Update random generators (#1152)

Update random generators to support long generation and bounded
integers.

Author: AaronGhost

common/src/main/java/com/graphicsfuzz/common/util/CannedRandom.java

@@ -30,14 +30,14 @@ public class CannedRandom implements IRandom {
    * Constructs a canned random instance that will iterate over the given lists of integers
    * and booleans.
    *
-   * @param intsAndBools Ordered sequence of integers and booleans
+   * @param intsLongsAndBools Ordered sequence of integers, long and booleans
    */
-  public CannedRandom(Object... intsAndBools) {
-    if (Arrays.stream(intsAndBools).anyMatch(item -> !(item instanceof Integer
-        || item instanceof Boolean))) {
-      throw new IllegalArgumentException("Only Integer and Boolean items allowed.");
+  public CannedRandom(Object... intsLongsAndBools) {
+    if (Arrays.stream(intsLongsAndBools).anyMatch(item -> !(item instanceof Integer
+        || item instanceof Boolean || item instanceof Long))) {
+      throw new IllegalArgumentException("Only Integer, Long and Boolean items allowed.");
     }
-    this.items = Arrays.asList(intsAndBools).iterator();
+    this.items = Arrays.asList(intsLongsAndBools).iterator();
   }
 
   @Override
@@ -50,6 +50,21 @@ public int nextInt(int bound) {
     return Math.abs((Integer)next) % bound;
   }
 
+  @Override
+  public int nextInt(int origin, int bound) {
+    return nextInt(bound);
+  }
+
+  @Override
+  public long nextLong(long bound) {
+    Object next = items.next();
+    if (!(next instanceof Long)) {
+      throw new UnsupportedOperationException("nextLong failed because next item was a "
+         + next.getClass() + "(" + next + ")");
+    }
+    return (Long) next;
+  }
+
   @Override
   public Float nextFloat() {
     throw new RuntimeException("Not yet supported.");

common/src/main/java/com/graphicsfuzz/common/util/IRandom.java

@@ -24,6 +24,19 @@ public interface IRandom {
 
   int nextInt(int bound);
 
+  /**
+   * Return an integer in the range [origin, bound) if bound > origin
+   * @param origin minimal integer that the generator can produce
+   * @param bound maximal (excluded) integer that the generator can produce
+   * @return an integer from the range [origin, bound)
+   */
+  default int nextInt(int origin, int bound) {
+    assert bound > origin;
+    return (int) (nextLong(((long)bound - (long) origin)) + (long) origin);
+  }
+
+  long nextLong(long bound);
+
   Float nextFloat();
 
   default int nextPositiveInt(int bound) {

common/src/main/java/com/graphicsfuzz/common/util/RandomWrapper.java

@@ -43,6 +43,11 @@ public Float nextFloat() {
     return provider.nextFloat();
   }
 
+  @Override
+  public long nextLong(long bound) {
+    return provider.nextLong(bound);
+  }
+
   @Override
   public boolean nextBoolean() {
     return provider.nextBoolean();

common/src/main/java/com/graphicsfuzz/common/util/SameValueRandom.java

@@ -20,10 +20,12 @@ public class SameValueRandom implements IRandom {
 
   private final boolean boolValue;
   private final int intValue;
+  private final long longValue;
 
-  public SameValueRandom(boolean boolValue, int intValue) {
+  public SameValueRandom(boolean boolValue, int intValue, long longValue) {
     this.boolValue = boolValue;
     this.intValue = intValue;
+    this.longValue = longValue;
   }
 
   @Override
@@ -32,6 +34,19 @@ public int nextInt(int bound) {
     return intValue;
   }
 
+  @Override
+  public int nextInt(int origin, int bound) {
+    assert intValue < bound;
+    assert intValue >= origin;
+    return intValue;
+  }
+
+  @Override
+  public long nextLong(long bound) {
+    assert longValue < bound;
+    return longValue;
+  }
+
   @Override
   public Float nextFloat() {
     throw new RuntimeException("Not yet supported.");

common/src/main/java/com/graphicsfuzz/common/util/ZeroCannedRandom.java

@@ -23,6 +23,16 @@ public int nextInt(int bound) {
     return 0;
   }
 
+  @Override
+  public int nextInt(int origin, int bound) {
+    return 0;
+  }
+
+  @Override
+  public long nextLong(long bound) {
+    return 0L;
+  }
+
   @Override
   public Float nextFloat() {
     return 0.0f;

generator/src/test/java/com/graphicsfuzz/generator/semanticschanging/Expr2BinaryMutationFinderTest.java

