--- a/src/java.base/share/classes/java/util/random/MRG32k3a.java Thu Jun 27 18:02:51 2019 -0300
+++ b/src/java.base/share/classes/java/util/random/MRG32k3a.java Thu Jun 27 18:30:27 2019 -0300
@@ -22,7 +22,8 @@
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
-package java.util;
+
+package java.util.random;
import java.math.BigInteger;
import java.util.concurrent.atomic.AtomicLong;
@@ -30,30 +31,29 @@
/**
* A generator of uniform pseudorandom values applicable for use in
* (among other contexts) isolated parallel computations that may
- * generate subtasks. Class {@code MRG32k3a} implements
- * interfaces {@link java.util.Rng} and {@link java.util.AbstractArbitrarilyJumpableRng},
+ * generate subtasks. Class {@link MRG32k3a} implements
+ * interfaces {@link RandomNumberGenerator} and {@link AbstractArbitrarilyJumpableRNG},
* and therefore supports methods for producing pseudorandomly chosen
* numbers of type {@code int}, {@code long}, {@code float}, and {@code double}
- * as well as creating new {@code Xoroshiro128PlusMRG32k3a} objects
+ * as well as creating new {@link Xoroshiro128PlusMRG32k3a} objects
* by "jumping" or "leaping".
- *
- * <p>Instances {@code Xoroshiro128Plus} are <em>not</em> thread-safe.
+ * <p>
+ * Instances {@link Xoroshiro128Plus} are <em>not</em> thread-safe.
* They are designed to be used so that each thread as its own instance.
* The methods {@link #jump} and {@link #leap} and {@link #jumps} and {@link #leaps}
- * can be used to construct new instances of {@code Xoroshiro128Plus} that traverse
+ * can be used to construct new instances of {@link Xoroshiro128Plus} that traverse
* other parts of the state cycle.
- *
- * <p>Instances of {@code MRG32k3a} are not cryptographically
+ * <p>
+ * Instances of {@link MRG32k3a} are not cryptographically
* secure. Consider instead using {@link java.security.SecureRandom}
* in security-sensitive applications. Additionally,
* default-constructed instances do not use a cryptographically random
* seed unless the {@linkplain System#getProperty system property}
* {@code java.util.secureRandomSeed} is set to {@code true}.
*
- * @author Guy Steele
- * @since 1.9
+ * @since 14
*/
-public final class MRG32k3a extends AbstractArbitrarilyJumpableRng {
+public final class MRG32k3a extends AbstractArbitrarilyJumpableRNG {
/*
* Implementation Overview.
@@ -65,31 +65,29 @@
* some custom spliterator classes needed for stream methods.
*/
- private final static double norm1 = 2.328306549295728e-10;
- private final static double norm2 = 2.328318824698632e-10;
- private final static double m1 = 4294967087.0;
- private final static double m2 = 4294944443.0;
- private final static double a12 = 1403580.0;
- private final static double a13n = 810728.0;
- private final static double a21 = 527612.0;
- private final static double a23n = 1370589.0;
- private final static int m1_deficit = 209;
-
- // IllegalArgumentException messages
- private static final String BadLogDistance = "logDistance must be non-negative and not greater than 192";
+ private final static double NORM1 = 2.328306549295728e-10;
+ private final static double NORM2 = 2.328318824698632e-10;
+ private final static double M1 = 4294967087.0;
+ private final static double M2 = 4294944443.0;
+ private final static double A12 = 1403580.0;
+ private final static double A13N = 810728.0;
+ private final static double A21 = 527612.0;
+ private final static double A23N = 1370589.0;
+ private final static int M1_DEFICIT = 209;
/**
* The per-instance state.
- The seeds for s10, s11, s12 must be integers in [0, m1 - 1] and not all 0.
- The seeds for s20, s21, s22 must be integers in [0, m2 - 1] and not all 0.
+ The seeds for s10, s11, s12 must be integers in [0, m1 - 1] and not all 0.
+ The seeds for s20, s21, s22 must be integers in [0, m2 - 1] and not all 0.
*/
private double s10, s11, s12,
- s20, s21, s22;
+ s20, s21, s22;
/**
* The seed generator for default constructors.
*/
- private static final AtomicLong defaultGen = new AtomicLong(RngSupport.initialSeed());
+ private static final AtomicLong DEFAULT_GEN =
+ new AtomicLong(RNGSupport.initialSeed());
/*
32-bits Random number generator U(0,1): MRG32k3a
@@ -98,58 +96,59 @@
Number Generators,
Shorter version in Operations Research,
47, 1 (1999), 159--164.
