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7128441: StrictMath performance improvement note shared with Math

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Reviewed-by: darcy
This commit is contained in:
Martin Desruisseaux 2012-01-09 15:54:44 -08:00 committed by Joe Darcy
parent 6eb76c4598
commit f8400651e0
2 changed files with 43 additions and 62 deletions
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41
jdk/src/share/classes/java/lang/Math.java
View File

@ -818,8 +818,9 @@ public final class Math {
return (a >= b) ? a : b;
}
private static long negativeZeroFloatBits = Float.floatToIntBits(-0.0f);
private static long negativeZeroDoubleBits = Double.doubleToLongBits(-0.0d);
// Use raw bit-wise conversions on guaranteed non-NaN arguments.
private static long negativeZeroFloatBits = Float.floatToRawIntBits(-0.0f);
private static long negativeZeroDoubleBits = Double.doubleToRawLongBits(-0.0d);
/**
* Returns the greater of two {@code float} values. That is,
@ -836,9 +837,12 @@ public final class Math {
* @return the larger of {@code a} and {@code b}.
*/
public static float max(float a, float b) {
if (a != a) return a; // a is NaN
if ((a == 0.0f) && (b == 0.0f)
&& (Float.floatToIntBits(a) == negativeZeroFloatBits)) {
if (a != a)
return a; // a is NaN
if ((a == 0.0f) &&
(b == 0.0f) &&
(Float.floatToRawIntBits(a) == negativeZeroFloatBits)) {
// Raw conversion ok since NaN can't map to -0.0.
return b;
}
return (a >= b) ? a : b;
@ -859,9 +863,12 @@ public final class Math {
* @return the larger of {@code a} and {@code b}.
*/
public static double max(double a, double b) {
if (a != a) return a; // a is NaN
if ((a == 0.0d) && (b == 0.0d)
&& (Double.doubleToLongBits(a) == negativeZeroDoubleBits)) {
if (a != a)
return a; // a is NaN
if ((a == 0.0d) &&
(b == 0.0d) &&
(Double.doubleToRawLongBits(a) == negativeZeroDoubleBits)) {
// Raw conversion ok since NaN can't map to -0.0.
return b;
}
return (a >= b) ? a : b;
@ -910,9 +917,12 @@ public final class Math {
* @return the smaller of {@code a} and {@code b}.
*/
public static float min(float a, float b) {
if (a != a) return a; // a is NaN
if ((a == 0.0f) && (b == 0.0f)
&& (Float.floatToIntBits(b) == negativeZeroFloatBits)) {
if (a != a)
return a; // a is NaN
if ((a == 0.0f) &&
(b == 0.0f) &&
(Float.floatToRawIntBits(b) == negativeZeroFloatBits)) {
// Raw conversion ok since NaN can't map to -0.0.
return b;
}
return (a <= b) ? a : b;
@ -933,9 +943,12 @@ public final class Math {
* @return the smaller of {@code a} and {@code b}.
*/
public static double min(double a, double b) {
if (a != a) return a; // a is NaN
if ((a == 0.0d) && (b == 0.0d)
&& (Double.doubleToLongBits(b) == negativeZeroDoubleBits)) {
if (a != a)
return a; // a is NaN
if ((a == 0.0d) &&
(b == 0.0d) &&
(Double.doubleToRawLongBits(b) == negativeZeroDoubleBits)) {
// Raw conversion ok since NaN can't map to -0.0.
return b;
}
return (a <= b) ? a : b;

