BigDecimal(BigInteger unscaledVal, int scale) {
// Negative scales are now allowed
intVal = unscaledVal;
this(unscaledVal);
this.scale = scale;
if (unscaledVal.bitLength() <= MAX_BIGINT_BITS) {
intCompact = unscaledVal.longValue();
}
}
/**
......@@ -856,7 +930,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @since 1.5
*/
public BigDecimal(BigInteger unscaledVal, int scale, MathContext mc) {
intVal = unscaledVal;
this(unscaledVal);
this.scale = scale;
if (mc.precision > 0)
roundThis(mc);
......@@ -899,10 +973,8 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @since 1.5
*/
public BigDecimal(long val) {
if (compactLong(val))
intCompact = val;
else
intVal = BigInteger.valueOf(val);
this.intCompact = val;
this.intVal = (val == INFLATED) ? BigInteger.valueOf(val) : null;
}
/**
......@@ -917,31 +989,11 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @since 1.5
*/
public BigDecimal(long val, MathContext mc) {
if (compactLong(val))
intCompact = val;
else
intVal = BigInteger.valueOf(val);
this(val);
if (mc.precision > 0)
roundThis(mc);
}
/**
* Trusted internal constructor
*/
private BigDecimal(long val, int scale) {
this.intCompact = val;
this.scale = scale;
}
/**
* Trusted internal constructor
*/
private BigDecimal(BigInteger intVal, long val, int scale) {
this.intVal = intVal;
this.intCompact = val;
this.scale = scale;
}
// Static Factory Methods
/**
......@@ -957,12 +1009,17 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* <tt>(unscaledVal &times; 10<sup>-scale</sup>)</tt>.
*/
public static BigDecimal valueOf(long unscaledVal, int scale) {
if (scale == 0 && unscaledVal >= 0 && unscaledVal <= 10) {
return zeroThroughTen[(int)unscaledVal];
if (scale == 0)
return valueOf(unscaledVal);
else if (unscaledVal == 0) {
if (scale > 0 && scale < ZERO_SCALED_BY.length)
return ZERO_SCALED_BY[scale];
else
return new BigDecimal(BigInteger.ZERO, 0, scale, 1);
}
if (compactLong(unscaledVal))
return new BigDecimal(unscaledVal, scale);
return new BigDecimal(BigInteger.valueOf(unscaledVal), scale);
return new BigDecimal(unscaledVal == INFLATED ?
BigInteger.valueOf(unscaledVal) : null,
unscaledVal, scale, 0);
}
/**
......@@ -976,7 +1033,11 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @return a {@code BigDecimal} whose value is {@code val}.
*/
public static BigDecimal valueOf(long val) {
return valueOf(val, 0);
if (val >= 0 && val < zeroThroughTen.length)
return zeroThroughTen[(int)val];
else if (val != INFLATED)
return new BigDecimal(null, val, 0, 0);
return new BigDecimal(BigInteger.valueOf(val), val, 0, 0);
}
/**
......@@ -1014,27 +1075,42 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @return {@code this + augend}
*/
public BigDecimal add(BigDecimal augend) {
BigDecimal arg[] = {this, augend};
matchScale(arg);
long x = arg[0].intCompact;
long y = arg[1].intCompact;
// Might be able to do a more clever check incorporating the
// inflated check into the overflow computation.
if (x != INFLATED && y != INFLATED) {
long sum = x + y;
/*
* If the sum is not an overflowed value, continue to use
* the compact representation. if either of x or y is
* INFLATED, the sum should also be regarded as an
* overflow. See "Hacker's Delight" section 2-12 for
* explanation of the overflow test.
*/
if ( (((sum ^ x) & (sum ^ y)) >> 63) == 0L ) // not overflowed
return BigDecimal.valueOf(sum, arg[0].scale);
long xs = this.intCompact;
long ys = augend.intCompact;
BigInteger fst = (xs != INFLATED) ? null : this.intVal;
BigInteger snd = (ys != INFLATED) ? null : augend.intVal;
int rscale = this.scale;
long sdiff = (long)rscale - augend.scale;
if (sdiff != 0) {
if (sdiff < 0) {
int raise = checkScale(-sdiff);
rscale = augend.scale;
if (xs == INFLATED ||
(xs = longMultiplyPowerTen(xs, raise)) == INFLATED)
fst = bigMultiplyPowerTen(raise);
} else {
int raise = augend.checkScale(sdiff);
if (ys == INFLATED ||
(ys = longMultiplyPowerTen(ys, raise)) == INFLATED)
snd = augend.bigMultiplyPowerTen(raise);
}
return new BigDecimal(arg[0].inflate().intVal.add(arg[1].inflate().intVal), arg[0].scale);
}
if (xs != INFLATED && ys != INFLATED) {
long sum = xs + ys;
// See "Hacker's Delight" section 2-12 for explanation of
// the overflow test.
if ( (((sum ^ xs) & (sum ^ ys))) >= 0L) // not overflowed
return new BigDecimal(null, sum, rscale, 0);
}
if (fst == null)
fst = BigInteger.valueOf(xs);
if (snd == null)
snd = BigInteger.valueOf(ys);
BigInteger sum = fst.add(snd);
return (fst.signum == snd.signum) ?
new BigDecimal(sum, INFLATED, rscale, 0) :
new BigDecimal(sum, rscale);
}
/**
......@@ -1072,17 +1148,19 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
// Could use a factory for zero instead of a new object
if (lhsIsZero && augendIsZero)
return new BigDecimal(BigInteger.ZERO, 0, preferredScale);
return new BigDecimal(BigInteger.ZERO, 0, preferredScale, 0);
result = lhsIsZero ? augend.doRound(mc) : lhs.doRound(mc);
result = lhsIsZero ? doRound(augend, mc) : doRound(lhs, mc);
if (result.scale() == preferredScale)
return result;
else if (result.scale() > preferredScale)
return new BigDecimal(result.intVal, result.intCompact, result.scale).
stripZerosToMatchScale(preferredScale);
else { // result.scale < preferredScale
else if (result.scale() > preferredScale) {
BigDecimal scaledResult =
new BigDecimal(result.intVal, result.intCompact,
result.scale, 0);
scaledResult.stripZerosToMatchScale(preferredScale);
return scaledResult;
} else { // result.scale < preferredScale
int precisionDiff = mc.precision - result.precision();
int scaleDiff = preferredScale - result.scale();
......@@ -1102,8 +1180,9 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
augend = arg[1];
}
return new BigDecimal(lhs.inflate().intVal.add(augend.inflate().intVal),
lhs.scale).doRound(mc);
BigDecimal d = new BigDecimal(lhs.inflate().add(augend.inflate()),
lhs.scale);
return doRound(d, mc);
}
/**
......@@ -1181,28 +1260,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @return {@code this - subtrahend}
*/
public BigDecimal subtract(BigDecimal subtrahend) {
BigDecimal arg[] = {this, subtrahend};
matchScale(arg);
long x = arg[0].intCompact;
long y = arg[1].intCompact;
// Might be able to do a more clever check incorporating the
// inflated check into the overflow computation.
if (x != INFLATED && y != INFLATED) {
long difference = x - y;
/*
* If the difference is not an overflowed value, continue
* to use the compact representation. if either of x or y
* is INFLATED, the difference should also be regarded as
* an overflow. See "Hacker's Delight" section 2-12 for
* explanation of the overflow test.
*/
if ( ((x ^ y) & (difference ^ x) ) >> 63 == 0L ) // not overflowed
return BigDecimal.valueOf(difference, arg[0].scale);
}
return new BigDecimal(arg[0].inflate().intVal.subtract(arg[1].inflate().intVal),
arg[0].scale);
return add(subtrahend.negate());
}
/**
......@@ -1220,14 +1278,11 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @since 1.5
*/
public BigDecimal subtract(BigDecimal subtrahend, MathContext mc) {
BigDecimal nsubtrahend = subtrahend.negate();
if (mc.precision == 0)
return subtract(subtrahend);
return add(nsubtrahend);
// share the special rounding code in add()
this.inflate();
subtrahend.inflate();
BigDecimal rhs = new BigDecimal(subtrahend.intVal.negate(), subtrahend.scale);
rhs.precision = subtrahend.precision;
return add(rhs, mc);
return add(nsubtrahend, mc);
}
/**
......@@ -1241,7 +1296,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
public BigDecimal multiply(BigDecimal multiplicand) {
long x = this.intCompact;
long y = multiplicand.intCompact;
int productScale = checkScale((long)scale+multiplicand.scale);
int productScale = checkScale((long)scale + multiplicand.scale);
// Might be able to do a more clever check incorporating the
// inflated check into the overflow computation.
......@@ -1250,16 +1305,26 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* If the product is not an overflowed value, continue
* to use the compact representation. if either of x or y
* is INFLATED, the product should also be regarded as
* an overflow. See "Hacker's Delight" section 2-12 for
* explanation of the overflow test.
* an overflow. Before using the overflow test suggested in
* "Hacker's Delight" section 2-12, we perform quick checks
* using the precision information to see whether the overflow
* would occur since division is expensive on most CPUs.
*/
long product = x * y;
if ( !(y != 0L && product/y != x) ) // not overflowed
return BigDecimal.valueOf(product, productScale);
}
BigDecimal result = new BigDecimal(this.inflate().intVal.multiply(multiplicand.inflate().intVal), productScale);
return result;
int prec = this.precision() + multiplicand.precision();
if (prec < 19 || (prec < 21 && (y == 0 || product / y == x)))
return new BigDecimal(null, product, productScale, 0);
return new BigDecimal(BigInteger.valueOf(x).multiply(y), INFLATED,
productScale, 0);
}
BigInteger rb;
if (x == INFLATED && y == INFLATED)
rb = this.intVal.multiply(multiplicand.intVal);
else if (x != INFLATED)
rb = multiplicand.intVal.multiply(x);
else
rb = this.intVal.multiply(y);
return new BigDecimal(rb, INFLATED, productScale, 0);
}
/**
......@@ -1276,8 +1341,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
public BigDecimal multiply(BigDecimal multiplicand, MathContext mc) {
if (mc.precision == 0)
return multiply(multiplicand);
BigDecimal lhs = this;
return lhs.inflate().multiply(multiplicand.inflate()).doRound(mc);
return doRound(this.multiply(multiplicand), mc);
}
/**
......@@ -1311,7 +1375,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
public BigDecimal divide(BigDecimal divisor, int scale, int roundingMode) {
/*
* IMPLEMENTATION NOTE: This method *must* return a new object
* since dropDigits uses divide to generate a value whose
* since divideAndRound uses divide to generate a value whose
* scale is then modified.
*/
if (roundingMode < ROUND_UP || roundingMode > ROUND_UNNECESSARY)
......@@ -1321,87 +1385,103 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* produce correctly scaled quotient).
* Take care to detect out-of-range scales
*/
BigDecimal dividend;
if (checkScale((long)scale + divisor.scale) >= this.scale) {
dividend = this.setScale(scale + divisor.scale);
BigDecimal dividend = this;
if (checkScale((long)scale + divisor.scale) > this.scale)
dividend = this.setScale(scale + divisor.scale, ROUND_UNNECESSARY);
else
divisor = divisor.setScale(checkScale((long)this.scale - scale),
ROUND_UNNECESSARY);
return divideAndRound(dividend.intCompact, dividend.intVal,
divisor.intCompact, divisor.intVal,
scale, roundingMode, scale);
}
/**
* Internally used for division operation. The dividend and divisor are
* passed both in {@code long} format and {@code BigInteger} format. The
* returned {@code BigDecimal} object is the quotient whose scale is set to
* the passed in scale. If the remainder is not zero, it will be rounded
* based on the passed in roundingMode. Also, if the remainder is zero and
* the last parameter, i.e. preferredScale is NOT equal to scale, the
* trailing zeros of the result is stripped to match the preferredScale.
*/
private static BigDecimal divideAndRound(long ldividend, BigInteger bdividend,
long ldivisor, BigInteger bdivisor,
int scale, int roundingMode,
int preferredScale) {
boolean isRemainderZero; // record remainder is zero or not
int qsign; // quotient sign
long q = 0, r = 0; // store quotient & remainder in long
MutableBigInteger mq = null; // store quotient
MutableBigInteger mr = null; // store remainder
MutableBigInteger mdivisor = null;
boolean isLongDivision = (ldividend != INFLATED && ldivisor != INFLATED);
if (isLongDivision) {
q = ldividend / ldivisor;
if (roundingMode == ROUND_DOWN && scale == preferredScale)
return new BigDecimal(null, q, scale, 0);
r = ldividend % ldivisor;
isRemainderZero = (r == 0);
qsign = ((ldividend < 0) == (ldivisor < 0)) ? 1 : -1;
} else {
dividend = this;
divisor = divisor.setScale(checkScale((long)this.scale - scale));
}
boolean compact = dividend.intCompact != INFLATED && divisor.intCompact != INFLATED;
long div = INFLATED;
long rem = INFLATED;;
BigInteger q=null, r=null;
if (compact) {
div = dividend.intCompact / divisor.intCompact;
rem = dividend.intCompact % divisor.intCompact;
if (bdividend == null)
bdividend = BigInteger.valueOf(ldividend);
// Descend into mutables for faster remainder checks
MutableBigInteger mdividend = new MutableBigInteger(bdividend.mag);
mq = new MutableBigInteger();
if (ldivisor != INFLATED) {
r = mdividend.divide(ldivisor, mq);
isRemainderZero = (r == 0);
qsign = (ldivisor < 0) ? -bdividend.signum : bdividend.signum;
} else {
// Do the division and return result if it's exact.
BigInteger i[] = dividend.inflate().intVal.divideAndRemainder(divisor.inflate().intVal);
q = i[0];
r = i[1];
mdivisor = new MutableBigInteger(bdivisor.mag);
mr = mdividend.divide(mdivisor, mq);
isRemainderZero = mr.isZero();
qsign = (bdividend.signum != bdivisor.signum) ? -1 : 1;
}
// Check for exact result
if (compact) {
if (rem == 0)
return new BigDecimal(div, scale);
} else {
if (r.signum() == 0)
return new BigDecimal(q, scale);
}
if (roundingMode == ROUND_UNNECESSARY) // Rounding prohibited
throw new ArithmeticException("Rounding necessary");
boolean increment = false;
if (!isRemainderZero) {
int cmpFracHalf;
/* Round as appropriate */
int signum = dividend.signum() * divisor.signum(); // Sign of result
boolean increment;
if (roundingMode == ROUND_UP) { // Away from zero
if (roundingMode == ROUND_UNNECESSARY) { // Rounding prohibited
throw new ArithmeticException("Rounding necessary");
} else if (roundingMode == ROUND_UP) { // Away from zero
increment = true;
} else if (roundingMode == ROUND_DOWN) { // Towards zero
increment = false;
} else if (roundingMode == ROUND_CEILING) { // Towards +infinity
increment = (signum > 0);
increment = (qsign > 0);
} else if (roundingMode == ROUND_FLOOR) { // Towards -infinity
increment = (signum < 0);
} else { // Remaining modes based on nearest-neighbor determination
int cmpFracHalf;
if (compact) {
cmpFracHalf = longCompareTo(Math.abs(2*rem), Math.abs(divisor.intCompact));
increment = (qsign < 0);
} else {
// add(r) here is faster than multiply(2) or shiftLeft(1)
cmpFracHalf= r.add(r).abs().compareTo(divisor.intVal.abs());
}
if (cmpFracHalf < 0) { // We're closer to higher digit
increment = false;
} else if (cmpFracHalf > 0) { // We're closer to lower digit
if (isLongDivision || ldivisor != INFLATED)
cmpFracHalf = longCompareMagnitude(2 * r, ldivisor);
else
cmpFracHalf = mr.compareHalf(mdivisor);
if (cmpFracHalf < 0)
increment = false; // We're closer to higher digit
else if (cmpFracHalf > 0) // We're closer to lower digit
increment = true;
} else { // We're dead-center
if (roundingMode == ROUND_HALF_UP)
else if (roundingMode == ROUND_HALF_UP)
increment = true;
else if (roundingMode == ROUND_HALF_DOWN)
increment = false;
else { // roundingMode == ROUND_HALF_EVEN
if (compact)
increment = (div & 1L) != 0L;
else
increment = q.testBit(0); // true iff q is odd
}
else // roundingMode == ROUND_HALF_EVEN, true iff quotient is odd
increment = isLongDivision ? (q & 1L) != 0L : mq.isOdd();
}
}
if (compact) {
BigDecimal res;
if (isLongDivision)
res = new BigDecimal(null, (increment ? q + qsign : q), scale, 0);
else {
if (increment)
div += signum; // guaranteed not to overflow
return new BigDecimal(div, scale);
} else {
return (increment
? new BigDecimal(q.add(BigInteger.valueOf(signum)), scale)
: new BigDecimal(q, scale));
mq.add(MutableBigInteger.ONE);
res = mq.toBigDecimal(qsign, scale);
}
if (isRemainderZero && preferredScale != scale)
res.stripZerosToMatchScale(preferredScale);
return res;
}
/**
......@@ -1499,10 +1579,12 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
}
// Calculate preferred scale
int preferredScale = (int)Math.max(Math.min((long)this.scale() - divisor.scale(),
Integer.MAX_VALUE), Integer.MIN_VALUE);
int preferredScale = saturateLong((long)this.scale - divisor.scale);
if (this.signum() == 0) // 0/y
return new BigDecimal(0, preferredScale);
return (preferredScale >= 0 &&
preferredScale < ZERO_SCALED_BY.length) ?