- ---------------------------------------------------------
+ ---------------------------------------------------------
*/
private void nextState() {
- /* Component 1 */
- double p1 = a12 * s11 - a13n * s10;
- double k1 = p1 / m1; p1 -= k1 * m1; if (p1 < 0.0) p1 += m1;
- s10 = s11; s11 = s12; s12 = p1;
- /* Component 2 */
- double p2 = a21 * s22 - a23n * s20;
- double k2 = p2 / m2; p2 -= k2 * m2; if (p2 < 0.0) p2 += m2;
- s20 = s21; s21 = s22; s22 = p2;
+ /* Component 1 */
+ double p1 = A12 * s11 - A13N * s10;
+ double k1 = p1 / M1; p1 -= k1 * M1; if (p1 < 0.0) p1 += M1;
+ s10 = s11; s11 = s12; s12 = p1;
+ /* Component 2 */
+ double p2 = A21 * s22 - A23N * s20;
+ double k2 = p2 / M2; p2 -= k2 * M2; if (p2 < 0.0) p2 += M2;
+ s20 = s21; s21 = s22; s22 = p2;
}
-
+
/**
* The form of nextInt used by IntStream Spliterators.
* Exactly the same as long version, except for types.
*
* @param origin the least value, unless greater than bound
* @param bound the upper bound (exclusive), must not equal origin
+ *
* @return a pseudorandom value
*/
private int internalNextInt(int origin, int bound) {
if (origin < bound) {
final int n = bound - origin;
- final int m = n - 1;
- if (n > 0) {
- int r;
+ final int m = n - 1;
+ if (n > 0) {
+ int r;
for (int u = (int)nextDouble() >>> 1;
- u + m + ((m1_deficit + 1) >>> 1) - (r = u % n) < 0;
+ u + m + ((M1_DEFICIT + 1) >>> 1) - (r = u % n) < 0;
u = (int)nextDouble() >>> 1)
;
return (r + origin);
} else {
- return RngSupport.boundedNextInt(this, origin, bound);
+ return RNGSupport.boundedNextInt(this, origin, bound);
}
} else {
- return nextInt();
- }
+ return nextInt();
+ }
}
private int internalNextInt(int bound) {
// Specialize internalNextInt for origin == 0, bound > 0
- final int n = bound;
- final int m = n - 1;
- int r;
- for (int u = (int)nextDouble() >>> 1;
- u + m + ((m1_deficit + 1) >>> 1) - (r = u % n) < 0;
- u = (int)nextDouble() >>> 1)
- ;
- return r;
+ final int n = bound;
+ final int m = n - 1;
+ int r;
+ for (int u = (int)nextDouble() >>> 1;
+ u + m + ((M1_DEFICIT + 1) >>> 1) - (r = u % n) < 0;
+ u = (int)nextDouble() >>> 1)
+ ;
+ return r;
}
/**
@@ -157,15 +156,15 @@
* less than the appropriate modulus.
*/
private MRG32k3a(double s10, double s11, double s12,
- double s20, double s21, double s22) {
- this.s10 = s10; this.s11 = s11; this.s12 = s12;
- this.s20 = s20; this.s21 = s21; this.s22 = s22;
- if ((s10 == 0.0) && (s11 == 0.0) && (s12 == 0.0)) {
- this.s10 = this.s11 = this.s12 = 12345.0;
- }
- if ((s20 == 0.0) && (s21 == 0.0) && (s22 == 0.0)) {
- this.s20 = this.s21 = this.s21 = 12345.0;
- }
+ double s20, double s21, double s22) {
+ this.s10 = s10; this.s11 = s11; this.s12 = s12;
+ this.s20 = s20; this.s21 = s21; this.s22 = s22;
+ if ((s10 == 0.0) && (s11 == 0.0) && (s12 == 0.0)) {
+ this.s10 = this.s11 = this.s12 = 12345.0;
+ }
+ if ((s20 == 0.0) && (s21 == 0.0) && (s22 == 0.0)) {
+ this.s20 = this.s21 = this.s21 = 12345.0;
+ }
}
/* ---------------- public methods ---------------- */
@@ -186,13 +185,13 @@
* @param s22 the third seed value for the second subgenerator
*/
public MRG32k3a(int s10, int s11, int s12,
- int s20, int s21, int s22) {
- this(((double)(((long)s10) & 0x00000000ffffffffL)) % m1,
- ((double)(((long)s11) & 0x00000000ffffffffL)) % m1,
- ((double)(((long)s12) & 0x00000000ffffffffL)) % m1,
- ((double)(((long)s20) & 0x00000000ffffffffL)) % m2,
- ((double)(((long)s21) & 0x00000000ffffffffL)) % m2,
- ((double)(((long)s22) & 0x00000000ffffffffL)) % m2);
+ int s20, int s21, int s22) {
+ this(((double)(((long)s10) & 0x00000000ffffffffL)) % M1,
+ ((double)(((long)s11) & 0x00000000ffffffffL)) % M1,
+ ((double)(((long)s12) & 0x00000000ffffffffL)) % M1,
+ ((double)(((long)s20) & 0x00000000ffffffffL)) % M2,
+ ((double)(((long)s21) & 0x00000000ffffffffL)) % M2,
+ ((double)(((long)s22) & 0x00000000ffffffffL)) % M2);
}
/**
@@ -206,11 +205,11 @@
*/
