sun.misc.FloatConsts Java Examples
The following examples show how to use
sun.misc.FloatConsts.
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Example #1
| Source File: Math.java From JDKSourceCode1.8 with MIT License | 5 votes |
|
/**
* Returns a floating-point power of two in the normal range.
*/
static float powerOfTwoF(int n) {
assert(n >= FloatConsts.MIN_EXPONENT && n <= FloatConsts.MAX_EXPONENT);
return Float.intBitsToFloat(((n + FloatConsts.EXP_BIAS) <<
(FloatConsts.SIGNIFICAND_WIDTH-1))
& FloatConsts.EXP_BIT_MASK);
}
Example #2
| Source File: Math.java From AndroidComponentPlugin with Apache License 2.0 | 5 votes |
|
/**
* Returns the closest {@code int} to the argument, with ties
* rounding to positive infinity.
*
* <p>
* Special cases:
* <ul><li>If the argument is NaN, the result is 0.
* <li>If the argument is negative infinity or any value less than or
* equal to the value of {@code Integer.MIN_VALUE}, the result is
* equal to the value of {@code Integer.MIN_VALUE}.
* <li>If the argument is positive infinity or any value greater than or
* equal to the value of {@code Integer.MAX_VALUE}, the result is
* equal to the value of {@code Integer.MAX_VALUE}.</ul>
*
* @param a a floating-point value to be rounded to an integer.
* @return the value of the argument rounded to the nearest
* {@code int} value.
* @see java.lang.Integer#MAX_VALUE
* @see java.lang.Integer#MIN_VALUE
*/
public static int round(float a) {
int intBits = Float.floatToRawIntBits(a);
int biasedExp = (intBits & FloatConsts.EXP_BIT_MASK)
>> (FloatConsts.SIGNIFICAND_WIDTH - 1);
int shift = (FloatConsts.SIGNIFICAND_WIDTH - 2
+ FloatConsts.EXP_BIAS) - biasedExp;
if ((shift & -32) == 0) { // shift >= 0 && shift < 32
// a is a finite number such that pow(2,-32) <= ulp(a) < 1
int r = ((intBits & FloatConsts.SIGNIF_BIT_MASK)
| (FloatConsts.SIGNIF_BIT_MASK + 1));
if (intBits < 0) {
r = -r;
}
// In the comments below each Java expression evaluates to the value
// the corresponding mathematical expression:
// (r) evaluates to a / ulp(a)
// (r >> shift) evaluates to floor(a * 2)
// ((r >> shift) + 1) evaluates to floor((a + 1/2) * 2)
// (((r >> shift) + 1) >> 1) evaluates to floor(a + 1/2)
return ((r >> shift) + 1) >> 1;
} else {
// a is either
// - a finite number with abs(a) < exp(2,FloatConsts.SIGNIFICAND_WIDTH-32) < 1/2
// - a finite number with ulp(a) >= 1 and hence a is a mathematical integer
// - an infinity or NaN
return (int) a;
}
}
Example #3
| Source File: IeeeRecommendedTests.java From openjdk-jdk8u-backup with GNU General Public License v2.0 | 5 votes |
|
public static int testFloatNextDown() {
int failures=0;
/*
* Each row of testCases represents one test case for nextDown;
* the first column is the input and the second column is the
* expected result.
*/
float testCases [][] = {
{NaNf, NaNf},
{-infinityF, -infinityF},
{-Float.MAX_VALUE, -infinityF},
{-Float_MAX_VALUEmm, -Float.MAX_VALUE},
{-Float_MAX_SUBNORMAL, -FloatConsts.MIN_NORMAL},
{-Float_MAX_SUBNORMALmm, -Float_MAX_SUBNORMAL},
{-0.0f, -Float.MIN_VALUE},
{+0.0f, -Float.MIN_VALUE},
{Float.MIN_VALUE, 0.0f},
{Float.MIN_VALUE*2, Float.MIN_VALUE},
{Float_MAX_SUBNORMAL, Float_MAX_SUBNORMALmm},
{FloatConsts.MIN_NORMAL, Float_MAX_SUBNORMAL},
{FloatConsts.MIN_NORMAL+
Float.MIN_VALUE, FloatConsts.MIN_NORMAL},
{Float.MAX_VALUE, Float_MAX_VALUEmm},
{infinityF, Float.MAX_VALUE},
};
for(int i = 0; i < testCases.length; i++) {
failures+=Tests.test("Math.nextDown(float)",
testCases[i][0], Math.nextDown(testCases[i][0]), testCases[i][1]);
failures+=Tests.test("StrictMath.nextDown(float)",
testCases[i][0], StrictMath.nextDown(testCases[i][0]), testCases[i][1]);
}
return failures;
}
Example #4
| Source File: IeeeRecommendedTests.java From openjdk-8 with GNU General Public License v2.0 | 5 votes |
|
public static int testFloatNextUp() {
int failures=0;
/*
* Each row of testCases represents one test case for nextUp;
* the first column is the input and the second column is the
* expected result.
*/
float testCases [][] = {
{NaNf, NaNf},
{-infinityF, -Float.MAX_VALUE},
{-Float.MAX_VALUE, -Float_MAX_VALUEmm},
{-FloatConsts.MIN_NORMAL, -Float_MAX_SUBNORMAL},
{-Float_MAX_SUBNORMAL, -Float_MAX_SUBNORMALmm},
{-Float.MIN_VALUE, -0.0f},
{-0.0f, Float.MIN_VALUE},
{+0.0f, Float.MIN_VALUE},
{Float.MIN_VALUE, Float.MIN_VALUE*2},
{Float_MAX_SUBNORMALmm, Float_MAX_SUBNORMAL},
{Float_MAX_SUBNORMAL, FloatConsts.MIN_NORMAL},
{FloatConsts.MIN_NORMAL, FloatConsts.MIN_NORMAL+Float.MIN_VALUE},
{Float_MAX_VALUEmm, Float.MAX_VALUE},
{Float.MAX_VALUE, infinityF},
{infinityF, infinityF}
};
for(int i = 0; i < testCases.length; i++) {
failures+=Tests.test("Math.nextUp(float)",
testCases[i][0], Math.nextUp(testCases[i][0]), testCases[i][1]);
failures+=Tests.test("StrictMath.nextUp(float)",
testCases[i][0], StrictMath.nextUp(testCases[i][0]), testCases[i][1]);
}
return failures;
}
Example #5
| Source File: Math.java From jdk1.8-source-analysis with Apache License 2.0 | 5 votes |
|
/**
* Returns the closest {@code int} to the argument, with ties
* rounding to positive infinity.
*
* <p>
* Special cases:
* <ul><li>If the argument is NaN, the result is 0.
* <li>If the argument is negative infinity or any value less than or
* equal to the value of {@code Integer.MIN_VALUE}, the result is
* equal to the value of {@code Integer.MIN_VALUE}.
* <li>If the argument is positive infinity or any value greater than or
* equal to the value of {@code Integer.MAX_VALUE}, the result is
* equal to the value of {@code Integer.MAX_VALUE}.</ul>
*
* @param a a floating-point value to be rounded to an integer.
* @return the value of the argument rounded to the nearest
* {@code int} value.
