-package net.mograsim.logic.core.wires;
-
-import static net.mograsim.logic.core.types.Bit.U;
-import static net.mograsim.logic.core.types.Bit.Z;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-
-import net.mograsim.logic.core.LogicObservable;
-import net.mograsim.logic.core.LogicObserver;
-import net.mograsim.logic.core.timeline.Timeline;
-import net.mograsim.logic.core.types.Bit;
-import net.mograsim.logic.core.types.BitVector;
-import net.mograsim.logic.core.types.BitVector.BitVectorMutator;
-
-/**
- * Represents an array of wires that can store n bits of information.
- *
- * @author Fabian Stemmler
- *
- */
-public class Wire
-{
- public final String name;
- private BitVector cachedValues;
- public final int travelTime;
- private List<ReadEnd> attached = new ArrayList<>();
- public final int width;
- List<ReadWriteEnd> inputs = new ArrayList<>();
- Timeline timeline;
- private Bit[] bitsWithoutFusions;
- FusedBit[] fusedBits;
-
- public Wire(Timeline timeline, int width, int travelTime)
- {
- this(timeline, width, travelTime, null);
- }
-
- public Wire(Timeline timeline, int width, int travelTime, String name)
- {
- if (width < 1)
- throw new IllegalArgumentException(
- String.format("Tried to create an array of wires with width %d, but a width of less than 1 makes no sense.", width));
- this.name = name;
- this.timeline = timeline;
- this.width = width;
- this.travelTime = travelTime;
- initValues();
- }
-
- private void initValues()
- {
- cachedValues = U.toVector(width);
- bitsWithoutFusions = cachedValues.getBits();
- }
-
- private void setNewValues(BitVector newValues)
- {
- cachedValues = newValues;
- notifyObservers();
- }
-
- private void invalidateCachedValuesForAllFusedWires()
- {
- invalidateCachedValues();
- if (fusedBits != null)
- for (FusedBit fusion : fusedBits)
- if (fusion != null)
- fusion.invalidateCachedValuesForAllParticipatingWires();
- }
-
- private void invalidateCachedValues()
- {
- cachedValues = null;
- notifyObservers();
- }
-
- void recalculateValuesWithoutFusions()
- {
- Bit[] bits = new Bit[width];
- if (inputs.isEmpty())
- Arrays.fill(bits, U);
- else
- {
- System.arraycopy(inputs.get(0).getInputValues().getBits(), 0, bits, 0, width);
- for (int i = 1; i < inputs.size(); i++)
- Bit.join(bits, inputs.get(i).getInputValues().getBits());
- }
- bitsWithoutFusions = bits;
- if (fusedBits == null)
- setNewValues(BitVector.of(bits));
- else
- invalidateCachedValuesForAllFusedWires();
- }
-
- private void recalculatedCachedValues()
- {
- Bit[] bits;
- if (fusedBits == null)
- bits = bitsWithoutFusions;
- else
- {
- bits = new Bit[width];
- for (int i = 0; i < width; i++)
- {
- FusedBit fusion = fusedBits[i];
- if (fusion == null)
- bits[i] = bitsWithoutFusions[i];
- else
- bits[i] = fusion.getValue();
- }
- }
- cachedValues = BitVector.of(bits);
- }
-
- /**
- * Forces a Wire to take on specific values. If the new values differ from the old ones, the observers of the Wire will be notified.
- * WARNING! Use this with care! The preferred way of writing the values is ReadWriteEnd.feedSignals(BitVector)
- *
- * @param values The values the <code>Wire</code> will have immediately after this method is called
- */
- public void forceValues(BitVector values)
- {
- setNewValues(values);
- }
-
- /**
- * The {@link Wire} is interpreted as an unsigned integer with n bits.
- *
- * @return <code>true</code> if all bits are either <code>Bit.ONE</code> or <code>Bit.ZERO</code> (they do not all have to have the same
- * value), not <code>Bit.U</code>, <code>Bit.X</code> or <code>Bit.Z</code>. <code>false</code> is returned otherwise.
