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Merge "Improve support for half floats and expose as public API"

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This commit is contained in:
Romain Guy
2016-11-10 23:55:15 +00:00
committed by Android (Google) Code Review
parent 5d682ce725 12ae9a0736
commit 972fad90d4
4 changed files with 524 additions and 51 deletions
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39
api/current.txt
View File

@@ -40576,6 +40576,45 @@ package android.util {
method public abstract void setValue(T, float);
}
public final class Half {
method public static short abs(short);
method public static short ceil(short);
method public static short copySign(short, short);
method public static boolean equals(short, short);
method public static short floor(short);
method public static int getExponent(short);
method public static int getSign(short);
method public static int getSignificand(short);
method public static boolean greater(short, short);
method public static boolean greaterEquals(short, short);
method public static boolean isInfinite(short);
method public static boolean isNaN(short);
method public static boolean isNormalized(short);
method public static boolean less(short, short);
method public static boolean lessEquals(short, short);
method public static short max(short, short);
method public static short min(short, short);
method public static short round(short);
method public static float toFloat(short);
method public static java.lang.String toHexString(short);
method public static java.lang.String toString(short);
method public static short trunc(short);
method public static short valueOf(float);
field public static final short EPSILON = 5120; // 0x1400
field public static final short LOWEST_VALUE = -1025; // 0xfffffbff
field public static final int MAX_EXPONENT = 15; // 0xf
field public static final short MAX_VALUE = 31743; // 0x7bff
field public static final int MIN_EXPONENT = -14; // 0xfffffff2
field public static final short MIN_NORMAL = 1024; // 0x400
field public static final short MIN_VALUE = 1; // 0x1
field public static final short NEGATIVE_INFINITY = -1024; // 0xfffffc00
field public static final short NEGATIVE_ZERO = -32768; // 0xffff8000
field public static final short NaN = 32256; // 0x7e00
field public static final short POSITIVE_INFINITY = 31744; // 0x7c00
field public static final short POSITIVE_ZERO = 0; // 0x0
field public static final int SIZE = 16; // 0x10
}
public abstract class IntProperty<T> extends android.util.Property {
ctor public IntProperty(java.lang.String);
method public final void set(T, java.lang.Integer);

39
api/system-current.txt
View File

@@ -43743,6 +43743,45 @@ package android.util {
method public abstract void setValue(T, float);
}
public final class Half {
method public static short abs(short);
method public static short ceil(short);
method public static short copySign(short, short);
method public static boolean equals(short, short);
method public static short floor(short);
method public static int getExponent(short);
method public static int getSign(short);
method public static int getSignificand(short);
method public static boolean greater(short, short);
method public static boolean greaterEquals(short, short);
method public static boolean isInfinite(short);
method public static boolean isNaN(short);
method public static boolean isNormalized(short);
method public static boolean less(short, short);
method public static boolean lessEquals(short, short);
method public static short max(short, short);
method public static short min(short, short);
method public static short round(short);
method public static float toFloat(short);
method public static java.lang.String toHexString(short);
method public static java.lang.String toString(short);
method public static short trunc(short);
method public static short valueOf(float);
field public static final short EPSILON = 5120; // 0x1400
field public static final short LOWEST_VALUE = -1025; // 0xfffffbff
field public static final int MAX_EXPONENT = 15; // 0xf
field public static final short MAX_VALUE = 31743; // 0x7bff
field public static final int MIN_EXPONENT = -14; // 0xfffffff2
field public static final short MIN_NORMAL = 1024; // 0x400
field public static final short MIN_VALUE = 1; // 0x1
field public static final short NEGATIVE_INFINITY = -1024; // 0xfffffc00
field public static final short NEGATIVE_ZERO = -32768; // 0xffff8000
field public static final short NaN = 32256; // 0x7e00
field public static final short POSITIVE_INFINITY = 31744; // 0x7c00
field public static final short POSITIVE_ZERO = 0; // 0x0
field public static final int SIZE = 16; // 0x10
}
public abstract class IntProperty<T> extends android.util.Property {
ctor public IntProperty(java.lang.String);
method public final void set(T, java.lang.Integer);

39
api/test-current.txt
View File

@@ -40669,6 +40669,45 @@ package android.util {
method public abstract void setValue(T, float);