* @see java.lang.Integer#MAX_VALUE
* @see java.lang.Integer#MIN_VALUE
*/
public static int round(float a) {
int intBits = Float.floatToRawIntBits(a);
int biasedExp = (intBits & FloatConsts.EXP_BIT_MASK)
>> (FloatConsts.SIGNIFICAND_WIDTH - 1);
int shift = (FloatConsts.SIGNIFICAND_WIDTH - 2
+ FloatConsts.EXP_BIAS) - biasedExp;
if ((shift & -32) == 0) { // shift >= 0 && shift < 32
// a is a finite number such that pow(2,-32) <= ulp(a) < 1
int r = ((intBits & FloatConsts.SIGNIF_BIT_MASK)
| (FloatConsts.SIGNIF_BIT_MASK + 1));
if (intBits < 0) {
r = -r;
}
// In the comments below each Java expression evaluates to the value
// the corresponding mathematical expression:
// (r) evaluates to a / ulp(a)
// (r >> shift) evaluates to floor(a * 2)
// ((r >> shift) + 1) evaluates to floor((a + 1/2) * 2)
// (((r >> shift) + 1) >> 1) evaluates to floor(a + 1/2)
return ((r >> shift) + 1) >> 1;
} else {
// a is either
// - a finite number with abs(a) < exp(2,FloatConsts.SIGNIFICAND_WIDTH-32) < 1/2
// - a finite number with ulp(a) >= 1 and hence a is a mathematical integer
// - an infinity or NaN
return (int) a;
}
}
Example #6
| Source File: IeeeRecommendedTests.java From jdk8u-jdk with GNU General Public License v2.0 | 5 votes |
|
public static int testFloatSignum() {
int failures = 0;
float testCases [][] = {
{NaNf, NaNf},
{-infinityF, -1.0f},
{-Float.MAX_VALUE, -1.0f},
{-FloatConsts.MIN_NORMAL, -1.0f},
{-1.0f, -1.0f},
{-2.0f, -1.0f},
{-Float_MAX_SUBNORMAL, -1.0f},
{-Float.MIN_VALUE, -1.0f},
{-0.0f, -0.0f},
{+0.0f, +0.0f},
{Float.MIN_VALUE, 1.0f},
{Float_MAX_SUBNORMALmm, 1.0f},
{Float_MAX_SUBNORMAL, 1.0f},
{FloatConsts.MIN_NORMAL, 1.0f},
{1.0f, 1.0f},
{2.0f, 1.0f},
{Float_MAX_VALUEmm, 1.0f},
{Float.MAX_VALUE, 1.0f},
{infinityF, 1.0f}
};
for(int i = 0; i < testCases.length; i++) {
failures+=Tests.test("Math.signum(float)",
testCases[i][0], Math.signum(testCases[i][0]), testCases[i][1]);
failures+=Tests.test("StrictMath.signum(float)",
testCases[i][0], StrictMath.signum(testCases[i][0]), testCases[i][1]);
}
return failures;
}
Example #7
| Source File: Math.java From j2objc with Apache License 2.0 | 5 votes |
|
/**
* Returns the closest {@code int} to the argument, with ties
* rounding to positive infinity.
*
* <p>
* Special cases:
* <ul><li>If the argument is NaN, the result is 0.
* <li>If the argument is negative infinity or any value less than or
* equal to the value of {@code Integer.MIN_VALUE}, the result is
* equal to the value of {@code Integer.MIN_VALUE}.
* <li>If the argument is positive infinity or any value greater than or
* equal to the value of {@code Integer.MAX_VALUE}, the result is
* equal to the value of {@code Integer.MAX_VALUE}.</ul>
*
* @param a a floating-point value to be rounded to an integer.
* @return the value of the argument rounded to the nearest
* {@code int} value.
* @see java.lang.Integer#MAX_VALUE
* @see java.lang.Integer#MIN_VALUE
*/
public static int round(float a) {
int intBits = Float.floatToRawIntBits(a);
int biasedExp = (intBits & FloatConsts.EXP_BIT_MASK)
>> (FloatConsts.SIGNIFICAND_WIDTH - 1);
int shift = (FloatConsts.SIGNIFICAND_WIDTH - 2
+ FloatConsts.EXP_BIAS) - biasedExp;
if ((shift & -32) == 0) { // shift >= 0 && shift < 32
// a is a finite number such that pow(2,-32) <= ulp(a) < 1
int r = ((intBits & FloatConsts.SIGNIF_BIT_MASK)
| (FloatConsts.SIGNIF_BIT_MASK + 1));
if (intBits < 0) {
r = -r;
}
// In the comments below each Java expression evaluates to the value
// the corresponding mathematical expression:
// (r) evaluates to a / ulp(a)
// (r >> shift) evaluates to floor(a * 2)
// ((r >> shift) + 1) evaluates to floor((a + 1/2) * 2)
// (((r >> shift) + 1) >> 1) evaluates to floor(a + 1/2)
return ((r >> shift) + 1) >> 1;
} else {
// a is either
// - a finite number with abs(a) < exp(2,FloatConsts.SIGNIFICAND_WIDTH-32) < 1/2
// - a finite number with ulp(a) >= 1 and hence a is a mathematical integer
// - an infinity or NaN
return (int) a;
}
}
Example #8
| Source File: IeeeRecommendedTests.java From openjdk-jdk8u-backup with GNU General Public License v2.0 | 5 votes |
|
public static int testFloatNextUp() {
int failures=0;
/*
* Each row of testCases represents one test case for nextUp;
* the first column is the input and the second column is the
* expected result.
*/
float testCases [][] = {
{NaNf, NaNf},
{-infinityF, -Float.MAX_VALUE},
{-Float.MAX_VALUE, -Float_MAX_VALUEmm},
{-FloatConsts.MIN_NORMAL, -Float_MAX_SUBNORMAL},
{-Float_MAX_SUBNORMAL, -Float_MAX_SUBNORMALmm},
{-Float.MIN_VALUE, -0.0f},
{-0.0f, Float.MIN_VALUE},
{+0.0f, Float.MIN_VALUE},
{Float.MIN_VALUE, Float.MIN_VALUE*2},
{Float_MAX_SUBNORMALmm, Float_MAX_SUBNORMAL},
{Float_MAX_SUBNORMAL, FloatConsts.MIN_NORMAL},
{FloatConsts.MIN_NORMAL, FloatConsts.MIN_NORMAL+Float.MIN_VALUE},
{Float_MAX_VALUEmm, Float.MAX_VALUE},
{Float.MAX_VALUE, infinityF},
{infinityF, infinityF}
};
for(int i = 0; i < testCases.length; i++) {
failures+=Tests.test("Math.nextUp(float)",
testCases[i][0], Math.nextUp(testCases[i][0]), testCases[i][1]);
failures+=Tests.test("StrictMath.nextUp(float)",
testCases[i][0], StrictMath.nextUp(testCases[i][0]), testCases[i][1]);
}
return failures;
}
Example #9
| Source File: Math.java From Java8CN with Apache License 2.0 | 5 votes |
|
/**
* Returns a floating-point power of two in the normal range.
*/
static float powerOfTwoF(int n) {
assert(n >= FloatConsts.MIN_EXPONENT && n <= FloatConsts.MAX_EXPONENT);
return Float.intBitsToFloat(((n + FloatConsts.EXP_BIAS) <<
(FloatConsts.SIGNIFICAND_WIDTH-1))
& FloatConsts.EXP_BIT_MASK);
}
Example #10
| Source File: Math.java From openjdk-8 with GNU General Public License v2.0 | 5 votes |
|
/**
* Returns the closest {@code int} to the argument, with ties
* rounding to positive infinity.
*
* <p>
* Special cases:
* <ul><li>If the argument is NaN, the result is 0.
* <li>If the argument is negative infinity or any value less than or
* equal to the value of {@code Integer.MIN_VALUE}, the result is
* equal to the value of {@code Integer.MIN_VALUE}.
* <li>If the argument is positive infinity or any value greater than or
* equal to the value of {@code Integer.MAX_VALUE}, the result is
* equal to the value of {@code Integer.MAX_VALUE}.</ul>
*
* @param a a floating-point value to be rounded to an integer.
* @return the value of the argument rounded to the nearest
* {@code int} value.