public MRG32k3a(long seed) {
this((double)((seed & 0x7FF) + 12345),
- (double)(((seed >>> 11) & 0x7FF) + 12345),
- (double)(((seed >>> 22) & 0x7FF) + 12345),
- (double)(((seed >>> 33) & 0x7FF) + 12345),
- (double)(((seed >>> 44) & 0x7FF) + 12345),
- (double)((seed >>> 55) + 12345));
+ (double)(((seed >>> 11) & 0x7FF) + 12345),
+ (double)(((seed >>> 22) & 0x7FF) + 12345),
+ (double)(((seed >>> 33) & 0x7FF) + 12345),
+ (double)(((seed >>> 44) & 0x7FF) + 12345),
+ (double)((seed >>> 55) + 12345));
}
/**
@@ -220,36 +219,38 @@
* may, and typically does, vary across program invocations.
*/
public MRG32k3a() {
- this(defaultGen.getAndAdd(RngSupport.GOLDEN_RATIO_64));
+ this(DEFAULT_GEN.getAndAdd(RNGSupport.GOLDEN_RATIO_64));
}
/**
- * Creates a new instance of {@code Xoshiro256StarStar} using the specified array of
- * initial seed bytes. Instances of {@code Xoshiro256StarStar} created with the same
+ * Creates a new instance of {@link Xoshiro256StarStar} using the specified array of
+ * initial seed bytes. Instances of {@link Xoshiro256StarStar} created with the same
* seed array in the same program execution generate identical sequences of values.
*
* @param seed the initial seed
*/
public MRG32k3a(byte[] seed) {
- // Convert the seed to 6 int values.
- int[] data = RngSupport.convertSeedBytesToInts(seed, 6, 0);
- int s10 = data[0], s11 = data[1], s12 = data[2];
- int s20 = data[3], s21 = data[4], s22 = data[5];
- this.s10 = ((double)(((long)s10) & 0x00000000ffffffffL)) % m1;
- this.s11 = ((double)(((long)s11) & 0x00000000ffffffffL)) % m1;
- this.s12 = ((double)(((long)s12) & 0x00000000ffffffffL)) % m1;
- this.s20 = ((double)(((long)s20) & 0x00000000ffffffffL)) % m2;
- this.s21 = ((double)(((long)s21) & 0x00000000ffffffffL)) % m2;
- this.s22 = ((double)(((long)s22) & 0x00000000ffffffffL)) % m2;
- if ((s10 == 0.0) && (s11 == 0.0) && (s12 == 0.0)) {
- this.s10 = this.s11 = this.s12 = 12345.0;
- }
- if ((s20 == 0.0) && (s21 == 0.0) && (s22 == 0.0)) {
- this.s20 = this.s21 = this.s21 = 12345.0;
- }
+ // Convert the seed to 6 int values.
+ int[] data = RNGSupport.convertSeedBytesToInts(seed, 6, 0);
+ int s10 = data[0], s11 = data[1], s12 = data[2];
+ int s20 = data[3], s21 = data[4], s22 = data[5];
+ this.s10 = ((double)(((long)s10) & 0x00000000ffffffffL)) % M1;
+ this.s11 = ((double)(((long)s11) & 0x00000000ffffffffL)) % M1;
+ this.s12 = ((double)(((long)s12) & 0x00000000ffffffffL)) % M1;
+ this.s20 = ((double)(((long)s20) & 0x00000000ffffffffL)) % M2;
+ this.s21 = ((double)(((long)s21) & 0x00000000ffffffffL)) % M2;
+ this.s22 = ((double)(((long)s22) & 0x00000000ffffffffL)) % M2;
+ if ((s10 == 0.0) && (s11 == 0.0) && (s12 == 0.0)) {
+ this.s10 = this.s11 = this.s12 = 12345.0;
+ }
+ if ((s20 == 0.0) && (s21 == 0.0) && (s22 == 0.0)) {
+ this.s20 = this.s21 = this.s21 = 12345.0;
+ }
}
- public MRG32k3a copy() { return new MRG32k3a(s10, s11, s12, s20, s21, s22); }
+ public MRG32k3a copy() {
+ return new MRG32k3a(s10, s11, s12, s20, s21, s22);
+ }
/**
* Returns a pseudorandom {@code double} value between zero
@@ -259,12 +260,12 @@
* (exclusive) and one (exclusive)
*/
public double nextOpenDouble() {
- nextState();
- double p1 = s12, p2 = s22;
- if (p1 <= p2)
- return ((p1 - p2 + m1) * norm1);
- else
- return ((p1 - p2) * norm1);
+ nextState();
+ double p1 = s12, p2 = s22;
+ if (p1 <= p2)
+ return ((p1 - p2 + M1) * NORM1);
+ else
+ return ((p1 - p2) * NORM1);
}
/**
@@ -275,14 +276,14 @@
* (inclusive) and one (exclusive)
*/
public double nextDouble() {
- nextState();
- double p1 = s12, p2 = s22;
- final double p = p1 * norm1 - p2 * norm2;
- if (p < 0.0) return (p + 1.0);
- else return p;
+ nextState();
+ double p1 = s12, p2 = s22;
+ final double p = p1 * NORM1 - p2 * NORM2;
+ if (p < 0.0) return (p + 1.0);
+ else return p;
}
-
+
/**
* Returns a pseudorandom {@code float} value between zero
* (inclusive) and one (exclusive).
