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8081778: Use Intel x64 CPU instructions for RSA acceleration

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Add intrinsics for BigInteger squareToLen and mulAdd methods.

Reviewed-by: kvn, jrose, aph, ascarpino, fweimer
This commit is contained in:
Vladimir Kozlov 2015-06-03 12:54:08 -07:00
parent eaf1406cf4
commit 438dec2d0d
1 changed files with 63 additions and 3 deletions
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66
jdk/src/java.base/share/classes/java/math/BigInteger.java
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@ -1963,6 +1963,43 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* int array z. The contents of x are not changed.
*/
private static final int[] squareToLen(int[] x, int len, int[] z) {
int zlen = len << 1;
if (z == null || z.length < zlen)
z = new int[zlen];
// Execute checks before calling intrinsified method.
implSquareToLenChecks(x, len, z, zlen);
return implSquareToLen(x, len, z, zlen);
}
/**
* Parameters validation.
*/
private static void implSquareToLenChecks(int[] x, int len, int[] z, int zlen) throws RuntimeException {
if (len < 1) {
throw new IllegalArgumentException("invalid input length: " + len);
}
if (len > x.length) {
throw new IllegalArgumentException("input length out of bound: " +
len + " > " + x.length);
}
if (len * 2 > z.length) {
throw new IllegalArgumentException("input length out of bound: " +
(len * 2) + " > " + z.length);
}
if (zlen < 1) {
throw new IllegalArgumentException("invalid input length: " + zlen);
}
if (zlen > z.length) {
throw new IllegalArgumentException("input length out of bound: " +
len + " > " + z.length);
}
}
/**
* Java Runtime may use intrinsic for this method.
*/
private static final int[] implSquareToLen(int[] x, int len, int[] z, int zlen) {
/*
* The algorithm used here is adapted from Colin Plumb's C library.
* Technique: Consider the partial products in the multiplication
@ -1997,9 +2034,6 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* again. The low bit is simply a copy of the low bit of the
* input, so it doesn't need special care.
*/
int zlen = len << 1;
if (z == null || z.length < zlen)
z = new int[zlen];
// Store the squares, right shifted one bit (i.e., divided by 2)
int lastProductLowWord = 0;
@ -2857,6 +2891,32 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
* Multiply an array by one word k and add to result, return the carry
*/
static int mulAdd(int[] out, int[] in, int offset, int len, int k) {
implMulAddCheck(out, in, offset, len, k);
return implMulAdd(out, in, offset, len, k);
}
/**
* Parameters validation.
*/
private static void implMulAddCheck(int[] out, int[] in, int offset, int len, int k) {
if (len > in.length) {
throw new IllegalArgumentException("input length is out of bound: " + len + " > " + in.length);
}
if (offset < 0) {
throw new IllegalArgumentException("input offset is invalid: " + offset);
}
if (offset > (out.length - 1)) {
throw new IllegalArgumentException("input offset is out of bound: " + offset + " > " + (out.length - 1));
}
if (len > (out.length - offset)) {
throw new IllegalArgumentException("input len is out of bound: " + len + " > " + (out.length - offset));
}
}
/**
* Java Runtime may use intrinsic for this method.
*/
private static int implMulAdd(int[] out, int[] in, int offset, int len, int k) {
long kLong = k & LONG_MASK;
long carry = 0;