* @see java.lang.Integer#MAX_VALUE
* @see java.lang.Integer#MIN_VALUE
*/
public static int round(float a) {
int intBits = Float.floatToRawIntBits(a);
int biasedExp = (intBits & FloatConsts.EXP_BIT_MASK)
>> (FloatConsts.SIGNIFICAND_WIDTH - 1);
int shift = (FloatConsts.SIGNIFICAND_WIDTH - 2
+ FloatConsts.EXP_BIAS) - biasedExp;
if ((shift & -32) == 0) { // shift >= 0 && shift < 32
// a is a finite number such that pow(2,-32) <= ulp(a) < 1
int r = ((intBits & FloatConsts.SIGNIF_BIT_MASK)
| (FloatConsts.SIGNIF_BIT_MASK + 1));
if (intBits < 0) {
r = -r;
}
// In the comments below each Java expression evaluates to the value
// the corresponding mathematical expression:
// (r) evaluates to a / ulp(a)
// (r >> shift) evaluates to floor(a * 2)
// ((r >> shift) + 1) evaluates to floor((a + 1/2) * 2)
// (((r >> shift) + 1) >> 1) evaluates to floor(a + 1/2)
return ((r >> shift) + 1) >> 1;
} else {
// a is either
// - a finite number with abs(a) < exp(2,FloatConsts.SIGNIFICAND_WIDTH-32) < 1/2
// - a finite number with ulp(a) >= 1 and hence a is a mathematical integer
// - an infinity or NaN
return (int) a;
}
}
Example #11
| Source File: IeeeRecommendedTests.java From jdk8u_jdk with GNU General Public License v2.0 | 5 votes |
|
public static int testFloatNextUp() {
int failures=0;
/*
* Each row of testCases represents one test case for nextUp;
* the first column is the input and the second column is the
* expected result.
*/
float testCases [][] = {
{NaNf, NaNf},
{-infinityF, -Float.MAX_VALUE},
{-Float.MAX_VALUE, -Float_MAX_VALUEmm},
{-FloatConsts.MIN_NORMAL, -Float_MAX_SUBNORMAL},
{-Float_MAX_SUBNORMAL, -Float_MAX_SUBNORMALmm},
{-Float.MIN_VALUE, -0.0f},
{-0.0f, Float.MIN_VALUE},
{+0.0f, Float.MIN_VALUE},
{Float.MIN_VALUE, Float.MIN_VALUE*2},
{Float_MAX_SUBNORMALmm, Float_MAX_SUBNORMAL},
{Float_MAX_SUBNORMAL, FloatConsts.MIN_NORMAL},
{FloatConsts.MIN_NORMAL, FloatConsts.MIN_NORMAL+Float.MIN_VALUE},
{Float_MAX_VALUEmm, Float.MAX_VALUE},
{Float.MAX_VALUE, infinityF},
{infinityF, infinityF}
};
for(int i = 0; i < testCases.length; i++) {
failures+=Tests.test("Math.nextUp(float)",
testCases[i][0], Math.nextUp(testCases[i][0]), testCases[i][1]);
failures+=Tests.test("StrictMath.nextUp(float)",
testCases[i][0], StrictMath.nextUp(testCases[i][0]), testCases[i][1]);
}
return failures;
}
Example #12
| Source File: Math.java From TencentKona-8 with GNU General Public License v2.0 | 5 votes |
|
/**
* Returns a floating-point power of two in the normal range.
*/
static float powerOfTwoF(int n) {
assert(n >= FloatConsts.MIN_EXPONENT && n <= FloatConsts.MAX_EXPONENT);
return Float.intBitsToFloat(((n + FloatConsts.EXP_BIAS) <<
(FloatConsts.SIGNIFICAND_WIDTH-1))
& FloatConsts.EXP_BIT_MASK);
}
Example #13
| Source File: Math.java From openjdk-jdk8u with GNU General Public License v2.0 | 5 votes |
|
/**
* Returns the closest {@code int} to the argument, with ties
* rounding to positive infinity.
*
* <p>
* Special cases:
* <ul><li>If the argument is NaN, the result is 0.
* <li>If the argument is negative infinity or any value less than or
* equal to the value of {@code Integer.MIN_VALUE}, the result is
* equal to the value of {@code Integer.MIN_VALUE}.
* <li>If the argument is positive infinity or any value greater than or
* equal to the value of {@code Integer.MAX_VALUE}, the result is
* equal to the value of {@code Integer.MAX_VALUE}.</ul>
*
* @param a a floating-point value to be rounded to an integer.
* @return the value of the argument rounded to the nearest
* {@code int} value.
* @see java.lang.Integer#MAX_VALUE
* @see java.lang.Integer#MIN_VALUE
*/
public static int round(float a) {
int intBits = Float.floatToRawIntBits(a);
int biasedExp = (intBits & FloatConsts.EXP_BIT_MASK)
>> (FloatConsts.SIGNIFICAND_WIDTH - 1);
int shift = (FloatConsts.SIGNIFICAND_WIDTH - 2
+ FloatConsts.EXP_BIAS) - biasedExp;
if ((shift & -32) == 0) { // shift >= 0 && shift < 32
// a is a finite number such that pow(2,-32) <= ulp(a) < 1
int r = ((intBits & FloatConsts.SIGNIF_BIT_MASK)
| (FloatConsts.SIGNIF_BIT_MASK + 1));
if (intBits < 0) {
r = -r;
}
// In the comments below each Java expression evaluates to the value
// the corresponding mathematical expression:
// (r) evaluates to a / ulp(a)
// (r >> shift) evaluates to floor(a * 2)
// ((r >> shift) + 1) evaluates to floor((a + 1/2) * 2)
// (((r >> shift) + 1) >> 1) evaluates to floor(a + 1/2)
return ((r >> shift) + 1) >> 1;
} else {
// a is either
// - a finite number with abs(a) < exp(2,FloatConsts.SIGNIFICAND_WIDTH-32) < 1/2
// - a finite number with ulp(a) >= 1 and hence a is a mathematical integer
// - an infinity or NaN
return (int) a;
}
}
Example #14
| Source File: IeeeRecommendedTests.java From jdk8u_jdk with GNU General Public License v2.0 | 5 votes |
|
public static int testFloatSignum() {
int failures = 0;
float testCases [][] = {
{NaNf, NaNf},
{-infinityF, -1.0f},
{-Float.MAX_VALUE, -1.0f},
{-FloatConsts.MIN_NORMAL, -1.0f},
{-1.0f, -1.0f},
{-2.0f, -1.0f},
{-Float_MAX_SUBNORMAL, -1.0f},
{-Float.MIN_VALUE, -1.0f},
{-0.0f, -0.0f},
{+0.0f, +0.0f},
{Float.MIN_VALUE, 1.0f},
{Float_MAX_SUBNORMALmm, 1.0f},
{Float_MAX_SUBNORMAL, 1.0f},
{FloatConsts.MIN_NORMAL, 1.0f},
{1.0f, 1.0f},
{2.0f, 1.0f},
{Float_MAX_VALUEmm, 1.0f},
{Float.MAX_VALUE, 1.0f},
{infinityF, 1.0f}
};
for(int i = 0; i < testCases.length; i++) {
failures+=Tests.test("Math.signum(float)",
testCases[i][0], Math.signum(testCases[i][0]), testCases[i][1]);
failures+=Tests.test("StrictMath.signum(float)",
testCases[i][0], StrictMath.signum(testCases[i][0]), testCases[i][1]);
}
return failures;
}
Example #15
| Source File: Math.java From JDKSourceCode1.8 with MIT License | 5 votes |
|
/**
* Returns the closest {@code int} to the argument, with ties
* rounding to positive infinity.
*
* <p>
* Special cases:
* <ul><li>If the argument is NaN, the result is 0.
* <li>If the argument is negative infinity or any value less than or
* equal to the value of {@code Integer.MIN_VALUE}, the result is
* equal to the value of {@code Integer.MIN_VALUE}.