- *
- * @author Fabian Stemmler
- */
- public boolean hasNumericValue()
- {
- return getValues().isBinary();
- }
-
- /**
- * The {@link Wire} is interpreted as an unsigned integer with n bits.
- *
- * @return The unsigned value of the {@link Wire}'s bits, where value 0 corresponds with 2^0, value 1 is 2^1 and so on.
- *
- * @author Fabian Stemmler
- */
- public long getUnsignedValue()
- {
- long val = 0;
- long mask = 1;
- for (Bit bit : getValues())
- {
- switch (bit)
- {
- default:
- case Z:
- case X:
- return 0; // TODO: Proper handling for getUnsignedValue(), if not all bits are 1 or 0;
- case ONE:
- val |= mask;
- break;
- case ZERO:
- }
- mask = mask << 1;
- }
- return val;
- }
-
- /**
- * The {@link Wire} is interpreted as a signed integer with n bits.
- *
- * @return The signed value of the {@link Wire}'s bits, where value 0 corresponds with 2^0, value 1 is 2^1 and so on.
- *
- * @author Fabian Stemmler
- */
- public long getSignedValue()
- {
- long val = getUnsignedValue();
- long mask = 1 << (width - 1);
- if ((mask & val) != 0)
- {
- int shifts = 64 - width;
- return (val << shifts) >> shifts;
- }
- return val;
- }
-
- /**
- * Returns the least significant bit (LSB)
- */
- public Bit getValue()
- {
- return getValue(0);
- }
-
- /**
- * Returns the least significant bit (LSB) of the given index
- */
- public Bit getValue(int index)
- {
- return getValues().getLSBit(index);
- }
-
- public BitVector getValues(int start, int end)
- {
- return getValues().subVector(start, end);
- }
-
- public BitVector getValues()
- {
- if (cachedValues == null)
- recalculatedCachedValues();
- return cachedValues;
- }
-
- /**
- * Adds an {@link LogicObserver}, who will be notified when the value of the {@link Wire} is updated.
- *
- * @param ob The {@link LogicObserver} to be notified of changes.
- * @return true if the given {@link LogicObserver} was not already registered, false otherwise
- *
- * @author Fabian Stemmler
- */
- boolean attachEnd(ReadEnd end)
- {
- return attached.add(end);
- }
-
- void detachEnd(ReadEnd end)
- {
- attached.remove(end);
- }
-
- private void notifyObservers()
- {
- attached.forEach(ReadEnd::update);
- }
-
- /**
- * Create and register a {@link ReadWriteEnd} object, which is tied to this {@link Wire}. This {@link ReadWriteEnd} can be written to.
- */
- public ReadWriteEnd createReadWriteEnd()
- {
- return new ReadWriteEnd();
- }
-
- /**
- * Create a {@link ReadEnd} object, which is tied to this {@link Wire}. This {@link ReadEnd} cannot be written to.
- */
- public ReadEnd createReadOnlyEnd()
- {
- return new ReadEnd();
- }
-
- void registerInput(ReadWriteEnd toRegister)
- {
- inputs.add(toRegister);
- recalculateValuesWithoutFusions();
- }
-
- /**
- * A {@link ReadEnd} feeds a constant signal into the {@link Wire} it is tied to. The combination of all inputs determines the
- * {@link Wire}s final value. X dominates all other inputs Z does not affect the final value, unless there are no other inputs than Z 0
- * and 1 turn into X when they are mixed
- *
- * @author Fabian Stemmler
- */
- public class ReadEnd implements LogicObservable
- {
- private List<LogicObserver> observers = new ArrayList<>();
-
- ReadEnd()
- {
- super();
- Wire.this.attachEnd(this);
- }
-
- public void update()
- {
- notifyObservers();
- }
-
- /**
- * Included for convenient use on {@link Wire}s of width 1.
- *
- * @return The value of bit 0.
- *
- * @author Fabian Stemmler
- */
- public Bit getValue()
- {
- return Wire.this.getValue();
- }
-
- /**
- * @param index Index of the requested bit.
