Author: tn
Date: Fri Oct 18 21:40:42 2013
New Revision: 1533643
URL: http://svn.apache.org/r1533643
Log:
[MATH-1035] Simplified and improved performance of
ArithmeticUtils.addAndCheck(long, long), thanks to derphead
Modified:
commons/proper/math/trunk/src/changes/changes.xml
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/util/ArithmeticUtils.java
commons/proper/math/trunk/src/test/java/org/apache/commons/math3/util/ArithmeticUtilsTest.java
Modified: commons/proper/math/trunk/src/changes/changes.xml
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/changes/changes.xml?rev=1533643&r1=1533642&r2=1533643&view=diff
==============================================================================
--- commons/proper/math/trunk/src/changes/changes.xml (original)
+++ commons/proper/math/trunk/src/changes/changes.xml Fri Oct 18 21:40:42 2013
@@ -51,6 +51,9 @@ If the output is not quite correct, chec
</properties>
<body>
<release version="x.y" date="TBD" description="TBD">
+ <action dev="tn" type="fix" issue="MATH-1035" due-to="derphead">
+ Simplified and improved performance of
"ArithmeticUtils#addAndCheck(long, long)".
+ </action>
<action dev="tn" type="add" issue="MATH-1004" due-to="Ajo Fod">
Added new methods to compute the inverse of a matrix to
"DiagonalMatrix"
and "MatrixUtils".
Modified:
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/util/ArithmeticUtils.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math3/util/ArithmeticUtils.java?rev=1533643&r1=1533642&r2=1533643&view=diff
==============================================================================
---
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/util/ArithmeticUtils.java
(original)
+++
commons/proper/math/trunk/src/main/java/org/apache/commons/math3/util/ArithmeticUtils.java
Fri Oct 18 21:40:42 2013
@@ -62,12 +62,11 @@ public final class ArithmeticUtils {
* @param a an addend
* @param b an addend
* @return the sum {@code a+b}
- * @throws MathArithmeticException if the result can not be represented as
an
- * long
+ * @throws MathArithmeticException if the result can not be represented as
an long
* @since 1.2
*/
public static long addAndCheck(long a, long b) throws
MathArithmeticException {
- return ArithmeticUtils.addAndCheck(a, b,
LocalizedFormats.OVERFLOW_IN_ADDITION);
+ return addAndCheck(a, b, LocalizedFormats.OVERFLOW_IN_ADDITION);
}
/**
@@ -247,9 +246,7 @@ public final class ArithmeticUtils {
* a non-negative {@code int} value.
* @since 1.1
*/
- public static int gcd(int p,
- int q)
- throws MathArithmeticException {
+ public static int gcd(int p, int q) throws MathArithmeticException {
int a = p;
int b = q;
if (a == 0 ||
@@ -326,8 +323,7 @@ public final class ArithmeticUtils {
* @param b Positive number.
* @return the greatest common divisor.
*/
- private static int gcdPositive(int a,
- int b) {
+ private static int gcdPositive(int a, int b) {
if (a == 0) {
return b;
}
@@ -842,38 +838,11 @@ public final class ArithmeticUtils {
* @since 1.2
*/
private static long addAndCheck(long a, long b, Localizable pattern)
throws MathArithmeticException {
- long ret;
- if (a > b) {
- // use symmetry to reduce boundary cases
- ret = addAndCheck(b, a, pattern);
- } else {
- // assert a <= b
-
- if (a < 0) {
- if (b < 0) {
- // check for negative overflow
- if (Long.MIN_VALUE - b <= a) {
- ret = a + b;
- } else {
- throw new MathArithmeticException(pattern, a, b);
- }
- } else {
- // opposite sign addition is always safe
- ret = a + b;
- }
- } else {
- // assert a >= 0
- // assert b >= 0
-
- // check for positive overflow
- if (a <= Long.MAX_VALUE - b) {
- ret = a + b;
- } else {
- throw new MathArithmeticException(pattern, a, b);
- }
- }
- }
- return ret;
+ final long result = a + b;
+ if (!((a ^ b) < 0 | (a ^ result) >= 0)) {
+ throw new MathArithmeticException(pattern, a, b);
+ }
+ return result;
}
/**
Modified:
commons/proper/math/trunk/src/test/java/org/apache/commons/math3/util/ArithmeticUtilsTest.java
URL:
http://svn.apache.org/viewvc/commons/proper/math/trunk/src/test/java/org/apache/commons/math3/util/ArithmeticUtilsTest.java?rev=1533643&r1=1533642&r2=1533643&view=diff
==============================================================================
---
commons/proper/math/trunk/src/test/java/org/apache/commons/math3/util/ArithmeticUtilsTest.java
(original)
+++
commons/proper/math/trunk/src/test/java/org/apache/commons/math3/util/ArithmeticUtilsTest.java
Fri Oct 18 21:40:42 2013
@@ -62,10 +62,13 @@ public class ArithmeticUtilsTest {
Assert.assertEquals(1, ArithmeticUtils.addAndCheck(2L, -1L));
Assert.assertEquals(-3, ArithmeticUtils.addAndCheck(-2L, -1L));
Assert.assertEquals(min, ArithmeticUtils.addAndCheck(min + 1, -1L));
+ Assert.assertEquals(-1, ArithmeticUtils.addAndCheck(min, max));
testAddAndCheckLongFailure(max, 1L);
testAddAndCheckLongFailure(min, -1L);
testAddAndCheckLongFailure(1L, max);
testAddAndCheckLongFailure(-1L, min);
+ testAddAndCheckLongFailure(max, max);
+ testAddAndCheckLongFailure(min, min);
}
@Test
