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提交 01c5bbe6 编写于 作者: B bpb
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8020641: Clean up some code style in recent BigInteger contributions 

Summary: Some minor cleanup to adhere better to Java coding conventions.
Reviewed-by: darcy
Contributed-by: NBrian Burkhalter <brian.burkhalter@oracle.com>
上级 36fe3287
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Showing with 281 addition and 255 deletion
src/share/classes/java/math/BigInteger.java
浏览文件 @ 01c5bbe6
...@@ -298,7 +298,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -298,7 +298,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (signum < -1 || signum > 1) if (signum < -1 || signum > 1)
throw(new NumberFormatException("Invalid signum value")); throw(new NumberFormatException("Invalid signum value"));
if (this.mag.length==0) { if (this.mag.length == 0) {
this.signum = 0; this.signum = 0;
} else { } else {
if (signum == 0) if (signum == 0)
...@@ -319,7 +319,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -319,7 +319,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (signum < -1 || signum > 1) if (signum < -1 || signum > 1)
throw(new NumberFormatException("Invalid signum value")); throw(new NumberFormatException("Invalid signum value"));
if (this.mag.length==0) { if (this.mag.length == 0) {
this.signum = 0; this.signum = 0;
} else { } else {
if (signum == 0) if (signum == 0)
...@@ -372,8 +372,10 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -372,8 +372,10 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// Skip leading zeros and compute number of digits in magnitude // Skip leading zeros and compute number of digits in magnitude
while (cursor < len && while (cursor < len &&
Character.digit(val.charAt(cursor), radix) == 0) Character.digit(val.charAt(cursor), radix) == 0) {
cursor++; cursor++;
}
if (cursor == len) { if (cursor == len) {
signum = 0; signum = 0;
mag = ZERO.mag; mag = ZERO.mag;
...@@ -463,7 +465,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -463,7 +465,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (result == -1) if (result == -1)
throw new NumberFormatException(new String(source)); throw new NumberFormatException(new String(source));
for (int index = start; index<end; index++) { for (int index = start; index < end; index++) {
int nextVal = Character.digit(source[index], 10); int nextVal = Character.digit(source[index], 10);
if (nextVal == -1) if (nextVal == -1)
throw new NumberFormatException(new String(source)); throw new NumberFormatException(new String(source));
...@@ -630,9 +632,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -630,9 +632,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int highBit = 1 << ((bitLength+31) & 0x1f); // High bit of high int int highBit = 1 << ((bitLength+31) & 0x1f); // High bit of high int
int highMask = (highBit << 1) - 1; // Bits to keep in high int int highMask = (highBit << 1) - 1; // Bits to keep in high int
while(true) { while (true) {
// Construct a candidate // Construct a candidate
for (int i=0; i<magLen; i++) for (int i=0; i < magLen; i++)
temp[i] = rnd.nextInt(); temp[i] = rnd.nextInt();
temp[0] = (temp[0] & highMask) | highBit; // Ensure exact length temp[0] = (temp[0] & highMask) | highBit; // Ensure exact length
if (bitLength > 2) if (bitLength > 2)
...@@ -718,7 +720,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -718,7 +720,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (!result.testBit(0)) if (!result.testBit(0))
result = result.add(ONE); result = result.add(ONE);
while(true) { while (true) {
// Do cheap "pre-test" if applicable // Do cheap "pre-test" if applicable
if (result.bitLength() > 6) { if (result.bitLength() > 6) {
long r = result.remainder(SMALL_PRIME_PRODUCT).longValue(); long r = result.remainder(SMALL_PRIME_PRODUCT).longValue();
...@@ -749,7 +751,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -749,7 +751,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// Looking for the next large prime // Looking for the next large prime
int searchLen = (result.bitLength() / 20) * 64; int searchLen = (result.bitLength() / 20) * 64;
while(true) { while (true) {
BitSieve searchSieve = new BitSieve(result, searchLen); BitSieve searchSieve = new BitSieve(result, searchLen);
BigInteger candidate = searchSieve.retrieve(result, BigInteger candidate = searchSieve.retrieve(result,
DEFAULT_PRIME_CERTAINTY, null); DEFAULT_PRIME_CERTAINTY, null);
...@@ -816,7 +818,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -816,7 +818,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int d = 5; int d = 5;
while (jacobiSymbol(d, this) != -1) { while (jacobiSymbol(d, this) != -1) {
// 5, -7, 9, -11, ... // 5, -7, 9, -11, ...
d = (d<0) ? Math.abs(d)+2 : -(d+2); d = (d < 0) ? Math.abs(d)+2 : -(d+2);
} }
// Step 2 // Step 2
...@@ -889,7 +891,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -889,7 +891,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
BigInteger u = ONE; BigInteger u2; BigInteger u = ONE; BigInteger u2;
BigInteger v = ONE; BigInteger v2; BigInteger v = ONE; BigInteger v2;
for (int i=k.bitLength()-2; i>=0; i--) { for (int i=k.bitLength()-2; i >= 0; i--) {
u2 = u.multiply(v).mod(n); u2 = u.multiply(v).mod(n);
v2 = v.square().add(d.multiply(u.square())).mod(n); v2 = v.square().add(d.multiply(u.square())).mod(n);
...@@ -945,7 +947,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -945,7 +947,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (rnd == null) { if (rnd == null) {
rnd = getSecureRandom(); rnd = getSecureRandom();
} }
for (int i=0; i<iterations; i++) { for (int i=0; i < iterations; i++) {
// Generate a uniform random on (1, this) // Generate a uniform random on (1, this)
BigInteger b; BigInteger b;
do { do {
...@@ -954,8 +956,8 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -954,8 +956,8 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int j = 0; int j = 0;
BigInteger z = b.modPow(m, this); BigInteger z = b.modPow(m, this);
while(!((j==0 && z.equals(ONE)) || z.equals(thisMinusOne))) { while (!((j == 0 && z.equals(ONE)) || z.equals(thisMinusOne))) {
if (j>0 && z.equals(ONE) || ++j==a) if (j > 0 && z.equals(ONE) || ++j == a)
return false; return false;
z = z.modPow(TWO, this); z = z.modPow(TWO, this);
} }
...@@ -969,7 +971,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -969,7 +971,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* arguments are correct, and it doesn't copy the magnitude array. * arguments are correct, and it doesn't copy the magnitude array.
*/ */
BigInteger(int[] magnitude, int signum) { BigInteger(int[] magnitude, int signum) {
this.signum = (magnitude.length==0 ? 0 : signum); this.signum = (magnitude.length == 0 ? 0 : signum);
this.mag = magnitude; this.mag = magnitude;
} }
...@@ -978,7 +980,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -978,7 +980,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* arguments are correct. * arguments are correct.
*/ */
private BigInteger(byte[] magnitude, int signum) { private BigInteger(byte[] magnitude, int signum) {
this.signum = (magnitude.length==0 ? 0 : signum); this.signum = (magnitude.length == 0 ? 0 : signum);
this.mag = stripLeadingZeroBytes(magnitude); this.mag = stripLeadingZeroBytes(magnitude);
} }
...@@ -1017,7 +1019,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1017,7 +1019,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
} }
int highWord = (int)(val >>> 32); int highWord = (int)(val >>> 32);
if (highWord==0) { if (highWord == 0) {
mag = new int[1]; mag = new int[1];
mag[0] = (int)val; mag[0] = (int)val;
} else { } else {
...@@ -1033,7 +1035,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1033,7 +1035,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* BigInteger will reference the input array if feasible). * BigInteger will reference the input array if feasible).
*/ */
private static BigInteger valueOf(int val[]) { private static BigInteger valueOf(int val[]) {
return (val[0]>0 ? new BigInteger(val, 1) : new BigInteger(val)); return (val[0] > 0 ? new BigInteger(val, 1) : new BigInteger(val));
} }
// Constants // Constants
...@@ -1074,8 +1076,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1074,8 +1076,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
powerCache = new BigInteger[Character.MAX_RADIX+1][]; powerCache = new BigInteger[Character.MAX_RADIX+1][];
logCache = new double[Character.MAX_RADIX+1]; logCache = new double[Character.MAX_RADIX+1];
for (int i=Character.MIN_RADIX; i<=Character.MAX_RADIX; i++) for (int i=Character.MIN_RADIX; i <= Character.MAX_RADIX; i++) {
{
powerCache[i] = new BigInteger[] { BigInteger.valueOf(i) }; powerCache[i] = new BigInteger[] { BigInteger.valueOf(i) };
logCache[i] = Math.log(i); logCache[i] = Math.log(i);
} }
...@@ -1169,7 +1170,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1169,7 +1170,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int xIndex = x.length; int xIndex = x.length;
int[] result; int[] result;
int highWord = (int)(val >>> 32); int highWord = (int)(val >>> 32);
if (highWord==0) { if (highWord == 0) {
result = new int[xIndex]; result = new int[xIndex];
sum = (x[--xIndex] & LONG_MASK) + val; sum = (x[--xIndex] & LONG_MASK) + val;
result[xIndex] = (int)sum; result[xIndex] = (int)sum;
...@@ -1222,12 +1223,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1222,12 +1223,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int yIndex = y.length; int yIndex = y.length;
int result[] = new int[xIndex]; int result[] = new int[xIndex];
long sum = 0; long sum = 0;
if(yIndex==1) { if (yIndex == 1) {
sum = (x[--xIndex] & LONG_MASK) + (y[0] & LONG_MASK) ; sum = (x[--xIndex] & LONG_MASK) + (y[0] & LONG_MASK) ;
result[xIndex] = (int)sum; result[xIndex] = (int)sum;
} else { } else {
// Add common parts of both numbers // Add common parts of both numbers
while(yIndex > 0) { while (yIndex > 0) {
sum = (x[--xIndex] & LONG_MASK) + sum = (x[--xIndex] & LONG_MASK) +
(y[--yIndex] & LONG_MASK) + (sum >>> 32); (y[--yIndex] & LONG_MASK) + (sum >>> 32);
result[xIndex] = (int)sum; result[xIndex] = (int)sum;
...@@ -1254,24 +1255,24 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1254,24 +1255,24 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
private static int[] subtract(long val, int[] little) { private static int[] subtract(long val, int[] little) {
int highWord = (int)(val >>> 32); int highWord = (int)(val >>> 32);
if (highWord==0) { if (highWord == 0) {
int result[] = new int[1]; int result[] = new int[1];
result[0] = (int)(val - (little[0] & LONG_MASK)); result[0] = (int)(val - (little[0] & LONG_MASK));
return result; return result;
} else { } else {
int result[] = new int[2]; int result[] = new int[2];
if(little.length==1) { if (little.length == 1) {