- * @return The value of the indexed bit.
- *
- * @author Fabian Stemmler
- */
- public Bit getValue(int index)
- {
- return Wire.this.getValue(index);
- }
-
- public BitVector getValues()
- {
- return Wire.this.getValues();
- }
-
- /**
- * @param start Start of the wanted segment. (inclusive)
- * @param end End of the wanted segment. (exclusive)
- * @return The values of the segment of {@link Bit}s indexed.
- *
- * @author Fabian Stemmler
- */
- public BitVector getValues(int start, int end)
- {
- return Wire.this.getValues(start, end);
- }
-
- /**
- * The {@link Wire} is interpreted as an unsigned integer with n bits.
- *
- * @return <code>true</code> if all bits are either <code>Bit.ONE</code> or <code>Bit.ZERO</code> (they do not all have to have the
- * same value), not <code>Bit.X</code> or <code>Bit.Z</code>. <code>false</code> is returned otherwise.
- *
- * @author Fabian Stemmler
- */
- public boolean hasNumericValue()
- {
- return Wire.this.hasNumericValue();
- }
-
- /**
- * The {@link Wire} is interpreted as an unsigned integer with n bits.
- *
- * @return The unsigned value of the {@link Wire}'s bits, where value 0 corresponds with 2^0, value 1 is 2^1 and so on.
- *
- * @author Fabian Stemmler
- */
- public long getUnsignedValue()
- {
- return Wire.this.getUnsignedValue();
- }
-
- /**
- * The {@link Wire} is interpreted as a signed integer with n bits.
- *
- * @return The signed value of the {@link Wire}'s bits, where value 0 corresponds with 2^0, value 1 is 2^1 and so on.
- *
- * @author Fabian Stemmler
- */
- public long getSignedValue()
- {
- return Wire.this.getSignedValue();
- }
-
- @Override
- public String toString()
- {
- return Wire.this.toString();
- }
-
- public void close()
- {
- inputs.remove(this);
- detachEnd(this);
- recalculateValuesWithoutFusions();
- }
-
- public int width()
- {
- return width;
- }
-
- public Wire getWire()
- {
- return Wire.this;
- }
-
- @Override
- public void registerObserver(LogicObserver ob)
- {
- observers.add(ob);
- }
-
- @Override
- public void deregisterObserver(LogicObserver ob)
- {
- observers.remove(ob);
- }
-
-// void registerCloseObserver(LogicObserver ob)
-// {
-// closeObserver.add(ob);
-// }
-//
-// void deregisterCloseObserver(LogicObserver ob)
-// {
-// closeObserver.remove(ob);
-// }
-
- @Override
- public void notifyObservers()
- {
- observers.forEach(ob -> ob.update(this));
- }
- }
-
- public class ReadWriteEnd extends ReadEnd
- {
- private boolean open;
- private boolean isWriting;
- private BitVector inputValues;
-
- ReadWriteEnd()
- {
- super();
- open = true;
- isWriting = true;
- initValues();
- registerInput(this);
- }
-
- private void initValues()
- {
- inputValues = U.toVector(width);
- }
-
- /**
- * Sets the wires values. This takes up time, as specified by the {@link Wire}s travel time.
- *
- * @param newValues The new values the wires should take on.
- *
- * @author Fabian Stemmler
- */
- public void feedSignals(Bit... newValues)
- {
- feedSignals(BitVector.of(newValues));
- }
-
- public void feedSignals(BitVector newValues)
- {
- if (newValues.length() != width)
- throw new IllegalArgumentException(
- String.format("Attempted to input %d bits instead of %d bits.", newValues.length(), width));
- if (!open)
- throw new IllegalStateException("Attempted to write to closed WireArrayEnd.");
- timeline.addEvent(e -> setValues(newValues), travelTime);
- }
-
- /**
- * Sets values of a subarray of wires. This takes up time, as specified by the {@link Wire}s travel time.
- *
- * @param bitVector The new values the wires should take on.
- * @param startingBit The first index of the subarray of wires.