ZERO_SCALED_BY[preferredScale] :
new BigDecimal(null, 0, preferredScale, 1);
else {
this.inflate();
divisor.inflate();
......@@ -1534,7 +1616,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
// limit, we can add zeros too.
if (preferredScale > quotientScale)
return quotient.setScale(preferredScale);
return quotient.setScale(preferredScale, ROUND_UNNECESSARY);
return quotient;
}
......@@ -1554,14 +1636,12 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @since 1.5
*/
public BigDecimal divide(BigDecimal divisor, MathContext mc) {
if (mc.precision == 0)
int mcp = mc.precision;
if (mcp == 0)
return divide(divisor);
BigDecimal lhs = this.inflate(); // left-hand-side
BigDecimal rhs = divisor.inflate(); // right-hand-side
BigDecimal result; // work
long preferredScale = (long)lhs.scale() - rhs.scale();
BigDecimal dividend = this;
long preferredScale = (long)dividend.scale - divisor.scale;
// Now calculate the answer. We use the existing
// divide-and-round method, but as this rounds to scale we have
// to normalize the values here to achieve the desired result.
......@@ -1574,54 +1654,43 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
// the right number of digits (except in the case of a result of
// 1.000... which can arise when x=y, or when rounding overflows
// The 1.000... case will reduce properly to 1.
if (rhs.signum() == 0) { // x/0
if (lhs.signum() == 0) // 0/0
if (divisor.signum() == 0) { // x/0
if (dividend.signum() == 0) // 0/0
throw new ArithmeticException("Division undefined"); // NaN
throw new ArithmeticException("Division by zero");
}
if (lhs.signum() == 0) // 0/y
return new BigDecimal(BigInteger.ZERO,
(int)Math.max(Math.min(preferredScale,
Integer.MAX_VALUE),
Integer.MIN_VALUE));
BigDecimal xprime = new BigDecimal(lhs.intVal.abs(), lhs.precision());
BigDecimal yprime = new BigDecimal(rhs.intVal.abs(), rhs.precision());
// xprime and yprime are now both in range 0.1 through 0.999...
if (mc.roundingMode == RoundingMode.CEILING ||
mc.roundingMode == RoundingMode.FLOOR) {
// The floor (round toward negative infinity) and ceil
// (round toward positive infinity) rounding modes are not
// invariant under a sign flip. If xprime/yprime has a
// different sign than lhs/rhs, the rounding mode must be
// changed.
if ((xprime.signum() != lhs.signum()) ^
(yprime.signum() != rhs.signum())) {
mc = new MathContext(mc.precision,
(mc.roundingMode==RoundingMode.CEILING)?
RoundingMode.FLOOR:RoundingMode.CEILING);
}
}
if (xprime.compareTo(yprime) > 0) // satisfy constraint (b)
yprime.scale -= 1; // [that is, yprime *= 10]
result = xprime.divide(yprime, mc.precision, mc.roundingMode.oldMode);
// correct the scale of the result...
result.scale = checkScale((long)yprime.scale - xprime.scale
- (rhs.scale - lhs.scale) + mc.precision);
// apply the sign
if (lhs.signum() != rhs.signum())
result = result.negate();
if (dividend.signum() == 0) // 0/y
return new BigDecimal(BigInteger.ZERO, 0,
saturateLong(preferredScale), 1);
// Normalize dividend & divisor so that both fall into [0.1, 0.999...]
int xscale = dividend.precision();
int yscale = divisor.precision();
dividend = new BigDecimal(dividend.intVal, dividend.intCompact,
xscale, xscale);
divisor = new BigDecimal(divisor.intVal, divisor.intCompact,
yscale, yscale);
if (dividend.compareMagnitude(divisor) > 0) // satisfy constraint (b)
yscale = divisor.scale -= 1; // [that is, divisor *= 10]
// In order to find out whether the divide generates the exact result,
// we avoid calling the above divide method. 'quotient' holds the
// return BigDecimal object whose scale will be set to 'scl'.
BigDecimal quotient;
int scl = checkScale(preferredScale + yscale - xscale + mcp);
if (checkScale((long)mcp + yscale) > xscale)
dividend = dividend.setScale(mcp + yscale, ROUND_UNNECESSARY);
else
divisor = divisor.setScale(checkScale((long)xscale - mcp),
ROUND_UNNECESSARY);
quotient = divideAndRound(dividend.intCompact, dividend.intVal,
divisor.intCompact, divisor.intVal,
scl, mc.roundingMode.oldMode,
checkScale(preferredScale));
// doRound, here, only affects 1000000000 case.
result = result.doRound(mc);
quotient = doRound(quotient, mc);
if (result.multiply(divisor).compareTo(this) == 0) {
// Apply preferred scale rules for exact quotients
return result.stripZerosToMatchScale(preferredScale);
}
else {
return result;
}
return quotient;
}
/**
......@@ -1637,17 +1706,14 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
*/
public BigDecimal divideToIntegralValue(BigDecimal divisor) {
// Calculate preferred scale
int preferredScale = (int)Math.max(Math.min((long)this.scale() - divisor.scale(),
Integer.MAX_VALUE), Integer.MIN_VALUE);
this.inflate();
divisor.inflate();
if (this.abs().compareTo(divisor.abs()) < 0) {
int preferredScale = saturateLong((long)this.scale - divisor.scale);
if (this.compareMagnitude(divisor) < 0) {
// much faster when this << divisor
return BigDecimal.valueOf(0, preferredScale);
}
if(this.signum() == 0 && divisor.signum() != 0)
return this.setScale(preferredScale);
return this.setScale(preferredScale, ROUND_UNNECESSARY);
// Perform a divide with enough digits to round to a correct
// integer value; then remove any fractional digits
......@@ -1656,19 +1722,17 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
(long)Math.ceil(10.0*divisor.precision()/3.0) +
Math.abs((long)this.scale() - divisor.scale()) + 2,
Integer.MAX_VALUE);
BigDecimal quotient = this.divide(divisor, new MathContext(maxDigits,
RoundingMode.DOWN));
if (quotient.scale > 0) {
quotient = quotient.setScale(0, RoundingMode.DOWN).
stripZerosToMatchScale(preferredScale);
quotient = quotient.setScale(0, RoundingMode.DOWN);
quotient.stripZerosToMatchScale(preferredScale);
}
if (quotient.scale < preferredScale) {
// pad with zeros if necessary
quotient = quotient.setScale(preferredScale);
quotient = quotient.setScale(preferredScale, ROUND_UNNECESSARY);
}
return quotient;
}
......@@ -1694,12 +1758,11 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
*/
public BigDecimal divideToIntegralValue(BigDecimal divisor, MathContext mc) {
if (mc.precision == 0 || // exact result
(this.abs().compareTo(divisor.abs()) < 0) ) // zero result
(this.compareMagnitude(divisor) < 0) ) // zero result
return divideToIntegralValue(divisor);
// Calculate preferred scale
int preferredScale = (int)Math.max(Math.min((long)this.scale() - divisor.scale(),
Integer.MAX_VALUE), Integer.MIN_VALUE);
int preferredScale = saturateLong((long)this.scale - divisor.scale);
/*
* Perform a normal divide to mc.precision digits. If the
......@@ -1708,9 +1771,8 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* digits. Next, remove any fractional digits from the
* quotient and adjust the scale to the preferred value.
*/
BigDecimal result = this.divide(divisor, new MathContext(mc.precision,
RoundingMode.DOWN));
int resultScale = result.scale();
BigDecimal result = this.
divide(divisor, new MathContext(mc.precision, RoundingMode.DOWN));
if (result.scale() < 0) {
/*
......@@ -1721,7 +1783,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
BigDecimal product = result.multiply(divisor);
// If the quotient is the full integer value,
// |dividend-product| < |divisor|.
if (this.subtract(product).abs().compareTo(divisor.abs()) >= 0) {
if (this.subtract(product).compareMagnitude(divisor) >= 0) {
throw new ArithmeticException("Division impossible");
}
} else if (result.scale() > 0) {
......@@ -1736,11 +1798,13 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
int precisionDiff;
if ((preferredScale > result.scale()) &&
(precisionDiff = mc.precision - result.precision()) > 0 ) {
(precisionDiff = mc.precision - result.precision()) > 0) {
return result.setScale(result.scale() +
Math.min(precisionDiff, preferredScale - result.scale) );
} else
return result.stripZerosToMatchScale(preferredScale);
} else {
result.stripZerosToMatchScale(preferredScale);
return result;
}
}
/**
......@@ -1949,7 +2013,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
int mag = Math.abs(n); // magnitude of n
if (mc.precision > 0) {
int elength = intLength(mag); // length of n in digits
int elength = longDigitLength(mag); // length of n in digits
if (elength > mc.precision) // X3.274 rule
throw new ArithmeticException("Invalid operation");
workmc = new MathContext(mc.precision + elength + 1,
......@@ -1974,7 +2038,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
if (n<0) // [hence mc.precision>0]
acc=ONE.divide(acc, workmc);
// round to final precision and strip zeros
return acc.doRound(mc);
return doRound(acc, mc);
}
/**
......@@ -2068,7 +2132,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
public BigDecimal plus(MathContext mc) {
if (mc.precision == 0) // no rounding please
return this;
return this.doRound(mc);
return doRound(this, mc);
}
/**
......@@ -2109,7 +2173,11 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
public int precision() {
int result = precision;
if (result == 0) {
result = digitLength();
long s = intCompact;
if (s != INFLATED)
result = longDigitLength(s);
else
result = bigDigitLength(inflate());
precision = result;
}
return result;
......@@ -2125,7 +2193,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @since 1.2
*/
public BigInteger unscaledValue() {
return this.inflate().intVal;
return this.inflate();
}
// Rounding Modes
......@@ -2302,30 +2370,34 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
if (roundingMode < ROUND_UP || roundingMode > ROUND_UNNECESSARY)
throw new IllegalArgumentException("Invalid rounding mode");
if (newScale == this.scale) // easy case
int oldScale = this.scale;
if (newScale == oldScale) // easy case
return this;
if (this.signum() == 0) // zero can have any scale
return BigDecimal.valueOf(0, newScale);
if (newScale > this.scale) {
// [we can use checkScale to assure multiplier is valid]
int raise = checkScale((long)newScale - this.scale);
if (intCompact != INFLATED) {
long scaledResult = longTenToThe(intCompact, raise);
if (scaledResult != INFLATED)
return BigDecimal.valueOf(scaledResult, newScale);
this.inflate();
}
BigDecimal result = new BigDecimal(intVal.multiply(tenToThe(raise)),
newScale);
if (this.precision > 0)
result.precision = this.precision + newScale - this.scale;
return result;
long rs = this.intCompact;
if (newScale > oldScale) {
int raise = checkScale((long)newScale - oldScale);
BigInteger rb = null;
if (rs == INFLATED ||
(rs = longMultiplyPowerTen(rs, raise)) == INFLATED)
rb = bigMultiplyPowerTen(raise);
return new BigDecimal(rb, rs, newScale,
(precision > 0) ? precision + raise : 0);
} else {
// newScale < oldScale -- drop some digits
// Can't predict the precision due to the effect of rounding.
int drop = checkScale((long)oldScale - newScale);
if (drop < LONG_TEN_POWERS_TABLE.length)
return divideAndRound(rs, this.intVal,
LONG_TEN_POWERS_TABLE[drop], null,
newScale, roundingMode, newScale);
else
return divideAndRound(rs, this.intVal,
INFLATED, bigTenToThe(drop),
newScale, roundingMode, newScale);
}
// scale < this.scale
// we cannot perfectly predict the precision after rounding
return divide(ONE, newScale, roundingMode);
}
/**
......@@ -2388,12 +2460,8 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
public BigDecimal movePointLeft(int n) {
// Cannot use movePointRight(-n) in case of n==Integer.MIN_VALUE
int newScale = checkScale((long)scale + n);
BigDecimal num;
if (intCompact != INFLATED)
num = BigDecimal.valueOf(intCompact, newScale);
else
num = new BigDecimal(intVal, newScale);
return (num.scale<0 ? num.setScale(0) : num);
BigDecimal num = new BigDecimal(intVal, intCompact, newScale, 0);
return num.scale < 0 ? num.setScale(0, ROUND_UNNECESSARY) : num;
}
/**
......@@ -2414,12 +2482,8 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
public BigDecimal movePointRight(int n) {
// Cannot use movePointLeft(-n) in case of n==Integer.MIN_VALUE
int newScale = checkScale((long)scale - n);
BigDecimal num;
if (intCompact != INFLATED)
num = BigDecimal.valueOf(intCompact, newScale);
else
num = new BigDecimal(intVal, newScale);
return (num.scale<0 ? num.setScale(0) : num);
BigDecimal num = new BigDecimal(intVal, intCompact, newScale, 0);
return num.scale < 0 ? num.setScale(0, ROUND_UNNECESSARY) : num;
}
/**
......@@ -2433,10 +2497,8 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @since 1.5
*/
public BigDecimal scaleByPowerOfTen(int n) {
this.inflate();
BigDecimal num = new BigDecimal(intVal, checkScale((long)scale - n));
num.precision = precision;
return num;
return new BigDecimal(intVal, intCompact,
checkScale((long)scale - n), precision);
}
/**
......@@ -2454,7 +2516,9 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
*/
public BigDecimal stripTrailingZeros() {
this.inflate();
return (new BigDecimal(intVal, scale)).stripZerosToMatchScale(Long.MIN_VALUE);
BigDecimal result = new BigDecimal(intVal, scale);
result.stripZerosToMatchScale(Long.MIN_VALUE);
return result;
}
// Comparison Operations
......@@ -2477,32 +2541,67 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* less than, equal to, or greater than {@code val}.