@@ -300,7 +301,7 @@
* @return a pseudorandom {@code int} value
*/
public int nextInt() {
- return (internalNextInt(0x10000) << 16) | internalNextInt(0x10000);
+ return (internalNextInt(0x10000) << 16) | internalNextInt(0x10000);
}
/**
@@ -310,147 +311,156 @@
*/
public long nextLong() {
- return (((long)internalNextInt(0x200000) << 43) |
- ((long)internalNextInt(0x200000) << 22) |
- ((long)internalNextInt(0x400000)));
+ return (((long)internalNextInt(0x200000) << 43) |
+ ((long)internalNextInt(0x200000) << 22) |
+ ((long)internalNextInt(0x400000)));
}
// Period is (m1**3 - 1)(m2**3 - 1)/2, or approximately 2**191.
static BigInteger calculateThePeriod() {
- BigInteger bigm1 = BigInteger.valueOf((long)m1);
- BigInteger bigm2 = BigInteger.valueOf((long)m2);
- BigInteger t1 = bigm1.multiply(bigm1).multiply(bigm1).subtract(BigInteger.ONE);
- BigInteger t2 = bigm2.multiply(bigm2).multiply(bigm2).subtract(BigInteger.ONE);
- return t1.shiftRight(1).multiply(t2);
+ BigInteger bigm1 = BigInteger.valueOf((long)M1);
+ BigInteger bigm2 = BigInteger.valueOf((long)M2);
+ BigInteger t1 = bigm1.multiply(bigm1).multiply(bigm1).subtract(BigInteger.ONE);
+ BigInteger t2 = bigm2.multiply(bigm2).multiply(bigm2).subtract(BigInteger.ONE);
+ return t1.shiftRight(1).multiply(t2);
}
- static final BigInteger thePeriod = calculateThePeriod();
- public BigInteger period() { return thePeriod; }
+
+ static final BigInteger PERIOD = calculateThePeriod();
+
+ public BigInteger period() {
+ return PERIOD;
+ }
// Jump and leap distances recommended in Section 1.3 of this paper:
// Pierre L'Ecuyer, Richard Simard, E. Jack Chen, and W. David Kelton.
// An Object-Oriented Random-Number Package with Many Long Streams and Substreams.
// Operations Research 50, 6 (Nov--Dec 2002), 1073--1075.
- public double defaultJumpDistance() { return 0x1.0p76; } // 2**76
- public double defaultLeapDistance() { return 0x1.0p127; } // 2**127
-
+ public double defaultJumpDistance() {
+ return 0x1.0p76; // 2**76
+ }
+
+ public double defaultLeapDistance() {
+ return 0x1.0p127; // 2**127
+ }
+
public void jump(double distance) {
if (distance < 0.0 || Double.isInfinite(distance) || distance != Math.floor(distance))
throw new IllegalArgumentException("jump distance must be a nonnegative finite integer");
- // We will compute a jump transformation (s => M s) for each LCG.
- // We initialize each transformation to the identity transformation.
- // Each will be turned into the d'th power of the corresponding base transformation.
- long m1_00 = 1, m1_01 = 0, m1_02 = 0,
- m1_10 = 0, m1_11 = 1, m1_12 = 0,
- m1_20 = 0, m1_21 = 0, m1_22 = 1;
- long m2_00 = 1, m2_01 = 0, m2_02 = 0,
- m2_10 = 0, m2_11 = 1, m2_12 = 0,
- m2_20 = 0, m2_21 = 0, m2_22 = 1;
- // These are the base transformations, which will be repeatedly squared,
- // and composed with the computed transformations for each 1-bit in distance.