- *
- * @author Fabian Stemmler
- */
- public void feedSignals(int startingBit, BitVector bitVector)
- {
- if (!open)
- throw new IllegalStateException("Attempted to write to closed WireArrayEnd.");
- timeline.addEvent(e -> setValues(startingBit, bitVector), travelTime);
- }
-
- /**
- * Sets the values that are being fed into the {@link Wire}. The preferred way of setting {@link ReadWriteEnd} values is via
- * feedValues(...) with a delay.
- */
- void setValues(int startingBit, BitVector newValues)
- {
- // index check covered in equals
- if (!inputValues.equalsWithOffset(newValues, startingBit))
- {
- Bit[] vals = inputValues.getBits();
- System.arraycopy(newValues.getBits(), 0, vals, startingBit, newValues.length());
- inputValues = BitVector.of(vals);
- Wire.this.recalculateValuesWithoutFusions();
- }
- }
-
- /**
- * Sets the values that are being fed into the {@link Wire}. The preferred way of setting {@link ReadWriteEnd} values is via
- * feedValues(...) with a delay.
- */
- void setValues(BitVector newValues)
- {
- if (inputValues.equals(newValues))
- return;
- inputValues = newValues;
- Wire.this.recalculateValuesWithoutFusions();
- }
-
- /**
- * @return The value (of bit 0) the {@link ReadEnd} is currently feeding into the associated {@link Wire}.Returns the least
- * significant bit (LSB)
- */
- public Bit getInputValue()
- {
- return getInputValue(0);
- }
-
- /**
- * @return The value which the {@link ReadEnd} is currently feeding into the associated {@link Wire} at the indexed {@link Bit}.
- * Returns the least significant bit (LSB)
- *
- */
- public Bit getInputValue(int index)
- {
- return inputValues.getLSBit(index);
- }
-
- /**
- * @return A copy (safe to modify) of the values the {@link ReadEnd} is currently feeding into the associated {@link Wire}.
- */
- public BitVector getInputValues()
- {
- return inputValues;
- }
-
- public BitVector getInputValues(int start, int end)
- {
- return inputValues.subVector(start, end);
- }
-
- /**
- * {@link ReadEnd} now feeds Z into the associated {@link Wire}.
- */
- public void clearSignals()
- {
- feedSignals(Z.toVector(width));
- }
-
- public BitVector wireValuesExcludingMe()
- {
- BitVectorMutator mutator = BitVectorMutator.empty();
- boolean modified = false;
- for (ReadWriteEnd wireEnd : inputs)
- {
- if (wireEnd == this)
- continue;
- modified = true;
- mutator.join(wireEnd.inputValues);
- }
- if (!modified)
- mutator.join(BitVector.of(Bit.Z, width));
- return mutator.toBitVector();
- }
-
- @Override
- public String toString()
- {
- return inputValues.toString();
- }
-
- @Override
- public void close()
- {
- super.close();
- open = false;
- }
-
- void setWriting(boolean isWriting)
- {
- if (this.isWriting != isWriting)
- {
- this.isWriting = isWriting;
- if (isWriting)
- inputs.add(this);
- else
- inputs.remove(this);
- Wire.this.recalculateValuesWithoutFusions();
- }
- }
-
- boolean isWriting()
- {
- return isWriting;
- }
- }
-
- @Override
- public String toString()
- {
- String name = this.name == null ? String.format("0x%08x", hashCode()) : this.name;
- return String.format("wire %s value: %s inputs: %s", name, getValues(), inputs);
- }
-
- public static ReadEnd[] extractEnds(Wire[] w)
- {
- ReadEnd[] inputs = new ReadEnd[w.length];
- for (int i = 0; i < w.length; i++)
- inputs[i] = w[i].createReadWriteEnd();
- return inputs;
- }
-
- /**
- *
- * Fuses two wires together. If the bits change in one Wire, the other is changed accordingly immediately. Warning: The bits are
- * permanently fused together.