long difference = ((int)val & LONG_MASK) - (little[0] & LONG_MASK); long difference = ((int)val & LONG_MASK) - (little[0] & LONG_MASK);
result[1] = (int)difference; result[1] = (int)difference;
// Subtract remainder of longer number while borrow propagates // Subtract remainder of longer number while borrow propagates
boolean borrow = (difference >> 32 != 0); boolean borrow = (difference >> 32 != 0);
if(borrow) { if (borrow) {
result[0] = highWord - 1; result[0] = highWord - 1;
} else { // Copy remainder of longer number } else { // Copy remainder of longer number
result[0] = highWord; result[0] = highWord;
} }
return result; return result;
} else { // little.length==2 } else { // little.length == 2
long difference = ((int)val & LONG_MASK) - (little[1] & LONG_MASK); long difference = ((int)val & LONG_MASK) - (little[1] & LONG_MASK);
result[1] = (int)difference; result[1] = (int)difference;
difference = (highWord & LONG_MASK) - (little[0] & LONG_MASK) + (difference >> 32); difference = (highWord & LONG_MASK) - (little[0] & LONG_MASK) + (difference >> 32);
...@@ -1294,7 +1295,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1294,7 +1295,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int result[] = new int[bigIndex]; int result[] = new int[bigIndex];
long difference = 0; long difference = 0;
if (highWord==0) { if (highWord == 0) {
difference = (big[--bigIndex] & LONG_MASK) - val; difference = (big[--bigIndex] & LONG_MASK) - val;
result[bigIndex] = (int)difference; result[bigIndex] = (int)difference;
} else { } else {
...@@ -1304,7 +1305,6 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1304,7 +1305,6 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
result[bigIndex] = (int)difference; result[bigIndex] = (int)difference;
} }
// Subtract remainder of longer number while borrow propagates // Subtract remainder of longer number while borrow propagates
boolean borrow = (difference >> 32 != 0); boolean borrow = (difference >> 32 != 0);
while (bigIndex > 0 && borrow) while (bigIndex > 0 && borrow)
...@@ -1353,7 +1353,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1353,7 +1353,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
long difference = 0; long difference = 0;
// Subtract common parts of both numbers // Subtract common parts of both numbers
while(littleIndex > 0) { while (littleIndex > 0) {
difference = (big[--bigIndex] & LONG_MASK) - difference = (big[--bigIndex] & LONG_MASK) -
(little[--littleIndex] & LONG_MASK) + (little[--littleIndex] & LONG_MASK) +
(difference >> 32); (difference >> 32);
...@@ -1385,29 +1385,29 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1385,29 +1385,29 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int xlen = mag.length; int xlen = mag.length;
int ylen = val.mag.length; int ylen = val.mag.length;
if ((xlen < KARATSUBA_THRESHOLD) || (ylen < KARATSUBA_THRESHOLD)) if ((xlen < KARATSUBA_THRESHOLD) || (ylen < KARATSUBA_THRESHOLD)) {
{
int resultSign = signum == val.signum ? 1 : -1; int resultSign = signum == val.signum ? 1 : -1;
if (val.mag.length == 1) { if (val.mag.length == 1) {
return multiplyByInt(mag,val.mag[0], resultSign); return multiplyByInt(mag,val.mag[0], resultSign);
} }
if(mag.length == 1) { if (mag.length == 1) {
return multiplyByInt(val.mag,mag[0], resultSign); return multiplyByInt(val.mag,mag[0], resultSign);
} }
int[] result = multiplyToLen(mag, xlen, int[] result = multiplyToLen(mag, xlen,
val.mag, ylen, null); val.mag, ylen, null);
result = trustedStripLeadingZeroInts(result); result = trustedStripLeadingZeroInts(result);
return new BigInteger(result, resultSign); return new BigInteger(result, resultSign);
} } else {
else if ((xlen < TOOM_COOK_THRESHOLD) && (ylen < TOOM_COOK_THRESHOLD)) {
if ((xlen < TOOM_COOK_THRESHOLD) && (ylen < TOOM_COOK_THRESHOLD))
return multiplyKaratsuba(this, val); return multiplyKaratsuba(this, val);
else } else {
return multiplyToomCook3(this, val); return multiplyToomCook3(this, val);
} }
}
}
private static BigInteger multiplyByInt(int[] x, int y, int sign) { private static BigInteger multiplyByInt(int[] x, int y, int sign) {
if(Integer.bitCount(y)==1) { if (Integer.bitCount(y) == 1) {
return new BigInteger(shiftLeft(x,Integer.numberOfTrailingZeros(y)), sign); return new BigInteger(shiftLeft(x,Integer.numberOfTrailingZeros(y)), sign);
} }
int xlen = x.length; int xlen = x.length;
...@@ -1482,7 +1482,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1482,7 +1482,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
z = new int[xlen+ylen]; z = new int[xlen+ylen];
long carry = 0; long carry = 0;
for (int j=ystart, k=ystart+1+xstart; j>=0; j--, k--) { for (int j=ystart, k=ystart+1+xstart; j >= 0; j--, k--) {
long product = (y[j] & LONG_MASK) * long product = (y[j] & LONG_MASK) *
(x[xstart] & LONG_MASK) + carry; (x[xstart] & LONG_MASK) + carry;
z[k] = (int)product; z[k] = (int)product;
...@@ -1492,7 +1492,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1492,7 +1492,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
for (int i = xstart-1; i >= 0; i--) { for (int i = xstart-1; i >= 0; i--) {
carry = 0; carry = 0;
for (int j=ystart, k=ystart+1+i; j>=0; j--, k--) { for (int j=ystart, k=ystart+1+i; j >= 0; j--, k--) {
long product = (y[j] & LONG_MASK) * long product = (y[j] & LONG_MASK) *
(x[i] & LONG_MASK) + (x[i] & LONG_MASK) +
(z[k] & LONG_MASK) + carry; (z[k] & LONG_MASK) + carry;
...@@ -1519,8 +1519,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1519,8 +1519,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* *
* See: http://en.wikipedia.org/wiki/Karatsuba_algorithm * See: http://en.wikipedia.org/wiki/Karatsuba_algorithm
*/ */
private static BigInteger multiplyKaratsuba(BigInteger x, BigInteger y) private static BigInteger multiplyKaratsuba(BigInteger x, BigInteger y) {
{
int xlen = x.mag.length; int xlen = x.mag.length;
int ylen = y.mag.length; int ylen = y.mag.length;
...@@ -1543,11 +1542,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1543,11 +1542,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// result = p1 * 2^(32*2*half) + (p3 - p1 - p2) * 2^(32*half) + p2 // result = p1 * 2^(32*2*half) + (p3 - p1 - p2) * 2^(32*half) + p2
BigInteger result = p1.shiftLeft(32*half).add(p3.subtract(p1).subtract(p2)).shiftLeft(32*half).add(p2); BigInteger result = p1.shiftLeft(32*half).add(p3.subtract(p1).subtract(p2)).shiftLeft(32*half).add(p2);
if (x.signum != y.signum) if (x.signum != y.signum) {
return result.negate(); return result.negate();
else } else {
return result; return result;
} }
}
/** /**
* Multiplies two BigIntegers using a 3-way Toom-Cook multiplication * Multiplies two BigIntegers using a 3-way Toom-Cook multiplication
...@@ -1577,8 +1577,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1577,8 +1577,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* LNCS #4547. Springer, Madrid, Spain, June 21-22, 2007. * LNCS #4547. Springer, Madrid, Spain, June 21-22, 2007.
* *
*/ */
private static BigInteger multiplyToomCook3(BigInteger a, BigInteger b) private static BigInteger multiplyToomCook3(BigInteger a, BigInteger b) {
{
int alen = a.mag.length; int alen = a.mag.length;
int blen = b.mag.length; int blen = b.mag.length;
...@@ -1613,12 +1612,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1613,12 +1612,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
db1.add(b2).shiftLeft(1).subtract(b0)); db1.add(b2).shiftLeft(1).subtract(b0));
vinf = a2.multiply(b2); vinf = a2.multiply(b2);
/* The algorithm requires two divisions by 2 and one by 3. // The algorithm requires two divisions by 2 and one by 3.
All divisions are known to be exact, that is, they do not produce // All divisions are known to be exact, that is, they do not produce
remainders, and all results are positive. The divisions by 2 are // remainders, and all results are positive. The divisions by 2 are
implemented as right shifts which are relatively efficient, leaving // implemented as right shifts which are relatively efficient, leaving
only an exact division by 3, which is done by a specialized // only an exact division by 3, which is done by a specialized
linear-time algorithm. */ // linear-time algorithm.
t2 = v2.subtract(vm1).exactDivideBy3(); t2 = v2.subtract(vm1).exactDivideBy3();
tm1 = v1.subtract(vm1).shiftRight(1); tm1 = v1.subtract(vm1).shiftRight(1);
t1 = v1.subtract(v0); t1 = v1.subtract(v0);
...@@ -1632,11 +1631,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1632,11 +1631,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
BigInteger result = vinf.shiftLeft(ss).add(t2).shiftLeft(ss).add(t1).shiftLeft(ss).add(tm1).shiftLeft(ss).add(v0); BigInteger result = vinf.shiftLeft(ss).add(t2).shiftLeft(ss).add(t1).shiftLeft(ss).add(tm1).shiftLeft(ss).add(v0);
if (a.signum != b.signum) if (a.signum != b.signum) {
return result.negate(); return result.negate();
else } else {
return result; return result;
} }
}
/** /**
...@@ -1653,38 +1653,38 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1653,38 +1653,38 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* numbers. * numbers.
*/ */
private BigInteger getToomSlice(int lowerSize, int upperSize, int slice, private BigInteger getToomSlice(int lowerSize, int upperSize, int slice,
int fullsize) int fullsize) {
{
int start, end, sliceSize, len, offset; int start, end, sliceSize, len, offset;
len = mag.length; len = mag.length;
offset = fullsize - len; offset = fullsize - len;
if (slice == 0) if (slice == 0) {
{
start = 0 - offset; start = 0 - offset;
end = upperSize - 1 - offset; end = upperSize - 1 - offset;
} } else {
else
{
start = upperSize + (slice-1)*lowerSize - offset; start = upperSize + (slice-1)*lowerSize - offset;
end = start + lowerSize - 1; end = start + lowerSize - 1;
} }
if (start < 0) if (start < 0) {
start = 0; start = 0;
if (end < 0) }
if (end < 0) {
return ZERO; return ZERO;
}
sliceSize = (end-start) + 1; sliceSize = (end-start) + 1;
if (sliceSize <= 0) if (sliceSize <= 0) {
return ZERO; return ZERO;
}
// While performing Toom-Cook, all slices are positive and // While performing Toom-Cook, all slices are positive and
// the sign is adjusted when the final number is composed. // the sign is adjusted when the final number is composed.
if (start==0 && sliceSize >= len) if (start == 0 && sliceSize >= len) {
return this.abs(); return this.abs();
}
int intSlice[] = new int[sliceSize]; int intSlice[] = new int[sliceSize];
System.arraycopy(mag, start, intSlice, 0, sliceSize); System.arraycopy(mag, start, intSlice, 0, sliceSize);
...@@ -1700,20 +1700,19 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1700,20 +1700,19 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* undefined. Note that this is expected to be called with positive * undefined. Note that this is expected to be called with positive
* arguments only. * arguments only.