- long t1_00 = 0, t1_01 = 1, t1_02 = 0,
- t1_10 = 0, t1_11 = 0, t1_12 = 1,
- t1_20 = -(long)a13n, t1_21 = (long)a12, t1_22 = 0;
- long t2_00 = 0, t2_01 = 1, t2_02 = 0,
- t2_10 = 0, t2_11 = 0, t2_12 = 1,
- t2_20 = -(long)a23n, t2_21 = (long)a21, t2_22 = 0;
- while (distance > 0.0) {
- final double dhalf = 0.5 * distance;
- if (Math.floor(dhalf) != dhalf) {
- // distance is odd: accumulate current squaring
- final long n1_00 = m1_00 * t1_00 + m1_01 * t1_10 + m1_02 * t1_20;
- final long n1_01 = m1_00 * t1_01 + m1_01 * t1_11 + m1_02 * t1_21;
- final long n1_02 = m1_00 * t1_02 + m1_01 * t1_12 + m1_02 * t1_22;
- final long n1_10 = m1_10 * t1_00 + m1_11 * t1_10 + m1_12 * t1_20;
- final long n1_11 = m1_10 * t1_01 + m1_11 * t1_11 + m1_12 * t1_21;
- final long n1_12 = m1_10 * t1_02 + m1_11 * t1_12 + m1_12 * t1_22;
- final long n1_20 = m1_20 * t1_00 + m1_21 * t1_10 + m1_22 * t1_20;
- final long n1_21 = m1_20 * t1_01 + m1_21 * t1_11 + m1_22 * t1_21;
- final long n1_22 = m1_20 * t1_02 + m1_21 * t1_12 + m1_22 * t1_22;
- m1_00 = Math.floorMod(n1_00, (long)m1);
- m1_01 = Math.floorMod(n1_01, (long)m1);
- m1_02 = Math.floorMod(n1_02, (long)m1);
- m1_10 = Math.floorMod(n1_10, (long)m1);
- m1_11 = Math.floorMod(n1_11, (long)m1);
- m1_12 = Math.floorMod(n1_12, (long)m1);
- m1_20 = Math.floorMod(n1_20, (long)m1);
- m1_21 = Math.floorMod(n1_21, (long)m1);
- m1_22 = Math.floorMod(n1_22, (long)m1);
- final long n2_00 = m2_00 * t2_00 + m2_01 * t2_10 + m2_02 * t2_20;
- final long n2_01 = m2_00 * t2_01 + m2_01 * t2_11 + m2_02 * t2_21;
- final long n2_02 = m2_00 * t2_02 + m2_01 * t2_12 + m2_02 * t2_22;
- final long n2_10 = m2_10 * t2_00 + m2_11 * t2_10 + m2_12 * t2_20;
- final long n2_11 = m2_10 * t2_01 + m2_11 * t2_11 + m2_12 * t2_21;
- final long n2_12 = m2_10 * t2_02 + m2_11 * t2_12 + m2_12 * t2_22;
- final long n2_20 = m2_20 * t2_00 + m2_21 * t2_10 + m2_22 * t2_20;
- final long n2_21 = m2_20 * t2_01 + m2_21 * t2_11 + m2_22 * t2_21;
- final long n2_22 = m2_20 * t2_02 + m2_21 * t2_12 + m2_22 * t2_22;
- m2_00 = Math.floorMod(n2_00, (long)m2);
- m2_01 = Math.floorMod(n2_01, (long)m2);
- m2_02 = Math.floorMod(n2_02, (long)m2);
- m2_10 = Math.floorMod(n2_10, (long)m2);
- m2_11 = Math.floorMod(n2_11, (long)m2);
- m2_12 = Math.floorMod(n2_12, (long)m2);
- m2_20 = Math.floorMod(n2_20, (long)m2);
- m2_21 = Math.floorMod(n2_21, (long)m2);
- m2_22 = Math.floorMod(n2_22, (long)m2);
- }
- // Square the base transformations.
