Merge branch 'master' into genModCirc

# Conflicts:
#	src/test/java/de/neemann/digital/hdl/verilog2/VerilogSimulatorTest.java
#	src/test/java/de/neemann/digital/hdl/vhdl2/VHDLSimulatorTest.java
#	src/test/java/de/neemann/digital/integration/TestExamples.java

src/main/java/de/neemann/digital/hdl/model2/HDLCircuit.java

@@ -537,6 +537,7 @@ public class HDLCircuit implements Iterable<HDLNode>, HDLModel.BitProvider, Prin
     public HDLCircuit applyDefaultOptimizations() throws HDLException {
         apply(new ReplaceOneToMany());
         apply(new MergeAssignments());
+        apply(new OptimizeExpressions(new ExprNot.OptimizeNotNot()));
         apply(new InlineManyToOne());
         apply(new RemoveConstantSignals());
         apply(new MergeConstants());  // under certain circumstances there are still constants

src/main/java/de/neemann/digital/hdl/model2/HDLNodeAssignment.java

@@ -9,6 +9,7 @@ package de.neemann.digital.hdl.model2;
 import de.neemann.digital.core.element.ElementAttributes;
 import de.neemann.digital.hdl.model2.expression.ExprVar;
 import de.neemann.digital.hdl.model2.expression.Expression;
+import de.neemann.digital.hdl.model2.expression.ExpressionOptimizer;
 import de.neemann.digital.hdl.model2.expression.Visitor;
 import de.neemann.digital.hdl.printer.CodePrinter;
 
@@ -80,4 +81,12 @@ public class HDLNodeAssignment extends HDLNode {
         return getOutput().getNet();
     }
 
+    /**
+     * Optimizes the expression
+     *
+     * @param eo the optimizer
+     */
+    public void optimize(ExpressionOptimizer eo) {
+        expression = eo.optimize(expression);
+    }
 }

src/main/java/de/neemann/digital/hdl/model2/expression/ExprNot.java

@@ -53,4 +53,25 @@ public class ExprNot implements Expression {
         visitor.visit(this);
         expr.traverse(visitor);
     }
+
+    @Override
+    public void optimize(ExpressionOptimizer eo) {
+        expr = eo.optimize(expr);
+        expr.optimize(eo);
+    }
+
+    /**
+     * Optimizes not(not a) expressions to a
+     */
+    public static class OptimizeNotNot implements ExpressionOptimizer {
+        @Override
+        public Expression optimize(Expression expression) {
+            if (expression instanceof ExprNot) {
+                ExprNot not = (ExprNot) expression;
+                if (not.expr instanceof ExprNot)
+                    return optimize(((ExprNot) not.expr).expr);
+            }
+            return expression;
+        }
+    }
 }

src/main/java/de/neemann/digital/hdl/model2/expression/ExprOperate.java

@@ -93,4 +93,13 @@ public class ExprOperate implements Expression {
         for (Expression o : operands)
             o.traverse(visitor);
     }
+
+    @Override
+    public void optimize(ExpressionOptimizer eo) {
+        for (int i = 0; i < operands.size(); i++) {
+            Expression expr = eo.optimize(operands.get(i));
+            expr.optimize(eo);
+            operands.set(i, expr);
+        }
+    }
 }

src/main/java/de/neemann/digital/hdl/model2/expression/Expression.java

@@ -30,6 +30,15 @@ public interface Expression extends Printable {
         visitor.visit(this);
     }
 