* <li>If the argument is positive infinity or any value greater than or
* equal to the value of {@code Integer.MAX_VALUE}, the result is
* equal to the value of {@code Integer.MAX_VALUE}.</ul>
*
* @param a a floating-point value to be rounded to an integer.
* @return the value of the argument rounded to the nearest
* {@code int} value.
* @see java.lang.Integer#MAX_VALUE
* @see java.lang.Integer#MIN_VALUE
*/
public static int round(float a) {
int intBits = Float.floatToRawIntBits(a);
int biasedExp = (intBits & FloatConsts.EXP_BIT_MASK)
>> (FloatConsts.SIGNIFICAND_WIDTH - 1);
int shift = (FloatConsts.SIGNIFICAND_WIDTH - 2
+ FloatConsts.EXP_BIAS) - biasedExp;
if ((shift & -32) == 0) { // shift >= 0 && shift < 32
// a is a finite number such that pow(2,-32) <= ulp(a) < 1
int r = ((intBits & FloatConsts.SIGNIF_BIT_MASK)
| (FloatConsts.SIGNIF_BIT_MASK + 1));
if (intBits < 0) {
r = -r;
}
// In the comments below each Java expression evaluates to the value
// the corresponding mathematical expression:
// (r) evaluates to a / ulp(a)
// (r >> shift) evaluates to floor(a * 2)
// ((r >> shift) + 1) evaluates to floor((a + 1/2) * 2)
// (((r >> shift) + 1) >> 1) evaluates to floor(a + 1/2)
return ((r >> shift) + 1) >> 1;
} else {
// a is either
// - a finite number with abs(a) < exp(2,FloatConsts.SIGNIFICAND_WIDTH-32) < 1/2
// - a finite number with ulp(a) >= 1 and hence a is a mathematical integer
// - an infinity or NaN
return (int) a;
}
}
Example #16
| Source File: Math.java From dragonwell8_jdk with GNU General Public License v2.0 | 5 votes |
|
/**
* Returns a floating-point power of two in the normal range.
*/
static float powerOfTwoF(int n) {
assert(n >= FloatConsts.MIN_EXPONENT && n <= FloatConsts.MAX_EXPONENT);
return Float.intBitsToFloat(((n + FloatConsts.EXP_BIAS) <<
(FloatConsts.SIGNIFICAND_WIDTH-1))
& FloatConsts.EXP_BIT_MASK);
}
Example #17
| Source File: Math.java From jdk8u_jdk with GNU General Public License v2.0 | 5 votes |
|
/**
* Returns a floating-point power of two in the normal range.
*/
static float powerOfTwoF(int n) {
assert(n >= FloatConsts.MIN_EXPONENT && n <= FloatConsts.MAX_EXPONENT);
return Float.intBitsToFloat(((n + FloatConsts.EXP_BIAS) <<
(FloatConsts.SIGNIFICAND_WIDTH-1))
& FloatConsts.EXP_BIT_MASK);
}
Example #18
| Source File: BigInteger.java From jdk8u60 with GNU General Public License v2.0 | 4 votes |
|
/**
* Converts this BigInteger to a {@code float}. This
* conversion is similar to the
* <i>narrowing primitive conversion</i> from {@code double} to
* {@code float} as defined in section 5.1.3 of
* <cite>The Java™ Language Specification</cite>:
* if this BigInteger has too great a magnitude
* to represent as a {@code float}, it will be converted to
* {@link Float#NEGATIVE_INFINITY} or {@link
* Float#POSITIVE_INFINITY} as appropriate. Note that even when
* the return value is finite, this conversion can lose
* information about the precision of the BigInteger value.
*
* @return this BigInteger converted to a {@code float}.
*/
public float floatValue() {
if (signum == 0) {
return 0.0f;
}
int exponent = ((mag.length - 1) << 5) + bitLengthForInt(mag[0]) - 1;
// exponent == floor(log2(abs(this)))
if (exponent < Long.SIZE - 1) {
return longValue();
} else if (exponent > Float.MAX_EXPONENT) {
return signum > 0 ? Float.POSITIVE_INFINITY : Float.NEGATIVE_INFINITY;
}
/*
* We need the top SIGNIFICAND_WIDTH bits, including the "implicit"
* one bit. To make rounding easier, we pick out the top
* SIGNIFICAND_WIDTH + 1 bits, so we have one to help us round up or
* down. twiceSignifFloor will contain the top SIGNIFICAND_WIDTH + 1
* bits, and signifFloor the top SIGNIFICAND_WIDTH.
*
* It helps to consider the real number signif = abs(this) *
* 2^(SIGNIFICAND_WIDTH - 1 - exponent).
*/
int shift = exponent - FloatConsts.SIGNIFICAND_WIDTH;
int twiceSignifFloor;
// twiceSignifFloor will be == abs().shiftRight(shift).intValue()
// We do the shift into an int directly to improve performance.
int nBits = shift & 0x1f;
int nBits2 = 32 - nBits;
if (nBits == 0) {
twiceSignifFloor = mag[0];
} else {
twiceSignifFloor = mag[0] >>> nBits;
if (twiceSignifFloor == 0) {
twiceSignifFloor = (mag[0] << nBits2) | (mag[1] >>> nBits);
}
}
int signifFloor = twiceSignifFloor >> 1;
signifFloor &= FloatConsts.SIGNIF_BIT_MASK; // remove the implied bit
/*
* We round up if either the fractional part of signif is strictly
* greater than 0.5 (which is true if the 0.5 bit is set and any lower
* bit is set), or if the fractional part of signif is >= 0.5 and
* signifFloor is odd (which is true if both the 0.5 bit and the 1 bit
* are set). This is equivalent to the desired HALF_EVEN rounding.
*/
boolean increment = (twiceSignifFloor & 1) != 0
&& ((signifFloor & 1) != 0 || abs().getLowestSetBit() < shift);
int signifRounded = increment ? signifFloor + 1 : signifFloor;
int bits = ((exponent + FloatConsts.EXP_BIAS))
<< (FloatConsts.SIGNIFICAND_WIDTH - 1);
bits += signifRounded;
/*
* If signifRounded == 2^24, we'd need to set all of the significand
* bits to zero and add 1 to the exponent. This is exactly the behavior
* we get from just adding signifRounded to bits directly. If the
* exponent is Float.MAX_EXPONENT, we round up (correctly) to
* Float.POSITIVE_INFINITY.
*/
bits |= signum & FloatConsts.SIGN_BIT_MASK;
return Float.intBitsToFloat(bits);
}
Example #19
| Source File: IeeeRecommendedTests.java From openjdk-8-source with GNU General Public License v2.0 | 4 votes |
|
public static int testFloatNextAfter() {
int failures=0;
/*
* Each row of the testCases matrix represents one test case
* for nexAfter; given the input of the first two columns, the
* result in the last column is expected.