}
public final class Half {
method public static short abs(short);
method public static short ceil(short);
method public static short copySign(short, short);
method public static boolean equals(short, short);
method public static short floor(short);
method public static int getExponent(short);
method public static int getSign(short);
method public static int getSignificand(short);
method public static boolean greater(short, short);
method public static boolean greaterEquals(short, short);
method public static boolean isInfinite(short);
method public static boolean isNaN(short);
method public static boolean isNormalized(short);
method public static boolean less(short, short);
method public static boolean lessEquals(short, short);
method public static short max(short, short);
method public static short min(short, short);
method public static short round(short);
method public static float toFloat(short);
method public static java.lang.String toHexString(short);
method public static java.lang.String toString(short);
method public static short trunc(short);
method public static short valueOf(float);
field public static final short EPSILON = 5120; // 0x1400
field public static final short LOWEST_VALUE = -1025; // 0xfffffbff
field public static final int MAX_EXPONENT = 15; // 0xf
field public static final short MAX_VALUE = 31743; // 0x7bff
field public static final int MIN_EXPONENT = -14; // 0xfffffff2
field public static final short MIN_NORMAL = 1024; // 0x400
field public static final short MIN_VALUE = 1; // 0x1
field public static final short NEGATIVE_INFINITY = -1024; // 0xfffffc00
field public static final short NEGATIVE_ZERO = -32768; // 0xffff8000
field public static final short NaN = 32256; // 0x7e00
field public static final short POSITIVE_INFINITY = 31744; // 0x7c00
field public static final short POSITIVE_ZERO = 0; // 0x0
field public static final int SIZE = 16; // 0x10
}
public abstract class IntProperty<T> extends android.util.Property {
ctor public IntProperty(java.lang.String);
method public final void set(T, java.lang.Integer);

458
core/java/android/util/Half.java
View File

@@ -27,20 +27,64 @@ package android.util;
* <ul>
* <li>Sign bit: 1 bit</li>
* <li>Exponent width: 5 bits</li>
* <li>Mantissa: 10 bits</li>
* <li>Significand: 10 bits</li>
* </ul>
*
* <p>The format is laid out thusly:</p>
* <p>The format is laid out as follows:</p>
* <pre>
* 1 11111 1111111111
* ^ --^-- -----^----
* sign | |_______ mantissa
* sign | |_______ significand
* |
* -- exponent
* </pre>
*
* @hide
* <p>Half-precision floating points can be useful to save memory and/or
* bandwidth at the expense of range and precision when compared to single-precision
* floating points (fp32).</p>
* <p>To help you decide whether fp16 is the right storage type for you need, please
* refer to the table below that shows the available precision throughout the range of
* possible values. The <em>precision</em> column indicates the step size between two
* consecutive numbers in a specific part of the range.</p>
*
* <table summary="Precision of fp16 across the range">
* <tr><th>Range start</th><th>Precision</th></tr>
* <tr><td>0</td><td>1 &frasl; 16,777,216</td></tr>
* <tr><td>1 &frasl; 16,384</td><td>1 &frasl; 16,777,216</td></tr>
* <tr><td>1 &frasl; 8,192</td><td>1 &frasl; 8,388,608</td></tr>
* <tr><td>1 &frasl; 4,096</td><td>1 &frasl; 4,194,304</td></tr>
* <tr><td>1 &frasl; 2,048</td><td>1 &frasl; 2,097,152</td></tr>
* <tr><td>1 &frasl; 1,024</td><td>1 &frasl; 1,048,576</td></tr>
* <tr><td>1 &frasl; 512</td><td>1 &frasl; 524,288</td></tr>
* <tr><td>1 &frasl; 256</td><td>1 &frasl; 262,144</td></tr>
* <tr><td>1 &frasl; 128</td><td>1 &frasl; 131,072</td></tr>
* <tr><td>1 &frasl; 64</td><td>1 &frasl; 65,536</td></tr>
* <tr><td>1 &frasl; 32</td><td>1 &frasl; 32,768</td></tr>
* <tr><td>1 &frasl; 16</td><td>1 &frasl; 16,384</td></tr>
* <tr><td>1 &frasl; 8</td><td>1 &frasl; 8,192</td></tr>
* <tr><td>1 &frasl; 4</td><td>1 &frasl; 4,096</td></tr>
* <tr><td>1 &frasl; 2</td><td>1 &frasl; 2,048</td></tr>
* <tr><td>1</td><td>1 &frasl; 1,024</td></tr>
* <tr><td>2</td><td>1 &frasl; 512</td></tr>
* <tr><td>4</td><td>1 &frasl; 256</td></tr>
* <tr><td>8</td><td>1 &frasl; 128</td></tr>
* <tr><td>16</td><td>1 &frasl; 64</td></tr>
* <tr><td>32</td><td>1 &frasl; 32</td></tr>
* <tr><td>64</td><td>1 &frasl; 16</td></tr>
* <tr><td>128</td><td>1 &frasl; 8</td></tr>
* <tr><td>256</td><td>1 &frasl; 4</td></tr>
* <tr><td>512</td><td>1 &frasl; 2</td></tr>
* <tr><td>1,024</td><td>1</td></tr>
* <tr><td>2,048</td><td>2</td></tr>
* <tr><td>4,096</td><td>4</td></tr>
* <tr><td>8,192</td><td>8</td></tr>
* <tr><td>16,384</td><td>16</td></tr>
* <tr><td>32,768</td><td>32</td></tr>
* </table>
*
* <p>This table shows that numbers higher than 1024 lose all fractional precision.</p>
*/
@SuppressWarnings("SimplifiableIfStatement")
public final class Half {
/**
* The number of bits used to represent a half-precision float value.