@@ -80,6 +80,20 @@ public int nextInt(int bound) {
         return 2;
       }
 
+      @Override
+      public int nextInt(int origin, int bound) {
+        throw new RuntimeException("This method was added to the IRandom interface after this test"
+            + " was written and thus should not be called; if it becomes required the IRandom"
+            + " implementation in the test should be revised.");
+      }
+
+      @Override
+      public long nextLong(long bound) {
+        throw new RuntimeException("This method was added to the IRandom interface after this test"
+            + " was written and thus should not be called; if it becomes required the IRandom"
+            + " implementation in the test should be revised.");
+      }
+
       @Override
       public Float nextFloat() {
         throw new UnsupportedOperationException();

reducer/src/test/java/com/graphicsfuzz/reducer/reductionopportunities/UnwrapReductionOpportunitiesTest.java

@@ -45,7 +45,7 @@ public void testBlock1() throws Exception {
     List<UnwrapReductionOpportunity> ops = UnwrapReductionOpportunities
         .findOpportunities(MakeShaderJobFromFragmentShader.make(tu),
           new ReducerContext(false,
-        ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0), new IdGenerator()));
+        ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0, 0L), new IdGenerator()));
     assertEquals(1, ops.size());
   }
 
@@ -56,7 +56,7 @@ public void testEmptyBlock() throws Exception {
     List<UnwrapReductionOpportunity> ops = UnwrapReductionOpportunities
         .findOpportunities(MakeShaderJobFromFragmentShader.make(tu),
           new ReducerContext(false,
-          ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0),
+          ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0, 0L),
               new IdGenerator()));
     // No opportunities because the inner block is empty.  Another reduction pass may be able to
     // delete it, but it cannot be unwrapped.
@@ -70,7 +70,7 @@ public void testNestedEmptyBlocks() throws Exception {
     List<UnwrapReductionOpportunity> ops = UnwrapReductionOpportunities
         .findOpportunities(MakeShaderJobFromFragmentShader.make(tu),
         new ReducerContext(false,
-            ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0),
+            ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0, 0L),
             new IdGenerator()));
     assertEquals(1, ops.size());
   }
@@ -83,7 +83,7 @@ public void testUnwrapWithDeclNoClash() throws Exception {
     List<UnwrapReductionOpportunity> ops = UnwrapReductionOpportunities
         .findOpportunities(MakeShaderJobFromFragmentShader.make(tu),
         new ReducerContext(false,
-            ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0), new IdGenerator()));
+            ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0, 0L), new IdGenerator()));
     assertEquals(1, ops.size());
     ops.get(0).applyReduction();
     CompareAsts.assertEqualAsts(expected, tu);
@@ -97,7 +97,7 @@ public void testNoUnwrapWithDeclClash() throws Exception {
     List<UnwrapReductionOpportunity> ops = UnwrapReductionOpportunities
         .findOpportunities(MakeShaderJobFromFragmentShader.make(tu),
         new ReducerContext(false,
-            ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0),
+            ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0, 0L),
             new IdGenerator()));
     // The inner block cannot be unwrapped as it would change which variable 'x = 2' refers to.
     assertEquals(1, ops.size());
@@ -110,7 +110,7 @@ public void testNoUnwrapWithDeclClash2() throws Exception {
     List<UnwrapReductionOpportunity> ops = UnwrapReductionOpportunities
         .findOpportunities(MakeShaderJobFromFragmentShader.make(tu),
         new ReducerContext(false,
-            ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0),
+            ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0, 0L),
             new IdGenerator()));
     assertEquals(0, ops.size());
   }
@@ -122,7 +122,7 @@ public void testOneUnwrapDisablesAnother() throws Exception {
     List<UnwrapReductionOpportunity> ops = UnwrapReductionOpportunities
         .findOpportunities(MakeShaderJobFromFragmentShader.make(tu),
         new ReducerContext(false,
-            ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0),
+            ShadingLanguageVersion.GLSL_440, new SameValueRandom(false, 0, 0L),
             new IdGenerator()));
     assertEquals(2, ops.size());
     assertTrue(ops.get(0).preconditionHolds());

tester/src/test/java/com/graphicsfuzz/tester/MiscellaneousGenerateThenReduceTest.java

@@ -68,7 +68,7 @@ private void checkControlFlowWrapElimination(String program)
     final ShadingLanguageVersion shadingLanguageVersion = ShadingLanguageVersion.GLSL_440;
     new AddWrappingConditionalTransformation().apply(tu,
         TransformationProbabilities.onlyWrap(),
-        new SameValueRandom(false, 0),
+        new SameValueRandom(false, 0, 0L),
         GenerationParams.normal(ShaderKind.FRAGMENT, true));
 
     System.out.println(PrettyPrinterVisitor.prettyPrintAsString(tu));
@@ -78,7 +78,7 @@ private void checkControlFlowWrapElimination(String program)
           .getReductionOpportunities(new GlslShaderJob(Optional.empty(),
                   new PipelineInfo(), tu),
                 new ReducerContext(false, shadingLanguageVersion,
-              new SameValueRandom(false, 0), new IdGenerator()), fileOps);
+              new SameValueRandom(false, 0, 0L), new IdGenerator()), fileOps);
       if (ops.isEmpty()) {
         break;
       }