src/share/classes/java/math/BigInteger.java
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@@ -29,10 +29,11 @@
package java.math;
import java.util.Random;
import java.io.*;
+import java.util.Arrays;
/**
* Immutable arbitrary-precision integers. All operations behave as if
* BigIntegers were represented in two's-complement notation (like Java's
* primitive integer types). BigInteger provides analogues to all of Java's
@@ -1610,18 +1611,16 @@
primitiveLeftShift(a, len, nBits);
return a;
} else { // Array must be resized
if (nBits <= (32-bitsInHighWord)) {
int result[] = new int[nInts+len];
- for (int i=0; i<len; i++)
- result[i] = a[i];
+ System.arraycopy(a, 0, result, 0, len);
primitiveLeftShift(result, result.length, nBits);
return result;
} else {
int result[] = new int[nInts+len+1];
- for (int i=0; i<len; i++)
- result[i] = a[i];
+ System.arraycopy(a, 0, result, 0, len);
primitiveRightShift(result, result.length, 32 - nBits);
return result;
}
}
}
@@ -1905,13 +1904,11 @@
// Set b to the square of the base
int[] b = squareToLen(table[0], modLen, null);
b = montReduce(b, mod, modLen, inv);
// Set t to high half of b
- int[] t = new int[modLen];
- for(int i=0; i<modLen; i++)
- t[i] = b[i];
+ int[] t = Arrays.copyOf(b, modLen);
// Fill in the table with odd powers of the base
for (int i=1; i<tblmask; i++) {
int[] prod = multiplyToLen(t, modLen, table[i-1], modLen, null);
table[i] = montReduce(prod, mod, modLen, inv);
@@ -2004,18 +2001,15 @@
}
}
// Convert result out of Montgomery form and return
int[] t2 = new int[2*modLen];
- for(int i=0; i<modLen; i++)
- t2[i+modLen] = b[i];
+ System.arraycopy(b, 0, t2, modLen, modLen);
b = montReduce(t2, mod, modLen, inv);
- t2 = new int[modLen];
- for(int i=0; i<modLen; i++)
- t2[i] = b[i];
+ t2 = Arrays.copyOf(b, modLen);
return new BigInteger(1, t2);
}
/**
@@ -2152,12 +2146,11 @@
return this;
// Copy remaining ints of mag
int numInts = (p + 31) >>> 5;
int[] mag = new int[numInts];
- for (int i=0; i<numInts; i++)
- mag[i] = this.mag[i + (this.mag.length - numInts)];
+ System.arraycopy(this.mag, (this.mag.length - numInts), mag, 0, numInts);
// Mask out any excess bits
int excessBits = (numInts << 5) - p;
mag[0] &= (1L << (32-excessBits)) - 1;
@@ -2219,11 +2212,11 @@
throw new ArithmeticException("Shift distance of Integer.MIN_VALUE not supported.");
} else {
return shiftRight(-n);
}
}
- int[] newMag = shiftLeft(mag,n);
+ int[] newMag = shiftLeft(mag, n);
return new BigInteger(newMag, signum);
}
private static int[] shiftLeft(int[] mag, int n) {
@@ -2232,12 +2225,11 @@
int magLen = mag.length;
int newMag[] = null;
if (nBits == 0) {
newMag = new int[magLen + nInts];
- for (int i=0; i<magLen; i++)
- newMag[i] = mag[i];
+ System.arraycopy(mag, 0, newMag, 0, magLen);
} else {
int i = 0;
int nBits2 = 32 - nBits;
int highBits = mag[0] >>> nBits2;
if (highBits != 0) {
@@ -2286,13 +2278,11 @@
if (nInts >= magLen)
return (signum >= 0 ? ZERO : negConst[1]);
if (nBits == 0) {
int newMagLen = magLen - nInts;
- newMag = new int[newMagLen];
- for (int i=0; i<newMagLen; i++)
- newMag[i] = mag[i];
+ newMag = Arrays.copyOf(mag, newMagLen);
} else {
int i = 0;
int highBits = mag[0] >>> nBits;
if (highBits != 0) {
newMag = new int[magLen - nInts];
@@ -2559,11 +2549,11 @@
// Calculate the bit length of the magnitude
int magBitLength = ((len - 1) << 5) + bitLengthForInt(mag[0]);
if (signum < 0) {
// Check if magnitude is a power of two
boolean pow2 = (Integer.bitCount(mag[0]) == 1);
- for(int i=1; i< len && pow2; i++)
+ for (int i=1; i< len && pow2; i++)
pow2 = (mag[i] == 0);
n = (pow2 ? magBitLength -1 : magBitLength);
} else {
n = magBitLength;