- {
- final long z1_00 = m1_00 * m1_00 + m1_01 * m1_10 + m1_02 * m1_20;
- final long z1_01 = m1_00 * m1_01 + m1_01 * m1_11 + m1_02 * m1_21;
- final long z1_02 = m1_00 * m1_02 + m1_01 * m1_12 + m1_02 * m1_22;
- final long z1_10 = m1_10 * m1_00 + m1_11 * m1_10 + m1_12 * m1_20;
- final long z1_11 = m1_10 * m1_01 + m1_11 * m1_11 + m1_12 * m1_21;
- final long z1_12 = m1_10 * m1_02 + m1_11 * m1_12 + m1_12 * m1_22;
- final long z1_20 = m1_20 * m1_00 + m1_21 * m1_10 + m1_22 * m1_20;
- final long z1_21 = m1_20 * m1_01 + m1_21 * m1_11 + m1_22 * m1_21;
- final long z1_22 = m1_20 * m1_02 + m1_21 * m1_12 + m1_22 * m1_22;
- m1_00 = Math.floorMod(z1_00, (long)m1);
- m1_01 = Math.floorMod(z1_01, (long)m1);
- m1_02 = Math.floorMod(z1_02, (long)m1);
- m1_10 = Math.floorMod(z1_10, (long)m1);
- m1_11 = Math.floorMod(z1_11, (long)m1);
- m1_12 = Math.floorMod(z1_12, (long)m1);
- m1_20 = Math.floorMod(z1_20, (long)m1);
- m1_21 = Math.floorMod(z1_21, (long)m1);
- m1_22 = Math.floorMod(z1_22, (long)m1);
- final long z2_00 = m2_00 * m2_00 + m2_01 * m2_10 + m2_02 * m2_20;
- final long z2_01 = m2_00 * m2_01 + m2_01 * m2_11 + m2_02 * m2_21;
- final long z2_02 = m2_00 * m2_02 + m2_01 * m2_12 + m2_02 * m2_22;
- final long z2_10 = m2_10 * m2_00 + m2_11 * m2_10 + m2_12 * m2_20;
- final long z2_11 = m2_10 * m2_01 + m2_11 * m2_11 + m2_12 * m2_21;
- final long z2_12 = m2_10 * m2_02 + m2_11 * m2_12 + m2_12 * m2_22;
- final long z2_20 = m2_20 * m2_00 + m2_21 * m2_10 + m2_22 * m2_20;
- final long z2_21 = m2_20 * m2_01 + m2_21 * m2_11 + m2_22 * m2_21;
- final long z2_22 = m2_20 * m2_02 + m2_21 * m2_12 + m2_22 * m2_22;
- m2_00 = Math.floorMod(z2_00, (long)m2);
- m2_01 = Math.floorMod(z2_01, (long)m2);
- m2_02 = Math.floorMod(z2_02, (long)m2);
- m2_10 = Math.floorMod(z2_10, (long)m2);
- m2_11 = Math.floorMod(z2_11, (long)m2);
- m2_12 = Math.floorMod(z2_12, (long)m2);
- m2_20 = Math.floorMod(z2_20, (long)m2);
- m2_21 = Math.floorMod(z2_21, (long)m2);
- m2_22 = Math.floorMod(z2_22, (long)m2);
- }
- // Divide distance by 2.
- distance = dhalf;
- }
- final long w10 = m1_00 * (long)s10 + m1_01 * (long)s11 + m1_02 * (long)s12;
- final long w11 = m1_10 * (long)s10 + m1_11 * (long)s11 + m1_12 * (long)s12;
- final long w12 = m1_20 * (long)s10 + m1_21 * (long)s11 + m1_22 * (long)s12;
- s10 = Math.floorMod(w10, (long)m1);
- s11 = Math.floorMod(w11, (long)m1);
- s12 = Math.floorMod(w12, (long)m1);
- final long w20 = m2_00 * (long)s20 + m2_01 * (long)s21 + m2_02 * (long)s22;
- final long w21 = m2_10 * (long)s20 + m2_11 * (long)s21 + m2_12 * (long)s22;
- final long w22 = m2_20 * (long)s20 + m2_21 * (long)s21 + m2_22 * (long)s22;
- s20 = Math.floorMod(w20, (long)m2);
- s21 = Math.floorMod(w21, (long)m2);
- s22 = Math.floorMod(w22, (long)m2);
+ // We will compute a jump transformation (s => M s) for each LCG.
+ // We initialize each transformation to the identity transformation.
+ // Each will be turned into the d'th power of the corresponding base transformation.
+ long m1_00 = 1, m1_01 = 0, m1_02 = 0,
+ m1_10 = 0, m1_11 = 1, m1_12 = 0,
+ m1_20 = 0, m1_21 = 0, m1_22 = 1;
+ long m2_00 = 1, m2_01 = 0, m2_02 = 0,
+ m2_10 = 0, m2_11 = 1, m2_12 = 0,
+ m2_20 = 0, m2_21 = 0, m2_22 = 1;
+ // These are the base transformations, which will be repeatedly squared,
+ // and composed with the computed transformations for each 1-bit in distance.