@@ -59,7 +103,7 @@ public final class Half {
/**
* Maximum exponent a finite half-precision float may have.
*/
public static final short MAX_EXPONENT = 15;
public static final int MAX_EXPONENT = 15;
/**
* Maximum positive finite value a half-precision float may have.
*/
@@ -67,7 +111,7 @@ public final class Half {
/**
* Minimum exponent a normalized half-precision float may have.
*/
public static final short MIN_EXPONENT = -14;
public static final int MIN_EXPONENT = -14;
/**
* Smallest positive normal value a half-precision float may have.
*/
@@ -97,25 +141,329 @@ public final class Half {
*/
public static final short POSITIVE_ZERO = (short) 0x0000;
private static final int FP16_SIGN_SHIFT = 15;
private static final int FP16_EXPONENT_SHIFT = 10;
private static final int FP16_EXPONENT_MASK = 0x1f;
private static final int FP16_MANTISSA_MASK = 0x3ff;
private static final int FP16_EXPONENT_BIAS = 15;
private static final int FP16_SIGN_SHIFT = 15;
private static final int FP16_SIGN_MASK = 0x8000;
private static final int FP16_EXPONENT_SHIFT = 10;
private static final int FP16_EXPONENT_MASK = 0x1f;
private static final int FP16_SIGNIFICAND_MASK = 0x3ff;
private static final int FP16_EXPONENT_BIAS = 15;
private static final int FP16_COMBINED = 0x7fff;
private static final int FP16_EXPONENT_MAX = 0x7c00;
private static final int FP32_SIGN_SHIFT = 31;
private static final int FP32_EXPONENT_SHIFT = 23;
private static final int FP32_EXPONENT_MASK = 0xff;
private static final int FP32_MANTISSA_MASK = 0x7fffff;
private static final int FP32_EXPONENT_BIAS = 127;
private static final int FP32_SIGN_SHIFT = 31;
private static final int FP32_EXPONENT_SHIFT = 23;
private static final int FP32_EXPONENT_MASK = 0xff;
private static final int FP32_SIGNIFICAND_MASK = 0x7fffff;
private static final int FP32_EXPONENT_BIAS = 127;
private static final int FP32_DENORMAL_MAGIC = 126 << 23;
private static final float FP32_DENORMAL_FLOAT =
Float.intBitsToFloat(FP32_DENORMAL_MAGIC);
private static final int FP32_DENORMAL_MAGIC = 126 << 23;
private static final float FP32_DENORMAL_FLOAT = Float.intBitsToFloat(FP32_DENORMAL_MAGIC);
private Half() {
}
/**
* Returns the first parameter with the sign of the second parameter.
* This method treats NaNs as having a sign.
*
* @param magnitude A half-precision float value providing the magnitude of the result
* @param sign A half-precision float value providing the sign of the result
* @return A value with the magnitude of the first parameter and the sign
* of the second parameter
*/
public static short copySign(short magnitude, short sign) {
return (short) ((sign & FP16_SIGN_MASK) | (magnitude & FP16_COMBINED));
}
/**
* Returns the absolute value of the specified half-precision float.