*/ */
private BigInteger exactDivideBy3() private BigInteger exactDivideBy3() {
{
int len = mag.length; int len = mag.length;
int[] result = new int[len]; int[] result = new int[len];
long x, w, q, borrow; long x, w, q, borrow;
borrow = 0L; borrow = 0L;
for (int i=len-1; i>=0; i--) for (int i=len-1; i >= 0; i--) {
{
x = (mag[i] & LONG_MASK); x = (mag[i] & LONG_MASK);
w = x - borrow; w = x - borrow;
if (borrow > x) // Did we make the number go negative? if (borrow > x) { // Did we make the number go negative?
borrow = 1L; borrow = 1L;
else } else {
borrow = 0L; borrow = 0L;
}
// 0xAAAAAAAB is the modular inverse of 3 (mod 2^32). Thus, // 0xAAAAAAAB is the modular inverse of 3 (mod 2^32). Thus,
// the effect of this is to divide by 3 (mod 2^32). // the effect of this is to divide by 3 (mod 2^32).
...@@ -1723,8 +1722,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1723,8 +1722,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// Now check the borrow. The second check can of course be // Now check the borrow. The second check can of course be
// eliminated if the first fails. // eliminated if the first fails.
if (q >= 0x55555556L) if (q >= 0x55555556L) {
{
borrow++; borrow++;
if (q >= 0xAAAAAAABL) if (q >= 0xAAAAAAABL)
borrow++; borrow++;
...@@ -1741,8 +1739,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1741,8 +1739,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
private BigInteger getLower(int n) { private BigInteger getLower(int n) {
int len = mag.length; int len = mag.length;
if (len <= n) if (len <= n) {
return this; return this;
}
int lowerInts[] = new int[n]; int lowerInts[] = new int[n];
System.arraycopy(mag, len-n, lowerInts, 0, n); System.arraycopy(mag, len-n, lowerInts, 0, n);
...@@ -1758,8 +1757,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1758,8 +1757,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
private BigInteger getUpper(int n) { private BigInteger getUpper(int n) {
int len = mag.length; int len = mag.length;
if (len <= n) if (len <= n) {
return ZERO; return ZERO;
}
int upperLen = len - n; int upperLen = len - n;
int upperInts[] = new int[upperLen]; int upperInts[] = new int[upperLen];
...@@ -1776,21 +1776,22 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1776,21 +1776,22 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* @return {@code this<sup>2</sup>} * @return {@code this<sup>2</sup>}
*/ */
private BigInteger square() { private BigInteger square() {
if (signum == 0) if (signum == 0) {
return ZERO; return ZERO;
}
int len = mag.length; int len = mag.length;
if (len < KARATSUBA_SQUARE_THRESHOLD) if (len < KARATSUBA_SQUARE_THRESHOLD) {
{
int[] z = squareToLen(mag, len, null); int[] z = squareToLen(mag, len, null);
return new BigInteger(trustedStripLeadingZeroInts(z), 1); return new BigInteger(trustedStripLeadingZeroInts(z), 1);
} } else {
else if (len < TOOM_COOK_SQUARE_THRESHOLD) {
if (len < TOOM_COOK_SQUARE_THRESHOLD)
return squareKaratsuba(); return squareKaratsuba();
else } else {
return squareToomCook3(); return squareToomCook3();
} }
}
}
/** /**
* Squares the contents of the int array x. The result is placed into the * Squares the contents of the int array x. The result is placed into the
...@@ -1837,7 +1838,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1837,7 +1838,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// Store the squares, right shifted one bit (i.e., divided by 2) // Store the squares, right shifted one bit (i.e., divided by 2)
int lastProductLowWord = 0; int lastProductLowWord = 0;
for (int j=0, i=0; j<len; j++) { for (int j=0, i=0; j < len; j++) {
long piece = (x[j] & LONG_MASK); long piece = (x[j] & LONG_MASK);
long product = piece * piece; long product = piece * piece;
z[i++] = (lastProductLowWord << 31) | (int)(product >>> 33); z[i++] = (lastProductLowWord << 31) | (int)(product >>> 33);
...@@ -1846,7 +1847,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1846,7 +1847,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
} }
// Add in off-diagonal sums // Add in off-diagonal sums
for (int i=len, offset=1; i>0; i--, offset+=2) { for (int i=len, offset=1; i > 0; i--, offset+=2) {
int t = x[i-1]; int t = x[i-1];
t = mulAdd(z, x, offset, i-1, t); t = mulAdd(z, x, offset, i-1, t);
addOne(z, offset-1, i, t); addOne(z, offset-1, i, t);
...@@ -1866,8 +1867,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1866,8 +1867,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* has better asymptotic performance than the algorithm used in * has better asymptotic performance than the algorithm used in
* squareToLen. * squareToLen.
*/ */
private BigInteger squareKaratsuba() private BigInteger squareKaratsuba() {
{
int half = (mag.length+1) / 2; int half = (mag.length+1) / 2;
BigInteger xl = getLower(half); BigInteger xl = getLower(half);
...@@ -1887,8 +1887,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1887,8 +1887,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* that has better asymptotic performance than the algorithm used in * that has better asymptotic performance than the algorithm used in
* squareToLen or squareKaratsuba. * squareToLen or squareKaratsuba.
*/ */
private BigInteger squareToomCook3() private BigInteger squareToomCook3() {
{
int len = mag.length; int len = mag.length;
// k is the size (in ints) of the lower-order slices. // k is the size (in ints) of the lower-order slices.
...@@ -1913,13 +1912,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1913,13 +1912,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
vinf = a2.square(); vinf = a2.square();
v2 = da1.add(a2).shiftLeft(1).subtract(a0).square(); v2 = da1.add(a2).shiftLeft(1).subtract(a0).square();
/* The algorithm requires two divisions by 2 and one by 3. // The algorithm requires two divisions by 2 and one by 3.
All divisions are known to be exact, that is, they do not produce // All divisions are known to be exact, that is, they do not produce
remainders, and all results are positive. The divisions by 2 are // remainders, and all results are positive. The divisions by 2 are
implemented as right shifts which are relatively efficient, leaving // implemented as right shifts which are relatively efficient, leaving
only a division by 3. // only a division by 3.
The division by 3 is done by an optimized algorithm for this case. // The division by 3 is done by an optimized algorithm for this case.
*/
t2 = v2.subtract(vm1).exactDivideBy3(); t2 = v2.subtract(vm1).exactDivideBy3();
tm1 = v1.subtract(vm1).shiftRight(1); tm1 = v1.subtract(vm1).shiftRight(1);
t1 = v1.subtract(v0); t1 = v1.subtract(v0);
...@@ -1944,11 +1942,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1944,11 +1942,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* @throws ArithmeticException if {@code val} is zero. * @throws ArithmeticException if {@code val} is zero.
*/ */
public BigInteger divide(BigInteger val) { public BigInteger divide(BigInteger val) {
if (mag.length<BURNIKEL_ZIEGLER_THRESHOLD || val.mag.length<BURNIKEL_ZIEGLER_THRESHOLD) if (mag.length < BURNIKEL_ZIEGLER_THRESHOLD ||
val.mag.length < BURNIKEL_ZIEGLER_THRESHOLD) {
return divideKnuth(val); return divideKnuth(val);
else } else {
return divideBurnikelZiegler(val); return divideBurnikelZiegler(val);
} }
}
/** /**
* Returns a BigInteger whose value is {@code (this / val)} using an O(n^2) algorithm from Knuth. * Returns a BigInteger whose value is {@code (this / val)} using an O(n^2) algorithm from Knuth.
...@@ -1979,11 +1979,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -1979,11 +1979,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* @throws ArithmeticException if {@code val} is zero. * @throws ArithmeticException if {@code val} is zero.
*/ */
public BigInteger[] divideAndRemainder(BigInteger val) { public BigInteger[] divideAndRemainder(BigInteger val) {
if (mag.length<BURNIKEL_ZIEGLER_THRESHOLD || val.mag.length<BURNIKEL_ZIEGLER_THRESHOLD) if (mag.length < BURNIKEL_ZIEGLER_THRESHOLD ||
val.mag.length < BURNIKEL_ZIEGLER_THRESHOLD) {
return divideAndRemainderKnuth(val); return divideAndRemainderKnuth(val);
else } else {
return divideAndRemainderBurnikelZiegler(val); return divideAndRemainderBurnikelZiegler(val);
} }
}
/** Long division */ /** Long division */
private BigInteger[] divideAndRemainderKnuth(BigInteger val) { private BigInteger[] divideAndRemainderKnuth(BigInteger val) {
...@@ -2006,11 +2008,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2006,11 +2008,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* @throws ArithmeticException if {@code val} is zero. * @throws ArithmeticException if {@code val} is zero.
*/ */
public BigInteger remainder(BigInteger val) { public BigInteger remainder(BigInteger val) {
if (mag.length<BURNIKEL_ZIEGLER_THRESHOLD || val.mag.length<BURNIKEL_ZIEGLER_THRESHOLD) if (mag.length < BURNIKEL_ZIEGLER_THRESHOLD ||
val.mag.length < BURNIKEL_ZIEGLER_THRESHOLD) {
return remainderKnuth(val); return remainderKnuth(val);
else } else {
return remainderBurnikelZiegler(val); return remainderBurnikelZiegler(val);
} }
}
/** Long division */ /** Long division */
private BigInteger remainderKnuth(BigInteger val) { private BigInteger remainderKnuth(BigInteger val) {
...@@ -2063,10 +2067,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2063,10 +2067,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* cause the operation to yield a non-integer value.) * cause the operation to yield a non-integer value.)
*/ */
public BigInteger pow(int exponent) { public BigInteger pow(int exponent) {
if (exponent < 0) if (exponent < 0) {
throw new ArithmeticException("Negative exponent"); throw new ArithmeticException("Negative exponent");
if (signum==0) }
return (exponent==0 ? ONE : this); if (signum == 0) {
return (exponent == 0 ? ONE : this);
}
BigInteger partToSquare = this.abs(); BigInteger partToSquare = this.abs();
...@@ -2079,25 +2085,26 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2079,25 +2085,26 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int remainingBits; int remainingBits;
// Factor the powers of two out quickly by shifting right, if needed. // Factor the powers of two out quickly by shifting right, if needed.
if (powersOfTwo > 0) if (powersOfTwo > 0) {
{
partToSquare = partToSquare.shiftRight(powersOfTwo); partToSquare = partToSquare.shiftRight(powersOfTwo);
remainingBits = partToSquare.bitLength(); remainingBits = partToSquare.bitLength();
if (remainingBits == 1) // Nothing left but +/- 1? if (remainingBits == 1) { // Nothing left but +/- 1?
if (signum<0 && (exponent&1)==1) if (signum < 0 && (exponent&1) == 1) {
return NEGATIVE_ONE.shiftLeft(powersOfTwo*exponent); return NEGATIVE_ONE.shiftLeft(powersOfTwo*exponent);
else } else {
return ONE.shiftLeft(powersOfTwo*exponent); return ONE.shiftLeft(powersOfTwo*exponent);
} }
else }
{ } else {
remainingBits = partToSquare.bitLength(); remainingBits = partToSquare.bitLength();
if (remainingBits == 1) // Nothing left but +/- 1? if (remainingBits == 1) { // Nothing left but +/- 1?
if (signum<0 && (exponent&1)==1) if (signum < 0 && (exponent&1) == 1) {
return NEGATIVE_ONE; return NEGATIVE_ONE;
else } else {
return ONE; return ONE;
} }
}
}
// This is a quick way to approximate the size of the result, // This is a quick way to approximate the size of the result,
// similar to doing log2[n] * exponent. This will give an upper bound // similar to doing log2[n] * exponent. This will give an upper bound
...@@ -2106,10 +2113,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2106,10 +2113,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// Use slightly different algorithms for small and large operands. // Use slightly different algorithms for small and large operands.