+ long t1_00 = 0, t1_01 = 1, t1_02 = 0,
+ t1_10 = 0, t1_11 = 0, t1_12 = 1,
+ t1_20 = -(long)A13N, t1_21 = (long)A12, t1_22 = 0;
+ long t2_00 = 0, t2_01 = 1, t2_02 = 0,
+ t2_10 = 0, t2_11 = 0, t2_12 = 1,
+ t2_20 = -(long)A23N, t2_21 = (long)A21, t2_22 = 0;
+ while (distance > 0.0) {
+ final double dhalf = 0.5 * distance;
+ if (Math.floor(dhalf) != dhalf) {
+ // distance is odd: accumulate current squaring
+ final long n1_00 = m1_00 * t1_00 + m1_01 * t1_10 + m1_02 * t1_20;
+ final long n1_01 = m1_00 * t1_01 + m1_01 * t1_11 + m1_02 * t1_21;
+ final long n1_02 = m1_00 * t1_02 + m1_01 * t1_12 + m1_02 * t1_22;
+ final long n1_10 = m1_10 * t1_00 + m1_11 * t1_10 + m1_12 * t1_20;
+ final long n1_11 = m1_10 * t1_01 + m1_11 * t1_11 + m1_12 * t1_21;
+ final long n1_12 = m1_10 * t1_02 + m1_11 * t1_12 + m1_12 * t1_22;
+ final long n1_20 = m1_20 * t1_00 + m1_21 * t1_10 + m1_22 * t1_20;
+ final long n1_21 = m1_20 * t1_01 + m1_21 * t1_11 + m1_22 * t1_21;
+ final long n1_22 = m1_20 * t1_02 + m1_21 * t1_12 + m1_22 * t1_22;
+ m1_00 = Math.floorMod(n1_00, (long)M1);
+ m1_01 = Math.floorMod(n1_01, (long)M1);
+ m1_02 = Math.floorMod(n1_02, (long)M1);
+ m1_10 = Math.floorMod(n1_10, (long)M1);
+ m1_11 = Math.floorMod(n1_11, (long)M1);
+ m1_12 = Math.floorMod(n1_12, (long)M1);
+ m1_20 = Math.floorMod(n1_20, (long)M1);
+ m1_21 = Math.floorMod(n1_21, (long)M1);
+ m1_22 = Math.floorMod(n1_22, (long)M1);
+ final long n2_00 = m2_00 * t2_00 + m2_01 * t2_10 + m2_02 * t2_20;
+ final long n2_01 = m2_00 * t2_01 + m2_01 * t2_11 + m2_02 * t2_21;
+ final long n2_02 = m2_00 * t2_02 + m2_01 * t2_12 + m2_02 * t2_22;
+ final long n2_10 = m2_10 * t2_00 + m2_11 * t2_10 + m2_12 * t2_20;
+ final long n2_11 = m2_10 * t2_01 + m2_11 * t2_11 + m2_12 * t2_21;
+ final long n2_12 = m2_10 * t2_02 + m2_11 * t2_12 + m2_12 * t2_22;
+ final long n2_20 = m2_20 * t2_00 + m2_21 * t2_10 + m2_22 * t2_20;
+ final long n2_21 = m2_20 * t2_01 + m2_21 * t2_11 + m2_22 * t2_21;
+ final long n2_22 = m2_20 * t2_02 + m2_21 * t2_12 + m2_22 * t2_22;
+ m2_00 = Math.floorMod(n2_00, (long)M2);
+ m2_01 = Math.floorMod(n2_01, (long)M2);
+ m2_02 = Math.floorMod(n2_02, (long)M2);
+ m2_10 = Math.floorMod(n2_10, (long)M2);
+ m2_11 = Math.floorMod(n2_11, (long)M2);
+ m2_12 = Math.floorMod(n2_12, (long)M2);
+ m2_20 = Math.floorMod(n2_20, (long)M2);
+ m2_21 = Math.floorMod(n2_21, (long)M2);
+ m2_22 = Math.floorMod(n2_22, (long)M2);
+ }
+ // Square the base transformations.
