import static java.lang.String.format;
+import java.math.BigInteger;
import java.util.Arrays;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* Immutable class representing a {@link Bit}Vector
*
- *
* @author Christian Femers
*
*/
public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit>, RandomAccess
{
+ public static final BitVector SINGLE_U = new BitVector(Bit.U);
+ public static final BitVector SINGLE_X = new BitVector(Bit.X);
+ public static final BitVector SINGLE_0 = new BitVector(Bit.ZERO);
+ public static final BitVector SINGLE_1 = new BitVector(Bit.ONE);
+ public static final BitVector SINGLE_Z = new BitVector(Bit.Z);
+
+ private static final BitVector[] SINGLE_BIT_MAPPING = { SINGLE_U, SINGLE_X, SINGLE_0, SINGLE_1, SINGLE_Z };
+
private final Bit[] bits;
+ private BitVector(Bit single)
+ {
+ Objects.requireNonNull(single);
+ bits = new Bit[] { single };
+ }
+
private BitVector(Bit[] bits)
{
- this.bits = Objects.requireNonNull(bits);// do this first to "catch" bits==null before the foreach loop
+ this.bits = Objects.requireNonNull(bits); // do this first to "catch" bits==null before the foreach loop
for (Bit bit : bits)
if (bit == null)
throw new NullPointerException();
public static BitVector of(Bit... bits)
{
+ if (bits.length == 1)
+ return SINGLE_BIT_MAPPING[bits[0].ordinal()];
return new BitVector(bits.clone());
}
public static BitVector of(Bit bit, int length)
{
+ if (length == 1)
+ return SINGLE_BIT_MAPPING[bit.ordinal()];
return new BitVector(bit.makeArray(length));
}
+ public static BitVector from(long value, int bits)
+ {
+ return from(BigInteger.valueOf(value), bits);
+ }
+
+ public static BitVector from(BigInteger value, int bits)
+ {
+ Bit[] values = new Bit[bits];
+ for (int i = 0; i < bits; i++)
+ values[bits - i - 1] = Bit.of(value.testBit(i));
+ return new BitVector(values);
+ }
+
public BitVectorMutator mutator()
{
return BitVectorMutator.of(this);
}
- public Bit getBit(int bitIndex)
+ /**
+ * Returns the most significant bit at <code>bitIndex</code>. (leftmost bit of a binary number at the given index)
+ */
+ public Bit getMSBit(int bitIndex)
{
return bits[bitIndex];
}
+ /**
+ * Returns the least significant bit at <code>bitIndex</code>. (rightmost bit of a binary number at the given index)
+ */
+ public Bit getLSBit(int bitIndex)
+ {
+ return bits[bits.length - bitIndex - 1];
+ }
+
public Bit[] getBits()
{
return bits.clone();
}
+ /**
+ * Checks if all bits are {@link Bit#isBinary() binary}.
+ *
+ * @see Bit#isBinary()
+ */
+ public boolean isBinary()
+ {
+ for (int i = 0; i < bits.length; i++)
+ {
+ if (!bits[i].isBinary())
+ return false;
+ }
+ return true;
+ }
+
@Override
public BitVector join(BitVector t)
{
checkCompatibility(t);
+ if (bits.length == 1)
+ return SINGLE_BIT_MAPPING[bits[0].join(t.bits[0]).ordinal()];
return new BitVector(binOp(bits.clone(), t.bits, Bit::join));
}
public BitVector and(BitVector t)
{
checkCompatibility(t);
+ if (bits.length == 1)
+ return SINGLE_BIT_MAPPING[bits[0].and(t.bits[0]).ordinal()];
return new BitVector(binOp(bits.clone(), t.bits, Bit::and));
}
public BitVector or(BitVector t)
{
checkCompatibility(t);
+ if (bits.length == 1)
+ return SINGLE_BIT_MAPPING[bits[0].or(t.bits[0]).ordinal()];
return new BitVector(binOp(bits.clone(), t.bits, Bit::or));
}
public BitVector xor(BitVector t)
{
checkCompatibility(t);
+ if (bits.length == 1)
+ return SINGLE_BIT_MAPPING[bits[0].xor(t.bits[0]).ordinal()];
return new BitVector(binOp(bits.clone(), t.bits, Bit::xor));
}
@Override
public BitVector not()
{
+ if (bits.length == 1)
+ return SINGLE_BIT_MAPPING[bits[0].not().ordinal()];
return new BitVector(unOp(bits.clone(), Bit::not));
}
/**
* Returns an empty mutator which has no bits set and will simply copy the values from the first binary operation performed.
+ * <p>
+ * An empty BitVectorMutator <b>must not</b> be converted to BitVector or used to manipulate single bits until at least one two
+ * operand logic operation is performed.