+
+    /**
+     * Tries to optimize the expression by replacing it by a optimized one.
+     *
+     * @param eo the optimizer
+     */
+    default void optimize(ExpressionOptimizer eo) {
+    }
+
     /**
      * Helper to check if an expression is a net reference
      *

src/main/java/de/neemann/digital/hdl/model2/expression/ExpressionOptimizer.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2021 Helmut Neemann.
+ * Use of this source code is governed by the GPL v3 license
+ * that can be found in the LICENSE file.
+ */
+package de.neemann.digital.hdl.model2.expression;
+
+/**
+ * Interface to optimize an expression
+ */
+public interface ExpressionOptimizer {
+
+    /**
+     * Optimizes the given expression.
+     * Should call itself on the returned expression if a optimization was made.
+     * See {@link ExprNot.OptimizeNotNot} as an example.
+     *
+     * @param expression the expression to optimize
+     * @return the optimizes expression or the given expression if optimization is not possible
+     */
+    Expression optimize(Expression expression);
+}

src/main/java/de/neemann/digital/hdl/model2/optimizations/OptimizeExpressions.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2021 Helmut Neemann.
+ * Use of this source code is governed by the GPL v3 license
+ * that can be found in the LICENSE file.
+ */
+package de.neemann.digital.hdl.model2.optimizations;
+
+import de.neemann.digital.hdl.model2.HDLCircuit;
+import de.neemann.digital.hdl.model2.HDLException;
+import de.neemann.digital.hdl.model2.HDLNode;
+import de.neemann.digital.hdl.model2.HDLNodeAssignment;
+import de.neemann.digital.hdl.model2.expression.ExpressionOptimizer;
+
+/**
+ * Optimization which addresses the used expressions.
+ */
+public class OptimizeExpressions implements Optimization {
+
+    private final ExpressionOptimizer eo;
+
+    /**
+     * Creates a new instance
+     *
+     * @param eo the expression optimizer to use.
+     */
+    public OptimizeExpressions(ExpressionOptimizer eo) {
+        this.eo = eo;
+    }
+
+    @Override
+    public void optimize(HDLCircuit circuit) throws HDLException {
+        for (HDLNode n : circuit.getNodes()) {
+            if (n instanceof HDLNodeAssignment) {
+                HDLNodeAssignment a = (HDLNodeAssignment) n;
+                a.optimize(eo);
+            }
+        }
+    }
+}

src/main/java/de/neemann/digital/hdl/verilog2/VerilogCreator.java

@@ -300,7 +300,13 @@ public class VerilogCreator {
             out.print(value(constant));
         } else if (expression instanceof ExprNot) {
             out.print("~ ");
-            printExpression(((ExprNot) expression).getExpression());
+            Expression inner = ((ExprNot) expression).getExpression();
+            if (inner instanceof ExprNot) { // Quartus does not like a NOT NOT
+                out.print("(");
+                printExpression(inner);
+                out.print(")");
+            } else
+                printExpression(inner);
         } else if (expression instanceof ExprOperate) {
             out.print("(");
             boolean first = true;

src/main/java/de/neemann/digital/hdl/vhdl2/VHDLCreator.java

@@ -290,7 +290,13 @@ public class VHDLCreator {
             out.print(value(constant));
         } else if (expression instanceof ExprNot) {
             out.print("NOT ");
-            printExpression(((ExprNot) expression).getExpression());
+            Expression inner = ((ExprNot) expression).getExpression();
+            if (inner instanceof ExprNot) { // Quartus does not like a NOT NOT
+                out.print("(");
+                printExpression(inner);
+                out.print(")");
+            } else
+                printExpression(inner);
         } else if (expression instanceof ExprOperate) {
             out.print("(");
             boolean first = true;