*/
public int compareTo(BigDecimal val) {
if (this.scale == val.scale &&
this.intCompact != INFLATED &&
val.intCompact != INFLATED)
return longCompareTo(this.intCompact, val.intCompact);
// Optimization: would run fine without the next three lines
int sigDiff = signum() - val.signum();
if (sigDiff != 0)
return (sigDiff > 0 ? 1 : -1);
// If the (adjusted) exponents are different we do not need to
// expensively match scales and compare the significands
int aethis = this.precision() - this.scale; // [-1]
int aeval = val.precision() - val.scale; // [-1]
if (aethis < aeval)
return -this.signum();
else if (aethis > aeval)
return this.signum();
// Scale and compare intVals
BigDecimal arg[] = {this, val};
matchScale(arg);
if (arg[0].intCompact != INFLATED &&
arg[1].intCompact != INFLATED)
return longCompareTo(arg[0].intCompact, arg[1].intCompact);
return arg[0].inflate().intVal.compareTo(arg[1].inflate().intVal);
// Quick path for equal scale and non-inflated case.
if (scale == val.scale) {
long xs = intCompact;
long ys = val.intCompact;
if (xs != INFLATED && ys != INFLATED)
return xs != ys ? ((xs > ys) ? 1 : -1) : 0;
}
int xsign = this.signum();
int ysign = val.signum();
if (xsign != ysign)
return (xsign > ysign) ? 1 : -1;
if (xsign == 0)
return 0;
int cmp = compareMagnitude(val);
return (xsign > 0) ? cmp : -cmp;
}
/**
* Version of compareTo that ignores sign.
*/
private int compareMagnitude(BigDecimal val) {
// Match scales, avoid unnecessary inflation
long ys = val.intCompact;
long xs = this.intCompact;
if (xs == 0)
return (ys == 0) ? 0 : -1;
if (ys == 0)
return 1;
int sdiff = this.scale - val.scale;
if (sdiff != 0) {
// Avoid matching scales if the (adjusted) exponents differ
int xae = this.precision() - this.scale; // [-1]
int yae = val.precision() - val.scale; // [-1]
if (xae < yae)
return -1;
if (xae > yae)
return 1;
BigInteger rb = null;
if (sdiff < 0) {
if ( (xs == INFLATED ||
(xs = longMultiplyPowerTen(xs, -sdiff)) == INFLATED) &&
ys == INFLATED) {
rb = bigMultiplyPowerTen(-sdiff);
return rb.compareMagnitude(val.intVal);
}
} else { // sdiff > 0
if ( (ys == INFLATED ||
(ys = longMultiplyPowerTen(ys, sdiff)) == INFLATED) &&
xs == INFLATED) {
rb = val.bigMultiplyPowerTen(sdiff);
return this.intVal.compareMagnitude(rb);
}
}
}
if (xs != INFLATED)
return (ys != INFLATED) ? longCompareMagnitude(xs, ys) : -1;
else if (ys != INFLATED)
return 1;
else
return this.intVal.compareMagnitude(val.intVal);
}
/**
......@@ -2521,15 +2620,25 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @see #compareTo(java.math.BigDecimal)
* @see #hashCode
*/
@Override
public boolean equals(Object x) {
if (!(x instanceof BigDecimal))
return false;
BigDecimal xDec = (BigDecimal) x;
if (x == this)
return true;
if (scale != xDec.scale)
return false;
if (this.intCompact != INFLATED && xDec.intCompact != INFLATED)
return this.intCompact == xDec.intCompact;
return this.inflate().intVal.equals(xDec.inflate().intVal);
long s = this.intCompact;
long xs = xDec.intCompact;
if (s != INFLATED) {
if (xs == INFLATED)
xs = compactValFor(xDec.intVal);
return xs == s;
} else if (xs != INFLATED)
return xs == compactValFor(this.intVal);
return this.inflate().equals(xDec.inflate());
}
/**
......@@ -2572,11 +2681,12 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @return hash code for this {@code BigDecimal}.
* @see #equals(Object)
*/
@Override
public int hashCode() {
if (intCompact != INFLATED) {
long val2 = (intCompact < 0)?-intCompact:intCompact;
long val2 = (intCompact < 0)? -intCompact : intCompact;
int temp = (int)( ((int)(val2 >>> 32)) * 31 +
(val2 & 0xffffffffL));
(val2 & LONG_MASK));
return 31*((intCompact < 0) ?-temp:temp) + scale;
} else
return 31*intVal.hashCode() + scale;
......@@ -2683,10 +2793,12 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @see Character#forDigit
* @see #BigDecimal(java.lang.String)
*/
@Override
public String toString() {
if (stringCache == null)
stringCache = layoutChars(true);
return stringCache;
String sc = stringCache;
if (sc == null)
stringCache = sc = layoutChars(true);
return sc;
}
/**
......@@ -2802,7 +2914,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
*/
public BigInteger toBigInteger() {
// force to an integer, quietly
return this.setScale(0, ROUND_DOWN).inflate().intVal;
return this.setScale(0, ROUND_DOWN).inflate();
}
/**
......@@ -2817,7 +2929,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
*/
public BigInteger toBigIntegerExact() {
// round to an integer, with Exception if decimal part non-0
return this.setScale(0, ROUND_UNNECESSARY).inflate().intVal;
return this.setScale(0, ROUND_UNNECESSARY).inflate();
}
/**
......@@ -2868,10 +2980,10 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
if ((this.precision() - this.scale) <= 0)
throw new ArithmeticException("Rounding necessary");
// round to an integer, with Exception if decimal part non-0
BigDecimal num = this.setScale(0, ROUND_UNNECESSARY).inflate();
BigDecimal num = this.setScale(0, ROUND_UNNECESSARY);
if (num.precision() >= 19) // need to check carefully
LongOverflow.check(num);
return num.intVal.longValue();
return num.inflate().longValue();
}
private static class LongOverflow {
......@@ -2882,6 +2994,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
private static final BigInteger LONGMAX = BigInteger.valueOf(Long.MAX_VALUE);
public static void check(BigDecimal num) {
num.inflate();
if ((num.intVal.compareTo(LONGMIN) < 0) ||
(num.intVal.compareTo(LONGMAX) > 0))
throw new java.lang.ArithmeticException("Overflow");
......@@ -3037,7 +3150,105 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
return BigDecimal.valueOf(1, this.scale());
}
// Private "Helper" Methods
// Private class to build a string representation for BigDecimal object.
// "StringBuilderHelper" is constructed as a thread local variable so it is
// thread safe. The StringBuilder field acts as a buffer to hold the temporary
// representation of BigDecimal. The cmpCharArray holds all the characters for
// the compact representation of BigDecimal (except for '-' sign' if it is
// negative) if its intCompact field is not INFLATED. It is shared by all
// calls to toString() and its variants in that particular thread.
static class StringBuilderHelper {
final StringBuilder sb; // Placeholder for BigDecimal string
final char[] cmpCharArray; // character array to place the intCompact
StringBuilderHelper() {
sb = new StringBuilder();
// All non negative longs can be made to fit into 19 character array.
cmpCharArray = new char[19];
}
// Accessors.
StringBuilder getStringBuilder() {
sb.setLength(0);
return sb;
}
char[] getCompactCharArray() {
return cmpCharArray;
}
/**
* Places characters representing the intCompact in {@code long} into
* cmpCharArray and returns the offset to the array where the
* representation starts.
*
* @param intCompact the number to put into the cmpCharArray.
* @return offset to the array where the representation starts.
* Note: intCompact must be greater or equal to zero.
*/
int putIntCompact(long intCompact) {
assert intCompact >= 0;
long q;
int r;
// since we start from the least significant digit, charPos points to
// the last character in cmpCharArray.
int charPos = cmpCharArray.length;
// Get 2 digits/iteration using longs until quotient fits into an int
while (intCompact > Integer.MAX_VALUE) {
q = intCompact / 100;
r = (int)(intCompact - q * 100);
intCompact = q;
cmpCharArray[--charPos] = DIGIT_ONES[r];
cmpCharArray[--charPos] = DIGIT_TENS[r];
}
// Get 2 digits/iteration using ints when i2 >= 100
int q2;
int i2 = (int)intCompact;
while (i2 >= 100) {
q2 = i2 / 100;
r = i2 - q2 * 100;
i2 = q2;
cmpCharArray[--charPos] = DIGIT_ONES[r];
cmpCharArray[--charPos] = DIGIT_TENS[r];
}
cmpCharArray[--charPos] = DIGIT_ONES[i2];
if (i2 >= 10)
cmpCharArray[--charPos] = DIGIT_TENS[i2];
return charPos;
}
final static char[] DIGIT_TENS = {
'0', '0', '0', '0', '0', '0', '0', '0', '0', '0',
'1', '1', '1', '1', '1', '1', '1', '1', '1', '1',
'2', '2', '2', '2', '2', '2', '2', '2', '2', '2',
'3', '3', '3', '3', '3', '3', '3', '3', '3', '3',
'4', '4', '4', '4', '4', '4', '4', '4', '4', '4',
'5', '5', '5', '5', '5', '5', '5', '5', '5', '5',
'6', '6', '6', '6', '6', '6', '6', '6', '6', '6',
'7', '7', '7', '7', '7', '7', '7', '7', '7', '7',
'8', '8', '8', '8', '8', '8', '8', '8', '8', '8',
'9', '9', '9', '9', '9', '9', '9', '9', '9', '9',
};
final static char[] DIGIT_ONES = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
};
}
/**
* Lay out this {@code BigDecimal} into a {@code char[]} array.
......@@ -3054,41 +3265,47 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
Long.toString(intCompact):
intVal.toString();
StringBuilderHelper sbHelper = threadLocalStringBuilderHelper.get();
char[] coeff;
int offset; // offset is the starting index for coeff array
// Get the significand as an absolute value
char coeff[];
if (intCompact != INFLATED)
coeff = Long.toString(Math.abs(intCompact)).toCharArray();
else
if (intCompact != INFLATED) {
offset = sbHelper.putIntCompact(Math.abs(intCompact));
coeff = sbHelper.getCompactCharArray();
} else {
offset = 0;
coeff = intVal.abs().toString().toCharArray();
}
// Construct a buffer, with sufficient capacity for all cases.
// If E-notation is needed, length will be: +1 if negative, +1
// if '.' needed, +2 for "E+", + up to 10 for adjusted exponent.
// Otherwise it could have +1 if negative, plus leading "0.00000"
StringBuilder buf=new StringBuilder(coeff.length+14);
StringBuilder buf = sbHelper.getStringBuilder();
if (signum() < 0) // prefix '-' if negative
buf.append('-');
long adjusted = -(long)scale + (coeff.length-1);
int coeffLen = coeff.length - offset;
long adjusted = -(long)scale + (coeffLen -1);
if ((scale >= 0) && (adjusted >= -6)) { // plain number
int pad = scale - coeff.length; // count of padding zeros
int pad = scale - coeffLen; // count of padding zeros
if (pad >= 0) { // 0.xxx form
buf.append('0');
buf.append('.');
for (; pad>0; pad--) {
buf.append('0');
}
buf.append(coeff);
buf.append(coeff, offset, coeffLen);
} else { // xx.xx form
buf.append(coeff, 0, -pad);
buf.append(coeff, offset, -pad);
buf.append('.');
buf.append(coeff, -pad, scale);
buf.append(coeff, -pad + offset, scale);
}
} else { // E-notation is needed
if (sci) { // Scientific notation
buf.append(coeff[0]); // first character
if (coeff.length > 1) { // more to come
buf.append(coeff[offset]); // first character
if (coeffLen > 1) { // more to come
buf.append('.');
buf.append(coeff, 1, coeff.length-1);
buf.append(coeff, offset + 1, coeffLen - 1);
}
} else { // Engineering notation
int sig = (int)(adjusted % 3);
......@@ -3112,15 +3329,15 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
default:
throw new AssertionError("Unexpected sig value " + sig);
}
} else if (sig >= coeff.length) { // significand all in integer
buf.append(coeff, 0, coeff.length);
} else if (sig >= coeffLen) { // significand all in integer
buf.append(coeff, offset, coeffLen);
// may need some zeros, too
for (int i = sig - coeff.length; i > 0; i--)
for (int i = sig - coeffLen; i > 0; i--)
buf.append('0');
} else { // xx.xxE form
buf.append(coeff, 0, sig);
buf.append(coeff, offset, sig);
buf.append('.');
buf.append(coeff, sig, coeff.length-sig);
buf.append(coeff, offset + sig, coeffLen - sig);
}
}
if (adjusted != 0) { // [!sci could have made 0]
......@@ -3139,9 +3356,17 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @param n the power of ten to be returned (>=0)
* @return a {@code BigInteger} with the value (10<sup>n</sup>)
*/
private static BigInteger tenToThe(int n) {
if (n < TENPOWERS.length) // use value from constant array
return TENPOWERS[n];
private static BigInteger bigTenToThe(int n) {
if (n < 0)
return BigInteger.ZERO;
if (n < BIG_TEN_POWERS_TABLE_MAX) {
BigInteger[] pows = BIG_TEN_POWERS_TABLE;
if (n < pows.length)
return pows[n];
else
return expandBigIntegerTenPowers(n);
}
// BigInteger.pow is slow, so make 10**n by constructing a
// BigInteger from a character string (still not very fast)
char tenpow[] = new char[n + 1];
......@@ -3150,58 +3375,145 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
tenpow[i] = '0';
return new BigInteger(tenpow);
}
private static BigInteger TENPOWERS[] = {BigInteger.ONE,
/**
* Expand the BIG_TEN_POWERS_TABLE array to contain at least 10**n.
*
* @param n the power of ten to be returned (>=0)
* @return a {@code BigDecimal} with the value (10<sup>n</sup>) and
* in the meantime, the BIG_TEN_POWERS_TABLE array gets
* expanded to the size greater than n.
*/
private static BigInteger expandBigIntegerTenPowers(int n) {
synchronized(BigDecimal.class) {
BigInteger[] pows = BIG_TEN_POWERS_TABLE;
int curLen = pows.length;
// The following comparison and the above synchronized statement is
// to prevent multiple threads from expanding the same array.
if (curLen <= n) {
int newLen = curLen << 1;
while (newLen <= n)
newLen <<= 1;
pows = Arrays.copyOf(pows, newLen);
for (int i = curLen; i < newLen; i++)
pows[i] = pows[i - 1].multiply(BigInteger.TEN);
// Based on the following facts:
// 1. pows is a private local varible;
// 2. the following store is a volatile store.
// the newly created array elements can be safely published.
BIG_TEN_POWERS_TABLE = pows;
}
return pows[n];
}
}
private static final long[] LONG_TEN_POWERS_TABLE = {
1, // 0 / 10^0
10, // 1 / 10^1
100, // 2 / 10^2
1000, // 3 / 10^3
10000, // 4 / 10^4
100000, // 5 / 10^5
1000000, // 6 / 10^6
10000000, // 7 / 10^7
100000000, // 8 / 10^8
1000000000, // 9 / 10^9
10000000000L, // 10 / 10^10
100000000000L, // 11 / 10^11
1000000000000L, // 12 / 10^12
10000000000000L, // 13 / 10^13
100000000000000L, // 14 / 10^14
1000000000000000L, // 15 / 10^15
10000000000000000L, // 16 / 10^16
100000000000000000L, // 17 / 10^17
1000000000000000000L // 18 / 10^18
};
private static volatile BigInteger BIG_TEN_POWERS_TABLE[] = {BigInteger.ONE,
BigInteger.valueOf(10), BigInteger.valueOf(100),
BigInteger.valueOf(1000), BigInteger.valueOf(10000),
BigInteger.valueOf(100000), BigInteger.valueOf(1000000),
BigInteger.valueOf(10000000), BigInteger.valueOf(100000000),
BigInteger.valueOf(1000000000)};
BigInteger.valueOf(1000000000),
BigInteger.valueOf(10000000000L),
BigInteger.valueOf(100000000000L),
BigInteger.valueOf(1000000000000L),
BigInteger.valueOf(10000000000000L),
BigInteger.valueOf(100000000000000L),
BigInteger.valueOf(1000000000000000L),
BigInteger.valueOf(10000000000000000L),
BigInteger.valueOf(100000000000000000L),
BigInteger.valueOf(1000000000000000000L)
};
private static final int BIG_TEN_POWERS_TABLE_INITLEN =
BIG_TEN_POWERS_TABLE.length;
private static final int BIG_TEN_POWERS_TABLE_MAX =
16 * BIG_TEN_POWERS_TABLE_INITLEN;
private static final long THRESHOLDS_TABLE[] = {
Long.MAX_VALUE, // 0
Long.MAX_VALUE/10L, // 1
Long.MAX_VALUE/100L, // 2
Long.MAX_VALUE/1000L, // 3
Long.MAX_VALUE/10000L, // 4
Long.MAX_VALUE/100000L, // 5
Long.MAX_VALUE/1000000L, // 6
Long.MAX_VALUE/10000000L, // 7
Long.MAX_VALUE/100000000L, // 8
Long.MAX_VALUE/1000000000L, // 9
Long.MAX_VALUE/10000000000L, // 10
Long.MAX_VALUE/100000000000L, // 11
Long.MAX_VALUE/1000000000000L, // 12
Long.MAX_VALUE/10000000000000L, // 13
Long.MAX_VALUE/100000000000000L, // 14
Long.MAX_VALUE/1000000000000000L, // 15
Long.MAX_VALUE/10000000000000000L, // 16
Long.MAX_VALUE/100000000000000000L, // 17
Long.MAX_VALUE/1000000000000000000L // 18
};
/**
* Compute val * 10 ^ n; return this product if it is
* representable as a long, INFLATED otherwise.