// See if the result will safely fit into a long. (Largest 2^63-1) // See if the result will safely fit into a long. (Largest 2^63-1)
if (partToSquare.mag.length==1 && scaleFactor <= 62) if (partToSquare.mag.length == 1 && scaleFactor <= 62) {
{
// Small number algorithm. Everything fits into a long. // Small number algorithm. Everything fits into a long.
int newSign = (signum<0 && (exponent&1)==1 ? -1 : 1); int newSign = (signum <0 && (exponent&1) == 1 ? -1 : 1);
long result = 1; long result = 1;
long baseToPow2 = partToSquare.mag[0] & LONG_MASK; long baseToPow2 = partToSquare.mag[0] & LONG_MASK;
...@@ -2117,27 +2123,28 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2117,27 +2123,28 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// Perform exponentiation using repeated squaring trick // Perform exponentiation using repeated squaring trick
while (workingExponent != 0) { while (workingExponent != 0) {
if ((workingExponent & 1)==1) if ((workingExponent & 1) == 1) {
result = result * baseToPow2; result = result * baseToPow2;
}
if ((workingExponent >>>= 1) != 0) if ((workingExponent >>>= 1) != 0) {
baseToPow2 = baseToPow2 * baseToPow2; baseToPow2 = baseToPow2 * baseToPow2;
} }
}
// Multiply back the powers of two (quickly, by shifting left) // Multiply back the powers of two (quickly, by shifting left)
if (powersOfTwo > 0) if (powersOfTwo > 0) {
{
int bitsToShift = powersOfTwo*exponent; int bitsToShift = powersOfTwo*exponent;
if (bitsToShift + scaleFactor <= 62) // Fits in long? if (bitsToShift + scaleFactor <= 62) { // Fits in long?
return valueOf((result << bitsToShift) * newSign); return valueOf((result << bitsToShift) * newSign);
else } else {
return valueOf(result*newSign).shiftLeft(bitsToShift); return valueOf(result*newSign).shiftLeft(bitsToShift);
} }
else }
else {
return valueOf(result*newSign); return valueOf(result*newSign);
} }
else } else {
{
// Large number algorithm. This is basically identical to // Large number algorithm. This is basically identical to
// the algorithm above, but calls multiply() and square() // the algorithm above, but calls multiply() and square()
// which may use more efficient algorithms for large numbers. // which may use more efficient algorithms for large numbers.
...@@ -2146,28 +2153,32 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2146,28 +2153,32 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int workingExponent = exponent; int workingExponent = exponent;
// Perform exponentiation using repeated squaring trick // Perform exponentiation using repeated squaring trick
while (workingExponent != 0) { while (workingExponent != 0) {
if ((workingExponent & 1)==1) if ((workingExponent & 1) == 1) {
answer = answer.multiply(partToSquare); answer = answer.multiply(partToSquare);
}
if ((workingExponent >>>= 1) != 0) if ((workingExponent >>>= 1) != 0) {
partToSquare = partToSquare.square(); partToSquare = partToSquare.square();
} }
}
// Multiply back the (exponentiated) powers of two (quickly, // Multiply back the (exponentiated) powers of two (quickly,
// by shifting left) // by shifting left)
if (powersOfTwo > 0) if (powersOfTwo > 0) {
answer = answer.shiftLeft(powersOfTwo*exponent); answer = answer.shiftLeft(powersOfTwo*exponent);
}
if (signum<0 && (exponent&1)==1) if (signum < 0 && (exponent&1) == 1) {
return answer.negate(); return answer.negate();
else } else {
return answer; return answer;
} }
} }
}
/** /**
* Returns a BigInteger whose value is the greatest common divisor of * Returns a BigInteger whose value is the greatest common divisor of
* {@code abs(this)} and {@code abs(val)}. Returns 0 if * {@code abs(this)} and {@code abs(val)}. Returns 0 if
* {@code this==0 && val==0}. * {@code this == 0 && val == 0}.
* *
* @param val value with which the GCD is to be computed. * @param val value with which the GCD is to be computed.
* @return {@code GCD(abs(this), abs(val))} * @return {@code GCD(abs(this), abs(val))}
...@@ -2224,7 +2235,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2224,7 +2235,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// shifts a up to len right n bits assumes no leading zeros, 0<n<32 // shifts a up to len right n bits assumes no leading zeros, 0<n<32
static void primitiveRightShift(int[] a, int len, int n) { static void primitiveRightShift(int[] a, int len, int n) {
int n2 = 32 - n; int n2 = 32 - n;
for (int i=len-1, c=a[i]; i>0; i--) { for (int i=len-1, c=a[i]; i > 0; i--) {
int b = c; int b = c;
c = a[i-1]; c = a[i-1];
a[i] = (c << n2) | (b >>> n); a[i] = (c << n2) | (b >>> n);
...@@ -2238,7 +2249,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2238,7 +2249,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
return; return;
int n2 = 32 - n; int n2 = 32 - n;
for (int i=0, c=a[i], m=i+len-1; i<m; i++) { for (int i=0, c=a[i], m=i+len-1; i < m; i++) {
int b = c; int b = c;
c = a[i+1]; c = a[i+1];
a[i] = (b << n) | (c >>> n2); a[i] = (b << n) | (c >>> n2);
...@@ -2449,7 +2460,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2449,7 +2460,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
return this; return this;
// Special case for base of zero // Special case for base of zero
if (signum==0) if (signum == 0)
return ZERO; return ZERO;
int[] base = mag.clone(); int[] base = mag.clone();
...@@ -2472,7 +2483,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2472,7 +2483,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// Allocate table for precomputed odd powers of base in Montgomery form // Allocate table for precomputed odd powers of base in Montgomery form
int[][] table = new int[tblmask][]; int[][] table = new int[tblmask][];
for (int i=0; i<tblmask; i++) for (int i=0; i < tblmask; i++)
table[i] = new int[modLen]; table[i] = new int[modLen];
// Compute the modular inverse // Compute the modular inverse
...@@ -2492,7 +2503,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2492,7 +2503,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (table[0].length < modLen) { if (table[0].length < modLen) {
int offset = modLen - table[0].length; int offset = modLen - table[0].length;
int[] t2 = new int[modLen]; int[] t2 = new int[modLen];
for (int i=0; i<table[0].length; i++) for (int i=0; i < table[0].length; i++)
t2[i+offset] = table[0][i]; t2[i+offset] = table[0][i];
table[0] = t2; table[0] = t2;
} }
...@@ -2505,7 +2516,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2505,7 +2516,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int[] t = Arrays.copyOf(b, modLen); int[] t = Arrays.copyOf(b, modLen);
// Fill in the table with odd powers of the base // Fill in the table with odd powers of the base
for (int i=1; i<tblmask; i++) { for (int i=1; i < tblmask; i++) {
int[] prod = multiplyToLen(t, modLen, table[i-1], modLen, null); int[] prod = multiplyToLen(t, modLen, table[i-1], modLen, null);
table[i] = montReduce(prod, mod, modLen, inv); table[i] = montReduce(prod, mod, modLen, inv);
} }
...@@ -2545,7 +2556,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2545,7 +2556,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
isone = false; isone = false;
// The main loop // The main loop
while(true) { while (true) {
ebits--; ebits--;
// Advance the window // Advance the window
buf <<= 1; buf <<= 1;
...@@ -2622,9 +2633,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2622,9 +2633,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int carry = mulAdd(n, mod, offset, mlen, inv * nEnd); int carry = mulAdd(n, mod, offset, mlen, inv * nEnd);
c += addOne(n, offset, mlen, carry); c += addOne(n, offset, mlen, carry);
offset++; offset++;
} while(--len > 0); } while (--len > 0);
while(c>0) while (c > 0)
c += subN(n, mod, mlen); c += subN(n, mod, mlen);
while (intArrayCmpToLen(n, mod, mlen) >= 0) while (intArrayCmpToLen(n, mod, mlen) >= 0)
...@@ -2639,7 +2650,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2639,7 +2650,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* equal to, or greater than arg2 up to length len. * equal to, or greater than arg2 up to length len.
*/ */
private static int intArrayCmpToLen(int[] arg1, int[] arg2, int len) { private static int intArrayCmpToLen(int[] arg1, int[] arg2, int len) {
for (int i=0; i<len; i++) { for (int i=0; i < len; i++) {
long b1 = arg1[i] & LONG_MASK; long b1 = arg1[i] & LONG_MASK;
long b2 = arg2[i] & LONG_MASK; long b2 = arg2[i] & LONG_MASK;
if (b1 < b2) if (b1 < b2)
...@@ -2656,7 +2667,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2656,7 +2667,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
private static int subN(int[] a, int[] b, int len) { private static int subN(int[] a, int[] b, int len) {
long sum = 0; long sum = 0;
while(--len >= 0) { while (--len >= 0) {
sum = (a[len] & LONG_MASK) - sum = (a[len] & LONG_MASK) -
(b[len] & LONG_MASK) + (sum >> 32); (b[len] & LONG_MASK) + (sum >> 32);
a[len] = (int)sum; a[len] = (int)sum;
...@@ -2750,7 +2761,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2750,7 +2761,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int excessBits = (numInts << 5) - p; int excessBits = (numInts << 5) - p;
mag[0] &= (1L << (32-excessBits)) - 1; mag[0] &= (1L << (32-excessBits)) - 1;
return (mag[0]==0 ? new BigInteger(1, mag) : new BigInteger(mag, 1)); return (mag[0] == 0 ? new BigInteger(1, mag) : new BigInteger(mag, 1));
} }
/** /**
...@@ -2801,9 +2812,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2801,9 +2812,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
public BigInteger shiftLeft(int n) { public BigInteger shiftLeft(int n) {
if (signum == 0) if (signum == 0)
return ZERO; return ZERO;
if (n==0) if (n == 0)
return this; return this;
if (n<0) { if (n < 0) {
if (n == Integer.MIN_VALUE) { if (n == Integer.MIN_VALUE) {
throw new ArithmeticException("Shift distance of Integer.MIN_VALUE not supported."); throw new ArithmeticException("Shift distance of Integer.MIN_VALUE not supported.");
} else { } else {
...@@ -2855,9 +2866,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2855,9 +2866,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* @see #shiftLeft * @see #shiftLeft
*/ */
public BigInteger shiftRight(int n) { public BigInteger shiftRight(int n) {
if (n==0) if (n == 0)
return this; return this;
if (n<0) { if (n < 0) {
if (n == Integer.MIN_VALUE) { if (n == Integer.MIN_VALUE) {
throw new ArithmeticException("Shift distance of Integer.MIN_VALUE not supported."); throw new ArithmeticException("Shift distance of Integer.MIN_VALUE not supported.");
} else { } else {
...@@ -2896,7 +2907,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2896,7 +2907,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (signum < 0) { if (signum < 0) {
// Find out whether any one-bits were shifted off the end. // Find out whether any one-bits were shifted off the end.