src/test/resources/dig/test/vhdl/not.dig

@@ -0,0 +1,281 @@
+<?xml version="1.0" encoding="utf-8"?>
+<circuit>
+  <version>1</version>
+  <attributes/>
+  <visualElements>
+    <visualElement>
+      <elementName>In</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>A</string>
+        </entry>
+      </elementAttributes>
+      <pos x="340" y="180"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="360" y="180"/>
+    </visualElement>
+    <visualElement>
+      <elementName>In</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>B</string>
+        </entry>
+      </elementAttributes>
+      <pos x="340" y="220"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="360" y="220"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="420" y="220"/>
+    </visualElement>
+    <visualElement>
+      <elementName>In</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>C</string>
+        </entry>
+      </elementAttributes>
+      <pos x="340" y="260"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="360" y="260"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="420" y="260"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="480" y="260"/>
+    </visualElement>
+    <visualElement>
+      <elementName>In</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>D</string>
+        </entry>
+      </elementAttributes>
+      <pos x="340" y="300"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="360" y="300"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="420" y="300"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="480" y="300"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="540" y="300"/>
+    </visualElement>
+    <visualElement>
+      <elementName>In</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>E</string>
+        </entry>
+      </elementAttributes>
+      <pos x="340" y="340"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="360" y="340"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="420" y="340"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="480" y="340"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="540" y="340"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Not</elementName>
+      <elementAttributes/>
+      <pos x="600" y="340"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Out</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>Y</string>
+        </entry>
+      </elementAttributes>
+      <pos x="660" y="340"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Out</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>X</string>
+        </entry>
+      </elementAttributes>
+      <pos x="660" y="300"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Out</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>Z</string>
+        </entry>
+      </elementAttributes>
+      <pos x="660" y="260"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Out</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>U</string>
+        </entry>
+      </elementAttributes>
+      <pos x="660" y="220"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Out</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>V</string>
+        </entry>
+      </elementAttributes>
+      <pos x="660" y="180"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Testcase</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Testdata</string>
+          <testData>
+            <dataString>A B C D E Y X Z U V 
+
+ 0 0 0 0 0 1 0 1 0 1
+ 1 1 1 1 1 0 1 0 1 0
+</dataString>
+          </testData>
+        </entry>
+      </elementAttributes>
+      <pos x="460" y="380"/>
+    </visualElement>
+  </visualElements>
+  <wires>
+    <wire>
+      <p1 x="340" y="180"/>
+      <p2 x="360" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="400" y="180"/>
+      <p2 x="660" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="340" y="260"/>
+      <p2 x="360" y="260"/>
+    </wire>
+    <wire>
+      <p1 x="400" y="260"/>
+      <p2 x="420" y="260"/>
+    </wire>
+    <wire>
+      <p1 x="460" y="260"/>
+      <p2 x="480" y="260"/>
+    </wire>
+    <wire>
+      <p1 x="520" y="260"/>
+      <p2 x="660" y="260"/>
+    </wire>
+    <wire>
+      <p1 x="340" y="340"/>
+      <p2 x="360" y="340"/>
+    </wire>
+    <wire>
+      <p1 x="400" y="340"/>
+      <p2 x="420" y="340"/>
+    </wire>
+    <wire>
+      <p1 x="460" y="340"/>
+      <p2 x="480" y="340"/>
+    </wire>
+    <wire>
+      <p1 x="520" y="340"/>
+      <p2 x="540" y="340"/>
+    </wire>
+    <wire>
+      <p1 x="580" y="340"/>
+      <p2 x="600" y="340"/>
+    </wire>
+    <wire>
+      <p1 x="640" y="340"/>
+      <p2 x="660" y="340"/>
+    </wire>
+    <wire>
+      <p1 x="340" y="220"/>
+      <p2 x="360" y="220"/>
+    </wire>
+    <wire>
+      <p1 x="400" y="220"/>
+      <p2 x="420" y="220"/>
+    </wire>
+    <wire>
+      <p1 x="460" y="220"/>
+      <p2 x="660" y="220"/>
+    </wire>
+    <wire>
+      <p1 x="340" y="300"/>
+      <p2 x="360" y="300"/>
+    </wire>
+    <wire>
+      <p1 x="400" y="300"/>
+      <p2 x="420" y="300"/>
+    </wire>
+    <wire>
+      <p1 x="460" y="300"/>
+      <p2 x="480" y="300"/>
+    </wire>
+    <wire>
+      <p1 x="520" y="300"/>
+      <p2 x="540" y="300"/>
+    </wire>
+    <wire>
+      <p1 x="580" y="300"/>
+      <p2 x="660" y="300"/>
+    </wire>
+  </wires>
+  <measurementOrdering/>
+</circuit>