7128441: StrictMath performance improvement note shared with Math
Reviewed-by: darcy
Contributed-by: Martin Desruisseaux <martin.desruisseaux@geomatys.fr>
--- a/jdk/src/share/classes/java/lang/Math.java Mon Jan 09 19:33:02 2012 +0000
+++ b/jdk/src/share/classes/java/lang/Math.java Mon Jan 09 15:54:44 2012 -0800
@@ -818,8 +818,9 @@
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 @@
* @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 @@
* @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 @@
* @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 @@
* @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;
--- a/jdk/src/share/classes/java/lang/StrictMath.java Mon Jan 09 19:33:02 2012 +0000
+++ b/jdk/src/share/classes/java/lang/StrictMath.java Mon Jan 09 15:54:44 2012 -0800
@@ -161,6 +161,8 @@
* 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 @@
* 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 @@
* @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 @@
* @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 @@
* @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 @@
* @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 @@
* @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 @@
* @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 @@
* @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 @@
* @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 @@
* @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 @@
* @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 @@
* @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 @@
* @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);
}
/**