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;
*/
public class Wire
{
- private BitVector values;
+ public final String name;
+ private BitVector cachedValues;
public final int travelTime;
private List<ReadEnd> attached = new ArrayList<>();
- public final int length;
+ public final int width;
List<ReadWriteEnd> inputs = new ArrayList<>();
Timeline timeline;
+ private Bit[] bitsWithoutFusions;
+ FusedBit[] fusedBits;
- public Wire(Timeline timeline, int length, int travelTime)
+ public Wire(Timeline timeline, int width, int travelTime)
{
- if (length < 1)
+ 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 length %d, but a length of less than 1 makes no sense.", length));
+ 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.length = length;
+ this.width = width;
this.travelTime = travelTime;
initValues();
}
private void initValues()
{
- values = U.toVector(length);
+ cachedValues = U.toVector(width);
+ bitsWithoutFusions = cachedValues.getBits();
}
- private void recalculateSingleInput()
+ private void setNewValues(BitVector newValues)
{
- setNewValues(inputs.get(0).getInputValues());
+ cachedValues = newValues;
+ notifyObservers();
}
- private void recalculateMultipleInputs()
+ private void invalidateCachedValuesForAllFusedWires()
{
- BitVectorMutator mutator = BitVectorMutator.empty();
- for (ReadWriteEnd wireArrayEnd : inputs)
- mutator.join(wireArrayEnd.getInputValues());
- setNewValues(mutator.get());
+ invalidateCachedValues();
+ if (fusedBits != null)
+ for (FusedBit fusion : fusedBits)
+ if (fusion != null)
+ fusion.invalidateCachedValuesForAllParticipatingWires();
}
- private void setNewValues(BitVector newValues)
+ private void invalidateCachedValues()
{
- if (values.equals(newValues))
- return;
-// BitVector oldValues = values;
- values = newValues;
+ cachedValues = null;
notifyObservers();
}
- void recalculate()
+ void recalculateValuesWithoutFusions()
{
- switch (inputs.size())
+ 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
{
- case 0:
- return;
- case 1:
- recalculateSingleInput();
- break;
- default:
- recalculateMultipleInputs();
+ 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.X</code> or <code>Bit.Z</code>. <code>false</code> is returned otherwise.
+ * 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()
{
- for (Bit b : values)
- {
- if (b != Bit.ZERO && b != Bit.ONE)
- return false;
- }
- return true;
+ return getValues().isBinary();
}
/**
{
long val = 0;
long mask = 1;
- for (Bit bit : values)
+ for (Bit bit : getValues())
{
switch (bit)
{
public long getSignedValue()
{
long val = getUnsignedValue();
- long mask = 1 << (length - 1);
+ long mask = 1 << (width - 1);
if ((mask & val) != 0)
{
- int shifts = 64 - length;
+ 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 values.getBit(index);
+ return getValues().getLSBit(index);
}
public BitVector getValues(int start, int end)
{
- return values.subVector(start, end);
+ return getValues().subVector(start, end);
}
public BitVector getValues()
{
- return values;
+ if (cachedValues == null)
+ recalculatedCachedValues();
+ return cachedValues;
}
/**
*
* @author Fabian Stemmler
*/
- void attachEnd(ReadEnd end)
+ boolean attachEnd(ReadEnd end)
{
- attached.add(end);
+ return attached.add(end);
}
void detachEnd(ReadEnd end)
private void notifyObservers()
{
- attached.forEach(r -> r.update());
+ attached.forEach(ReadEnd::update);
}
/**
void registerInput(ReadWriteEnd toRegister)
{
inputs.add(toRegister);
+ recalculateValuesWithoutFusions();
}
/**
}
/**
- * Included for convenient use on {@link Wire}s of length 1.
+ * Included for convenient use on {@link Wire}s of width 1.
*
* @return The value of bit 0.
*
return Wire.this.getValue(index);
}
- /**
- * @param index Index of the requested bit.
- * @return The value of the indexed bit.
- *
- * @author Fabian Stemmler
- */
public BitVector getValues()
{
return Wire.this.getValues();
{
inputs.remove(this);
detachEnd(this);
- recalculate();
+ recalculateValuesWithoutFusions();
}
- public int length()
+ public int width()
{
- return length;
+ return width;
}
public Wire getWire()
observers.remove(ob);
}
+// void registerCloseObserver(LogicObserver ob)
+// {
+// closeObserver.add(ob);
+// }
+//
+// void deregisterCloseObserver(LogicObserver ob)
+// {
+// closeObserver.remove(ob);
+// }
+
@Override
public void notifyObservers()
{
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(length);
+ inputValues = U.toVector(width);
}
/**
public void feedSignals(BitVector newValues)
{
- if (newValues.length() != length)
+ if (newValues.length() != width)
throw new IllegalArgumentException(
- String.format("Attempted to input %d bits instead of %d bits.", newValues.length(), length));
+ String.format("Attempted to input %d bits instead of %d bits.", newValues.length(), width));
if (!open)
- throw new RuntimeException("Attempted to write to closed WireArrayEnd.");
+ throw new IllegalStateException("Attempted to write to closed WireArrayEnd.");
timeline.addEvent(e -> setValues(newValues), travelTime);
}
public void feedSignals(int startingBit, BitVector bitVector)
{
if (!open)
- throw new RuntimeException("Attempted to write to closed WireArrayEnd.");
+ throw new IllegalStateException("Attempted to write to closed WireArrayEnd.");
timeline.addEvent(e -> setValues(startingBit, bitVector), travelTime);
}
- private void setValues(int startingBit, BitVector newValues)
+ /**
+ * 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.recalculate();
+ Wire.this.recalculateValuesWithoutFusions();
}
}
- private void setValues(BitVector newValues)
+ /**
+ * 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.recalculate();
+ Wire.this.recalculateValuesWithoutFusions();
}
/**
- * @return The value (of bit 0) the {@link ReadEnd} is currently feeding into the associated {@link Wire}.
+ * @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 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.getBit(index);
+ return inputValues.getLSBit(index);
}
/**
*/
public BitVector getInputValues()
{
- return getInputValues(0, length);
+ return inputValues;
}
public BitVector getInputValues(int start, int end)
*/
public void clearSignals()
{
- feedSignals(Z.toVector(length));
+ 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);
}
- return mutator.get();
+ if (!modified)
+ mutator.join(BitVector.of(Bit.Z, width));
+ return mutator.toBitVector();
}
@Override
{
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()
{
- return String.format("wire 0x%08x value: %s inputs: %s", hashCode(), values, inputs);
+ 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)
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
+ */
+ private 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
projects / Mograsim.git / blobdiff