*/
private static long longTenToThe(long val, int n) {
// System.err.print("\tval " + val + "\t power " + n + "\tresult ");
if (n >= 0 && n < thresholds.length) {
if (Math.abs(val) <= thresholds[n][0] ) {
// System.err.println(val * thresholds[n][1]);
return val * thresholds[n][1];
private static long longMultiplyPowerTen(long val, int n) {
if (val == 0 || n <= 0)
return val;
long[] tab = LONG_TEN_POWERS_TABLE;
long[] bounds = THRESHOLDS_TABLE;
if (n < tab.length && n < bounds.length) {
long tenpower = tab[n];
if (val == 1)
return tenpower;
if (Math.abs(val) <= bounds[n])
return val * tenpower;
}
}
// System.err.println(INFLATED);
return INFLATED;
}
private static long thresholds[][] = {
{Long.MAX_VALUE, 1L}, // 0
{Long.MAX_VALUE/10L, 10L}, // 1
{Long.MAX_VALUE/100L, 100L}, // 2
{Long.MAX_VALUE/1000L, 1000L}, // 3
{Long.MAX_VALUE/10000L, 10000L}, // 4
{Long.MAX_VALUE/100000L, 100000L}, // 5
{Long.MAX_VALUE/1000000L, 1000000L}, // 6
{Long.MAX_VALUE/10000000L, 10000000L}, // 7
{Long.MAX_VALUE/100000000L, 100000000L}, // 8
{Long.MAX_VALUE/1000000000L, 1000000000L}, // 9
{Long.MAX_VALUE/10000000000L, 10000000000L}, // 10
{Long.MAX_VALUE/100000000000L, 100000000000L}, // 11
{Long.MAX_VALUE/1000000000000L, 1000000000000L},// 12
{Long.MAX_VALUE/100000000000000L, 10000000000000L},// 13
};
/**
* Compute this * 10 ^ n.
* Needed mainly to allow special casing to trap zero value
*/
private BigInteger bigMultiplyPowerTen(int n) {
if (n <= 0)
return this.inflate();
private static boolean compactLong(long val) {
return (val != Long.MIN_VALUE);
if (intCompact != INFLATED)
return bigTenToThe(n).multiply(intCompact);
else
return intVal.multiply(bigTenToThe(n));
}
/**
* Assign appropriate BigInteger to intVal field if intVal is
* null, i.e. the compact representation is in use.
*/
private BigDecimal inflate() {
private BigInteger inflate() {
if (intVal == null)
intVal = BigInteger.valueOf(intCompact);
return this;
return intVal;
}
/**
......@@ -3218,10 +3530,13 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* {@code BigDecimal}s to be aligned.
*/
private static void matchScale(BigDecimal[] val) {
if (val[0].scale < val[1].scale)
val[0] = val[0].setScale(val[1].scale);
else if (val[1].scale < val[0].scale)
val[1] = val[1].setScale(val[0].scale);
if (val[0].scale == val[1].scale) {
return;
} else if (val[0].scale < val[1].scale) {
val[0] = val[0].setScale(val[1].scale, ROUND_UNNECESSARY);
} else if (val[1].scale < val[0].scale) {
val[1] = val[1].setScale(val[0].scale, ROUND_UNNECESSARY);
}
}
/**
......@@ -3240,9 +3555,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
throw new java.io.StreamCorruptedException(message);
// [all values of scale are now allowed]
}
// Set intCompact to uninitialized value; could also see if the
// intVal was small enough to fit as a compact value.
intCompact = INFLATED;
intCompact = compactValFor(intVal);
}
/**
......@@ -3259,84 +3572,66 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
s.defaultWriteObject();
}
/**
* Returns the length of this {@code BigDecimal}, in decimal digits.
*
* Notes:
*<ul>
* <li> This is performance-critical; most operations where a
* context is supplied will need at least one call to this
* method.
*
* <li> This should be a method on BigInteger; the call to this
* method in precision() can then be replaced with the
* term: intVal.digitLength(). It could also be called
* precision() in BigInteger.
*
* Better still -- the precision lookaside could be moved to
* BigInteger, too.
* Returns the length of the absolute value of a {@code long}, in decimal
* digits.
*
* <li> This could/should use MutableBigIntegers directly for the
* reduction loop.
*<ul>
* @return the length of the unscaled value, in decimal digits
* @param x the {@code long}
* @return the length of the unscaled value, in deciaml digits.
*/
private int digitLength() {
if (intCompact != INFLATED && Math.abs(intCompact) <= Integer.MAX_VALUE)
return intLength(Math.abs((int)intCompact));
if (signum() == 0) // 0 is one decimal digit
private static int longDigitLength(long x) {
/*
* As described in "Bit Twiddling Hacks" by Sean Anderson,
* (http://graphics.stanford.edu/~seander/bithacks.html)
* integer log 10 of x is within 1 of
* (1233/4096)* (1 + integer log 2 of x).
* The fraction 1233/4096 approximates log10(2). So we first
* do a version of log2 (a variant of Long class with
* pre-checks and opposite directionality) and then scale and
* check against powers table. This is a little simpler in
* present context than the version in Hacker's Delight sec
* 11-4. Adding one to bit length allows comparing downward
* from the LONG_TEN_POWERS_TABLE that we need anyway.
*/
assert x != INFLATED;
if (x < 0)
x = -x;
if (x < 10) // must screen for 0, might as well 10
return 1;
this.inflate();
// we have a nonzero magnitude
BigInteger work = intVal;
int digits = 0; // counter
for (;work.mag.length>1;) {
// here when more than one integer in the magnitude; divide
// by a billion (reduce by 9 digits) and try again
work = work.divide(TENPOWERS[9]);
digits += 9;
if (work.signum() == 0) // the division was exact
return digits; // (a power of a billion)
}
// down to a simple nonzero integer
digits += intLength(work.mag[0]);
// System.out.println("digitLength... "+this+" -> "+digits);
return digits;
}
private static int[] ilogTable = {
0,
9,
99,
999,
9999,
99999,
999999,
9999999,
99999999,
999999999,
Integer.MAX_VALUE};
/**
* Returns the length of an unsigned {@code int}, in decimal digits.
* @param i the {@code int} (treated as unsigned)
int n = 64; // not 63, to avoid needing to add 1 later
int y = (int)(x >>> 32);
if (y == 0) { n -= 32; y = (int)x; }
if (y >>> 16 == 0) { n -= 16; y <<= 16; }
if (y >>> 24 == 0) { n -= 8; y <<= 8; }
if (y >>> 28 == 0) { n -= 4; y <<= 4; }
if (y >>> 30 == 0) { n -= 2; y <<= 2; }
int r = (((y >>> 31) + n) * 1233) >>> 12;
long[] tab = LONG_TEN_POWERS_TABLE;
// if r >= length, must have max possible digits for long
return (r >= tab.length || x < tab[r])? r : r+1;
}
/**
* Returns the length of the absolute value of a BigInteger, in
* decimal digits.
*
* @param b the BigInteger
* @return the length of the unscaled value, in decimal digits
*/
private int intLength(int x) {
int digits;
if (x < 0) { // 'negative' is 10 digits unsigned
return 10;
} else { // positive integer
if (x <= 9)
private static int bigDigitLength(BigInteger b) {
/*
* Same idea as the long version, but we need a better
* approximation of log10(2). Using 646456993/2^31
* is accurate up to max possible reported bitLength.
*/
if (b.signum == 0)
return 1;
// "Hacker's Delight" section 11-4
for(int i = -1; ; i++) {
if (x <= ilogTable[i+1])
return i +1;
}
}
int r = (int)((((long)b.bitLength() + 1) * 646456993) >>> 31);
return b.compareMagnitude(bigTenToThe(r)) < 0? r : r+1;
}
/**
* Remove insignificant trailing zeros from this
* {@code BigDecimal} until the preferred scale is reached or no
......@@ -3352,10 +3647,9 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* to be closed to the preferred scale.
*/
private BigDecimal stripZerosToMatchScale(long preferredScale) {
boolean compact = (intCompact != INFLATED);
this.inflate();
BigInteger qr[]; // quotient-remainder pair
while ( intVal.abs().compareTo(BigInteger.TEN) >= 0 &&
while ( intVal.compareMagnitude(BigInteger.TEN) >= 0 &&
scale > preferredScale) {
if (intVal.testBit(0))
break; // odd number cannot end in 0
......@@ -3367,17 +3661,16 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
if (precision > 0) // adjust precision if known
precision--;
}
if (compact)
intCompact = intVal.longValue();
if (intVal != null)
intCompact = compactValFor(intVal);
return this;
}
/**
* Check a scale for Underflow or Overflow. If this BigDecimal is
* uninitialized or initialized and nonzero, throw an exception if
* the scale is out of range. If this is zero, saturate the scale
* to the extreme value of the right sign if the scale is out of
* range.
* nonzero, throw an exception if the scale is outof range. If this
* is zero, saturate the scale to the extreme value of the right
* sign if the scale is out of range.
*
* @param val The new scale.
* @throws ArithmeticException (overflow or underflow) if the new
......@@ -3385,19 +3678,15 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* @return validated scale as an int.
*/
private int checkScale(long val) {
if ((int)val != val) {
if ((this.intCompact != INFLATED && this.intCompact != 0) ||
(this.intVal != null && this.signum() != 0) ||
(this.intVal == null && this.intCompact == INFLATED) ) {
if (val > Integer.MAX_VALUE)
throw new ArithmeticException("Underflow");
if (val < Integer.MIN_VALUE)
throw new ArithmeticException("Overflow");
} else {
return (val > Integer.MAX_VALUE)?Integer.MAX_VALUE:Integer.MIN_VALUE;
}
int asInt = (int)val;
if (asInt != val) {
asInt = val>Integer.MAX_VALUE ? Integer.MAX_VALUE : Integer.MIN_VALUE;
BigInteger b;
if (intCompact != 0 &&
((b = intVal) == null || b.signum() != 0))
throw new ArithmeticException(asInt>0 ? "Underflow":"Overflow");
}
return (int)val;
return asInt;
}
/**
......@@ -3410,7 +3699,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* rounding mode is {@code UNNECESSARY}.
*/
private BigDecimal roundOp(MathContext mc) {
BigDecimal rounded = doRound(mc);
BigDecimal rounded = doRound(this, mc);
return rounded;
}
......@@ -3426,7 +3715,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* {@code BigDecimal} operation would require rounding.
*/
private void roundThis(MathContext mc) {
BigDecimal rounded = doRound(mc);
BigDecimal rounded = doRound(this, mc);
if (rounded == this) // wasn't rounded
return;
this.intVal = rounded.intVal;
......@@ -3448,56 +3737,56 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
* {@code RoundingMode.UNNECESSARY} and the
* result is inexact.
*/
private BigDecimal doRound(MathContext mc) {
this.inflate();
if (precision == 0) {
if (mc.roundingMax != null
&& intVal.compareTo(mc.roundingMax) < 0
&& intVal.compareTo(mc.roundingMin) > 0)
return this; // no rounding needed
precision(); // find it
}
int drop = precision - mc.precision; // digits to discard
if (drop <= 0) // we fit
return this;
BigDecimal rounded = dropDigits(mc, drop);
// we need to double-check, in case of the 999=>1000 case
return rounded.doRound(mc);
private static BigDecimal doRound(BigDecimal d, MathContext mc) {
int mcp = mc.precision;
int drop;
// This might (rarely) iterate to cover the 999=>1000 case
while ((drop = d.precision() - mcp) > 0) {
int newScale = d.checkScale((long)d.scale - drop);
int mode = mc.roundingMode.oldMode;
if (drop < LONG_TEN_POWERS_TABLE.length)
d = divideAndRound(d.intCompact, d.intVal,
LONG_TEN_POWERS_TABLE[drop], null,
newScale, mode, newScale);
else
d = divideAndRound(d.intCompact, d.intVal,
INFLATED, bigTenToThe(drop),
newScale, mode, newScale);
}
return d;
}
/**
* Removes digits from the significand of a {@code BigDecimal},
* rounding according to the MathContext settings. Does not
* change {@code this}; a new {@code BigDecimal} is always
* created and returned.
*
* <p>Actual rounding is carried out, as before, by the divide
* method, as this minimized code changes. It might be more
* efficient in most cases to move rounding to here, so we can do
* a round-to-length rather than round-to-scale.
*
* @param mc the context to use.
* @param drop the number of digits to drop, must be {@literal >} 0
* @return a {@code BigDecimal} rounded according to the MathContext
* settings. May return {@code this}, if no rounding needed.
* @throws ArithmeticException if the rounding mode is
* {@code RoundingMode.UNNECESSARY} and the
* result is inexact.
* Returns the compact value for given {@code BigInteger}, or
* INFLATED if too big. Relies on internal representation of
* {@code BigInteger}.
*/
private BigDecimal dropDigits(MathContext mc, int drop) {
// here if we need to round; make the divisor = 10**drop)
// [calculating the BigInteger here saves setScale later]
BigDecimal divisor = new BigDecimal(tenToThe(drop), 0);
private static long compactValFor(BigInteger b) {
int[] m = b.mag;
int len = m.length;
if (len == 0)
return 0;
int d = m[0];
if (len > 2 || (len == 2 && d < 0))
return INFLATED;
// divide to same scale to force round to length
BigDecimal rounded = this.divide(divisor, scale,
mc.roundingMode.oldMode);
rounded.scale = checkScale((long)rounded.scale - drop ); // adjust the scale
return rounded;
long u = (len == 2)?
(((long) m[1] & LONG_MASK) + (((long)d) << 32)) :
(((long)d) & LONG_MASK);
return (b.signum < 0)? -u : u;
}
private static int longCompareMagnitude(long x, long y) {
if (x < 0)
x = -x;
if (y < 0)
y = -y;
return (x < y) ? -1 : ((x == y) ? 0 : 1);
}
private static int longCompareTo(long x, long y) {
return (x < y) ? -1 : (x == y) ? 0 : 1;
private static int saturateLong(long s) {
int i = (int)s;
return (s == i) ? i : (s < 0 ? Integer.MIN_VALUE : Integer.MAX_VALUE);
}
/*
......@@ -3527,21 +3816,21 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
*
* <li>If precision is nonzero, it must have the right value.
* </ul>
*
* Note: Since this is an audit method, we are not supposed to change the
* state of this BigDecimal object.