boolean onesLost = false; boolean onesLost = false;
for (int i=magLen-1, j=magLen-nInts; i>=j && !onesLost; i--) for (int i=magLen-1, j=magLen-nInts; i >= j && !onesLost; i--)
onesLost = (mag[i] != 0); onesLost = (mag[i] != 0);
if (!onesLost && nBits != 0) if (!onesLost && nBits != 0)
onesLost = (mag[magLen - nInts - 1] << (32 - nBits) != 0); onesLost = (mag[magLen - nInts - 1] << (32 - nBits) != 0);
...@@ -2931,7 +2942,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2931,7 +2942,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
*/ */
public BigInteger and(BigInteger val) { public BigInteger and(BigInteger val) {
int[] result = new int[Math.max(intLength(), val.intLength())]; int[] result = new int[Math.max(intLength(), val.intLength())];
for (int i=0; i<result.length; i++) for (int i=0; i < result.length; i++)
result[i] = (getInt(result.length-i-1) result[i] = (getInt(result.length-i-1)
& val.getInt(result.length-i-1)); & val.getInt(result.length-i-1));
...@@ -2948,7 +2959,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2948,7 +2959,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
*/ */
public BigInteger or(BigInteger val) { public BigInteger or(BigInteger val) {
int[] result = new int[Math.max(intLength(), val.intLength())]; int[] result = new int[Math.max(intLength(), val.intLength())];
for (int i=0; i<result.length; i++) for (int i=0; i < result.length; i++)
result[i] = (getInt(result.length-i-1) result[i] = (getInt(result.length-i-1)
| val.getInt(result.length-i-1)); | val.getInt(result.length-i-1));
...@@ -2965,7 +2976,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2965,7 +2976,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
*/ */
public BigInteger xor(BigInteger val) { public BigInteger xor(BigInteger val) {
int[] result = new int[Math.max(intLength(), val.intLength())]; int[] result = new int[Math.max(intLength(), val.intLength())];
for (int i=0; i<result.length; i++) for (int i=0; i < result.length; i++)
result[i] = (getInt(result.length-i-1) result[i] = (getInt(result.length-i-1)
^ val.getInt(result.length-i-1)); ^ val.getInt(result.length-i-1));
...@@ -2981,7 +2992,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2981,7 +2992,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
*/ */
public BigInteger not() { public BigInteger not() {
int[] result = new int[intLength()]; int[] result = new int[intLength()];
for (int i=0; i<result.length; i++) for (int i=0; i < result.length; i++)
result[i] = ~getInt(result.length-i-1); result[i] = ~getInt(result.length-i-1);
return valueOf(result); return valueOf(result);
...@@ -2999,7 +3010,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -2999,7 +3010,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
*/ */
public BigInteger andNot(BigInteger val) { public BigInteger andNot(BigInteger val) {
int[] result = new int[Math.max(intLength(), val.intLength())]; int[] result = new int[Math.max(intLength(), val.intLength())];
for (int i=0; i<result.length; i++) for (int i=0; i < result.length; i++)
result[i] = (getInt(result.length-i-1) result[i] = (getInt(result.length-i-1)
& ~val.getInt(result.length-i-1)); & ~val.getInt(result.length-i-1));
...@@ -3018,7 +3029,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3018,7 +3029,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* @throws ArithmeticException {@code n} is negative. * @throws ArithmeticException {@code n} is negative.
*/ */
public boolean testBit(int n) { public boolean testBit(int n) {
if (n<0) if (n < 0)
throw new ArithmeticException("Negative bit address"); throw new ArithmeticException("Negative bit address");
return (getInt(n >>> 5) & (1 << (n & 31))) != 0; return (getInt(n >>> 5) & (1 << (n & 31))) != 0;
...@@ -3033,13 +3044,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3033,13 +3044,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* @throws ArithmeticException {@code n} is negative. * @throws ArithmeticException {@code n} is negative.
*/ */
public BigInteger setBit(int n) { public BigInteger setBit(int n) {
if (n<0) if (n < 0)
throw new ArithmeticException("Negative bit address"); throw new ArithmeticException("Negative bit address");
int intNum = n >>> 5; int intNum = n >>> 5;
int[] result = new int[Math.max(intLength(), intNum+2)]; int[] result = new int[Math.max(intLength(), intNum+2)];
for (int i=0; i<result.length; i++) for (int i=0; i < result.length; i++)
result[result.length-i-1] = getInt(i); result[result.length-i-1] = getInt(i);
result[result.length-intNum-1] |= (1 << (n & 31)); result[result.length-intNum-1] |= (1 << (n & 31));
...@@ -3057,13 +3068,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3057,13 +3068,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* @throws ArithmeticException {@code n} is negative. * @throws ArithmeticException {@code n} is negative.
*/ */
public BigInteger clearBit(int n) { public BigInteger clearBit(int n) {
if (n<0) if (n < 0)
throw new ArithmeticException("Negative bit address"); throw new ArithmeticException("Negative bit address");
int intNum = n >>> 5; int intNum = n >>> 5;
int[] result = new int[Math.max(intLength(), ((n + 1) >>> 5) + 1)]; int[] result = new int[Math.max(intLength(), ((n + 1) >>> 5) + 1)];
for (int i=0; i<result.length; i++) for (int i=0; i < result.length; i++)
result[result.length-i-1] = getInt(i); result[result.length-i-1] = getInt(i);
result[result.length-intNum-1] &= ~(1 << (n & 31)); result[result.length-intNum-1] &= ~(1 << (n & 31));
...@@ -3081,13 +3092,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3081,13 +3092,13 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* @throws ArithmeticException {@code n} is negative. * @throws ArithmeticException {@code n} is negative.
*/ */
public BigInteger flipBit(int n) { public BigInteger flipBit(int n) {
if (n<0) if (n < 0)
throw new ArithmeticException("Negative bit address"); throw new ArithmeticException("Negative bit address");
int intNum = n >>> 5; int intNum = n >>> 5;
int[] result = new int[Math.max(intLength(), intNum+2)]; int[] result = new int[Math.max(intLength(), intNum+2)];
for (int i=0; i<result.length; i++) for (int i=0; i < result.length; i++)
result[result.length-i-1] = getInt(i); result[result.length-i-1] = getInt(i);
result[result.length-intNum-1] ^= (1 << (n & 31)); result[result.length-intNum-1] ^= (1 << (n & 31));
...@@ -3099,7 +3110,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3099,7 +3110,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* Returns the index of the rightmost (lowest-order) one bit in this * Returns the index of the rightmost (lowest-order) one bit in this
* BigInteger (the number of zero bits to the right of the rightmost * BigInteger (the number of zero bits to the right of the rightmost
* one bit). Returns -1 if this BigInteger contains no one bits. * one bit). Returns -1 if this BigInteger contains no one bits.
* (Computes {@code (this==0? -1 : log2(this & -this))}.) * (Computes {@code (this == 0? -1 : log2(this & -this))}.)
* *
* @return index of the rightmost one bit in this BigInteger. * @return index of the rightmost one bit in this BigInteger.
*/ */
...@@ -3112,7 +3123,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3112,7 +3123,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
} else { } else {
// Search for lowest order nonzero int // Search for lowest order nonzero int
int i,b; int i,b;
for (i=0; (b = getInt(i))==0; i++) for (i=0; (b = getInt(i)) == 0; i++)
; ;
lsb += (i << 5) + Integer.numberOfTrailingZeros(b); lsb += (i << 5) + Integer.numberOfTrailingZeros(b);
} }
...@@ -3173,12 +3184,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3173,12 +3184,12 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
if (bc == -1) { // bitCount not initialized yet if (bc == -1) { // bitCount not initialized yet
bc = 0; // offset by one to initialize bc = 0; // offset by one to initialize
// Count the bits in the magnitude // Count the bits in the magnitude
for (int i=0; i<mag.length; i++) for (int i=0; i < mag.length; i++)
bc += Integer.bitCount(mag[i]); bc += Integer.bitCount(mag[i]);
if (signum < 0) { if (signum < 0) {
// Count the trailing zeros in the magnitude // Count the trailing zeros in the magnitude
int magTrailingZeroCount = 0, j; int magTrailingZeroCount = 0, j;
for (j=mag.length-1; mag[j]==0; j--) for (j=mag.length-1; mag[j] == 0; j--)
magTrailingZeroCount += 32; magTrailingZeroCount += 32;
magTrailingZeroCount += Integer.numberOfTrailingZeros(mag[j]); magTrailingZeroCount += Integer.numberOfTrailingZeros(mag[j]);
bc += magTrailingZeroCount - 1; bc += magTrailingZeroCount - 1;
...@@ -3279,14 +3290,14 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3279,14 +3290,14 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
assert val != Long.MIN_VALUE; assert val != Long.MIN_VALUE;
int[] m1 = mag; int[] m1 = mag;
int len = m1.length; int len = m1.length;
if(len > 2) { if (len > 2) {
return 1; return 1;
} }
if (val < 0) { if (val < 0) {
val = -val; val = -val;
} }
int highWord = (int)(val >>> 32); int highWord = (int)(val >>> 32);
if (highWord==0) { if (highWord == 0) {
if (len < 1) if (len < 1)
return -1; return -1;
if (len > 1) if (len > 1)
...@@ -3354,7 +3365,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3354,7 +3365,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* {@code val}. If they are equal, either may be returned. * {@code val}. If they are equal, either may be returned.
*/ */
public BigInteger min(BigInteger val) { public BigInteger min(BigInteger val) {
return (compareTo(val)<0 ? this : val); return (compareTo(val) < 0 ? this : val);
} }
/** /**
...@@ -3365,7 +3376,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3365,7 +3376,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* {@code val}. If they are equal, either may be returned. * {@code val}. If they are equal, either may be returned.
*/ */
public BigInteger max(BigInteger val) { public BigInteger max(BigInteger val) {
return (compareTo(val)>0 ? this : val); return (compareTo(val) > 0 ? this : val);
} }
...@@ -3379,7 +3390,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3379,7 +3390,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
public int hashCode() { public int hashCode() {
int hashCode = 0; int hashCode = 0;
for (int i=0; i<mag.length; i++) for (int i=0; i < mag.length; i++)
hashCode = (int)(31*hashCode + (mag[i] & LONG_MASK)); hashCode = (int)(31*hashCode + (mag[i] & LONG_MASK));
return hashCode * signum; return hashCode * signum;
...@@ -3427,8 +3438,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3427,8 +3438,9 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
/** This method is used to perform toString when arguments are small. */ /** This method is used to perform toString when arguments are small. */
private String smallToString(int radix) { private String smallToString(int radix) {
if (signum == 0) if (signum == 0) {
return "0"; return "0";
}
// Compute upper bound on number of digit groups and allocate space // Compute upper bound on number of digit groups and allocate space
int maxNumDigitGroups = (4*mag.length + 6)/7; int maxNumDigitGroups = (4*mag.length + 6)/7;
...@@ -3453,16 +3465,18 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3453,16 +3465,18 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// Put sign (if any) and first digit group into result buffer // Put sign (if any) and first digit group into result buffer
StringBuilder buf = new StringBuilder(numGroups*digitsPerLong[radix]+1); StringBuilder buf = new StringBuilder(numGroups*digitsPerLong[radix]+1);
if (signum<0) if (signum < 0) {
buf.append('-'); buf.append('-');
}
buf.append(digitGroup[numGroups-1]); buf.append(digitGroup[numGroups-1]);
// Append remaining digit groups padded with leading zeros // Append remaining digit groups padded with leading zeros
for (int i=numGroups-2; i>=0; i--) { for (int i=numGroups-2; i >= 0; i--) {
// Prepend (any) leading zeros for this digit group // Prepend (any) leading zeros for this digit group
int numLeadingZeros = digitsPerLong[radix]-digitGroup[i].length(); int numLeadingZeros = digitsPerLong[radix]-digitGroup[i].length();
if (numLeadingZeros != 0) if (numLeadingZeros != 0) {
buf.append(zeros[numLeadingZeros]); buf.append(zeros[numLeadingZeros]);
}
buf.append(digitGroup[i]); buf.append(digitGroup[i]);
} }
return buf.toString(); return buf.toString();
...@@ -3490,9 +3504,11 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3490,9 +3504,11 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
// Pad with internal zeros if necessary. // Pad with internal zeros if necessary.
