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
{
public final String name;
- private BitVector values;
+ 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)
{
private void initValues()
{
- values = U.toVector(width);
+ cachedValues = U.toVector(width);
+ bitsWithoutFusions = cachedValues.getBits();
}
private void setNewValues(BitVector newValues)
{
- if (values.equals(newValues))
- return;
- values = newValues;
+ cachedValues = newValues;
notifyObservers();
}
- void recalculate()
+ 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())
- setNewValues(U.toVector(width));
+ Arrays.fill(bits, U);
else
{
- BitVectorMutator mutator = BitVectorMutator.empty();
- for (ReadWriteEnd wireArrayEnd : inputs)
- mutator.join(wireArrayEnd.getInputValues());
- setNewValues(mutator.toBitVector());
+ 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);
}
/**
*/
public boolean hasNumericValue()
{
- return values.isBinary();
+ return getValues().isBinary();
}
/**
{
long val = 0;
long mask = 1;
- for (Bit bit : values)
+ for (Bit bit : getValues())
{
switch (bit)
{
*/
public Bit getValue(int index)
{
- return values.getLSBit(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;
}
/**
void registerInput(ReadWriteEnd toRegister)
{
inputs.add(toRegister);
+ recalculateValuesWithoutFusions();
}
/**
{
inputs.remove(this);
detachEnd(this);
- recalculate();
+ recalculateValuesWithoutFusions();
}
public int width()
observers.remove(ob);
}
+// void registerCloseObserver(LogicObserver ob)
+// {
+// closeObserver.add(ob);
+// }
+//
+// void deregisterCloseObserver(LogicObserver ob)
+// {
+// closeObserver.remove(ob);
+// }
+
@Override
public void notifyObservers()
{
Bit[] vals = inputValues.getBits();
System.arraycopy(newValues.getBits(), 0, vals, startingBit, newValues.length());
inputValues = BitVector.of(vals);
- Wire.this.recalculate();
+ Wire.this.recalculateValuesWithoutFusions();
}
}
if (inputValues.equals(newValues))
return;
inputValues = newValues;
- Wire.this.recalculate();
+ Wire.this.recalculateValuesWithoutFusions();
}
/**
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();
}
inputs.add(this);
else
inputs.remove(this);
- Wire.this.recalculate();
+ Wire.this.recalculateValuesWithoutFusions();
}
}
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, values, inputs);
+ return String.format("wire %s value: %s inputs: %s", name, getValues(), inputs);
}
public static ReadEnd[] extractEnds(Wire[] w)
return inputs;
}
- // TODO Fix ReadWriteEnd feeding signals to entire Wire (Z) instead of only selected Bits
+ /**
+ *
+ * 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.
*/
public static void fuse(Wire a, Wire b, int fromA, int fromB, int width)
{
- ReadWriteEnd rA = a.createReadWriteEnd(), rB = b.createReadWriteEnd();
- rA.setWriting(false);
- rB.setWriting(false);
- rA.setValues(BitVector.of(Bit.Z, a.width));
- rB.setValues(BitVector.of(Bit.Z, b.width));
- Fusion aF = new Fusion(rB, fromA, fromB, width), bF = new Fusion(rA, fromB, fromA, width);
- rA.registerObserver(aF);
- rB.registerObserver(bF);
- aF.update(rA);
- bF.update(rB);
+ // 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.
*
- * 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
+ * @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)
+ private static void fuse(Wire a, Wire b, int bitA, int bitB)
{
- fuse(a, b, 0, 0, a.width);
+ 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 Fusion implements LogicObserver
+ private static class FusedBit
{
- private ReadWriteEnd target;
- int fromSource, fromTarget, width;
+ private final List<WireBit> participatingWireBits;
- public Fusion(ReadWriteEnd target, int fromSource, int fromTarget, int width)
+ public FusedBit()
{
- this.target = target;
- this.fromSource = fromSource;
- this.fromTarget = fromTarget;
- this.width = width;
+ this.participatingWireBits = new ArrayList<>();
}
- @Override
- public void update(LogicObservable initiator)
+ public void addParticipatingWireBit(Wire w, int bit)
{
- ReadWriteEnd source = (ReadWriteEnd) initiator;
- if (source.getWire().inputs.size() - (source.isWriting() ? 1 : 0) == 0)
- target.setWriting(false);
- else
- {
- target.setWriting(true);
- BitVector targetInput = source.wireValuesExcludingMe().subVector(fromSource, fromSource + width);
- target.setValues(fromTarget, targetInput);
- }
+ 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