*/
private BigDecimal audit() {
// Check precision
if (precision > 0) {
if (precision != digitLength()) {
print("audit", this);
throw new AssertionError("precision mismatch");
}
}
if (intCompact == INFLATED) {
if (intVal == null) {
print("audit", this);
throw new AssertionError("null intVal");
}
// Check precision
if (precision > 0 && precision != bigDigitLength(intVal)) {
print("audit", this);
throw new AssertionError("precision mismatch");
}
} else {
if (intVal != null) {
long val = intVal.longValue();
......@@ -3551,6 +3840,11 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
intCompact + "\t intVal=" + val);
}
}
// Check precision
if (precision > 0 && precision != longDigitLength(intCompact)) {
print("audit", this);
throw new AssertionError("precision mismatch");
}
}
return this;
}
......
src/share/classes/java/math/BigInteger.java
浏览文件 @ 364bf2a3
......@@ -105,7 +105,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
*
* @serial
*/
int signum;
final int signum;
/**
* The magnitude of this BigInteger, in <i>big-endian</i> order: the
......@@ -116,61 +116,62 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* value. Note that this implies that the BigInteger zero has a
* zero-length mag array.
*/
int[] mag;
final int[] mag;
// These "redundant fields" are initialized with recognizable nonsense
// values, and cached the first time they are needed (or never, if they
// aren't needed).
/**
* The bitCount of this BigInteger, as returned by bitCount(), or -1
* (either value is acceptable).
* One plus the bitCount of this BigInteger. Zeros means unitialized.
*
* @serial
* @see #bitCount
* @deprecated Deprecated since logical value is offset from stored
* value and correction factor is applied in accessor method.
*/
private int bitCount = -1;
@Deprecated
private int bitCount;
/**
* The bitLength of this BigInteger, as returned by bitLength(), or -1
* One plus the bitLength of this BigInteger. Zeros means unitialized.
* (either value is acceptable).
*
* @serial
* @see #bitLength()
* @deprecated Deprecated since logical value is offset from stored
* value and correction factor is applied in accessor method.
*/
private int bitLength = -1;
@Deprecated
private int bitLength;
/**
* The lowest set bit of this BigInteger, as returned by getLowestSetBit(),
* or -2 (either value is acceptable).
* Two plus the lowest set bit of this BigInteger, as returned by
* getLowestSetBit().
*
* @serial
* @see #getLowestSetBit
* @deprecated Deprecated since logical value is offset from stored
* value and correction factor is applied in accessor method.
*/
private int lowestSetBit = -2;
@Deprecated
private int lowestSetBit;
/**
* The index of the lowest-order byte in the magnitude of this BigInteger
* that contains a nonzero byte, or -2 (either value is acceptable). The
* least significant byte has int-number 0, the next byte in order of
* increasing significance has byte-number 1, and so forth.
*
* @serial
*/
private int firstNonzeroByteNum = -2;
/**
* The index of the lowest-order int in the magnitude of this BigInteger
* that contains a nonzero int, or -2 (either value is acceptable). The
* least significant int has int-number 0, the next int in order of
* Two plus the index of the lowest-order int in the magnitude of this
* BigInteger that contains a nonzero int, or -2 (either value is acceptable).
* The least significant int has int-number 0, the next int in order of
* increasing significance has int-number 1, and so forth.
* @deprecated Deprecated since logical value is offset from stored
* value and correction factor is applied in accessor method.
*/
private int firstNonzeroIntNum = -2;
@Deprecated
private int firstNonzeroIntNum;
/**
* This mask is used to obtain the value of an int as if it were unsigned.
*/
private final static long LONG_MASK = 0xffffffffL;
final static long LONG_MASK = 0xffffffffL;
//Constructors
......@@ -295,7 +296,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
throw new NumberFormatException("Zero length BigInteger");
// Check for at most one leading sign
signum = 1;
int sign = 1;
int index1 = val.lastIndexOf('-');
int index2 = val.lastIndexOf('+');
if ((index1 + index2) <= -1) {
......@@ -306,7 +307,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
throw new NumberFormatException("Zero length BigInteger");
}
if (index1 == 0)
signum = -1;
sign = -1;
} else
throw new NumberFormatException("Illegal embedded sign character");
......@@ -318,23 +319,24 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
signum = 0;
mag = ZERO.mag;
return;
} else {
numDigits = len - cursor;
}
numDigits = len - cursor;
signum = sign;
// Pre-allocate array of expected size. May be too large but can
// never be too small. Typically exact.
int numBits = (int)(((numDigits * bitsPerDigit[radix]) >>> 10) + 1);
int numWords = (numBits + 31) /32;
mag = new int[numWords];
int numWords = (numBits + 31) >>> 5;
int[] magnitude = new int[numWords];
// Process first (potentially short) digit group
int firstGroupLen = numDigits % digitsPerInt[radix];
if (firstGroupLen == 0)
firstGroupLen = digitsPerInt[radix];
String group = val.substring(cursor, cursor += firstGroupLen);
mag[mag.length - 1] = Integer.parseInt(group, radix);
if (mag[mag.length - 1] < 0)
magnitude[numWords - 1] = Integer.parseInt(group, radix);
if (magnitude[numWords - 1] < 0)
throw new NumberFormatException("Illegal digit");
// Process remaining digit groups
......@@ -345,10 +347,10 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
groupVal = Integer.parseInt(group, radix);
if (groupVal < 0)
throw new NumberFormatException("Illegal digit");
destructiveMulAdd(mag, superRadix, groupVal);
destructiveMulAdd(magnitude, superRadix, groupVal);
}
// Required for cases where the array was overallocated.
mag = trustedStripLeadingZeroInts(mag);
mag = trustedStripLeadingZeroInts(magnitude);
}
// Constructs a new BigInteger using a char array with radix=10
......@@ -357,11 +359,11 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int len = val.length;
// Check for leading minus sign
signum = 1;
int sign = 1;
if (val[0] == '-') {
if (len == 1)
throw new NumberFormatException("Zero length BigInteger");
signum = -1;
sign = -1;
cursor = 1;
} else if (val[0] == '+') {
if (len == 1)
......@@ -376,32 +378,33 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
signum = 0;
mag = ZERO.mag;
return;
} else {
numDigits = len - cursor;
}
numDigits = len - cursor;
signum = sign;
// Pre-allocate array of expected size
int numWords;
if (len < 10) {
numWords = 1;
} else {
int numBits = (int)(((numDigits * bitsPerDigit[10]) >>> 10) + 1);
numWords = (numBits + 31) /32;
numWords = (numBits + 31) >>> 5;
}
mag = new int[numWords];
int[] magnitude = new int[numWords];
// Process first (potentially short) digit group
int firstGroupLen = numDigits % digitsPerInt[10];
if (firstGroupLen == 0)
firstGroupLen = digitsPerInt[10];
mag[mag.length-1] = parseInt(val, cursor, cursor += firstGroupLen);
magnitude[numWords - 1] = parseInt(val, cursor, cursor += firstGroupLen);
// Process remaining digit groups
while (cursor < len) {
int groupVal = parseInt(val, cursor, cursor += digitsPerInt[10]);
destructiveMulAdd(mag, intRadix[10], groupVal);
destructiveMulAdd(magnitude, intRadix[10], groupVal);
}
mag = trustedStripLeadingZeroInts(mag);
mag = trustedStripLeadingZeroInts(magnitude);
}
// Create an integer with the digits between the two indexes
......@@ -842,26 +845,21 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
u2 = u.multiply(v).mod(n);
v2 = v.square().add(d.multiply(u.square())).mod(n);
if (v2.testBit(0)) {
v2 = n.subtract(v2);
v2.signum = - v2.signum;
}
if (v2.testBit(0))
v2 = v2.subtract(n);
v2 = v2.shiftRight(1);
u = u2; v = v2;
if (k.testBit(i)) {
u2 = u.add(v).mod(n);
if (u2.testBit(0)) {
u2 = n.subtract(u2);
u2.signum = - u2.signum;
}
u2 = u2.shiftRight(1);
if (u2.testBit(0))
u2 = u2.subtract(n);
u2 = u2.shiftRight(1);
v2 = v.add(d.multiply(u)).mod(n);
if (v2.testBit(0)) {
v2 = n.subtract(v2);
v2.signum = - v2.signum;
}
if (v2.testBit(0))
v2 = v2.subtract(n);
v2 = v2.shiftRight(1);
u = u2; v = v2;
......@@ -918,11 +916,11 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
}
/**
* This private constructor differs from its public cousin
* This internal constructor differs from its public cousin
* with the arguments reversed in two ways: it assumes that its
* arguments are correct, and it doesn't copy the magnitude array.
*/
private BigInteger(int[] magnitude, int signum) {
BigInteger(int[] magnitude, int signum) {
this.signum = (magnitude.length==0 ? 0 : signum);
this.mag = magnitude;
}
......@@ -936,22 +934,6 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
this.mag = stripLeadingZeroBytes(magnitude);
}
/**
* This private constructor is for internal use in converting
* from a MutableBigInteger object into a BigInteger.
*/
BigInteger(MutableBigInteger val, int sign) {
if (val.offset > 0 || val.value.length != val.intLen) {
mag = new int[val.intLen];
for(int i=0; i<val.intLen; i++)
mag[i] = val.value[val.offset+i];
} else {
mag = val.value;
}
this.signum = (val.intLen == 0) ? 0 : sign;
}
//Static Factory Methods
/**
......@@ -980,8 +962,8 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
*/
private BigInteger(long val) {
if (val < 0) {
signum = -1;
val = -val;
signum = -1;
} else {
signum = 1;
}
......@@ -1058,7 +1040,6 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* @return {@code this + val}
*/
public BigInteger add(BigInteger val) {
int[] resultMag;
if (val.signum == 0)
return this;
if (signum == 0)
......@@ -1066,14 +1047,14 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (val.signum == signum)
return new BigInteger(add(mag, val.mag), signum);
int cmp = intArrayCmp(mag, val.mag);
if (cmp==0)
int cmp = compareMagnitude(val);
if (cmp == 0)
return ZERO;
resultMag = (cmp>0 ? subtract(mag, val.mag)
int[] resultMag = (cmp > 0 ? subtract(mag, val.mag)
: subtract(val.mag, mag));
resultMag = trustedStripLeadingZeroInts(resultMag);
return new BigInteger(resultMag, cmp*signum);
return new BigInteger(resultMag, cmp == signum ? 1 : -1);
}
/**
......@@ -1112,12 +1093,10 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// Grow result if necessary
if (carry) {
int newLen = result.length + 1;
int temp[] = new int[newLen];
for (int i = 1; i<newLen; i++)
temp[i] = result[i-1];
temp[0] = 0x01;
result = temp;
int bigger[] = new int[result.length + 1];
System.arraycopy(result, 0, bigger, 1, result.length);
bigger[0] = 0x01;
return bigger;
}
return result;
}
......@@ -1129,7 +1108,6 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* @return {@code this - val}
*/
public BigInteger subtract(BigInteger val) {
int[] resultMag;
if (val.signum == 0)
return this;
if (signum == 0)
......@@ -1137,13 +1115,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (val.signum != signum)
return new BigInteger(add(mag, val.mag), signum);
int cmp = intArrayCmp(mag, val.mag);
if (cmp==0)
int cmp = compareMagnitude(val);
if (cmp == 0)
return ZERO;
resultMag = (cmp>0 ? subtract(mag, val.mag)
int[] resultMag = (cmp > 0 ? subtract(mag, val.mag)
: subtract(val.mag, mag));
resultMag = trustedStripLeadingZeroInts(resultMag);
return new BigInteger(resultMag, cmp*signum);
return new BigInteger(resultMag, cmp == signum ? 1 : -1);
}
/**
......@@ -1191,12 +1169,54 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int[] result = multiplyToLen(mag, mag.length,
val.mag, val.mag.length, null);
result = trustedStripLeadingZeroInts(result);
return new BigInteger(result, signum*val.signum);
return new BigInteger(result, signum == val.signum ? 1 : -1);
}
/**
* Package private methods used by BigDecimal code to multiply a BigInteger
* with a long. Assumes v is not equal to INFLATED.
*/
BigInteger multiply(long v) {
if (v == 0 || signum == 0)
return ZERO;
if (v == BigDecimal.INFLATED)
return multiply(BigInteger.valueOf(v));
int rsign = (v > 0 ? signum : -signum);
if (v < 0)
v = -v;
long dh = v >>> 32; // higher order bits
long dl = v & LONG_MASK; // lower order bits
int xlen = mag.length;
int[] value = mag;
int[] rmag = (dh == 0L) ? (new int[xlen + 1]) : (new int[xlen + 2]);
long carry = 0;
int rstart = rmag.length - 1;
for (int i = xlen - 1; i >= 0; i--) {
long product = (value[i] & LONG_MASK) * dl + carry;
rmag[rstart--] = (int)product;
carry = product >>> 32;
}
rmag[rstart] = (int)carry;
if (dh != 0L) {
carry = 0;
rstart = rmag.length - 2;
for (int i = xlen - 1; i >= 0; i--) {
long product = (value[i] & LONG_MASK) * dh +
(rmag[rstart] & LONG_MASK) + carry;
rmag[rstart--] = (int)product;
carry = product >>> 32;
}
rmag[0] = (int)carry;
}
if (carry == 0L)
rmag = java.util.Arrays.copyOfRange(rmag, 1, rmag.length);
return new BigInteger(rmag, rsign);
}
/**
* Multiplies int arrays x and y to the specified lengths and places
* the result into z.
* the result into z. There will be no leading zeros in the resultant array.
*/
private int[] multiplyToLen(int[] x, int xlen, int[] y, int ylen, int[] z) {
int xstart = xlen - 1;
......@@ -1316,12 +1336,11 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
*/
public BigInteger divide(BigInteger val) {
MutableBigInteger q = new MutableBigInteger(),
r = new MutableBigInteger(),
a = new MutableBigInteger(this.mag),
b = new MutableBigInteger(val.mag);
a.divide(b, q, r);
return new BigInteger(q, this.signum * val.signum);
a.divide(b, q);
return q.toBigInteger(this.signum == val.signum ? 1 : -1);
}
/**
......@@ -1338,12 +1357,11 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
public BigInteger[] divideAndRemainder(BigInteger val) {
BigInteger[] result = new BigInteger[2];
MutableBigInteger q = new MutableBigInteger(),
r = new MutableBigInteger(),
a = new MutableBigInteger(this.mag),
b = new MutableBigInteger(val.mag);
a.divide(b, q, r);
result[0] = new BigInteger(q, this.signum * val.signum);
result[1] = new BigInteger(r, this.signum);
MutableBigInteger r = a.divide(b, q);
result[0] = q.toBigInteger(this.signum == val.signum ? 1 : -1);
result[1] = r.toBigInteger(this.signum);
return result;
}
......@@ -1357,12 +1375,10 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
*/
public BigInteger remainder(BigInteger val) {
MutableBigInteger q = new MutableBigInteger(),
r = new MutableBigInteger(),
a = new MutableBigInteger(this.mag),
b = new MutableBigInteger(val.mag);
a.divide(b, q, r);
return new BigInteger(r, this.signum);
return a.divide(b, q).toBigInteger(this.signum);
}
/**
......@@ -1418,7 +1434,14 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
MutableBigInteger result = a.hybridGCD(b);
return new BigInteger(result, 1);
return result.toBigInteger(1);
}
/**
* Package private method to return bit length for an integer.
*/
static int bitLengthForInt(int n) {
return 32 - Integer.numberOfLeadingZeros(n);
}
/**
......@@ -1428,7 +1451,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
private static int[] leftShift(int[] a, int len, int n) {
int nInts = n >>> 5;
int nBits = n&0x1F;
int bitsInHighWord = bitLen(a[0]);
int bitsInHighWord = bitLengthForInt(a[0]);
// If shift can be done without recopy, do so
if (n <= (32-bitsInHighWord)) {
......@@ -1481,9 +1504,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* assuming there are no leading zero ints.