// Don't pad if we're at the beginning of the string. // Don't pad if we're at the beginning of the string.
if ((s.length() < digits) && (sb.length() > 0)) if ((s.length() < digits) && (sb.length() > 0)) {
for (int i=s.length(); i<digits; i++) // May be a faster way to for (int i=s.length(); i < digits; i++) { // May be a faster way to
sb.append('0'); // do this? sb.append('0'); // do this?
}
}
sb.append(s); sb.append(s);
return; return;
...@@ -3549,7 +3565,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3549,7 +3565,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
static { static {
zeros[63] = zeros[63] =
"000000000000000000000000000000000000000000000000000000000000000"; "000000000000000000000000000000000000000000000000000000000000000";
for (int i=0; i<63; i++) for (int i=0; i < 63; i++)
zeros[i] = zeros[63].substring(0, i); zeros[i] = zeros[63].substring(0, i);
} }
...@@ -3587,7 +3603,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3587,7 +3603,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int byteLen = bitLength()/8 + 1; int byteLen = bitLength()/8 + 1;
byte[] byteArray = new byte[byteLen]; byte[] byteArray = new byte[byteLen];
for (int i=byteLen-1, bytesCopied=4, nextInt=0, intIndex=0; i>=0; i--) { for (int i=byteLen-1, bytesCopied=4, nextInt=0, intIndex=0; i >= 0; i--) {
if (bytesCopied == 4) { if (bytesCopied == 4) {
nextInt = getInt(intIndex++); nextInt = getInt(intIndex++);
bytesCopied = 1; bytesCopied = 1;
...@@ -3639,7 +3655,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3639,7 +3655,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
public long longValue() { public long longValue() {
long result = 0; long result = 0;
for (int i=1; i>=0; i--) for (int i=1; i >= 0; i--)
result = (result << 32) + (getInt(i) & LONG_MASK); result = (result << 32) + (getInt(i) & LONG_MASK);
return result; return result;
} }
...@@ -3855,7 +3871,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3855,7 +3871,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int keep; int keep;
// Find first nonzero byte // Find first nonzero byte
for (keep = 0; keep < byteLength && a[keep]==0; keep++) for (keep = 0; keep < byteLength && a[keep] == 0; keep++)
; ;
// Allocate new array and copy relevant part of input array // Allocate new array and copy relevant part of input array
...@@ -3881,16 +3897,16 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3881,16 +3897,16 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int byteLength = a.length; int byteLength = a.length;
// Find first non-sign (0xff) byte of input // Find first non-sign (0xff) byte of input
for (keep=0; keep<byteLength && a[keep]==-1; keep++) for (keep=0; keep < byteLength && a[keep] == -1; keep++)
; ;
/* Allocate output array. If all non-sign bytes are 0x00, we must /* Allocate output array. If all non-sign bytes are 0x00, we must
* allocate space for one extra output byte. */ * allocate space for one extra output byte. */
for (k=keep; k<byteLength && a[k]==0; k++) for (k=keep; k < byteLength && a[k] == 0; k++)
; ;
int extraByte = (k==byteLength) ? 1 : 0; int extraByte = (k == byteLength) ? 1 : 0;
int intLength = ((byteLength - keep + extraByte) + 3)/4; int intLength = ((byteLength - keep + extraByte) + 3)/4;
int result[] = new int[intLength]; int result[] = new int[intLength];
...@@ -3911,7 +3927,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3911,7 +3927,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
} }
// Add one to one's complement to generate two's complement // Add one to one's complement to generate two's complement
for (int i=result.length-1; i>=0; i--) { for (int i=result.length-1; i >= 0; i--) {
result[i] = (int)((result[i] & LONG_MASK) + 1); result[i] = (int)((result[i] & LONG_MASK) + 1);
if (result[i] != 0) if (result[i] != 0)
break; break;
...@@ -3928,23 +3944,23 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -3928,23 +3944,23 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
int keep, j; int keep, j;
// Find first non-sign (0xffffffff) int of input // Find first non-sign (0xffffffff) int of input
for (keep=0; keep<a.length && a[keep]==-1; keep++) for (keep=0; keep < a.length && a[keep] == -1; keep++)
; ;
/* Allocate output array. If all non-sign ints are 0x00, we must /* Allocate output array. If all non-sign ints are 0x00, we must
* allocate space for one extra output int. */ * allocate space for one extra output int. */
for (j=keep; j<a.length && a[j]==0; j++) for (j=keep; j < a.length && a[j] == 0; j++)
; ;
int extraInt = (j==a.length ? 1 : 0); int extraInt = (j == a.length ? 1 : 0);
int result[] = new int[a.length - keep + extraInt]; int result[] = new int[a.length - keep + extraInt];
/* Copy one's complement of input into output, leaving extra /* Copy one's complement of input into output, leaving extra
* int (if it exists) == 0x00 */ * int (if it exists) == 0x00 */
for (int i = keep; i<a.length; i++) for (int i = keep; i < a.length; i++)
result[i - keep + extraInt] = ~a[i]; result[i - keep + extraInt] = ~a[i];
// Add one to one's complement to generate two's complement // Add one to one's complement to generate two's complement
for (int i=result.length-1; ++result[i]==0; i--) for (int i=result.length-1; ++result[i] == 0; i--)
; ;
return result; return result;
...@@ -4202,7 +4218,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> { ...@@ -4202,7 +4218,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
byte[] result = new byte[byteLen]; byte[] result = new byte[byteLen];
for (int i = byteLen - 1, bytesCopied = 4, intIndex = len - 1, nextInt = 0; for (int i = byteLen - 1, bytesCopied = 4, intIndex = len - 1, nextInt = 0;
i>=0; i--) { i >= 0; i--) {
if (bytesCopied == 4) { if (bytesCopied == 4) {
nextInt = mag[intIndex--]; nextInt = mag[intIndex--];
bytesCopied = 1; bytesCopied = 1;
......
src/share/classes/java/math/MutableBigInteger.java
浏览文件 @ 01c5bbe6
...@@ -313,7 +313,7 @@ class MutableBigInteger { ...@@ -313,7 +313,7 @@ class MutableBigInteger {
int blen = b.intLen; int blen = b.intLen;
int len = intLen; int len = intLen;
if (len <= 0) if (len <= 0)
return blen <=0 ? 0 : -1; return blen <= 0 ? 0 : -1;
if (len > blen) if (len > blen)
return 1; return 1;
if (len < blen - 1) if (len < blen - 1)
...@@ -340,7 +340,7 @@ class MutableBigInteger { ...@@ -340,7 +340,7 @@ class MutableBigInteger {
return v < hb ? -1 : 1; return v < hb ? -1 : 1;
carry = (bv & 1) << 31; // carray will be either 0x80000000 or 0 carry = (bv & 1) << 31; // carray will be either 0x80000000 or 0
} }
return carry == 0? 0 : -1; return carry == 0 ? 0 : -1;
} }
/** /**
...@@ -351,10 +351,10 @@ class MutableBigInteger { ...@@ -351,10 +351,10 @@ class MutableBigInteger {
if (intLen == 0) if (intLen == 0)
return -1; return -1;
int j, b; int j, b;
for (j=intLen-1; (j>0) && (value[j+offset]==0); j--) for (j=intLen-1; (j > 0) && (value[j+offset] == 0); j--)
; ;
b = value[j+offset]; b = value[j+offset];
if (b==0) if (b == 0)
return -1; return -1;
return ((intLen-1-j)<<5) + Integer.numberOfTrailingZeros(b); return ((intLen-1-j)<<5) + Integer.numberOfTrailingZeros(b);
} }
...@@ -395,11 +395,11 @@ class MutableBigInteger { ...@@ -395,11 +395,11 @@ class MutableBigInteger {
int indexBound = index+intLen; int indexBound = index+intLen;
do { do {
index++; index++;
} while(index < indexBound && value[index]==0); } while(index < indexBound && value[index] == 0);
int numZeros = index - offset; int numZeros = index - offset;
intLen -= numZeros; intLen -= numZeros;
offset = (intLen==0 ? 0 : offset+numZeros); offset = (intLen == 0 ? 0 : offset+numZeros);
} }
/** /**
...@@ -420,7 +420,7 @@ class MutableBigInteger { ...@@ -420,7 +420,7 @@ class MutableBigInteger {
*/ */
int[] toIntArray() { int[] toIntArray() {
int[] result = new int[intLen]; int[] result = new int[intLen];
for(int i=0; i<intLen; i++) for(int i=0; i < intLen; i++)
result[i] = value[offset+i]; result[i] = value[offset+i];
return result; return result;
} }
...@@ -506,7 +506,7 @@ class MutableBigInteger { ...@@ -506,7 +506,7 @@ class MutableBigInteger {
boolean isNormal() { boolean isNormal() {
if (intLen + offset > value.length) if (intLen + offset > value.length)
return false; return false;
if (intLen ==0) if (intLen == 0)
return true; return true;
return (value[offset] != 0); return (value[offset] != 0);
} }
...@@ -523,11 +523,12 @@ class MutableBigInteger { ...@@ -523,11 +523,12 @@ class MutableBigInteger {
* Like {@link #rightShift(int)} but {@code n} can be greater than the length of the number. * Like {@link #rightShift(int)} but {@code n} can be greater than the length of the number.
*/ */
void safeRightShift(int n) { void safeRightShift(int n) {
if (n/32 >= intLen) if (n/32 >= intLen) {
reset(); reset();
else } else {
rightShift(n); rightShift(n);
} }
}
/** /**
* Right shift this MutableBigInteger n bits. The MutableBigInteger is left * Right shift this MutableBigInteger n bits. The MutableBigInteger is left
...@@ -554,9 +555,10 @@ class MutableBigInteger { ...@@ -554,9 +555,10 @@ class MutableBigInteger {
* Like {@link #leftShift(int)} but {@code n} can be zero. * Like {@link #leftShift(int)} but {@code n} can be zero.
*/ */
void safeLeftShift(int n) { void safeLeftShift(int n) {
if (n > 0) if (n > 0) {
leftShift(n); leftShift(n);
} }
}
/** /**
* Left shift this MutableBigInteger n bits. * Left shift this MutableBigInteger n bits.
