X-Git-Url: https://mograsim.net/gitweb/?a=blobdiff_plain;f=net.mograsim.logic.core%2Fsrc%2Fnet%2Fmograsim%2Flogic%2Fcore%2Ftypes%2FBitVector.java;h=134669494852256df8868924a63aa687e8b1fb00;hb=8bed58cd47f4e53a0a83e066d38864aa6875502f;hp=4d5365a0188a95961a37e867b36046cfaf165ae9;hpb=bec6c3a711448475c7b8e43dd031efe7b89aba24;p=Mograsim.git

diff --git a/net.mograsim.logic.core/src/net/mograsim/logic/core/types/BitVector.java b/net.mograsim.logic.core/src/net/mograsim/logic/core/types/BitVector.java
index 4d5365a0..13466949 100644
--- a/net.mograsim.logic.core/src/net/mograsim/logic/core/types/BitVector.java
+++ b/net.mograsim.logic.core/src/net/mograsim/logic/core/types/BitVector.java
@@ -2,6 +2,7 @@ package net.mograsim.logic.core.types;
 
 import static java.lang.String.format;
 
+import java.math.BigInteger;
 import java.util.Arrays;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
@@ -13,17 +14,30 @@ import java.util.function.UnaryOperator;
 /**
  * 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();
@@ -31,33 +45,78 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 
 	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));
 	}
 
@@ -65,6 +124,8 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 	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));
 	}
 
@@ -72,6 +133,8 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 	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));
 	}
 
@@ -79,12 +142,16 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 	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));
 	}
 
@@ -167,12 +234,23 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 
 		/**
 		 * 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>
 		 * 
@@ -224,18 +302,50 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 			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;
 		}
 
@@ -273,7 +383,7 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 
 	/**
 	 * 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>
 	 * 
@@ -287,7 +397,7 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 	}
 
 	/**
-	 * All {@link Bit}s symbols concatenated together
+	 * All {@link Bit}s symbols concatenated together (MSB first)
 	 * 
 	 * @see #parse(String)
 	 */
@@ -301,7 +411,59 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 	}
 
 	/**
-	 * 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()
 	 */
@@ -315,6 +477,23 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 		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()
 	{
@@ -327,7 +506,7 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 			{
 				if (!hasNext())
 					throw new NoSuchElementException();
-				return getBit(pos++);
+				return getMSBit(pos++);
 			}
 
 			@Override
@@ -337,4 +516,15 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 			}
 		};
 	}
+
+	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);
+	}
 }