*/
private static int bitLength(int[] val, int len) {
if (len==0)
if (len == 0)
return 0;
return ((len-1)<<5) + bitLen(val[0]);
return ((len - 1) << 5) + bitLengthForInt(val[0]);
}
/**
......@@ -1710,11 +1733,10 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int[] a = leftShift(base, base.length, modLen << 5);
MutableBigInteger q = new MutableBigInteger(),
r = new MutableBigInteger(),
a2 = new MutableBigInteger(a),
b2 = new MutableBigInteger(mod);
a2.divide(b2, q, r);
MutableBigInteger r= a2.divide(b2, q);
table[0] = r.toIntArray();
// Pad table[0] with leading zeros so its length is at least modLen
......@@ -1976,7 +1998,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
return this;
// Copy remaining ints of mag
int numInts = (p+31)/32;
int numInts = (p + 31) >>> 5;
int[] mag = new int[numInts];
for (int i=0; i<numInts; i++)
mag[i] = this.mag[i + (this.mag.length - numInts)];
......@@ -2006,7 +2028,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// Calculate (this mod m)
BigInteger modVal = this;
if (signum < 0 || (intArrayCmp(mag, m.mag) >= 0))
if (signum < 0 || (this.compareMagnitude(m) >= 0))
modVal = this.mod(m);
if (modVal.equals(ONE))
......@@ -2016,7 +2038,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
MutableBigInteger b = new MutableBigInteger(m);
MutableBigInteger result = a.mutableModInverse(b);
return new BigInteger(result, 1);
return result.toBigInteger(1);
}
// Shift Operations
......@@ -2241,7 +2263,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (n<0)
throw new ArithmeticException("Negative bit address");
return (getInt(n/32) & (1 << (n%32))) != 0;
return (getInt(n >>> 5) & (1 << (n & 31))) != 0;
}
/**
......@@ -2256,13 +2278,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (n<0)
throw new ArithmeticException("Negative bit address");
int intNum = n/32;
int intNum = n >>> 5;
int[] result = new int[Math.max(intLength(), intNum+2)];
for (int i=0; i<result.length; i++)
result[result.length-i-1] = getInt(i);
result[result.length-intNum-1] |= (1 << (n%32));
result[result.length-intNum-1] |= (1 << (n & 31));
return valueOf(result);
}
......@@ -2280,13 +2302,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (n<0)
throw new ArithmeticException("Negative bit address");
int intNum = n/32;
int[] result = new int[Math.max(intLength(), (n+1)/32+1)];
int intNum = n >>> 5;
int[] result = new int[Math.max(intLength(), ((n + 1) >>> 5) + 1)];
for (int i=0; i<result.length; i++)
result[result.length-i-1] = getInt(i);
result[result.length-intNum-1] &= ~(1 << (n%32));
result[result.length-intNum-1] &= ~(1 << (n & 31));
return valueOf(result);
}
......@@ -2304,13 +2326,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (n<0)
throw new ArithmeticException("Negative bit address");
int intNum = n/32;
int intNum = n >>> 5;
int[] result = new int[Math.max(intLength(), intNum+2)];
for (int i=0; i<result.length; i++)
result[result.length-i-1] = getInt(i);
result[result.length-intNum-1] ^= (1 << (n%32));
result[result.length-intNum-1] ^= (1 << (n & 31));
return valueOf(result);
}
......@@ -2324,23 +2346,21 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* @return index of the rightmost one bit in this BigInteger.
*/
public int getLowestSetBit() {
/*
* Initialize lowestSetBit field the first time this method is
* executed. This method depends on the atomicity of int modifies;
* without this guarantee, it would have to be synchronized.
*/
if (lowestSetBit == -2) {
@SuppressWarnings("deprecation") int lsb = lowestSetBit - 2;
if (lsb == -2) { // lowestSetBit not initialized yet
lsb = 0;
if (signum == 0) {
lowestSetBit = -1;
lsb -= 1;
} else {
// Search for lowest order nonzero int
int i,b;
for (i=0; (b = getInt(i))==0; i++)
;
lowestSetBit = (i << 5) + trailingZeroCnt(b);
lsb += (i << 5) + Integer.numberOfTrailingZeros(b);
}
lowestSetBit = lsb + 2;
}
return lowestSetBit;
return lsb;
}
......@@ -2357,78 +2377,31 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* representation of this BigInteger, <i>excluding</i> a sign bit.
*/
public int bitLength() {
/*
* Initialize bitLength field the first time this method is executed.
* This method depends on the atomicity of int modifies; without
* this guarantee, it would have to be synchronized.
*/
if (bitLength == -1) {
if (signum == 0) {
bitLength = 0;
@SuppressWarnings("deprecation") int n = bitLength - 1;
if (n == -1) { // bitLength not initialized yet
int[] m = mag;
int len = m.length;
if (len == 0) {
n = 0; // offset by one to initialize
} else {
// Calculate the bit length of the magnitude
int magBitLength = ((mag.length-1) << 5) + bitLen(mag[0]);
int magBitLength = ((len - 1) << 5) + bitLengthForInt(mag[0]);
if (signum < 0) {
// Check if magnitude is a power of two
boolean pow2 = (bitCnt(mag[0]) == 1);
for(int i=1; i<mag.length && pow2; i++)
pow2 = (mag[i]==0);
boolean pow2 = (Integer.bitCount(mag[0]) == 1);
for(int i=1; i< len && pow2; i++)
pow2 = (mag[i] == 0);
bitLength = (pow2 ? magBitLength-1 : magBitLength);
n = (pow2 ? magBitLength -1 : magBitLength);
} else {
bitLength = magBitLength;
n = magBitLength;
}
}
bitLength = n + 1;
}
return bitLength;
return n;
}
/**
* bitLen(val) is the number of bits in val.
*/
static int bitLen(int w) {
// Binary search - decision tree (5 tests, rarely 6)
return
(w < 1<<15 ?
(w < 1<<7 ?
(w < 1<<3 ?
(w < 1<<1 ? (w < 1<<0 ? (w<0 ? 32 : 0) : 1) : (w < 1<<2 ? 2 : 3)) :
(w < 1<<5 ? (w < 1<<4 ? 4 : 5) : (w < 1<<6 ? 6 : 7))) :
(w < 1<<11 ?
(w < 1<<9 ? (w < 1<<8 ? 8 : 9) : (w < 1<<10 ? 10 : 11)) :
(w < 1<<13 ? (w < 1<<12 ? 12 : 13) : (w < 1<<14 ? 14 : 15)))) :
(w < 1<<23 ?
(w < 1<<19 ?
(w < 1<<17 ? (w < 1<<16 ? 16 : 17) : (w < 1<<18 ? 18 : 19)) :
(w < 1<<21 ? (w < 1<<20 ? 20 : 21) : (w < 1<<22 ? 22 : 23))) :
(w < 1<<27 ?
(w < 1<<25 ? (w < 1<<24 ? 24 : 25) : (w < 1<<26 ? 26 : 27)) :
(w < 1<<29 ? (w < 1<<28 ? 28 : 29) : (w < 1<<30 ? 30 : 31)))));
}
/*
* trailingZeroTable[i] is the number of trailing zero bits in the binary
* representation of i.
*/
final static byte trailingZeroTable[] = {
-25, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0,
4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0};
/**
* Returns the number of bits in the two's complement representation
* of this BigInteger that differ from its sign bit. This method is
......@@ -2438,58 +2411,23 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* of this BigInteger that differ from its sign bit.
*/
public int bitCount() {
/*
* Initialize bitCount field the first time this method is executed.
* This method depends on the atomicity of int modifies; without
* this guarantee, it would have to be synchronized.
*/
if (bitCount == -1) {
@SuppressWarnings("deprecation") int bc = bitCount - 1;
if (bc == -1) { // bitCount not initialized yet
bc = 0; // offset by one to initialize
// Count the bits in the magnitude
int magBitCount = 0;
for (int i=0; i<mag.length; i++)
magBitCount += bitCnt(mag[i]);
bc += Integer.bitCount(mag[i]);
if (signum < 0) {
// Count the trailing zeros in the magnitude
int magTrailingZeroCount = 0, j;
for (j=mag.length-1; mag[j]==0; j--)
magTrailingZeroCount += 32;
magTrailingZeroCount +=
trailingZeroCnt(mag[j]);
bitCount = magBitCount + magTrailingZeroCount - 1;
} else {
bitCount = magBitCount;
}
magTrailingZeroCount += Integer.numberOfTrailingZeros(mag[j]);
bc += magTrailingZeroCount - 1;
}
return bitCount;
bitCount = bc + 1;
}
static int bitCnt(int val) {
val -= (0xaaaaaaaa & val) >>> 1;
val = (val & 0x33333333) + ((val >>> 2) & 0x33333333);
val = val + (val >>> 4) & 0x0f0f0f0f;
val += val >>> 8;
val += val >>> 16;
return val & 0xff;
}
static int trailingZeroCnt(int val) {
// Loop unrolled for performance
int byteVal = val & 0xff;
if (byteVal != 0)
return trailingZeroTable[byteVal];
byteVal = (val >>> 8) & 0xff;
if (byteVal != 0)
return trailingZeroTable[byteVal] + 8;
byteVal = (val >>> 16) & 0xff;
if (byteVal != 0)
return trailingZeroTable[byteVal] + 16;
byteVal = (val >>> 24) & 0xff;
return trailingZeroTable[byteVal] + 24;
return bc;
}
// Primality Testing
......@@ -2536,29 +2474,41 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* to, or greater than {@code val}.
*/
public int compareTo(BigInteger val) {
return (signum==val.signum
? signum*intArrayCmp(mag, val.mag)
: (signum>val.signum ? 1 : -1));
if (signum == val.signum) {
switch (signum) {
case 1:
return compareMagnitude(val);
case -1:
return val.compareMagnitude(this);
default:
return 0;
}
}
return signum > val.signum ? 1 : -1;
}
/*
* Returns -1, 0 or +1 as big-endian unsigned int array arg1 is
* less than, equal to, or greater than arg2.
/**
* Compares the magnitude array of this BigInteger with the specified
* BigInteger's. This is the version of compareTo ignoring sign.
*
* @param val BigInteger whose magnitude array to be compared.
* @return -1, 0 or 1 as this magnitude array is less than, equal to or
* greater than the magnitude aray for the specified BigInteger's.
*/
private static int intArrayCmp(int[] arg1, int[] arg2) {
if (arg1.length < arg2.length)
final int compareMagnitude(BigInteger val) {
int[] m1 = mag;
int len1 = m1.length;
int[] m2 = val.mag;
int len2 = m2.length;
if (len1 < len2)
return -1;
if (arg1.length > arg2.length)
return 1;
// Argument lengths are equal; compare the values
for (int i=0; i<arg1.length; i++) {
long b1 = arg1[i] & LONG_MASK;
long b2 = arg2[i] & LONG_MASK;
if (b1 < b2)
return -1;
if (b1 > b2)
if (len1 > len2)
return 1;
for (int i = 0; i < len1; i++) {
int a = m1[i];
int b = m2[i];
if (a != b)
return ((a & LONG_MASK) < (b & LONG_MASK)) ? -1 : 1;
}
return 0;
}
......@@ -2577,13 +2527,19 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (!(x instanceof BigInteger))
return false;
BigInteger xInt = (BigInteger) x;
if (xInt.signum != signum)
return false;
if (xInt.signum != signum || xInt.mag.length != mag.length)
int[] m = mag;
int len = m.length;
int[] xm = xInt.mag;
if (len != xm.length)
return false;
for (int i=0; i<mag.length; i++)
if (xInt.mag[i] != mag[i])
for (int i = 0; i < len; i++)
if (xm[i] != m[i])
return false;
return true;
......@@ -2662,12 +2618,11 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
BigInteger d = longRadix[radix];
MutableBigInteger q = new MutableBigInteger(),
r = new MutableBigInteger(),
a = new MutableBigInteger(tmp.mag),
b = new MutableBigInteger(d.mag);
a.divide(b, q, r);
BigInteger q2 = new BigInteger(q, tmp.signum * d.signum);
BigInteger r2 = new BigInteger(r, tmp.signum * d.signum);
MutableBigInteger r = a.divide(b, q);
BigInteger q2 = q.toBigInteger(tmp.signum * d.signum);
BigInteger r2 = r.toBigInteger(tmp.signum * d.signum);
digitGroup[numGroups++] = Long.toString(r2.longValue(), radix);
tmp = q2;
......@@ -2836,18 +2791,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* Returns a copy of the input array stripped of any leading zero bytes.
*/
private static int[] stripLeadingZeroInts(int val[]) {
int byteLength = val.length;
int vlen = val.length;
int keep;
// Find first nonzero byte
for (keep=0; keep<val.length && val[keep]==0; keep++)
for (keep = 0; keep < vlen && val[keep] == 0; keep++)
;
int result[] = new int[val.length - keep];
for(int i=0; i<val.length - keep; i++)
result[i] = val[keep+i];
return result;
return java.util.Arrays.copyOfRange(val, keep, vlen);
}
/**
......@@ -2855,21 +2805,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* Since the source is trusted the copying may be skipped.
*/
private static int[] trustedStripLeadingZeroInts(int val[]) {
int byteLength = val.length;
int vlen = val.length;
int keep;
// Find first nonzero byte
for (keep=0; keep<val.length && val[keep]==0; keep++)
for (keep = 0; keep < vlen && val[keep] == 0; keep++)
;
// Only perform copy if necessary
if (keep > 0) {
int result[] = new int[val.length - keep];
for(int i=0; i<val.length - keep; i++)
result[i] = val[keep+i];
return result;
}
return val;
return keep == 0 ? val : java.util.Arrays.copyOfRange(val, keep, vlen);
}
/**
......@@ -2880,18 +2822,18 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int keep;
// Find first nonzero byte
for (keep=0; keep<a.length && a[keep]==0; keep++)
for (keep = 0; keep < byteLength && a[keep]==0; keep++)
;
// Allocate new array and copy relevant part of input array
int intLength = ((byteLength - keep) + 3)/4;
int intLength = ((byteLength - keep) + 3) >>> 2;
int[] result = new int[intLength];
int b = byteLength - 1;
for (int i = intLength-1; i >= 0; i--) {
result[i] = a[b--] & 0xff;
int bytesRemaining = b - keep + 1;
int bytesToTransfer = Math.min(3, bytesRemaining);
for (int j=8; j <= 8*bytesToTransfer; j += 8)
for (int j=8; j <= (bytesToTransfer << 3); j += 8)
result[i] |= ((a[b--] & 0xff) << j);
}
return result;
......@@ -3037,7 +2979,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* including space for at least one sign bit.
*/
private int intLength() {
return bitLength()/32 + 1;
return (bitLength() >>> 5) + 1;
}
/* Returns sign bit */
......@@ -3074,19 +3016,19 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* least significant). If the magnitude is zero, return value is undefined.
*/
private int firstNonzeroIntNum() {
/*
* Initialize firstNonzeroIntNum field the first time this method is
* executed. This method depends on the atomicity of int modifies;
* without this guarantee, it would have to be synchronized.
*/
if (firstNonzeroIntNum == -2) {
int fn = firstNonzeroIntNum - 2;
if (fn == -2) { // firstNonzeroIntNum not initialized yet
fn = 0;
// Search for the first nonzero int
int i;
for (i=mag.length-1; i>=0 && mag[i]==0; i--)
int mlen = mag.length;
for (i = mlen - 1; i >= 0 && mag[i] == 0; i--)
;
firstNonzeroIntNum = mag.length-i-1;
fn = mlen - i - 1;
firstNonzeroIntNum = fn + 2; // offset by two to initialize
}
return firstNonzeroIntNum;
return fn;
}
/** use serialVersionUID from JDK 1.1. for interoperability */
......@@ -3121,6 +3063,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* deserialize it). The magnitude is read in as an array of bytes
* for historical reasons, but it is converted to an array of ints
* and the byte array is discarded.