*/
public static BitVectorMutator empty()
{
return new BitVectorMutator(null);
}
+ /**
+ * @see #empty()
+ */
+ public boolean isEmpty()
+ {
+ return bits == null;
+ }
+
/**
* Produces the resulting, immutable {@link BitVector}<br>
*
return this;
}
- public void setBit(int bitIndex, Bit bit)
+ /**
+ * Set the most significant bit at <code>bitIndex</code>. (leftmost bit of a binary number at the given index)
+ */
+ public void setMSBit(int bitIndex, Bit bit)
{
+ if (bits == null)
+ throw new IllegalStateException("cannot set a bit of an empty mutator");
bits[bitIndex] = bit;
}
- public Bit getBit(int bitIndex)
+ /**
+ * Set the least significant bit at <code>bitIndex</code>. (rightmost bit of a binary number at the given index)
+ */
+ public void setLSBit(int bitIndex, Bit bit)
{
+ if (bits == null)
+ throw new IllegalStateException("cannot set a bit of an empty mutator");
+ bits[bits.length - bitIndex - 1] = bit;
+ }
+
+ /**
+ * Returns the most significant bit at <code>bitIndex</code>. (leftmost bit of a binary number at the given index)
+ */
+ public Bit getMSBit(int bitIndex)
+ {
+ if (bits == null)
+ throw new IllegalStateException("cannot get a bit of an empty mutator");
return bits[bitIndex];
}
+ /**
+ * Returns the least significant bit at <code>bitIndex</code>. (rightmost bit of a binary number at the given index)
+ */
+ public Bit getLSBit(int bitIndex)
+ {
+ if (bits == null)
+ throw new IllegalStateException("cannot get a bit of an empty mutator");
+ return bits[bits.length - bitIndex - 1];
+ }
+
public int length()
{
+ if (bits == null)
+ throw new IllegalStateException("cannot obtain a length of an empty mutator");
return bits.length;
}
/**
* Does test for equality of values/content, shifting the other BitVector by <code>offset</code> to the right.<br>
- * Therefore <code>offset + other.length() <= this.length()</code> needs to be true.
+ * Therefore <code>offset + other.length() <= this.wdith()</code> needs to be true.
*
* @throws ArrayIndexOutOfBoundsException if <code>offset + other.length() > this.length()</code>
*
}
/**
- * All {@link Bit}s symbols concatenated together
+ * All {@link Bit}s symbols concatenated together (MSB first)
*
* @see #parse(String)
*/
}
/**
- * Parses a String containing solely {@link Bit} symbols
+ * Returns the value of the BitVector as BigInteger.
+ *
+ * @throws NumberFormatException if the BitVector is not {@link #isBinary() binary}.
+ */
+ public BigInteger getUnsignedValue()
+ {
+ if (!isBinary())
+ throw new NumberFormatException(this + " is not binary");
+ byte[] bytes = new byte[(bits.length / 8 + (bits.length % 8 == 0 ? 0 : 1)) + 1];
+ for (int i = bits.length - 1; i >= 0; i--)
+ {
+ if (Bit.ONE == bits[bits.length - i - 1])
+ {
+ try
+ {
+ bytes[bytes.length - (i / 8) - 1] |= 1 << (i % 8);
+ }
+ catch (IndexOutOfBoundsException e)
+ {
+ e.printStackTrace();
+ }
+ }
+ }
+ return new BigInteger(bytes);
+ }
+
+ public long getUnsignedValueLong()
+ {
+ return getUnsignedValue().longValue();
+ }
+
+ /**
+ * Returns the value of the BitVector as BigInteger interpreted as a two's complement number.
+ *
+ * @throws NumberFormatException if the BitVector is not {@link #isBinary() binary}.
+ *
+ * @author Daniel Kirschten
+ */
+ public BigInteger getSignedValue()
+ {
+ BigInteger unsignedValue = getUnsignedValue();
+ if (bits[bits.length - 1] == Bit.ZERO)
+ return unsignedValue;
+ return unsignedValue.subtract(BitVector.of(Bit.ONE, bits.length).getUnsignedValue()).subtract(BigInteger.ONE);// TODO speed this up!
+ }
+
+ public long getSignedValueLong()
+ {
+ return getSignedValue().longValue();
+ }
+
+ /**
+ * Parses a String containing solely {@link Bit} symbols (MSB first)
*
* @see #toString()
*/
return new BitVector(values);
}
+ /**
+ * Changes a single Bit using the given operation. This can be used to set, clear or flip bits.
+ *
+ * @param msbIndex index of the MSB to be changed
+ * @param singleBitOperation the operation to perform on that Bit
+ * @return the resulting, new BitVektor
+ */
+ public BitVector withBitChanged(int msbIndex, UnaryOperator<Bit> singleBitOperation)
+ {
+ Bit[] newBits = bits.clone();
+ newBits[msbIndex] = singleBitOperation.apply(newBits[msbIndex]);
+ return new BitVector(newBits);
+ }
+
+ /**
+ * Iterate over the {@link Bit}s of the BitVector <b>from MSB to LSB</b> (left to right).
+ */
@Override
public Iterator<Bit> iterator()
{
{
if (!hasNext())
throw new NoSuchElementException();
- return getBit(pos++);
+ return getMSBit(pos++);
}
@Override
}
};
}
+
+ public BitVector reverse()
+ {
+ int length = length();
+ Bit[] other = new Bit[length];
+ for (int i = 0, j = length - 1; i < length; i++, j--)
+ {
+ other[i] = bits[j];
+ }
+ return new BitVector(other);
+ }
}
projects / Mograsim.git / blobdiff