* Special values are handled in the following ways:
* <ul>
* <li>If the specified half-precision float is NaN, the result is NaN</li>
* <li>If the specified half-precision float is zero (negative or positive),
* the result is positive zero (see {@link #POSITIVE_ZERO})</li>
* <li>If the specified half-precision float is infinity (negative or positive),
* the result is positive infinity (see {@link #POSITIVE_INFINITY})</li>
* </ul>
*
* @param h A half-precision float value
* @return The absolute value of the specified half-precision float
*/
public static short abs(short h) {
return (short) (h & FP16_COMBINED);
}
/**
* Returns the closest integral half-precision float value to the specified
* half-precision float value. Special values are handled in the
* following ways:
* <ul>
* <li>If the specified half-precision float is NaN, the result is NaN</li>
* <li>If the specified half-precision float is infinity (negative or positive),
* the result is infinity (with the same sign)</li>
* <li>If the specified half-precision float is zero (negative or positive),
* the result is zero (with the same sign)</li>
* </ul>
*
* @param h A half-precision float value
* @return The value of the specified half-precision float rounded to the nearest
* half-precision float value
*/
public static short round(short h) {
int bits = h & 0xffff;
int e = bits & 0x7fff;
int result = bits;
if (e < 0x3c00) {
result &= FP16_SIGN_MASK;
result |= (0x3c00 & (e >= 0x3800 ? 0xffff : 0x0));
} else if (e < 0x6400) {
e = 25 - (e >> 10);
int mask = (1 << e) - 1;
result += (1 << (e - 1));
result &= ~mask;
}
return (short) result;
}
/**
* Returns the smallest half-precision float value toward negative infinity
* greater than or equal to the specified half-precision float value.
* Special values are handled in the following ways:
* <ul>
* <li>If the specified half-precision float is NaN, the result is NaN</li>
* <li>If the specified half-precision float is infinity (negative or positive),
* the result is infinity (with the same sign)</li>
* <li>If the specified half-precision float is zero (negative or positive),
* the result is zero (with the same sign)</li>
* </ul>
*
* @param h A half-precision float value
* @return The smallest half-precision float value toward negative infinity
* greater than or equal to the specified half-precision float value
*/
public static short ceil(short h) {
int bits = h & 0xffff;
int e = bits & 0x7fff;
int result = bits;
if (e < 0x3c00) {
result &= FP16_SIGN_MASK;
result |= 0x3c00 & -(~(bits >> 15) & (e != 0 ? 1 : 0));
} else if (e < 0x6400) {
e = 25 - (e >> 10);
int mask = (1 << e) - 1;
result += mask & ((bits >> 15) - 1);
result &= ~mask;
}
return (short) result;
}
/**
* Returns the largest half-precision float value toward positive infinity
* less than or equal to the specified half-precision float value.
* Special values are handled in the following ways:
* <ul>
* <li>If the specified half-precision float is NaN, the result is NaN</li>
* <li>If the specified half-precision float is infinity (negative or positive),
* the result is infinity (with the same sign)</li>
* <li>If the specified half-precision float is zero (negative or positive),
* the result is zero (with the same sign)</li>
* </ul>
*
* @param h A half-precision float value
* @return The largest half-precision float value toward positive infinity
* less than or equal to the specified half-precision float value
*/
public static short floor(short h) {
int bits = h & 0xffff;
int e = bits & 0x7fff;
int result = bits;
if (e < 0x3c00) {
result &= FP16_SIGN_MASK;
result |= 0x3c00 & (bits > 0x8000 ? 0xffff : 0x0);
} else if (e < 0x6400) {
e = 25 - (e >> 10);
int mask = (1 << e) - 1;
result += mask & -(bits >> 15);
result &= ~mask;
}
return (short) result;
}
/**
* Returns the truncated half-precision float value of the specified
* half-precision float value. Special values are handled in the following ways:
* <ul>
* <li>If the specified half-precision float is NaN, the result is NaN</li>
* <li>If the specified half-precision float is infinity (negative or positive),
* the result is infinity (with the same sign)</li>
* <li>If the specified half-precision float is zero (negative or positive),
* the result is zero (with the same sign)</li>
* </ul>
*
* @param h A half-precision float value