* Note:
* The current convention is to initialize the cache fields, bitCount,
* bitLength and lowestSetBit, to 0 rather than some other marker value.
* Therefore, no explicit action to set these fields needs to be taken in
* readObject because those fields already have a 0 value be default since
* defaultReadObject is not being used.
*/
private void readObject(java.io.ObjectInputStream s)
throws java.io.IOException, ClassNotFoundException {
......@@ -3136,29 +3084,44 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
ObjectInputStream.GetField fields = s.readFields();
// Read the alternate persistent fields that we care about
signum = fields.get("signum", -2);
int sign = fields.get("signum", -2);
byte[] magnitude = (byte[])fields.get("magnitude", null);
// Validate signum
if (signum < -1 || signum > 1) {
if (sign < -1 || sign > 1) {
String message = "BigInteger: Invalid signum value";
if (fields.defaulted("signum"))
message = "BigInteger: Signum not present in stream";
throw new java.io.StreamCorruptedException(message);
}
if ((magnitude.length==0) != (signum==0)) {
if ((magnitude.length == 0) != (sign == 0)) {
String message = "BigInteger: signum-magnitude mismatch";
if (fields.defaulted("magnitude"))
message = "BigInteger: Magnitude not present in stream";
throw new java.io.StreamCorruptedException(message);
}
// Set "cached computation" fields to their initial values
bitCount = bitLength = -1;
lowestSetBit = firstNonzeroByteNum = firstNonzeroIntNum = -2;
// Commit final fields via Unsafe
unsafe.putIntVolatile(this, signumOffset, sign);
// Calculate mag field from magnitude and discard magnitude
mag = stripLeadingZeroBytes(magnitude);
unsafe.putObjectVolatile(this, magOffset,
stripLeadingZeroBytes(magnitude));
}
// Support for resetting final fields while deserializing
private static final sun.misc.Unsafe unsafe = sun.misc.Unsafe.getUnsafe();
private static final long signumOffset;
private static final long magOffset;
static {
try {
signumOffset = unsafe.objectFieldOffset
(BigInteger.class.getDeclaredField("signum"));
magOffset = unsafe.objectFieldOffset
(BigInteger.class.getDeclaredField("mag"));
} catch (Exception ex) {
throw new Error(ex);
}
}
/**
......@@ -3174,6 +3137,8 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
ObjectOutputStream.PutField fields = s.putFields();
fields.put("signum", signum);
fields.put("magnitude", magSerializedForm());
// The values written for cached fields are compatible with older
// versions, but are ignored in readObject so don't otherwise matter.
fields.put("bitCount", -1);
fields.put("bitLength", -1);
fields.put("lowestSetBit", -2);
......@@ -3187,12 +3152,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* Returns the mag array as an array of bytes.
*/
private byte[] magSerializedForm() {
int bitLen = (mag.length == 0 ? 0 :
((mag.length - 1) << 5) + bitLen(mag[0]));
int byteLen = (bitLen + 7)/8;
int len = mag.length;
int bitLen = (len == 0 ? 0 : ((len - 1) << 5) + bitLengthForInt(mag[0]));
int byteLen = (bitLen + 7) >>> 3;
byte[] result = new byte[byteLen];
for (int i=byteLen-1, bytesCopied=4, intIndex=mag.length-1, nextInt=0;
for (int i = byteLen - 1, bytesCopied = 4, intIndex = len - 1, nextInt = 0;
i>=0; i--) {
if (bytesCopied == 4) {
nextInt = mag[intIndex--];
......
src/share/classes/java/math/BitSieve.java
浏览文件 @ 364bf2a3
......@@ -110,13 +110,11 @@ class BitSieve {
int convertedStep = (step *2) + 1;
// Construct the large sieve at an even offset specified by base
MutableBigInteger r = new MutableBigInteger();
MutableBigInteger b = new MutableBigInteger(base);
MutableBigInteger q = new MutableBigInteger();
do {
// Calculate base mod convertedStep
r.copyValue(base.mag);
r.divideOneWord(convertedStep, q);
start = r.value[r.offset];
start = b.divideOneWord(convertedStep, q);
// Take each multiple of step out of sieve
start = convertedStep - start;
......
src/share/classes/java/math/MathContext.java
浏览文件 @ 364bf2a3
......@@ -126,19 +126,6 @@ public final class MathContext implements Serializable {
*/
final RoundingMode roundingMode;
/**
* Lookaside for the rounding points (the numbers which determine
* whether the coefficient of a number will require rounding).
* These will be present if {@code precision > 0} and
* {@code precision <= MAX_LOOKASIDE}. In this case they will share the
* {@code BigInteger int[]} array. Note that the transients
* cannot be {@code final} because they are reconstructed on
* deserialization.
*/
transient BigInteger roundingMax = null;
transient BigInteger roundingMin = null;
private static final int MAX_LOOKASIDE = 1000;
/* ----- Constructors ----- */
/**
......@@ -173,11 +160,6 @@ public final class MathContext implements Serializable {
throw new NullPointerException("null RoundingMode");
precision = setPrecision;
if (precision > 0 && precision <= MAX_LOOKASIDE) {
roundingMax = BigInteger.TEN.pow(precision);
roundingMin = roundingMax.negate();
}
roundingMode = setRoundingMode;
return;
}
......@@ -221,10 +203,6 @@ public final class MathContext implements Serializable {
throw new IllegalArgumentException("Digits < 0");
// the other parameters cannot be invalid if we got here
precision = setPrecision;
if (precision > 0 && precision <= MAX_LOOKASIDE) {
roundingMax = BigInteger.TEN.pow(precision);
roundingMin = roundingMax.negate();
}
}
/**
......@@ -343,11 +321,6 @@ public final class MathContext implements Serializable {
String message = "MathContext: null roundingMode in stream";
throw new java.io.StreamCorruptedException(message);
}
// Set the lookaside, if applicable
if (precision <= MAX_LOOKASIDE) {
roundingMax = BigInteger.TEN.pow(precision);
roundingMin = roundingMax.negate();
}
}
}
src/share/classes/java/math/MutableBigInteger.java
浏览文件 @ 364bf2a3
......@@ -41,6 +41,11 @@ package java.math;
* @since 1.3
*/
import java.util.Arrays;
import static java.math.BigInteger.LONG_MASK;
import static java.math.BigDecimal.INFLATED;
class MutableBigInteger {
/**
* Holds the magnitude of this MutableBigInteger in big endian order.
......@@ -62,10 +67,13 @@ class MutableBigInteger {
*/
int offset = 0;
// Constants
/**
* This mask is used to obtain the value of an int as if it were unsigned.
* MutableBigInteger with one element value array with the value 1. Used by
* BigDecimal divideAndRound to increment the quotient. Use this constant
* only when the method is not going to modify this object.
*/
private final static long LONG_MASK = 0xffffffffL;
static final MutableBigInteger ONE = new MutableBigInteger(1);
// Constructors
......@@ -88,15 +96,6 @@ class MutableBigInteger {
value[0] = val;
}
/**
* Construct a new MutableBigInteger with the specified value array
* up to the specified length.
*/
MutableBigInteger(int[] val, int len) {
value = val;
intLen = len;
}
/**
* Construct a new MutableBigInteger with the specified value array
* up to the length of the array supplied.
......@@ -111,8 +110,8 @@ class MutableBigInteger {
* specified BigInteger.
*/
MutableBigInteger(BigInteger b) {
value = b.mag.clone();
intLen = value.length;
intLen = b.mag.length;
value = Arrays.copyOf(b.mag, intLen);
}
/**
......@@ -121,10 +120,58 @@ class MutableBigInteger {
*/
MutableBigInteger(MutableBigInteger val) {
intLen = val.intLen;
value = new int[intLen];
value = Arrays.copyOfRange(val.value, val.offset, val.offset + intLen);
}
for(int i=0; i<intLen; i++)
value[i] = val.value[val.offset+i];
/**
* Internal helper method to return the magnitude array. The caller is not
* supposed to modify the returned array.
*/
private int[] getMagnitudeArray() {
if (offset > 0 || value.length != intLen)
return Arrays.copyOfRange(value, offset, offset + intLen);
return value;
}
/**
* Convert this MutableBigInteger to a long value. The caller has to make
* sure this MutableBigInteger can be fit into long.
*/
private long toLong() {
assert (intLen <= 2) : "this MutableBigInteger exceeds the range of long";
if (intLen == 0)
return 0;
long d = value[offset] & LONG_MASK;
return (intLen == 2) ? d << 32 | (value[offset + 1] & LONG_MASK) : d;
}
/**
* Convert this MutableBigInteger to a BigInteger object.
*/
BigInteger toBigInteger(int sign) {
if (intLen == 0 || sign == 0)
return BigInteger.ZERO;
return new BigInteger(getMagnitudeArray(), sign);
}
/**
* Convert this MutableBigInteger to BigDecimal object with the specified sign
* and scale.
*/
BigDecimal toBigDecimal(int sign, int scale) {
if (intLen == 0 || sign == 0)
return BigDecimal.valueOf(0, scale);
int[] mag = getMagnitudeArray();
int len = mag.length;
int d = mag[0];
// If this MutableBigInteger can't be fit into long, we need to
// make a BigInteger object for the resultant BigDecimal object.
if (len > 2 || (d < 0 && len == 2))
return new BigDecimal(new BigInteger(mag, sign), INFLATED, scale, 0);
long v = (len == 2) ?
((mag[1] & LONG_MASK) | (d & LONG_MASK) << 32) :
d & LONG_MASK;
return new BigDecimal(null, sign == -1 ? -v : v, scale, 0);
}
/**
......@@ -146,17 +193,21 @@ class MutableBigInteger {
/**
* Compare the magnitude of two MutableBigIntegers. Returns -1, 0 or 1
* as this MutableBigInteger is numerically less than, equal to, or
* greater than {@code b}.
* greater than <tt>b</tt>.
*/
final int compare(MutableBigInteger b) {
if (intLen < b.intLen)
int blen = b.intLen;
if (intLen < blen)
return -1;
if (intLen > b.intLen)
if (intLen > blen)
return 1;
for (int i=0; i<intLen; i++) {
int b1 = value[offset+i] + 0x80000000;
int b2 = b.value[b.offset+i] + 0x80000000;
// Add Integer.MIN_VALUE to make the comparison act as unsigned integer
// comparison.
int[] bval = b.value;
for (int i = offset, j = b.offset; i < intLen + offset; i++, j++) {
int b1 = value[i] + 0x80000000;
int b2 = bval[j] + 0x80000000;
if (b1 < b2)
return -1;
if (b1 > b2)
......@@ -165,6 +216,46 @@ class MutableBigInteger {
return 0;
}
/**
* Compare this against half of a MutableBigInteger object (Needed for
* remainder tests).
* Assumes no leading unnecessary zeros, which holds for results
* from divide().
*/
final int compareHalf(MutableBigInteger b) {
int blen = b.intLen;
int len = intLen;
if (len <= 0)
return blen <=0 ? 0 : -1;
if (len > blen)
return 1;
if (len < blen - 1)
return -1;
int[] bval = b.value;
int bstart = 0;
int carry = 0;
// Only 2 cases left:len == blen or len == blen - 1
if (len != blen) { // len == blen - 1
if (bval[bstart] == 1) {
++bstart;
carry = 0x80000000;
} else
return -1;
}
// compare values with right-shifted values of b,
// carrying shifted-out bits across words
int[] val = value;
for (int i = offset, j = bstart; i < len + offset;) {
int bv = bval[j++];
long hb = ((bv >>> 1) + carry) & LONG_MASK;
long v = val[i++] & LONG_MASK;
if (v != hb)
return v < hb ? -1 : 1;
carry = (bv & 1) << 31; // carray will be either 0x80000000 or 0
}
return carry == 0? 0 : -1;
}
/**
* Return the index of the lowest set bit in this MutableBigInteger. If the
* magnitude of this MutableBigInteger is zero, -1 is returned.
......@@ -178,7 +269,7 @@ class MutableBigInteger {
b = value[j+offset];
if (b==0)
return -1;
return ((intLen-1-j)<<5) + BigInteger.trailingZeroCnt(b);
return ((intLen-1-j)<<5) + Integer.numberOfTrailingZeros(b);
}
/**
......@@ -270,13 +361,11 @@ class MutableBigInteger {
* Sets this MutableBigInteger's value array to a copy of the specified
* array. The intLen is set to the length of the new array.
*/
void copyValue(MutableBigInteger val) {
int len = val.intLen;
void copyValue(MutableBigInteger src) {
int len = src.intLen;
if (value.length < len)
value = new int[len];
for(int i=0; i<len; i++)
value[i] = val.value[val.offset+i];
System.arraycopy(src.value, src.offset, value, 0, len);
intLen = len;
offset = 0;
}
......@@ -289,8 +378,7 @@ class MutableBigInteger {
int len = val.length;
if (value.length < len)
value = new int[len];
for(int i=0; i<len; i++)
value[i] = val[i];
System.arraycopy(val, 0, value, 0, len);
intLen = len;
offset = 0;
}
......@@ -320,7 +408,7 @@ class MutableBigInteger {
* Returns true iff this MutableBigInteger is odd.
*/
boolean isOdd() {
return ((value[offset + intLen - 1] & 1) == 1);
return isZero() ? false : ((value[offset + intLen - 1] & 1) == 1);
}
/**
......@@ -340,7 +428,7 @@ class MutableBigInteger {
* Returns a String representation of this MutableBigInteger in radix 10.
*/
public String toString() {
BigInteger b = new BigInteger(this, 1);
BigInteger b = toBigInteger(1);
return b.toString();
}
......@@ -356,7 +444,7 @@ class MutableBigInteger {
this.intLen -= nInts;
if (nBits == 0)
return;
int bitsInHighWord = BigInteger.bitLen(value[offset]);
int bitsInHighWord = BigInteger.bitLengthForInt(value[offset]);
if (nBits >= bitsInHighWord) {
this.primitiveLeftShift(32 - nBits);
this.intLen--;
......@@ -379,7 +467,7 @@ class MutableBigInteger {
return;
int nInts = n >>> 5;
int nBits = n&0x1F;
int bitsInHighWord = BigInteger.bitLen(value[offset]);
int bitsInHighWord = BigInteger.bitLengthForInt(value[offset]);
// If shift can be done without moving words, do so
if (n <= (32-bitsInHighWord)) {
......@@ -499,34 +587,41 @@ class MutableBigInteger {
int[] result = (value.length < resultLen ? new int[resultLen] : value);
int rstart = result.length-1;
long sum = 0;
long sum;
long carry = 0;
// Add common parts of both numbers
while(x>0 && y>0) {
x--; y--;
sum = (value[x+offset] & LONG_MASK) +
(addend.value[y+addend.offset] & LONG_MASK) + (sum >>> 32);
(addend.value[y+addend.offset] & LONG_MASK) + carry;
result[rstart--] = (int)sum;
carry = sum >>> 32;
}
// Add remainder of the longer number
while(x>0) {
x--;
sum = (value[x+offset] & LONG_MASK) + (sum >>> 32);
if (carry == 0 && result == value && rstart == (x + offset))
return;
sum = (value[x+offset] & LONG_MASK) + carry;
result[rstart--] = (int)sum;
carry = sum >>> 32;
}
while(y>0) {
y--;
sum = (addend.value[y+addend.offset] & LONG_MASK) + (sum >>> 32);
sum = (addend.value[y+addend.offset] & LONG_MASK) + carry;
result[rstart--] = (int)sum;
carry = sum >>> 32;
}
if ((sum >>> 32) > 0) { // Result must grow in length
if (carry > 0) { // Result must grow in length
resultLen++;
if (result.length < resultLen) {
int temp[] = new int[resultLen];
for (int i=resultLen-1; i>0; i--)
temp[i] = result[i-1];
// Result one word longer from carry-out; copy low-order
// bits into new result.