...@@ -586,18 +588,18 @@ class MutableBigInteger { ...@@ -586,18 +588,18 @@ class MutableBigInteger {
if (value.length < newLen) { if (value.length < newLen) {
// The array must grow // The array must grow
int[] result = new int[newLen]; int[] result = new int[newLen];
for (int i=0; i<intLen; i++) for (int i=0; i < intLen; i++)
result[i] = value[offset+i]; result[i] = value[offset+i];
setValue(result, newLen); setValue(result, newLen);
} else if (value.length - offset >= newLen) { } else if (value.length - offset >= newLen) {
// Use space on right // Use space on right
for(int i=0; i<newLen - intLen; i++) for(int i=0; i < newLen - intLen; i++)
value[offset+intLen+i] = 0; value[offset+intLen+i] = 0;
} else { } else {
// Must use space on left // Must use space on left
for (int i=0; i<intLen; i++) for (int i=0; i < intLen; i++)
value[i] = value[offset+i]; value[i] = value[offset+i];
for (int i=intLen; i<newLen; i++) for (int i=intLen; i < newLen; i++)
value[i] = 0; value[i] = 0;
offset = 0; offset = 0;
} }
...@@ -674,7 +676,7 @@ class MutableBigInteger { ...@@ -674,7 +676,7 @@ class MutableBigInteger {
private final void primitiveRightShift(int n) { private final void primitiveRightShift(int n) {
int[] val = value; int[] val = value;
int n2 = 32 - n; int n2 = 32 - n;
for (int i=offset+intLen-1, c=val[i]; i>offset; i--) { for (int i=offset+intLen-1, c=val[i]; i > offset; i--) {
int b = c; int b = c;
c = val[i-1]; c = val[i-1];
val[i] = (c << n2) | (b >>> n); val[i] = (c << n2) | (b >>> n);
...@@ -690,7 +692,7 @@ class MutableBigInteger { ...@@ -690,7 +692,7 @@ class MutableBigInteger {
private final void primitiveLeftShift(int n) { private final void primitiveLeftShift(int n) {
int[] val = value; int[] val = value;
int n2 = 32 - n; int n2 = 32 - n;
for (int i=offset, c=val[i], m=i+intLen-1; i<m; i++) { for (int i=offset, c=val[i], m=i+intLen-1; i < m; i++) {
int b = c; int b = c;
c = val[i+1]; c = val[i+1];
val[i] = (b << n) | (c >>> n2); val[i] = (b << n) | (c >>> n2);
...@@ -703,16 +705,16 @@ class MutableBigInteger { ...@@ -703,16 +705,16 @@ class MutableBigInteger {
* low ints of this number. * low ints of this number.
*/ */
private BigInteger getLower(int n) { private BigInteger getLower(int n) {
if (isZero()) if (isZero()) {
return BigInteger.ZERO; return BigInteger.ZERO;
else if (intLen < n) } else if (intLen < n) {
return toBigInteger(1); return toBigInteger(1);
else { } else {
// strip zeros // strip zeros
int len = n; int len = n;
while (len>0 && value[offset+intLen-len]==0) while (len > 0 && value[offset+intLen-len] == 0)
len--; len--;
int sign = len>0 ? 1 : 0; int sign = len > 0 ? 1 : 0;
return new BigInteger(Arrays.copyOfRange(value, offset+intLen-len, offset+intLen), sign); return new BigInteger(Arrays.copyOfRange(value, offset+intLen-len, offset+intLen), sign);
} }
} }
...@@ -743,7 +745,7 @@ class MutableBigInteger { ...@@ -743,7 +745,7 @@ class MutableBigInteger {
long carry = 0; long carry = 0;
// Add common parts of both numbers // Add common parts of both numbers
while(x>0 && y>0) { while(x > 0 && y > 0) {
x--; y--; x--; y--;
sum = (value[x+offset] & LONG_MASK) + sum = (value[x+offset] & LONG_MASK) +
(addend.value[y+addend.offset] & LONG_MASK) + carry; (addend.value[y+addend.offset] & LONG_MASK) + carry;
...@@ -752,7 +754,7 @@ class MutableBigInteger { ...@@ -752,7 +754,7 @@ class MutableBigInteger {
} }
// Add remainder of the longer number // Add remainder of the longer number
while(x>0) { while(x > 0) {
x--; x--;
if (carry == 0 && result == value && rstart == (x + offset)) if (carry == 0 && result == value && rstart == (x + offset))
return; return;
...@@ -760,7 +762,7 @@ class MutableBigInteger { ...@@ -760,7 +762,7 @@ class MutableBigInteger {
result[rstart--] = (int)sum; result[rstart--] = (int)sum;
carry = sum >>> 32; carry = sum >>> 32;
} }
while(y>0) { while(y > 0) {
y--; y--;
sum = (addend.value[y+addend.offset] & LONG_MASK) + carry; sum = (addend.value[y+addend.offset] & LONG_MASK) + carry;
result[rstart--] = (int)sum; result[rstart--] = (int)sum;
...@@ -788,12 +790,13 @@ class MutableBigInteger { ...@@ -788,12 +790,13 @@ class MutableBigInteger {
/** /**
* Adds the value of {@code addend} shifted {@code n} ints to the left. * Adds the value of {@code addend} shifted {@code n} ints to the left.
* Has the same effect as {@code addend.leftShift(32*ints); add(b);} * Has the same effect as {@code addend.leftShift(32*ints); add(addend);}
* but doesn't change the value of {@code b}. * but doesn't change the value of {@code addend}.
*/ */
void addShifted(MutableBigInteger addend, int n) { void addShifted(MutableBigInteger addend, int n) {
if (addend.isZero()) if (addend.isZero()) {
return; return;
}
int x = intLen; int x = intLen;
int y = addend.intLen + n; int y = addend.intLen + n;
...@@ -805,9 +808,9 @@ class MutableBigInteger { ...@@ -805,9 +808,9 @@ class MutableBigInteger {
long carry = 0; long carry = 0;
// Add common parts of both numbers // Add common parts of both numbers
while(x>0 && y>0) { while (x > 0 && y > 0) {
x--; y--; x--; y--;
int bval = y+addend.offset<addend.value.length ? addend.value[y+addend.offset] : 0; int bval = y+addend.offset < addend.value.length ? addend.value[y+addend.offset] : 0;
sum = (value[x+offset] & LONG_MASK) + sum = (value[x+offset] & LONG_MASK) +
(bval & LONG_MASK) + carry; (bval & LONG_MASK) + carry;
result[rstart--] = (int)sum; result[rstart--] = (int)sum;
...@@ -815,17 +818,18 @@ class MutableBigInteger { ...@@ -815,17 +818,18 @@ class MutableBigInteger {
} }
// Add remainder of the longer number // Add remainder of the longer number
while(x>0) { while (x > 0) {
x--; x--;
if (carry == 0 && result == value && rstart == (x + offset)) if (carry == 0 && result == value && rstart == (x + offset)) {
return; return;
}
sum = (value[x+offset] & LONG_MASK) + carry; sum = (value[x+offset] & LONG_MASK) + carry;
result[rstart--] = (int)sum; result[rstart--] = (int)sum;
carry = sum >>> 32; carry = sum >>> 32;
} }
while(y>0) { while (y > 0) {
y--; y--;
int bval = y+addend.offset<addend.value.length ? addend.value[y+addend.offset] : 0; int bval = y+addend.offset < addend.value.length ? addend.value[y+addend.offset] : 0;
sum = (bval & LONG_MASK) + carry; sum = (bval & LONG_MASK) + carry;
result[rstart--] = (int)sum; result[rstart--] = (int)sum;
carry = sum >>> 32; carry = sum >>> 32;
...@@ -881,7 +885,7 @@ class MutableBigInteger { ...@@ -881,7 +885,7 @@ class MutableBigInteger {
System.arraycopy(addend.value, addend.offset, result, rstart+1-y, len); System.arraycopy(addend.value, addend.offset, result, rstart+1-y, len);
// zero the gap // zero the gap
for (int i=rstart+1-y+len; i<rstart+1; i++) for (int i=rstart+1-y+len; i < rstart+1; i++)
result[i] = 0; result[i] = 0;
value = result; value = result;
...@@ -932,7 +936,7 @@ class MutableBigInteger { ...@@ -932,7 +936,7 @@ class MutableBigInteger {
int rstart = result.length - 1; int rstart = result.length - 1;
// Subtract common parts of both numbers // Subtract common parts of both numbers
while (y>0) { while (y > 0) {
x--; y--; x--; y--;
diff = (a.value[x+a.offset] & LONG_MASK) - diff = (a.value[x+a.offset] & LONG_MASK) -
...@@ -940,7 +944,7 @@ class MutableBigInteger { ...@@ -940,7 +944,7 @@ class MutableBigInteger {
result[rstart--] = (int)diff; result[rstart--] = (int)diff;
} }
// Subtract remainder of longer number // Subtract remainder of longer number
while (x>0) { while (x > 0) {
x--; x--;
diff = (a.value[x+a.offset] & LONG_MASK) - ((int)-(diff>>32)); diff = (a.value[x+a.offset] & LONG_MASK) - ((int)-(diff>>32));
result[rstart--] = (int)diff; result[rstart--] = (int)diff;
...@@ -961,7 +965,7 @@ class MutableBigInteger { ...@@ -961,7 +965,7 @@ class MutableBigInteger {
private int difference(MutableBigInteger b) { private int difference(MutableBigInteger b) {
MutableBigInteger a = this; MutableBigInteger a = this;
int sign = a.compare(b); int sign = a.compare(b);
if (sign ==0) if (sign == 0)
return 0; return 0;
if (sign < 0) { if (sign < 0) {
MutableBigInteger tmp = a; MutableBigInteger tmp = a;
...@@ -974,14 +978,14 @@ class MutableBigInteger { ...@@ -974,14 +978,14 @@ class MutableBigInteger {
int y = b.intLen; int y = b.intLen;
// Subtract common parts of both numbers // Subtract common parts of both numbers
while (y>0) { while (y > 0) {
x--; y--; x--; y--;
diff = (a.value[a.offset+ x] & LONG_MASK) - diff = (a.value[a.offset+ x] & LONG_MASK) -
(b.value[b.offset+ y] & LONG_MASK) - ((int)-(diff>>32)); (b.value[b.offset+ y] & LONG_MASK) - ((int)-(diff>>32));
a.value[a.offset+x] = (int)diff; a.value[a.offset+x] = (int)diff;
} }
// Subtract remainder of longer number // Subtract remainder of longer number
while (x>0) { while (x > 0) {
x--; x--;
diff = (a.value[a.offset+ x] & LONG_MASK) - ((int)-(diff>>32)); diff = (a.value[a.offset+ x] & LONG_MASK) - ((int)-(diff>>32));
a.value[a.offset+x] = (int)diff; a.value[a.offset+x] = (int)diff;
...@@ -1050,7 +1054,7 @@ class MutableBigInteger { ...@@ -1050,7 +1054,7 @@ class MutableBigInteger {
// Perform the multiplication word by word // Perform the multiplication word by word
long ylong = y & LONG_MASK; long ylong = y & LONG_MASK;
int[] zval = (z.value.length<intLen+1 ? new int[intLen + 1] int[] zval = (z.value.length < intLen+1 ? new int[intLen + 1]
: z.value); : z.value);
long carry = 0; long carry = 0;
for (int i = intLen-1; i >= 0; i--) { for (int i = intLen-1; i >= 0; i--) {
...@@ -1144,11 +1148,13 @@ class MutableBigInteger { ...@@ -1144,11 +1148,13 @@ class MutableBigInteger {
} }
MutableBigInteger divide(MutableBigInteger b, MutableBigInteger quotient, boolean needRemainder) { MutableBigInteger divide(MutableBigInteger b, MutableBigInteger quotient, boolean needRemainder) {
if (intLen<BigInteger.BURNIKEL_ZIEGLER_THRESHOLD || b.intLen<BigInteger.BURNIKEL_ZIEGLER_THRESHOLD) if (intLen < BigInteger.BURNIKEL_ZIEGLER_THRESHOLD ||
b.intLen < BigInteger.BURNIKEL_ZIEGLER_THRESHOLD) {
return divideKnuth(b, quotient, needRemainder); return divideKnuth(b, quotient, needRemainder);
else } else {
return divideAndRemainderBurnikelZiegler(b, quotient); return divideAndRemainderBurnikelZiegler(b, quotient);
} }
}
/** /**
* @see #divideKnuth(MutableBigInteger, MutableBigInteger, boolean) * @see #divideKnuth(MutableBigInteger, MutableBigInteger, boolean)
...@@ -1236,9 +1242,9 @@ class MutableBigInteger { ...@@ -1236,9 +1242,9 @@ class MutableBigInteger {
int r = intLen; int r = intLen;
int s = b.intLen; int s = b.intLen;
if (r < s) if (r < s) {
return this; return this;
else { } else {
// Unlike Knuth division, we don't check for common powers of two here because // Unlike Knuth division, we don't check for common powers of two here because
// BZ already runs faster if both numbers contain powers of two and cancelling them has no // BZ already runs faster if both numbers contain powers of two and cancelling them has no
// additional benefit. // additional benefit.