* @return The truncated half-precision float value of the specified
* half-precision float value
*/
public static short trunc(short h) {
int bits = h & 0xffff;
int e = bits & 0x7fff;
int result = bits;
if (e < 0x3c00) {
result &= FP16_SIGN_MASK;
} else if (e < 0x6400) {
e = 25 - (e >> 10);
int mask = (1 << e) - 1;
result &= ~mask;
}
return (short) result;
}
/**
* Returns the smaller of two half-precision float values (the value closest
* to negative infinity). Special values are handled in the following ways:
* <ul>
* <li>If either value is NaN, the result is NaN</li>
* <li>{@link #NEGATIVE_ZERO} is smaller than {@link #POSITIVE_ZERO}</li>
* </ul>
*
* @param x The first half-precision value
* @param y The second half-precision value
* @return The smaller of the two specified half-precision values
*/
public static short min(short x, short y) {
if ((x & FP16_COMBINED) > FP16_EXPONENT_MAX) return NaN;
if ((y & FP16_COMBINED) > FP16_EXPONENT_MAX) return NaN;
if ((x & FP16_COMBINED) == 0 && (y & FP16_COMBINED) == 0) {
return (x & FP16_SIGN_MASK) != 0 ? x : y;
}
return ((x & FP16_SIGN_MASK) != 0 ? 0x8000 - (x & 0xffff) : x & 0xffff) <
((y & FP16_SIGN_MASK) != 0 ? 0x8000 - (y & 0xffff) : y & 0xffff) ? x : y;
}
/**
* Returns the larger of two half-precision float values (the value closest
* to positive infinity). Special values are handled in the following ways:
* <ul>
* <li>If either value is NaN, the result is NaN</li>
* <li>{@link #POSITIVE_ZERO} is greater than {@link #NEGATIVE_ZERO}</li>
* </ul>
*
* @param x The first half-precision value
* @param y The second half-precision value
*
* @return The larger of the two specified half-precision values
*/
public static short max(short x, short y) {
if ((x & FP16_COMBINED) > FP16_EXPONENT_MAX) return NaN;
if ((y & FP16_COMBINED) > FP16_EXPONENT_MAX) return NaN;
if ((x & FP16_COMBINED) == 0 && (y & FP16_COMBINED) == 0) {
return (x & FP16_SIGN_MASK) != 0 ? y : x;
}
return ((x & FP16_SIGN_MASK) != 0 ? 0x8000 - (x & 0xffff) : x & 0xffff) >
((y & FP16_SIGN_MASK) != 0 ? 0x8000 - (y & 0xffff) : y & 0xffff) ? x : y;
}
/**
* Returns true if the first half-precision float value is less (smaller
* toward negative infinity) than the second half-precision float value.
* If either of the values is NaN, the result is false.
*
* @param x The first half-precision value
* @param y The second half-precision value
*
* @return True if x is less than y, false otherwise
*/
public static boolean less(short x, short y) {
if ((x & FP16_COMBINED) > FP16_EXPONENT_MAX) return false;
if ((y & FP16_COMBINED) > FP16_EXPONENT_MAX) return false;
return ((x & FP16_SIGN_MASK) != 0 ? 0x8000 - (x & 0xffff) : x & 0xffff) <
((y & FP16_SIGN_MASK) != 0 ? 0x8000 - (y & 0xffff) : y & 0xffff);
}
/**
* Returns true if the first half-precision float value is less (smaller
* toward negative infinity) than or equal to the second half-precision
* float value. If either of the values is NaN, the result is false.
*
* @param x The first half-precision value
* @param y The second half-precision value
*
* @return True if x is less than or equal to y, false otherwise
*/
public static boolean lessEquals(short x, short y) {
if ((x & FP16_COMBINED) > FP16_EXPONENT_MAX) return false;
if ((y & FP16_COMBINED) > FP16_EXPONENT_MAX) return false;
return ((x & FP16_SIGN_MASK) != 0 ? 0x8000 - (x & 0xffff) : x & 0xffff) <=
((y & FP16_SIGN_MASK) != 0 ? 0x8000 - (y & 0xffff) : y & 0xffff);
}
/**
* Returns true if the first half-precision float value is greater (larger
* toward positive infinity) than the second half-precision float value.
* If either of the values is NaN, the result is false.
*
* @param x The first half-precision value
* @param y The second half-precision value
*
* @return True if x is greater than y, false otherwise
*/
public static boolean greater(short x, short y) {
if ((x & FP16_COMBINED) > FP16_EXPONENT_MAX) return false;
if ((y & FP16_COMBINED) > FP16_EXPONENT_MAX) return false;
return ((x & FP16_SIGN_MASK) != 0 ? 0x8000 - (x & 0xffff) : x & 0xffff) >
((y & FP16_SIGN_MASK) != 0 ? 0x8000 - (y & 0xffff) : y & 0xffff);
}
/**
* Returns true if the first half-precision float value is greater (larger
* toward positive infinity) than or equal to the second half-precision float
* value. If either of the values is NaN, the result is false.