*/
float [][] testCases = {
{NaNf, NaNf, NaNf},
{NaNf, 0.0f, NaNf},
{0.0f, NaNf, NaNf},
{NaNf, infinityF, NaNf},
{infinityF, NaNf, NaNf},
{infinityF, infinityF, infinityF},
{infinityF, -infinityF, Float.MAX_VALUE},
{infinityF, 0.0f, Float.MAX_VALUE},
{Float.MAX_VALUE, infinityF, infinityF},
{Float.MAX_VALUE, -infinityF, Float_MAX_VALUEmm},
{Float.MAX_VALUE, Float.MAX_VALUE, Float.MAX_VALUE},
{Float.MAX_VALUE, 0.0f, Float_MAX_VALUEmm},
{Float_MAX_VALUEmm, Float.MAX_VALUE, Float.MAX_VALUE},
{Float_MAX_VALUEmm, infinityF, Float.MAX_VALUE},
{Float_MAX_VALUEmm, Float_MAX_VALUEmm, Float_MAX_VALUEmm},
{FloatConsts.MIN_NORMAL, infinityF, FloatConsts.MIN_NORMAL+
Float.MIN_VALUE},
{FloatConsts.MIN_NORMAL, -infinityF, Float_MAX_SUBNORMAL},
{FloatConsts.MIN_NORMAL, 1.0f, FloatConsts.MIN_NORMAL+
Float.MIN_VALUE},
{FloatConsts.MIN_NORMAL, -1.0f, Float_MAX_SUBNORMAL},
{FloatConsts.MIN_NORMAL, FloatConsts.MIN_NORMAL, FloatConsts.MIN_NORMAL},
{Float_MAX_SUBNORMAL, FloatConsts.MIN_NORMAL, FloatConsts.MIN_NORMAL},
{Float_MAX_SUBNORMAL, Float_MAX_SUBNORMAL, Float_MAX_SUBNORMAL},
{Float_MAX_SUBNORMAL, 0.0f, Float_MAX_SUBNORMALmm},
{Float_MAX_SUBNORMALmm, Float_MAX_SUBNORMAL, Float_MAX_SUBNORMAL},
{Float_MAX_SUBNORMALmm, 0.0f, Float_MAX_SUBNORMALmm-Float.MIN_VALUE},
{Float_MAX_SUBNORMALmm, Float_MAX_SUBNORMALmm, Float_MAX_SUBNORMALmm},
{Float.MIN_VALUE, 0.0f, 0.0f},
{-Float.MIN_VALUE, 0.0f, -0.0f},
{Float.MIN_VALUE, Float.MIN_VALUE, Float.MIN_VALUE},
{Float.MIN_VALUE, 1.0f, 2*Float.MIN_VALUE},
// Make sure zero behavior is tested
{0.0f, 0.0f, 0.0f},
{0.0f, -0.0f, -0.0f},
{-0.0f, 0.0f, 0.0f},
{-0.0f, -0.0f, -0.0f},
{0.0f, infinityF, Float.MIN_VALUE},
{0.0f, -infinityF, -Float.MIN_VALUE},
{-0.0f, infinityF, Float.MIN_VALUE},
{-0.0f, -infinityF, -Float.MIN_VALUE},
{0.0f, Float.MIN_VALUE, Float.MIN_VALUE},
{0.0f, -Float.MIN_VALUE, -Float.MIN_VALUE},
{-0.0f, Float.MIN_VALUE, Float.MIN_VALUE},
{-0.0f, -Float.MIN_VALUE, -Float.MIN_VALUE}
};
for(int i = 0; i < testCases.length; i++) {
failures += testNextAfterCase(testCases[i][0], testCases[i][1],
testCases[i][2]);
}
return failures;
}
Example #20
| Source File: FpUtils.java From openjdk-jdk8u-backup with GNU General Public License v2.0 | 4 votes |
|
/**
* Returns unbiased exponent of a {@code float}; for
* subnormal values, the number is treated as if it were
* normalized. That is for all finite, non-zero, positive numbers
* <i>x</i>, <code>scalb(<i>x</i>, -ilogb(<i>x</i>))</code> is
* always in the range [1, 2).
* <p>
* Special cases:
* <ul>
* <li> If the argument is NaN, then the result is 2<sup>30</sup>.
* <li> If the argument is infinite, then the result is 2<sup>28</sup>.
* <li> If the argument is zero, then the result is -(2<sup>28</sup>).
* </ul>
*
* @param f floating-point number whose exponent is to be extracted
* @return unbiased exponent of the argument.
* @author Joseph D. Darcy
*/
public static int ilogb(float f) {
int exponent = getExponent(f);
switch (exponent) {
case FloatConsts.MAX_EXPONENT+1: // NaN or infinity
if( isNaN(f) )
return (1<<30); // 2^30
else // infinite value
return (1<<28); // 2^28
case FloatConsts.MIN_EXPONENT-1: // zero or subnormal
if(f == 0.0f) {
return -(1<<28); // -(2^28)
}
else {
int transducer = Float.floatToRawIntBits(f);
/*
* To avoid causing slow arithmetic on subnormals,
* the scaling to determine when f's significand
* is normalized is done in integer arithmetic.
* (there must be at least one "1" bit in the
* significand since zero has been screened out.
*/
// isolate significand bits
transducer &= FloatConsts.SIGNIF_BIT_MASK;
assert(transducer != 0);
// This loop is simple and functional. We might be
// able to do something more clever that was faster;
// e.g. number of leading zero detection on
// (transducer << (# exponent and sign bits).
while (transducer <
(1 << (FloatConsts.SIGNIFICAND_WIDTH - 1))) {
transducer *= 2;
exponent--;
}
exponent++;
assert( exponent >=
FloatConsts.MIN_EXPONENT - (FloatConsts.SIGNIFICAND_WIDTH-1) &&
exponent < FloatConsts.MIN_EXPONENT);
return exponent;
}
default:
assert( exponent >= FloatConsts.MIN_EXPONENT &&
exponent <= FloatConsts.MAX_EXPONENT);
return exponent;
}
}
Example #21
| Source File: IeeeRecommendedTests.java From jdk8u-jdk with GNU General Public License v2.0 | 4 votes |
|
public static int testFloatBooleanMethods() {
int failures = 0;
float testCases [] = {
NaNf,
-infinityF,
infinityF,
-Float.MAX_VALUE,
-3.0f,
-1.0f,
-FloatConsts.MIN_NORMAL,
-Float_MAX_SUBNORMALmm,
-Float_MAX_SUBNORMAL,
-Float.MIN_VALUE,
-0.0f,
+0.0f,
Float.MIN_VALUE,
Float_MAX_SUBNORMALmm,
Float_MAX_SUBNORMAL,
FloatConsts.MIN_NORMAL,
1.0f,
3.0f,
Float_MAX_VALUEmm,
Float.MAX_VALUE
};
for(int i = 0; i < testCases.length; i++) {
// isNaN
failures+=Tests.test("FpUtils.isNaN(float)", testCases[i],
FpUtils.isNaN(testCases[i]), (i ==0));
// isFinite
failures+=Tests.test("Float.isFinite(float)", testCases[i],
Float.isFinite(testCases[i]), (i >= 3));
// isInfinite
failures+=Tests.test("FpUtils.isInfinite(float)", testCases[i],
FpUtils.isInfinite(testCases[i]), (i==1 || i==2));
// isUnorderd
for(int j = 0; j < testCases.length; j++) {
failures+=Tests.test("FpUtils.isUnordered(float, float)", testCases[i],testCases[j],
FpUtils.isUnordered(testCases[i],testCases[j]), (i==0 || j==0));
}
}
return failures;
}
Example #22
| Source File: IeeeRecommendedTests.java From jdk8u-dev-jdk with GNU General Public License v2.0 | 4 votes |
|
public static int testFloatBooleanMethods() {
int failures = 0;
float testCases [] = {
NaNf,
-infinityF,
infinityF,
-Float.MAX_VALUE,
-3.0f,
-1.0f,
-FloatConsts.MIN_NORMAL,
-Float_MAX_SUBNORMALmm,
-Float_MAX_SUBNORMAL,
-Float.MIN_VALUE,
-0.0f,
+0.0f,
Float.MIN_VALUE,
Float_MAX_SUBNORMALmm,
Float_MAX_SUBNORMAL,
FloatConsts.MIN_NORMAL,
1.0f,
3.0f,
Float_MAX_VALUEmm,
Float.MAX_VALUE
};
for(int i = 0; i < testCases.length; i++) {
// isNaN
failures+=Tests.test("FpUtils.isNaN(float)", testCases[i],
FpUtils.isNaN(testCases[i]), (i ==0));
// isFinite
failures+=Tests.test("Float.isFinite(float)", testCases[i],
Float.isFinite(testCases[i]), (i >= 3));
// isInfinite
failures+=Tests.test("FpUtils.isInfinite(float)", testCases[i],
FpUtils.isInfinite(testCases[i]), (i==1 || i==2));
// isUnorderd
for(int j = 0; j < testCases.length; j++) {
failures+=Tests.test("FpUtils.isUnordered(float, float)", testCases[i],testCases[j],
FpUtils.isUnordered(testCases[i],testCases[j]), (i==0 || j==0));
}
}
return failures;
}
Example #23
| Source File: FpUtils.java From jdk8u60 with GNU General Public License v2.0 | 4 votes |
|
/**
* Returns unbiased exponent of a {@code float}; for
* subnormal values, the number is treated as if it were
* normalized. That is for all finite, non-zero, positive numbers
* <i>x</i>, <code>scalb(<i>x</i>, -ilogb(<i>x</i>))</code> is
* always in the range [1, 2).