System.arraycopy(result, 0, temp, 1, result.length);
temp[0] = 1;
result = temp;
} else {
......@@ -711,26 +806,23 @@ class MutableBigInteger {
/**
* This method is used for division of an n word dividend by a one word
* divisor. The quotient is placed into quotient. The one word divisor is
* specified by divisor. The value of this MutableBigInteger is the
* dividend at invocation but is replaced by the remainder.
* specified by divisor.
*
* @return the remainder of the division is returned.
*
* NOTE: The value of this MutableBigInteger is modified by this method.
*/
void divideOneWord(int divisor, MutableBigInteger quotient) {
long divLong = divisor & LONG_MASK;
int divideOneWord(int divisor, MutableBigInteger quotient) {
long divisorLong = divisor & LONG_MASK;
// Special case of one word dividend
if (intLen == 1) {
long remValue = value[offset] & LONG_MASK;
quotient.value[0] = (int) (remValue / divLong);
quotient.intLen = (quotient.value[0] == 0) ? 0 : 1;
long dividendValue = value[offset] & LONG_MASK;
int q = (int) (dividendValue / divisorLong);
int r = (int) (dividendValue - q * divisorLong);
quotient.value[0] = q;
quotient.intLen = (q == 0) ? 0 : 1;
quotient.offset = 0;
value[0] = (int) (remValue - (quotient.value[0] * divLong));
offset = 0;
intLen = (value[0] == 0) ? 0 : 1;
return;
return r;
}
if (quotient.value.length < intLen)
......@@ -739,15 +831,15 @@ class MutableBigInteger {
quotient.intLen = intLen;
// Normalize the divisor
int shift = 32 - BigInteger.bitLen(divisor);
int shift = Integer.numberOfLeadingZeros(divisor);
int rem = value[offset];
long remLong = rem & LONG_MASK;
if (remLong < divLong) {
if (remLong < divisorLong) {
quotient.value[0] = 0;
} else {
quotient.value[0] = (int)(remLong/divLong);
rem = (int) (remLong - (quotient.value[0] * divLong));
quotient.value[0] = (int)(remLong / divisorLong);
rem = (int) (remLong - (quotient.value[0] * divisorLong));
remLong = rem & LONG_MASK;
}
......@@ -757,8 +849,8 @@ class MutableBigInteger {
long dividendEstimate = (remLong<<32) |
(value[offset + intLen - xlen] & LONG_MASK);
if (dividendEstimate >= 0) {
qWord[0] = (int) (dividendEstimate/divLong);
qWord[1] = (int) (dividendEstimate - (qWord[0] * divLong));
qWord[0] = (int) (dividendEstimate / divisorLong);
qWord[1] = (int) (dividendEstimate - qWord[0] * divisorLong);
} else {
divWord(qWord, dividendEstimate, divisor);
}
......@@ -767,81 +859,110 @@ class MutableBigInteger {
remLong = rem & LONG_MASK;
}
quotient.normalize();
// Unnormalize
if (shift > 0)
value[0] = rem %= divisor;
return rem % divisor;
else
value[0] = rem;
intLen = (value[0] == 0) ? 0 : 1;
quotient.normalize();
return rem;
}
/**
* Calculates the quotient and remainder of this div b and places them
* in the MutableBigInteger objects provided.
* Calculates the quotient of this div b and places the quotient in the
* provided MutableBigInteger objects and the remainder object is returned.
*
* Uses Algorithm D in Knuth section 4.3.1.
* Many optimizations to that algorithm have been adapted from the Colin
* Plumb C library.
* It special cases one word divisors for speed.
* The contents of a and b are not changed.
* It special cases one word divisors for speed. The content of b is not
* changed.
*
*/
void divide(MutableBigInteger b,
MutableBigInteger quotient, MutableBigInteger rem) {
MutableBigInteger divide(MutableBigInteger b, MutableBigInteger quotient) {
if (b.intLen == 0)
throw new ArithmeticException("BigInteger divide by zero");
// Dividend is zero
if (intLen == 0) {
quotient.intLen = quotient.offset = rem.intLen = rem.offset = 0;
return;
quotient.intLen = quotient.offset;
return new MutableBigInteger();
}
int cmp = compare(b);
// Dividend less than divisor
if (cmp < 0) {
quotient.intLen = quotient.offset = 0;
rem.copyValue(this);
return;
return new MutableBigInteger(this);
}
// Dividend equal to divisor
if (cmp == 0) {
quotient.value[0] = quotient.intLen = 1;
quotient.offset = rem.intLen = rem.offset = 0;
return;
quotient.offset = 0;
return new MutableBigInteger();
}
quotient.clear();
// Special case one word divisor
if (b.intLen == 1) {
rem.copyValue(this);
rem.divideOneWord(b.value[b.offset], quotient);
return;
int r = divideOneWord(b.value[b.offset], quotient);
if (r == 0)
return new MutableBigInteger();
return new MutableBigInteger(r);
}
// Copy divisor value to protect divisor
int[] d = new int[b.intLen];
for(int i=0; i<b.intLen; i++)
d[i] = b.value[b.offset+i];
int dlen = b.intLen;
int[] div = Arrays.copyOfRange(b.value, b.offset, b.offset + b.intLen);
return divideMagnitude(div, quotient);
}
// Remainder starts as dividend with space for a leading zero
if (rem.value.length < intLen +1)
rem.value = new int[intLen+1];
/**
* Internally used to calculate the quotient of this div v and places the
* quotient in the provided MutableBigInteger object and the remainder is
* returned.
*
* @return the remainder of the division will be returned.
*/
long divide(long v, MutableBigInteger quotient) {
if (v == 0)
throw new ArithmeticException("BigInteger divide by zero");
for (int i=0; i<intLen; i++)
rem.value[i+1] = value[i+offset];
// Dividend is zero
if (intLen == 0) {
quotient.intLen = quotient.offset = 0;
return 0;
}
if (v < 0)
v = -v;
int d = (int)(v >>> 32);
quotient.clear();
// Special case on word divisor
if (d == 0)
return divideOneWord((int)v, quotient) & LONG_MASK;
else {
int[] div = new int[]{ d, (int)(v & LONG_MASK) };
return divideMagnitude(div, quotient).toLong();
}
}
/**
* Divide this MutableBigInteger by the divisor represented by its magnitude
* array. The quotient will be placed into the provided quotient object &
* the remainder object is returned.
*/
private MutableBigInteger divideMagnitude(int[] divisor,
MutableBigInteger quotient) {
// Remainder starts as dividend with space for a leading zero
MutableBigInteger rem = new MutableBigInteger(new int[intLen + 1]);
System.arraycopy(value, offset, rem.value, 1, intLen);
rem.intLen = intLen;
rem.offset = 1;
int nlen = rem.intLen;
// Set the quotient size
int dlen = divisor.length;
int limit = nlen - dlen + 1;
if (quotient.value.length < limit) {
quotient.value = new int[limit];
......@@ -851,10 +972,10 @@ class MutableBigInteger {
int[] q = quotient.value;
// D1 normalize the divisor
int shift = 32 - BigInteger.bitLen(d[0]);
int shift = Integer.numberOfLeadingZeros(divisor[0]);
if (shift > 0) {
// First shift will not grow array
BigInteger.primitiveLeftShift(d, dlen, shift);
BigInteger.primitiveLeftShift(divisor, dlen, shift);
// But this one might
rem.leftShift(shift);
}
......@@ -866,9 +987,9 @@ class MutableBigInteger {
rem.intLen++;
}
int dh = d[0];
int dh = divisor[0];
long dhLong = dh & LONG_MASK;
int dl = d[1];
int dl = divisor[1];
int[] qWord = new int[2];
// D2 Initialize j
......@@ -910,7 +1031,7 @@ class MutableBigInteger {
qhat--;
qrem = (int)((qrem & LONG_MASK) + dhLong);
if ((qrem & LONG_MASK) >= dhLong) {
estProduct = (dl & LONG_MASK) * (qhat & LONG_MASK);
estProduct -= (dl & LONG_MASK);
rs = ((qrem & LONG_MASK) << 32) | nl;
if (unsignedLongCompare(estProduct, rs))
qhat--;
......@@ -920,12 +1041,12 @@ class MutableBigInteger {
// D4 Multiply and subtract
rem.value[j+rem.offset] = 0;
int borrow = mulsub(rem.value, d, qhat, dlen, j+rem.offset);
int borrow = mulsub(rem.value, divisor, qhat, dlen, j+rem.offset);
// D5 Test remainder
if (borrow + 0x80000000 > nh2) {
// D6 Add back
divadd(d, rem.value, j+1+rem.offset);
divadd(divisor, rem.value, j+1+rem.offset);
qhat--;
}
......@@ -937,8 +1058,9 @@ class MutableBigInteger {
if (shift > 0)
rem.rightShift(shift);
rem.normalize();
quotient.normalize();
rem.normalize();
return rem;
}
/**
......@@ -989,16 +1111,15 @@ class MutableBigInteger {
// Use Euclid's algorithm until the numbers are approximately the
// same length, then use the binary GCD algorithm to find the GCD.
MutableBigInteger a = this;
MutableBigInteger q = new MutableBigInteger(),
r = new MutableBigInteger();
MutableBigInteger q = new MutableBigInteger();
while (b.intLen != 0) {
if (Math.abs(a.intLen - b.intLen) < 2)
return a.binaryGCD(b);
a.divide(b, q, r);
MutableBigInteger swapper = a;
a = b; b = r; r = swapper;
MutableBigInteger r = a.divide(b, q);
a = b;
b = r;
}
return a;
}
......@@ -1069,40 +1190,21 @@ class MutableBigInteger {
if (a==0)
return b;
int x;
int aZeros = 0;
while ((x = a & 0xff) == 0) {
a >>>= 8;
aZeros += 8;
}
int y = BigInteger.trailingZeroTable[x];
aZeros += y;
a >>>= y;
int bZeros = 0;
while ((x = b & 0xff) == 0) {
b >>>= 8;
bZeros += 8;
}
y = BigInteger.trailingZeroTable[x];
bZeros += y;
b >>>= y;
// Right shift a & b till their last bits equal to 1.
int aZeros = Integer.numberOfTrailingZeros(a);
int bZeros = Integer.numberOfTrailingZeros(b);
a >>>= aZeros;
b >>>= bZeros;
int t = (aZeros < bZeros ? aZeros : bZeros);
while (a != b) {
if ((a+0x80000000) > (b+0x80000000)) { // a > b as unsigned
a -= b;
while ((x = a & 0xff) == 0)
a >>>= 8;
a >>>= BigInteger.trailingZeroTable[x];
a >>>= Integer.numberOfTrailingZeros(a);
} else {
b -= a;
while ((x = b & 0xff) == 0)
b >>>= 8;
b >>>= BigInteger.trailingZeroTable[x];
b >>>= Integer.numberOfTrailingZeros(b);
}
}
return a<<t;
......@@ -1152,8 +1254,7 @@ class MutableBigInteger {
temp1.multiply(y2, temp2);
result.add(temp2);
result.divide(p, temp1, temp2);
return temp2;
return result.divide(p, temp1);
}
/*
......@@ -1321,40 +1422,45 @@ class MutableBigInteger {
MutableBigInteger a = new MutableBigInteger(this);
MutableBigInteger q = new MutableBigInteger();
MutableBigInteger r = new MutableBigInteger();
MutableBigInteger r = b.divide(a, q);
b.divide(a, q, r);
MutableBigInteger swapper = b; b = r; r = swapper;
MutableBigInteger swapper = b;
// swap b & r
b = r;
r = swapper;
MutableBigInteger t1 = new MutableBigInteger(q);
MutableBigInteger t0 = new MutableBigInteger(1);
MutableBigInteger temp = new MutableBigInteger();
while (!b.isOne()) {
a.divide(b, q, r);
r = a.divide(b, q);
if (r.intLen == 0)
throw new ArithmeticException("BigInteger not invertible.");
swapper = r; r = a; a = swapper;
swapper = r;
a = swapper;
if (q.intLen == 1)
t1.mul(q.value[q.offset], temp);
else
q.multiply(t1, temp);
swapper = q; q = temp; temp = swapper;
swapper = q;
q = temp;
temp = swapper;
t0.add(q);
if (a.isOne())
return t0;
b.divide(a, q, r);
r = b.divide(a, q);
if (r.intLen == 0)
throw new ArithmeticException("BigInteger not invertible.");
swapper = b; b = r; r = swapper;
swapper = b;
b = r;
if (q.intLen == 1)
t0.mul(q.value[q.offset], temp);
......
src/share/classes/java/math/SignedMutableBigInteger.java
浏览文件 @ 364bf2a3
......@@ -129,9 +129,7 @@ class SignedMutableBigInteger extends MutableBigInteger {
* array starting at offset.
*/
public String toString() {
BigInteger b = new BigInteger(this, sign);
return
b.toString();
return this.toBigInteger(sign).toString();
}
}
test/java/math/BigDecimal/AddTests.java
浏览文件 @ 364bf2a3
......@@ -38,6 +38,31 @@ public class AddTests {
private static Set<RoundingMode> nonExactRoundingModes =
EnumSet.complementOf(EnumSet.of(RoundingMode.UNNECESSARY));
/**
* Test for some simple additions, particularly, it will test
* the overflow case.
*/
private static int simpleTests() {
int failures = 0;
BigDecimal[] bd1 = {
new BigDecimal(new BigInteger("7812404666936930160"), 11),
new BigDecimal(new BigInteger("7812404666936930160"), 12),
new BigDecimal(new BigInteger("7812404666936930160"), 13),
};
BigDecimal bd2 = new BigDecimal(new BigInteger("2790000"), 1);
BigDecimal[] expectedResult = {
new BigDecimal("78403046.66936930160"),
new BigDecimal("8091404.666936930160"),
new BigDecimal("1060240.4666936930160"),
};
for (int i = 0; i < bd1.length; i++) {
if (!bd1[i].add(bd2).equals(expectedResult[i]))
failures++;
}
return failures;
}
/**
* Test for extreme value of scale and rounding precision that
* could cause integer overflow in right-shift-into-sticky-bit
......
test/java/math/BigDecimal/DivideTests.java
浏览文件 @ 364bf2a3
......@@ -281,6 +281,10 @@ public class DivideTests {
BigDecimal c = new BigDecimal("31425");
BigDecimal c_minus = c.negate();
// Ad hoc tests
BigDecimal d = new BigDecimal(new BigInteger("-37361671119238118911893939591735"), 10);
BigDecimal e = new BigDecimal(new BigInteger("74723342238476237823787879183470"), 15);
BigDecimal[][] testCases = {
{a, b, BigDecimal.valueOf(ROUND_UP, 3), new BigDecimal("3.142")},
{a_minus, b, BigDecimal.valueOf(ROUND_UP, 3), new BigDecimal("-3.142")},
......@@ -305,6 +309,10 @@ public class DivideTests {
{c, b, BigDecimal.valueOf(ROUND_HALF_EVEN, 3), new BigDecimal("3.142")},
{c_minus, b, BigDecimal.valueOf(ROUND_HALF_EVEN, 3), new BigDecimal("-3.142")},
{d, e, BigDecimal.valueOf(ROUND_HALF_UP, -5), BigDecimal.valueOf(-1, -5)},
{d, e, BigDecimal.valueOf(ROUND_HALF_DOWN, -5), BigDecimal.valueOf(0, -5)},
{d, e, BigDecimal.valueOf(ROUND_HALF_EVEN, -5), BigDecimal.valueOf(0, -5)},
};
for(BigDecimal tc[] : testCases) {
......
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