*
* @param x The first half-precision value
* @param y The second half-precision value
*
* @return True if x is greater than y, false otherwise
*/
public static boolean greaterEquals(short x, short y) {
if ((x & FP16_COMBINED) > FP16_EXPONENT_MAX) return false;
if ((y & FP16_COMBINED) > FP16_EXPONENT_MAX) return false;
return ((x & FP16_SIGN_MASK) != 0 ? 0x8000 - (x & 0xffff) : x & 0xffff) >=
((y & FP16_SIGN_MASK) != 0 ? 0x8000 - (y & 0xffff) : y & 0xffff);
}
/**
* Returns true if the two half-precision float values are equal.
* If either of the values is NaN, the result is false. {@link #POSITIVE_ZERO}
* and {@link #NEGATIVE_ZERO} are considered equal.
*
* @param x The first half-precision value
* @param y The second half-precision value
*
* @return True if x is equal to y, false otherwise
*/
public static boolean equals(short x, short y) {
if ((x & FP16_COMBINED) > FP16_EXPONENT_MAX) return false;
if ((y & FP16_COMBINED) > FP16_EXPONENT_MAX) return false;
return x == y || ((x | y) & FP16_COMBINED) == 0;
}
/**
* Returns the sign of the specified half-precision float.
*
@@ -123,15 +471,15 @@ public final class Half {
* @return 1 if the value is positive, -1 if the value is negative
*/
public static int getSign(short h) {
return (h >>> FP16_SIGN_SHIFT) == 0 ? 1 : -1;
return (h & FP16_SIGN_MASK) == 0 ? 1 : -1;
}
/**
* Returns the unbiased exponent used in the representation of
* the specified half-precision float value. if the value is NaN
* or infinite, this* method returns {@link #MAX_EXPONENT} + 1.
* If the argument is* 0 or denormal, this method returns
* {@link #MIN_EXPONENT} - 1.
* If the argument is 0 or a subnormal representation, this method
* returns {@link #MIN_EXPONENT} - 1.
*
* @param h A half-precision float value
* @return The unbiased exponent of the specified value
@@ -141,14 +489,14 @@ public final class Half {
}
/**
* Returns the mantissa, or significand, used in the representation
* Returns the significand, or mantissa, used in the representation
* of the specified half-precision float value.
*
* @param h A half-precision float value
* @return The mantissa, or significand, of the specified vlaue
* @return The significand, or significand, of the specified vlaue
*/
public static int getMantissa(short h) {
return h & FP16_MANTISSA_MASK;
public static int getSignificand(short h) {
return h & FP16_SIGNIFICAND_MASK;
}
/**
@@ -160,9 +508,7 @@ public final class Half {
* false otherwise
*/
public static boolean isInfinite(short h) {
int e = (h >>> FP16_EXPONENT_SHIFT) & FP16_EXPONENT_MASK;
int m = (h ) & FP16_MANTISSA_MASK;
return e == 0x1f && m == 0;
return (h & FP16_COMBINED) == FP16_EXPONENT_MAX;
}
/**
@@ -173,9 +519,21 @@ public final class Half {
* @return true if the value is a NaN, false otherwise
*/
public static boolean isNaN(short h) {
int e = (h >>> FP16_EXPONENT_SHIFT) & FP16_EXPONENT_MASK;
int m = (h ) & FP16_MANTISSA_MASK;
return e == 0x1f && m != 0;
return (h & FP16_COMBINED) > FP16_EXPONENT_MAX;
}
/**
* Returns true if the specified half-precision float value is normalized
* (does not have a subnormal representation). If the specified value is
* {@link #POSITIVE_INFINITY}, {@link #NEGATIVE_INFINITY},
* {@link #POSITIVE_ZERO}, {@link #NEGATIVE_ZERO}, NaN or any subnormal
* number, this method returns false.