64
jdk/src/share/classes/java/lang/StrictMath.java
View File

@ -161,6 +161,8 @@ public final class StrictMath {
* in radians.
*/
public static strictfp double toRadians(double angdeg) {
// Do not delegate to Math.toRadians(angdeg) because
// this method has the strictfp modifier.
return angdeg / 180.0 * PI;
}
@ -176,6 +178,8 @@ public final class StrictMath {
* in degrees.
*/
public static strictfp double toDegrees(double angrad) {
// Do not delegate to Math.toDegrees(angrad) because
// this method has the strictfp modifier.
return angrad * 180.0 / PI;
}
@ -708,7 +712,7 @@ public final class StrictMath {
* @return the absolute value of the argument.
*/
public static int abs(int a) {
return (a < 0) ? -a : a;
return Math.abs(a);
}
/**
@ -725,7 +729,7 @@ public final class StrictMath {
* @return the absolute value of the argument.
*/
public static long abs(long a) {
return (a < 0) ? -a : a;
return Math.abs(a);
}
/**
@ -744,7 +748,7 @@ public final class StrictMath {
* @return the absolute value of the argument.
*/
public static float abs(float a) {
return (a <= 0.0F) ? 0.0F - a : a;
return Math.abs(a);
}
/**
@ -763,7 +767,7 @@ public final class StrictMath {
* @return the absolute value of the argument.
*/
public static double abs(double a) {
return (a <= 0.0D) ? 0.0D - a : a;
return Math.abs(a);
}
/**
@ -777,7 +781,7 @@ public final class StrictMath {
* @return the larger of {@code a} and {@code b}.
*/
public static int max(int a, int b) {
return (a >= b) ? a : b;
return Math.max(a, b);
}
/**
@ -791,13 +795,9 @@ public final class StrictMath {
* @return the larger of {@code a} and {@code b}.
*/
public static long max(long a, long b) {
return (a >= b) ? a : b;
return Math.max(a, b);
}
// Use raw bit-wise conversions on guaranteed non-NaN arguments.
private static long negativeZeroFloatBits = Float.floatToRawIntBits(-0.0f);
private static long negativeZeroDoubleBits = Double.doubleToRawLongBits(-0.0d);
/**
* Returns the greater of two {@code float} values. That is,
* the result is the argument closer to positive infinity. If the
@ -813,15 +813,7 @@ public final class StrictMath {
* @return the larger of {@code a} and {@code b}.
*/
public static float max(float a, float b) {
if (a != a)
return a; // a is NaN
if ((a == 0.0f) &&
(b == 0.0f) &&
(Float.floatToRawIntBits(a) == negativeZeroFloatBits)) {
// Raw conversion ok since NaN can't map to -0.0.
return b;
}
return (a >= b) ? a : b;
return Math.max(a, b);
}
/**
@ -839,15 +831,7 @@ public final class StrictMath {
* @return the larger of {@code a} and {@code b}.
*/
public static double max(double a, double b) {
if (a != a)
return a; // a is NaN
if ((a == 0.0d) &&
(b == 0.0d) &&
(Double.doubleToRawLongBits(a) == negativeZeroDoubleBits)) {
// Raw conversion ok since NaN can't map to -0.0.
return b;
}
return (a >= b) ? a : b;
return Math.max(a, b);
}
/**
@ -861,7 +845,7 @@ public final class StrictMath {
* @return the smaller of {@code a} and {@code b}.
*/
public static int min(int a, int b) {
return (a <= b) ? a : b;
return Math.min(a, b);
}
/**
@ -875,7 +859,7 @@ public final class StrictMath {
* @return the smaller of {@code a} and {@code b}.
*/
public static long min(long a, long b) {
return (a <= b) ? a : b;
return Math.min(a, b);
}
/**
@ -893,15 +877,7 @@ public final class StrictMath {
* @return the smaller of {@code a} and {@code b.}
*/
public static float min(float a, float b) {
if (a != a)
return a; // a is NaN
if ((a == 0.0f) &&
(b == 0.0f) &&
(Float.floatToRawIntBits(b) == negativeZeroFloatBits)) {
// Raw conversion ok since NaN can't map to -0.0.
return b;
}
return (a <= b) ? a : b;
return Math.min(a, b);
}
/**
@ -919,15 +895,7 @@ public final class StrictMath {
* @return the smaller of {@code a} and {@code b}.
*/
public static double min(double a, double b) {
if (a != a)
return a; // a is NaN
if ((a == 0.0d) &&
(b == 0.0d) &&
(Double.doubleToRawLongBits(b) == negativeZeroDoubleBits)) {
// Raw conversion ok since NaN can't map to -0.0.
return b;
}
return (a <= b) ? a : b;
return Math.min(a, b);
}
/**