+ {
+ final long z1_00 = m1_00 * m1_00 + m1_01 * m1_10 + m1_02 * m1_20;
+ final long z1_01 = m1_00 * m1_01 + m1_01 * m1_11 + m1_02 * m1_21;
+ final long z1_02 = m1_00 * m1_02 + m1_01 * m1_12 + m1_02 * m1_22;
+ final long z1_10 = m1_10 * m1_00 + m1_11 * m1_10 + m1_12 * m1_20;
+ final long z1_11 = m1_10 * m1_01 + m1_11 * m1_11 + m1_12 * m1_21;
+ final long z1_12 = m1_10 * m1_02 + m1_11 * m1_12 + m1_12 * m1_22;
+ final long z1_20 = m1_20 * m1_00 + m1_21 * m1_10 + m1_22 * m1_20;
+ final long z1_21 = m1_20 * m1_01 + m1_21 * m1_11 + m1_22 * m1_21;
+ final long z1_22 = m1_20 * m1_02 + m1_21 * m1_12 + m1_22 * m1_22;
+ m1_00 = Math.floorMod(z1_00, (long)M1);
+ m1_01 = Math.floorMod(z1_01, (long)M1);
+ m1_02 = Math.floorMod(z1_02, (long)M1);
+ m1_10 = Math.floorMod(z1_10, (long)M1);
+ m1_11 = Math.floorMod(z1_11, (long)M1);
+ m1_12 = Math.floorMod(z1_12, (long)M1);
+ m1_20 = Math.floorMod(z1_20, (long)M1);
+ m1_21 = Math.floorMod(z1_21, (long)M1);
+ m1_22 = Math.floorMod(z1_22, (long)M1);
+ final long z2_00 = m2_00 * m2_00 + m2_01 * m2_10 + m2_02 * m2_20;
+ final long z2_01 = m2_00 * m2_01 + m2_01 * m2_11 + m2_02 * m2_21;
+ final long z2_02 = m2_00 * m2_02 + m2_01 * m2_12 + m2_02 * m2_22;
+ final long z2_10 = m2_10 * m2_00 + m2_11 * m2_10 + m2_12 * m2_20;
+ final long z2_11 = m2_10 * m2_01 + m2_11 * m2_11 + m2_12 * m2_21;
+ final long z2_12 = m2_10 * m2_02 + m2_11 * m2_12 + m2_12 * m2_22;
+ final long z2_20 = m2_20 * m2_00 + m2_21 * m2_10 + m2_22 * m2_20;
+ final long z2_21 = m2_20 * m2_01 + m2_21 * m2_11 + m2_22 * m2_21;
+ final long z2_22 = m2_20 * m2_02 + m2_21 * m2_12 + m2_22 * m2_22;
+ m2_00 = Math.floorMod(z2_00, (long)M2);
+ m2_01 = Math.floorMod(z2_01, (long)M2);
+ m2_02 = Math.floorMod(z2_02, (long)M2);
+ m2_10 = Math.floorMod(z2_10, (long)M2);
+ m2_11 = Math.floorMod(z2_11, (long)M2);
+ m2_12 = Math.floorMod(z2_12, (long)M2);
+ m2_20 = Math.floorMod(z2_20, (long)M2);
+ m2_21 = Math.floorMod(z2_21, (long)M2);
+ m2_22 = Math.floorMod(z2_22, (long)M2);
+ }
+ // Divide distance by 2.
+ distance = dhalf;
+ }
+ final long w10 = m1_00 * (long)s10 + m1_01 * (long)s11 + m1_02 * (long)s12;
+ final long w11 = m1_10 * (long)s10 + m1_11 * (long)s11 + m1_12 * (long)s12;
+ final long w12 = m1_20 * (long)s10 + m1_21 * (long)s11 + m1_22 * (long)s12;
+ s10 = Math.floorMod(w10, (long)M1);
+ s11 = Math.floorMod(w11, (long)M1);
+ s12 = Math.floorMod(w12, (long)M1);
+ final long w20 = m2_00 * (long)s20 + m2_01 * (long)s21 + m2_02 * (long)s22;
+ final long w21 = m2_10 * (long)s20 + m2_11 * (long)s21 + m2_12 * (long)s22;
+ final long w22 = m2_20 * (long)s20 + m2_21 * (long)s21 + m2_22 * (long)s22;
+ s20 = Math.floorMod(w20, (long)M2);
+ s21 = Math.floorMod(w21, (long)M2);
+ s22 = Math.floorMod(w22, (long)M2);
}
-
+
/**
* Alter the state of this pseudorandom number generator so as to
* jump forward a distance equal to 2<sup>{@code logDistance}</sup>
@@ -459,14 +469,15 @@
* @param logDistance the base-2 logarithm of the distance to jump
* forward within the state cycle. Must be non-negative and
* not greater than 192.
+ *
* @throws IllegalArgumentException if {@code logDistance} is
* less than zero or 2<sup>{@code logDistance}</sup> is
* greater than the period of this generator
*/
public void jumpPowerOfTwo(int logDistance) {
if (logDistance < 0 || logDistance > 192)
- throw new IllegalArgumentException(BadLogDistance);
- jump(Math.scalb(1.0, logDistance));
+ throw new IllegalArgumentException("logDistance must be non-negative and not greater than 192");
+ jump(Math.scalb(1.0, logDistance));
}
}