*
* @param h A half-precision float value
* @return true if the value is normalized, false otherwise
*/
public static boolean isNormalized(short h) {
return (h & FP16_EXPONENT_MAX) != 0 && (h & FP16_EXPONENT_MAX) != FP16_EXPONENT_MAX;
}
/**
@@ -195,9 +553,9 @@ public final class Half {
*/
public static float toFloat(short h) {
int bits = h & 0xffff;
int s = (bits >>> FP16_SIGN_SHIFT );
int s = bits & FP16_SIGN_MASK;
int e = (bits >>> FP16_EXPONENT_SHIFT) & FP16_EXPONENT_MASK;
int m = (bits ) & FP16_MANTISSA_MASK;
int m = (bits ) & FP16_SIGNIFICAND_MASK;
int outE = 0;
int outM = 0;
@@ -218,7 +576,7 @@ public final class Half {
}
}
int out = (s << FP32_SIGN_SHIFT) | (outE << FP32_EXPONENT_SHIFT) | outM;
int out = (s << 16) | (outE << FP32_EXPONENT_SHIFT) | outM;
return Float.intBitsToFloat(out);
}
@@ -249,7 +607,7 @@ public final class Half {
int bits = Float.floatToRawIntBits(f);
int s = (bits >>> FP32_SIGN_SHIFT );
int e = (bits >>> FP32_EXPONENT_SHIFT) & FP32_EXPONENT_MASK;
int m = (bits ) & FP32_MANTISSA_MASK;
int m = (bits ) & FP32_SIGNIFICAND_MASK;
int outE = 0;
int outM = 0;
@@ -278,14 +636,12 @@ public final class Half {
// Round to nearest "0.5" up
int out = (outE << FP16_EXPONENT_SHIFT) | outM;
out++;
out |= (s << FP16_SIGN_SHIFT);
return (short) out;
return (short) (out | (s << FP16_SIGN_SHIFT));
}
}
}
int out = (s << FP16_SIGN_SHIFT) | (outE << FP16_EXPONENT_SHIFT) | outM;
return (short) out;
return (short) ((s << FP16_SIGN_SHIFT) | (outE << FP16_EXPONENT_SHIFT) | outM);
}
/**
@@ -311,16 +667,16 @@ public final class Half {
* <li>If the value is inifinity, the string is <code>"Infinity"</code></li>
* <li>If the value is 0, the string is <code>"0x0.0p0"</code></li>
* <li>If the value has a normalized representation, the exponent and
* mantissa are represented in the string in two fields. The mantissa starts
* with <code>"0x1."</code> followed by its lowercase hexadecimal
* significand are represented in the string in two fields. The significand
* starts with <code>"0x1."</code> followed by its lowercase hexadecimal
* representation. Trailing zeroes are removed unless all digits are 0, then
* a single zero is used. The mantissa representation is followed by the
* a single zero is used. The significand representation is followed by the
* exponent, represented by <code>"p"</code>, itself followed by a decimal
* string of the unbiased exponent</li>
* <li>If the value has a denormal representation, the mantissa starts
* <li>If the value has a subnormal representation, the significand starts
* with <code>"0x0."</code> followed by its lowercase hexadecimal
* representation. Trailing zeroes are removed unless all digits are 0, then
* a single zero is used. The mantissa representation is followed by the
* a single zero is used. The significand representation is followed by the
* exponent, represented by <code>"p-14"</code></li>
* </ul>
*
@@ -333,11 +689,11 @@ public final class Half {
int bits = h & 0xffff;
int s = (bits >>> FP16_SIGN_SHIFT );
int e = (bits >>> FP16_EXPONENT_SHIFT) & FP16_EXPONENT_MASK;
int m = (bits ) & FP16_MANTISSA_MASK;
int m = (bits ) & FP16_SIGNIFICAND_MASK;
if (e == 0x1f) { // Infinite or NaN
if (m == 0) {
if (s == 1) o.append('-');
if (s != 0) o.append('-');
o.append("Infinity");
} else {
o.append("NaN");
@@ -349,14 +705,14 @@ public final class Half {
o.append("0x0.0p0");
} else {
o.append("0x0.");
String mantissa = Integer.toHexString(m);
o.append(mantissa.replaceFirst("0{2,}$", ""));
String significand = Integer.toHexString(m);
o.append(significand.replaceFirst("0{2,}$", ""));
o.append("p-14");
}
} else {
o.append("0x1.");
String mantissa = Integer.toHexString(m);
o.append(mantissa.replaceFirst("0{2,}$", ""));
String significand = Integer.toHexString(m);
o.append(significand.replaceFirst("0{2,}$", ""));
o.append('p');
o.append(Integer.toString(e - FP16_EXPONENT_BIAS));
}