- *
- * @param a The {@link Wire} to be fused with b
- * @param b The {@link Wire} to be fused with a
- */
- public static void fuse(Wire a, Wire b)
- {
- fuse(a, b, 0, 0, a.width);
- }
-
- /**
- * Fuses the selected bits of two wires together. If the bits change in one Wire, the other is changed accordingly immediately. Warning:
- * The bits are permanently fused together.
- *
- * @param a The {@link Wire} to be (partially) fused with b
- * @param b The {@link Wire} to be (partially) fused with a
- * @param fromA The first bit of {@link Wire} a to be fused
- * @param fromB The first bit of {@link Wire} b to be fused
- * @param width The amount of bits to fuse
- */
- public static void fuse(Wire a, Wire b, int fromA, int fromB, int width)
- {
- // iterate in this direction to be fail-fast (rely on the checks in fuse(Wire, Wire, int, int)
- for (int i = width - 1; i >= 0; i--)
- fuse(a, b, fromA + i, fromB + i);
- }
-
- /**
- * Fuses one bit of two wires together. If this bit changes in one Wire, the other is changed accordingly immediately. Warning: The bits
- * are permanently fused together.
- *
- * @param a The {@link Wire} to be (partially) fused with b
- * @param b The {@link Wire} to be (partially) fused with a
- * @param bitA The bit of {@link Wire} a to be fused
- * @param bitB The bit of {@link Wire} b to be fused
- */
- public static void fuse(Wire a, Wire b, int bitA, int bitB)
- {
- if (bitA >= a.width)
- throw new IllegalArgumentException("No bit " + bitA + " in " + a + " (width " + a.width + ")");
- if (bitB >= b.width)
- throw new IllegalArgumentException("No bit " + bitB + " in " + b + " (width " + b.width + ")");
- if (a.fusedBits == null)
- a.fusedBits = new FusedBit[a.width];
- if (b.fusedBits == null)
- b.fusedBits = new FusedBit[b.width];
- FusedBit oldFusionA = a.fusedBits[bitA];
- FusedBit oldFusionB = b.fusedBits[bitB];
- if (oldFusionA == null)
- if (oldFusionB == null)
- {
- FusedBit fusion = new FusedBit();
- fusion.addParticipatingWireBit(a, bitA);
- fusion.addParticipatingWireBit(b, bitB);
- } else
- oldFusionB.addParticipatingWireBit(a, bitA);
- else if (oldFusionB == null)
- oldFusionA.addParticipatingWireBit(b, bitB);
- else
- oldFusionA.mergeOtherIntoThis(oldFusionB);
- }
-
- private static class FusedBit
- {
- private final List<WireBit> participatingWireBits;
-
- public FusedBit()
- {
- this.participatingWireBits = new ArrayList<>();
- }
-
- public void addParticipatingWireBit(Wire w, int bit)
- {
- addParticipatingWireBit(new WireBit(w, bit));
- }
-
- private void addParticipatingWireBit(WireBit wb)
- {
- wb.wire.fusedBits[wb.bit] = this;
- participatingWireBits.add(wb);
- wb.wire.invalidateCachedValuesForAllFusedWires();
- }
-
- public void mergeOtherIntoThis(FusedBit other)
- {
- for (WireBit wb : other.participatingWireBits)
- addParticipatingWireBit(wb);
- }
-
- public void invalidateCachedValuesForAllParticipatingWires()
- {
- for (WireBit wb : participatingWireBits)
- wb.wire.invalidateCachedValues();
- }
-
- public Bit getValue()
- {
- Bit result = null;
- for (WireBit wb : participatingWireBits)
- if (!wb.wire.inputs.isEmpty())
- {
- Bit bit = wb.wire.bitsWithoutFusions[wb.bit];
- result = result == null ? bit : result.join(bit);
- }
- return result == null ? U : result;
- }
- }
-
- private static class WireBit
- {
- public final Wire wire;
- public final int bit;
-
- public WireBit(Wire wire, int bit)
- {
- this.wire = wire;
- this.bit = bit;
- }
- }
-}
\ No newline at end of file