...@@ -1256,8 +1262,9 @@ class MutableBigInteger { ...@@ -1256,8 +1262,9 @@ class MutableBigInteger {
// step 5: t is the number of blocks needed to accommodate this plus one additional bit // step 5: t is the number of blocks needed to accommodate this plus one additional bit
int t = (bitLength()+n32) / n32; int t = (bitLength()+n32) / n32;
if (t < 2) if (t < 2) {
t = 2; t = 2;
}
// step 6: conceptually split this into blocks a[t-1], ..., a[0] // step 6: conceptually split this into blocks a[t-1], ..., a[0]
MutableBigInteger a1 = getBlock(t-1, t, n); // the most significant block of this MutableBigInteger a1 = getBlock(t-1, t, n); // the most significant block of this
...@@ -1270,7 +1277,7 @@ class MutableBigInteger { ...@@ -1270,7 +1277,7 @@ class MutableBigInteger {
MutableBigInteger qi = new MutableBigInteger(); MutableBigInteger qi = new MutableBigInteger();
MutableBigInteger ri; MutableBigInteger ri;
quotient.offset = quotient.intLen = 0; quotient.offset = quotient.intLen = 0;
for (int i=t-2; i>0; i--) { for (int i=t-2; i > 0; i--) {
// step 8a: compute (qi,ri) such that z=b*qi+ri // step 8a: compute (qi,ri) such that z=b*qi+ri
ri = z.divide2n1n(bShifted, qi); ri = z.divide2n1n(bShifted, qi);
...@@ -1302,8 +1309,9 @@ class MutableBigInteger { ...@@ -1302,8 +1309,9 @@ class MutableBigInteger {
int n = b.intLen; int n = b.intLen;
// step 1: base case // step 1: base case
if (n%2!=0 || n<BigInteger.BURNIKEL_ZIEGLER_THRESHOLD) if (n%2 != 0 || n < BigInteger.BURNIKEL_ZIEGLER_THRESHOLD) {
return divideKnuth(b, quotient); return divideKnuth(b, quotient);
}
// step 2: view this as [a1,a2,a3,a4] where each ai is n/2 ints or less // step 2: view this as [a1,a2,a3,a4] where each ai is n/2 ints or less
MutableBigInteger aUpper = new MutableBigInteger(this); MutableBigInteger aUpper = new MutableBigInteger(this);
...@@ -1352,8 +1360,7 @@ class MutableBigInteger { ...@@ -1352,8 +1360,7 @@ class MutableBigInteger {
// step 4: d=quotient*b2 // step 4: d=quotient*b2
d = new MutableBigInteger(quotient.toBigInteger().multiply(b2)); d = new MutableBigInteger(quotient.toBigInteger().multiply(b2));
} } else {
else {
// step 3b: if a1>=b1, let quotient=beta^n-1 and r=a12-b1*2^n+b1 // step 3b: if a1>=b1, let quotient=beta^n-1 and r=a12-b1*2^n+b1
quotient.ones(n); quotient.ones(n);
a12.add(b1); a12.add(b1);
...@@ -1393,16 +1400,19 @@ class MutableBigInteger { ...@@ -1393,16 +1400,19 @@ class MutableBigInteger {
*/ */
private MutableBigInteger getBlock(int index, int numBlocks, int blockLength) { private MutableBigInteger getBlock(int index, int numBlocks, int blockLength) {
int blockStart = index * blockLength; int blockStart = index * blockLength;
if (blockStart >= intLen) if (blockStart >= intLen) {
return new MutableBigInteger(); return new MutableBigInteger();
}
int blockEnd; int blockEnd;
if (index == numBlocks-1) if (index == numBlocks-1) {
blockEnd = intLen; blockEnd = intLen;
else } else {
blockEnd = (index+1) * blockLength; blockEnd = (index+1) * blockLength;
if (blockEnd > intLen) }
if (blockEnd > intLen) {
return new MutableBigInteger(); return new MutableBigInteger();
}
int[] newVal = Arrays.copyOfRange(value, offset+intLen-blockEnd, offset+intLen-blockStart); int[] newVal = Arrays.copyOfRange(value, offset+intLen-blockEnd, offset+intLen-blockStart);
return new MutableBigInteger(newVal); return new MutableBigInteger(newVal);
...@@ -1473,7 +1483,7 @@ class MutableBigInteger { ...@@ -1473,7 +1483,7 @@ class MutableBigInteger {
if (shift > 0) { if (shift > 0) {
divisor = new int[dlen]; divisor = new int[dlen];
copyAndShift(div.value,div.offset,dlen,divisor,0,shift); copyAndShift(div.value,div.offset,dlen,divisor,0,shift);
if(Integer.numberOfLeadingZeros(value[offset])>=shift) { if (Integer.numberOfLeadingZeros(value[offset]) >= shift) {
int[] remarr = new int[intLen + 1]; int[] remarr = new int[intLen + 1];
rem = new MutableBigInteger(remarr); rem = new MutableBigInteger(remarr);
rem.intLen = intLen; rem.intLen = intLen;
...@@ -1526,7 +1536,7 @@ class MutableBigInteger { ...@@ -1526,7 +1536,7 @@ class MutableBigInteger {
int dl = divisor[1]; int dl = divisor[1];
// D2 Initialize j // D2 Initialize j
for(int j=0; j<limit-1; j++) { for (int j=0; j < limit-1; j++) {
// D3 Calculate qhat // D3 Calculate qhat
// estimate qhat // estimate qhat
int qhat = 0; int qhat = 0;
...@@ -1650,7 +1660,7 @@ class MutableBigInteger { ...@@ -1650,7 +1660,7 @@ class MutableBigInteger {
} }
if(needRemainder) { if (needRemainder) {
// D8 Unnormalize // D8 Unnormalize
if (shift > 0) if (shift > 0)
rem.rightShift(shift); rem.rightShift(shift);
...@@ -1892,7 +1902,7 @@ class MutableBigInteger { ...@@ -1892,7 +1902,7 @@ class MutableBigInteger {
} }
// step B2 // step B2
boolean uOdd = (k==s1); boolean uOdd = (k == s1);
MutableBigInteger t = uOdd ? v: u; MutableBigInteger t = uOdd ? v: u;
int tsign = uOdd ? -1 : 1; int tsign = uOdd ? -1 : 1;
...@@ -1934,9 +1944,9 @@ class MutableBigInteger { ...@@ -1934,9 +1944,9 @@ class MutableBigInteger {
* Calculate GCD of a and b interpreted as unsigned integers. * Calculate GCD of a and b interpreted as unsigned integers.
*/ */
static int binaryGcd(int a, int b) { static int binaryGcd(int a, int b) {
if (b==0) if (b == 0)
return a; return a;
if (a==0) if (a == 0)
return b; return b;
// Right shift a & b till their last bits equal to 1. // Right shift a & b till their last bits equal to 1.
...@@ -2087,7 +2097,7 @@ class MutableBigInteger { ...@@ -2087,7 +2097,7 @@ class MutableBigInteger {
} }
// The Almost Inverse Algorithm // The Almost Inverse Algorithm
while(!f.isOne()) { while (!f.isOne()) {
// If gcd(f, g) != 1, number is not invertible modulo mod // If gcd(f, g) != 1, number is not invertible modulo mod
if (f.isZero()) if (f.isZero())
throw new ArithmeticException("BigInteger not invertible."); throw new ArithmeticException("BigInteger not invertible.");
...@@ -2132,7 +2142,7 @@ class MutableBigInteger { ...@@ -2132,7 +2142,7 @@ class MutableBigInteger {
// Set r to the multiplicative inverse of p mod 2^32 // Set r to the multiplicative inverse of p mod 2^32
int r = -inverseMod32(p.value[p.offset+p.intLen-1]); int r = -inverseMod32(p.value[p.offset+p.intLen-1]);
for(int i=0, numWords = k >> 5; i<numWords; i++) { for (int i=0, numWords = k >> 5; i < numWords; i++) {
// V = R * c (mod 2^j) // V = R * c (mod 2^j)
int v = r * c.value[c.offset + c.intLen-1]; int v = r * c.value[c.offset + c.intLen-1];
// c = c + (v * p) // c = c + (v * p)
......
test/java/math/BigInteger/BigIntegerTest.java
浏览文件 @ 01c5bbe6
...@@ -48,7 +48,7 @@ import java.util.Random; ...@@ -48,7 +48,7 @@ import java.util.Random;
* *
* The tests are performed on arrays of random numbers which are * The tests are performed on arrays of random numbers which are
* generated by a Random class as well as special cases which * generated by a Random class as well as special cases which
* throw in boundary numbers such as 0, 1, maximum SIZEd, etc. * throw in boundary numbers such as 0, 1, maximum sized, etc.
* *
*/ */
public class BigIntegerTest { public class BigIntegerTest {
...@@ -1008,7 +1008,7 @@ public class BigIntegerTest { ...@@ -1008,7 +1008,7 @@ public class BigIntegerTest {
/* /*
* Get a random or boundary-case number. This is designed to provide * Get a random or boundary-case number. This is designed to provide
* a lot of numbers that will find failure points, such as max SIZEd * a lot of numbers that will find failure points, such as max sized
* numbers, empty BigIntegers, etc. * numbers, empty BigIntegers, etc.
* *
* If order is less than 2, order is changed to 2. * If order is less than 2, order is changed to 2.
......
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