X-Git-Url: https://mograsim.net/gitweb/?a=blobdiff_plain;f=net.mograsim.logic.core%2Fsrc%2Fnet%2Fmograsim%2Flogic%2Fcore%2Ftypes%2FBitVector.java;h=6a36403475c1ef7a2f5d5296b98d9a5268f046b8;hb=add92039f433cd315f2087da9c1a0de899927d96;hp=1e87f9a43cba1c5ec9c4d181571843987b0d599b;hpb=67c1d352795802dae0c045cedeed82c883819d4e;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 1e87f9a4..6a364034 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;
@@ -13,48 +14,137 @@ 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);
+		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 BigInteger getUnsignedValue()
+	{
+		if (!isBinary())
+			throw new NumberFormatException("BitVector is non binary: " + toString());
+		byte[] bytes = new byte[(bits.length / 8) + 1];
+		for (int i = 0; i < bits.length; i++)
+		{
+			if (Bit.ONE == bits[i])
+			{
+				bytes[i / 8] |= 1 << (i % 8);
+			}
+		}
+		return new BigInteger(bytes);
+	}
+
+	public static BitVector from(BigInteger b, int length)
+	{
+		int bitLength = b.bitLength();
+		int actualLength = Integer.min(bitLength, length);
+		Bit[] bits = new Bit[length];
+		for (int i = 0; i < actualLength; i++)
+			bits[i] = b.testBit(i) ? Bit.ONE : Bit.ZERO;
+		if (b.signum() < 0)
+			for (int i = actualLength; i < length; i++)
+				bits[i] = Bit.ONE;
+		else
+			for (int i = actualLength; i < length; i++)
+				bits[i] = Bit.ZERO;
+		return BitVector.of(bits);
+	}
+
+	public static BitVector of(long value, int bits)
+	{
+		return of(BigInteger.valueOf(value), bits);
+	}
+
+	public static BitVector of(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();
 	}
 
+	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));
 	}
 
@@ -62,6 +152,8 @@ 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));
 	}
 
@@ -69,6 +161,8 @@ 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));
 	}
 
@@ -76,12 +170,16 @@ 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));
 	}
 
@@ -140,7 +238,6 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 	 *
 	 * @author Christian Femers
 	 */
-	@SuppressWarnings("synthetic-access")
 	public static final class BitVectorMutator implements LogicType<BitVectorMutator, BitVector>
 	{
 		private Bit[] bits;
@@ -155,21 +252,39 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 			return new BitVectorMutator(bv.getBits());
 		}
 
+		/**
+		 * Returns a new mutator of the specified length, <b>with all bits set to <code>null</code></b>. Use with care!
+		 */
+		public static BitVectorMutator ofLength(int length)
+		{
+			return new BitVectorMutator(new Bit[length]);
+		}
+
 		/**
 		 * 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>
 		 * 
 		 * @throws IllegalStateException if the mutator is (still) empty
 		 */
-		public BitVector get()
+		public BitVector toBitVector()
 		{
 			if (bits == null)
 				throw new IllegalStateException("cannot create a BitVector from an empty mutator");
@@ -215,6 +330,53 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 			return this;
 		}
 
+		/**
+		 * 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;
+		}
+
+		/**
+		 * 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;
+		}
+
 		private void checkCompatibility(BitVector bv)
 		{
 			if (bits != null && bits.length != bv.length())
@@ -263,7 +425,7 @@ 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)
 	 */
@@ -277,7 +439,24 @@ 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 either unsigned or as two-complement.
+	 * 
+	 * @param signed if true and the BitVector represents a negative two-complement integer, an equivalent BigInteger is returned
+	 * @return the value of this BitVector as BigInteger
+	 * 
+	 */
+	public BigInteger toBigInteger(boolean signed)
+	{
+		if (!isBinary())
+			throw new NumberFormatException(this + " is not binary");
+		BigInteger val = new BigInteger(toString(), 2);
+		if (signed && bits[0] == Bit.ONE)
+			val = val.not().setBit(val.bitLength()).add(BigInteger.ONE);
+		return val;
+	}
+
+	/**
+	 * Parses a String containing solely {@link Bit} symbols (MSB first)
 	 * 
 	 * @see #toString()
 	 */
@@ -291,6 +470,9 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 		return new BitVector(values);
 	}
 
+	/**
+	 * Iterate over the {@link Bit}s of the BitVector <b>from MSB to LSB</b> (left to right).
+	 */
 	@Override
 	public Iterator<Bit> iterator()
 	{
@@ -303,7 +485,7 @@ public final class BitVector implements StrictLogicType<BitVector>, Iterable<Bit
 			{
 				if (!hasNext())
 					throw new NoSuchElementException();
-				return getBit(pos++);
+				return getMSBit(pos++);
 			}
 
 			@Override