* <p>
* Special cases:
* <ul>
* <li> If the argument is NaN, then the result is 2<sup>30</sup>.
* <li> If the argument is infinite, then the result is 2<sup>28</sup>.
* <li> If the argument is zero, then the result is -(2<sup>28</sup>).
* </ul>
*
* @param f floating-point number whose exponent is to be extracted
* @return unbiased exponent of the argument.
* @author Joseph D. Darcy
*/
public static int ilogb(float f) {
int exponent = getExponent(f);
switch (exponent) {
case FloatConsts.MAX_EXPONENT+1: // NaN or infinity
if( isNaN(f) )
return (1<<30); // 2^30
else // infinite value
return (1<<28); // 2^28
case FloatConsts.MIN_EXPONENT-1: // zero or subnormal
if(f == 0.0f) {
return -(1<<28); // -(2^28)
}
else {
int transducer = Float.floatToRawIntBits(f);
/*
* To avoid causing slow arithmetic on subnormals,
* the scaling to determine when f's significand
* is normalized is done in integer arithmetic.
* (there must be at least one "1" bit in the
* significand since zero has been screened out.
*/
// isolate significand bits
transducer &= FloatConsts.SIGNIF_BIT_MASK;
assert(transducer != 0);
// This loop is simple and functional. We might be
// able to do something more clever that was faster;
// e.g. number of leading zero detection on
// (transducer << (# exponent and sign bits).
while (transducer <
(1 << (FloatConsts.SIGNIFICAND_WIDTH - 1))) {
transducer *= 2;
exponent--;
}
exponent++;
assert( exponent >=
FloatConsts.MIN_EXPONENT - (FloatConsts.SIGNIFICAND_WIDTH-1) &&
exponent < FloatConsts.MIN_EXPONENT);
return exponent;
}
default:
assert( exponent >= FloatConsts.MIN_EXPONENT &&
exponent <= FloatConsts.MAX_EXPONENT);
return exponent;
}
}
Example #24
| Source File: IeeeRecommendedTests.java From openjdk-8 with GNU General Public License v2.0 | 4 votes |
|
public static int testFloatBooleanMethods() {
int failures = 0;
float testCases [] = {
NaNf,
-infinityF,
infinityF,
-Float.MAX_VALUE,
-3.0f,
-1.0f,
-FloatConsts.MIN_NORMAL,
-Float_MAX_SUBNORMALmm,
-Float_MAX_SUBNORMAL,
-Float.MIN_VALUE,
-0.0f,
+0.0f,
Float.MIN_VALUE,
Float_MAX_SUBNORMALmm,
Float_MAX_SUBNORMAL,
FloatConsts.MIN_NORMAL,
1.0f,
3.0f,
Float_MAX_VALUEmm,
Float.MAX_VALUE
};
for(int i = 0; i < testCases.length; i++) {
// isNaN
failures+=Tests.test("FpUtils.isNaN(float)", testCases[i],
FpUtils.isNaN(testCases[i]), (i ==0));
// isFinite
failures+=Tests.test("Float.isFinite(float)", testCases[i],
Float.isFinite(testCases[i]), (i >= 3));
// isInfinite
failures+=Tests.test("FpUtils.isInfinite(float)", testCases[i],
FpUtils.isInfinite(testCases[i]), (i==1 || i==2));
// isUnorderd
for(int j = 0; j < testCases.length; j++) {
failures+=Tests.test("FpUtils.isUnordered(float, float)", testCases[i],testCases[j],
FpUtils.isUnordered(testCases[i],testCases[j]), (i==0 || j==0));
}
}
return failures;
}
Example #25
| Source File: FpUtils.java From java-n-IDE-for-Android with Apache License 2.0 | 4 votes |
|
/**
* Returns unbiased exponent of a <code>float</code>; for
* subnormal values, the number is treated as if it were
* normalized. That is for all finite, non-zero, positive numbers
* <i>x</i>, <code>scalb(<i>x</i>, -ilogb(<i>x</i>))</code> is
* always in the range [1, 2).
* <p>
* Special cases:
* <ul>
* <li> If the argument is NaN, then the result is 2<sup>30</sup>.
* <li> If the argument is infinite, then the result is 2<sup>28</sup>.
* <li> If the argument is zero, then the result is -(2<sup>28</sup>).
* </ul>
*
* @param f floating-point number whose exponent is to be extracted
* @return unbiased exponent of the argument.
* @author Joseph D. Darcy
*/
public static int ilogb(float f) {
int exponent = getExponent(f);
switch (exponent) {
case FloatConsts.MAX_EXPONENT+1: // NaN or infinity
if( isNaN(f) )
return (1<<30); // 2^30
else // infinite value
return (1<<28); // 2^28
// break;
case FloatConsts.MIN_EXPONENT-1: // zero or subnormal
if(f == 0.0f) {
return -(1<<28); // -(2^28)
}
else {
int transducer = Float.floatToRawIntBits(f);
/*
* To avoid causing slow arithmetic on subnormals,
* the scaling to determine when f's significand
* is normalized is done in integer arithmetic.
* (there must be at least one "1" bit in the
* significand since zero has been screened out.
*/
// isolate significand bits
transducer &= FloatConsts.SIGNIF_BIT_MASK;
assert(transducer != 0);
// This loop is simple and functional. We might be
// able to do something more clever that was faster;
// e.g. number of leading zero detection on
// (transducer << (# exponent and sign bits).
while (transducer <
(1 << (FloatConsts.SIGNIFICAND_WIDTH - 1))) {
transducer *= 2;
exponent--;
}
exponent++;
assert( exponent >=
FloatConsts.MIN_EXPONENT - (FloatConsts.SIGNIFICAND_WIDTH-1) &&
exponent < FloatConsts.MIN_EXPONENT);
return exponent;
}
// break;
default:
assert( exponent >= FloatConsts.MIN_EXPONENT &&
exponent <= FloatConsts.MAX_EXPONENT);
return exponent;
// break;
}
}
Example #26
| Source File: Math.java From TencentKona-8 with GNU General Public License v2.0 | 4 votes |
|
/**
* Returns {@code f} ×
* 2<sup>{@code scaleFactor}</sup> rounded as if performed
* by a single correctly rounded floating-point multiply to a
* member of the float value set. See the Java
* Language Specification for a discussion of floating-point
* value sets. If the exponent of the result is between {@link
* Float#MIN_EXPONENT} and {@link Float#MAX_EXPONENT}, the
* answer is calculated exactly. If the exponent of the result
* would be larger than {@code Float.MAX_EXPONENT}, an
* infinity is returned. Note that if the result is subnormal,
* precision may be lost; that is, when {@code scalb(x, n)}
* is subnormal, {@code scalb(scalb(x, n), -n)} may not equal
* <i>x</i>. When the result is non-NaN, the result has the same
* sign as {@code f}.
*
* <p>Special cases:
* <ul>
* <li> If the first argument is NaN, NaN is returned.
* <li> If the first argument is infinite, then an infinity of the
* same sign is returned.
* <li> If the first argument is zero, then a zero of the same
* sign is returned.
* </ul>
*
* @param f number to be scaled by a power of two.
* @param scaleFactor power of 2 used to scale {@code f}
* @return {@code f} × 2<sup>{@code scaleFactor}</sup>
* @since 1.6
*/
public static float scalb(float f, int scaleFactor) {
// magnitude of a power of two so large that scaling a finite
// nonzero value by it would be guaranteed to over or
// underflow; due to rounding, scaling down takes takes an
// additional power of two which is reflected here
final int MAX_SCALE = FloatConsts.MAX_EXPONENT + -FloatConsts.MIN_EXPONENT +
FloatConsts.SIGNIFICAND_WIDTH + 1;
// Make sure scaling factor is in a reasonable range
scaleFactor = Math.max(Math.min(scaleFactor, MAX_SCALE), -MAX_SCALE);
/*
* Since + MAX_SCALE for float fits well within the double
* exponent range and + float -> double conversion is exact
* the multiplication below will be exact. Therefore, the
* rounding that occurs when the double product is cast to
* float will be the correctly rounded float result. Since
* all operations other than the final multiply will be exact,
* it is not necessary to declare this method strictfp.
*/
return (float)((double)f*powerOfTwoD(scaleFactor));
}
Example #27
| Source File: BigInteger.java From jdk1.8-source-analysis with Apache License 2.0 | 4 votes |
|
/**
* Converts this BigInteger to a {@code float}. This
* conversion is similar to the
* <i>narrowing primitive conversion</i> from {@code double} to
* {@code float} as defined in section 5.1.3 of
* <cite>The Java™ Language Specification</cite>:
* if this BigInteger has too great a magnitude
* to represent as a {@code float}, it will be converted to
* {@link Float#NEGATIVE_INFINITY} or {@link
* Float#POSITIVE_INFINITY} as appropriate. Note that even when
* the return value is finite, this conversion can lose
* information about the precision of the BigInteger value.
*
* @return this BigInteger converted to a {@code float}.
*/
public float floatValue() {
if (signum == 0) {
return 0.0f;
}
int exponent = ((mag.length - 1) << 5) + bitLengthForInt(mag[0]) - 1;
// exponent == floor(log2(abs(this)))
if (exponent < Long.SIZE - 1) {
return longValue();
} else if (exponent > Float.MAX_EXPONENT) {
return signum > 0 ? Float.POSITIVE_INFINITY : Float.NEGATIVE_INFINITY;
}
/*
* We need the top SIGNIFICAND_WIDTH bits, including the "implicit"
* one bit. To make rounding easier, we pick out the top
* SIGNIFICAND_WIDTH + 1 bits, so we have one to help us round up or
* down. twiceSignifFloor will contain the top SIGNIFICAND_WIDTH + 1
* bits, and signifFloor the top SIGNIFICAND_WIDTH.
*
* It helps to consider the real number signif = abs(this) *
* 2^(SIGNIFICAND_WIDTH - 1 - exponent).
*/
int shift = exponent - FloatConsts.SIGNIFICAND_WIDTH;
int twiceSignifFloor;
// twiceSignifFloor will be == abs().shiftRight(shift).intValue()
// We do the shift into an int directly to improve performance.
int nBits = shift & 0x1f;
int nBits2 = 32 - nBits;
if (nBits == 0) {
twiceSignifFloor = mag[0];
} else {
twiceSignifFloor = mag[0] >>> nBits;
if (twiceSignifFloor == 0) {
twiceSignifFloor = (mag[0] << nBits2) | (mag[1] >>> nBits);
}
}
int signifFloor = twiceSignifFloor >> 1;
signifFloor &= FloatConsts.SIGNIF_BIT_MASK; // remove the implied bit
/*
* We round up if either the fractional part of signif is strictly
* greater than 0.5 (which is true if the 0.5 bit is set and any lower
* bit is set), or if the fractional part of signif is >= 0.5 and
* signifFloor is odd (which is true if both the 0.5 bit and the 1 bit
* are set). This is equivalent to the desired HALF_EVEN rounding.
*/
boolean increment = (twiceSignifFloor & 1) != 0
&& ((signifFloor & 1) != 0 || abs().getLowestSetBit() < shift);
int signifRounded = increment ? signifFloor + 1 : signifFloor;
int bits = ((exponent + FloatConsts.EXP_BIAS))
<< (FloatConsts.SIGNIFICAND_WIDTH - 1);
bits += signifRounded;
/*
* If signifRounded == 2^24, we'd need to set all of the significand
* bits to zero and add 1 to the exponent. This is exactly the behavior
* we get from just adding signifRounded to bits directly. If the
* exponent is Float.MAX_EXPONENT, we round up (correctly) to
* Float.POSITIVE_INFINITY.
*/
bits |= signum & FloatConsts.SIGN_BIT_MASK;
return Float.intBitsToFloat(bits);
}
Example #28
| Source File: IeeeRecommendedTests.java From jdk8u_jdk with GNU General Public License v2.0 | 4 votes |
|
public static int testFloatCopySign() {
int failures = 0;
// testCases[0] are logically positive numbers;
// testCases[1] are negative numbers.
float testCases [][] = {
{+0.0f,
Float.MIN_VALUE,
Float_MAX_SUBNORMALmm,
Float_MAX_SUBNORMAL,
FloatConsts.MIN_NORMAL,
1.0f,
3.0f,
Float_MAX_VALUEmm,
Float.MAX_VALUE,
infinityF,
},
{-infinityF,
-Float.MAX_VALUE,
-3.0f,
-1.0f,
-FloatConsts.MIN_NORMAL,
-Float_MAX_SUBNORMALmm,
-Float_MAX_SUBNORMAL,
-Float.MIN_VALUE,
-0.0f}
};
float NaNs[] = {Float.intBitsToFloat(0x7fc00000), // "positive" NaN
Float.intBitsToFloat(0xFfc00000)}; // "negative" NaN
// Tests shared between raw and non-raw versions
for(int i = 0; i < 2; i++) {
for(int j = 0; j < 2; j++) {
for(int m = 0; m < testCases[i].length; m++) {
for(int n = 0; n < testCases[j].length; n++) {
// copySign(magnitude, sign)
failures+=Tests.test("Math.copySign(float,float)",
testCases[i][m],testCases[j][n],
Math.copySign(testCases[i][m], testCases[j][n]),
(j==0?1.0f:-1.0f)*Math.abs(testCases[i][m]) );
failures+=Tests.test("StrictMath.copySign(float,float)",
testCases[i][m],testCases[j][n],
StrictMath.copySign(testCases[i][m], testCases[j][n]),
(j==0?1.0f:-1.0f)*Math.abs(testCases[i][m]) );
}
}
}
}
// For rawCopySign, NaN may effectively have either sign bit
// while for copySign NaNs are treated as if they always have
// a zero sign bit (i.e. as positive numbers)
for(int i = 0; i < 2; i++) {
for(int j = 0; j < NaNs.length; j++) {
for(int m = 0; m < testCases[i].length; m++) {
// copySign(magnitude, sign)
failures += (Math.abs(Math.copySign(testCases[i][m], NaNs[j])) ==
Math.abs(testCases[i][m])) ? 0:1;
failures+=Tests.test("StrictMath.copySign(float,float)",
testCases[i][m], NaNs[j],
StrictMath.copySign(testCases[i][m], NaNs[j]),
Math.abs(testCases[i][m]) );
}
}
}
return failures;
}
Example #29
| Source File: Float.java From jdk8u-jdk with GNU General Public License v2.0 | 4 votes |
|
/**
* Returns a hexadecimal string representation of the
* {@code float} argument. All characters mentioned below are
* ASCII characters.
*
* <ul>
* <li>If the argument is NaN, the result is the string
* "{@code NaN}".
* <li>Otherwise, the result is a string that represents the sign and
* magnitude (absolute value) of the argument. If the sign is negative,
* the first character of the result is '{@code -}'
* ({@code '\u005Cu002D'}); if the sign is positive, no sign character
* appears in the result. As for the magnitude <i>m</i>:
*
* <ul>
* <li>If <i>m</i> is infinity, it is represented by the string
* {@code "Infinity"}; thus, positive infinity produces the
* result {@code "Infinity"} and negative infinity produces
* the result {@code "-Infinity"}.
*
* <li>If <i>m</i> is zero, it is represented by the string
* {@code "0x0.0p0"}; thus, negative zero produces the result
* {@code "-0x0.0p0"} and positive zero produces the result
* {@code "0x0.0p0"}.
*
* <li>If <i>m</i> is a {@code float} value with a
* normalized representation, substrings are used to represent the
* significand and exponent fields. The significand is
* represented by the characters {@code "0x1."}
* followed by a lowercase hexadecimal representation of the rest
* of the significand as a fraction. Trailing zeros in the
* hexadecimal representation are removed unless all the digits
* are zero, in which case a single zero is used. Next, the
* exponent is represented by {@code "p"} followed
* by a decimal string of the unbiased exponent as if produced by
* a call to {@link Integer#toString(int) Integer.toString} on the
* exponent value.
*
* <li>If <i>m</i> is a {@code float} value with a subnormal
* representation, the significand is represented by the
* characters {@code "0x0."} followed by a
* hexadecimal representation of the rest of the significand as a
* fraction. Trailing zeros in the hexadecimal representation are
* removed. Next, the exponent is represented by
* {@code "p-126"}. Note that there must be at
* least one nonzero digit in a subnormal significand.
*
* </ul>
*
* </ul>
*
* <table border>
* <caption>Examples</caption>
* <tr><th>Floating-point Value</th><th>Hexadecimal String</th>
* <tr><td>{@code 1.0}</td> <td>{@code 0x1.0p0}</td>
* <tr><td>{@code -1.0}</td> <td>{@code -0x1.0p0}</td>
* <tr><td>{@code 2.0}</td> <td>{@code 0x1.0p1}</td>
* <tr><td>{@code 3.0}</td> <td>{@code 0x1.8p1}</td>
* <tr><td>{@code 0.5}</td> <td>{@code 0x1.0p-1}</td>
* <tr><td>{@code 0.25}</td> <td>{@code 0x1.0p-2}</td>
* <tr><td>{@code Float.MAX_VALUE}</td>
* <td>{@code 0x1.fffffep127}</td>
* <tr><td>{@code Minimum Normal Value}</td>
* <td>{@code 0x1.0p-126}</td>
* <tr><td>{@code Maximum Subnormal Value}</td>
* <td>{@code 0x0.fffffep-126}</td>
* <tr><td>{@code Float.MIN_VALUE}</td>
* <td>{@code 0x0.000002p-126}</td>
* </table>
* @param f the {@code float} to be converted.
* @return a hex string representation of the argument.
* @since 1.5
* @author Joseph D. Darcy
*/
public static String toHexString(float f) {
if (Math.abs(f) < FloatConsts.MIN_NORMAL
&& f != 0.0f ) {// float subnormal
// Adjust exponent to create subnormal double, then
// replace subnormal double exponent with subnormal float
// exponent
String s = Double.toHexString(Math.scalb((double)f,
/* -1022+126 */
DoubleConsts.MIN_EXPONENT-
FloatConsts.MIN_EXPONENT));
return s.replaceFirst("p-1022$", "p-126");
}
else // double string will be the same as float string
return Double.toHexString(f);
}
Example #30
| Source File: IeeeRecommendedTests.java From openjdk-jdk8u-backup with GNU General Public License v2.0 | 4 votes |
|
public static int testFloatNextAfter() {
int failures=0;
/*
* Each row of the testCases matrix represents one test case
* for nexAfter; given the input of the first two columns, the
* result in the last column is expected.
*/
float [][] testCases = {
{NaNf, NaNf, NaNf},
{NaNf, 0.0f, NaNf},
{0.0f, NaNf, NaNf},
{NaNf, infinityF, NaNf},
{infinityF, NaNf, NaNf},
{infinityF, infinityF, infinityF},
{infinityF, -infinityF, Float.MAX_VALUE},
{infinityF, 0.0f, Float.MAX_VALUE},
{Float.MAX_VALUE, infinityF, infinityF},
{Float.MAX_VALUE, -infinityF, Float_MAX_VALUEmm},
{Float.MAX_VALUE, Float.MAX_VALUE, Float.MAX_VALUE},
{Float.MAX_VALUE, 0.0f, Float_MAX_VALUEmm},
{Float_MAX_VALUEmm, Float.MAX_VALUE, Float.MAX_VALUE},
{Float_MAX_VALUEmm, infinityF, Float.MAX_VALUE},
{Float_MAX_VALUEmm, Float_MAX_VALUEmm, Float_MAX_VALUEmm},
{FloatConsts.MIN_NORMAL, infinityF, FloatConsts.MIN_NORMAL+
Float.MIN_VALUE},
{FloatConsts.MIN_NORMAL, -infinityF, Float_MAX_SUBNORMAL},
{FloatConsts.MIN_NORMAL, 1.0f, FloatConsts.MIN_NORMAL+
Float.MIN_VALUE},
{FloatConsts.MIN_NORMAL, -1.0f, Float_MAX_SUBNORMAL},
{FloatConsts.MIN_NORMAL, FloatConsts.MIN_NORMAL, FloatConsts.MIN_NORMAL},
{Float_MAX_SUBNORMAL, FloatConsts.MIN_NORMAL, FloatConsts.MIN_NORMAL},
{Float_MAX_SUBNORMAL, Float_MAX_SUBNORMAL, Float_MAX_SUBNORMAL},
{Float_MAX_SUBNORMAL, 0.0f, Float_MAX_SUBNORMALmm},
{Float_MAX_SUBNORMALmm, Float_MAX_SUBNORMAL, Float_MAX_SUBNORMAL},
{Float_MAX_SUBNORMALmm, 0.0f, Float_MAX_SUBNORMALmm-Float.MIN_VALUE},
{Float_MAX_SUBNORMALmm, Float_MAX_SUBNORMALmm, Float_MAX_SUBNORMALmm},
{Float.MIN_VALUE, 0.0f, 0.0f},
{-Float.MIN_VALUE, 0.0f, -0.0f},
{Float.MIN_VALUE, Float.MIN_VALUE, Float.MIN_VALUE},
{Float.MIN_VALUE, 1.0f, 2*Float.MIN_VALUE},
// Make sure zero behavior is tested
{0.0f, 0.0f, 0.0f},
{0.0f, -0.0f, -0.0f},
{-0.0f, 0.0f, 0.0f},
{-0.0f, -0.0f, -0.0f},
{0.0f, infinityF, Float.MIN_VALUE},
{0.0f, -infinityF, -Float.MIN_VALUE},
{-0.0f, infinityF, Float.MIN_VALUE},
{-0.0f, -infinityF, -Float.MIN_VALUE},
{0.0f, Float.MIN_VALUE, Float.MIN_VALUE},
{0.0f, -Float.MIN_VALUE, -Float.MIN_VALUE},
{-0.0f, Float.MIN_VALUE, Float.MIN_VALUE},
{-0.0f, -Float.MIN_VALUE, -Float.MIN_VALUE}
};
for(int i = 0; i < testCases.length; i++) {
failures += testNextAfterCase(testCases[i][0], testCases[i][1],
testCases[i][2]);
}
return failures;
}
