--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.common/src/org/graalvm/compiler/core/common/type/IntegerStamp.java	Thu Oct 31 14:23:06 2019 -0700
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.common/src/org/graalvm/compiler/core/common/type/IntegerStamp.java	Thu Oct 31 16:54:16 2019 -0700
@@ -167,8 +167,15 @@
     @Override
     public Stamp constant(Constant c, MetaAccessProvider meta) {
         if (c instanceof PrimitiveConstant) {
-            long value = ((PrimitiveConstant) c).asLong();
-            return StampFactory.forInteger(getBits(), value, value);
+            PrimitiveConstant primitiveConstant = (PrimitiveConstant) c;
+            long value = primitiveConstant.asLong();
+            if (primitiveConstant.getJavaKind() == JavaKind.Boolean && value == 1) {
+                // Need to special case booleans as integer stamps are always signed values.
+                value = -1;
+            }
+            Stamp returnedStamp = StampFactory.forInteger(getBits(), value, value);
+            assert returnedStamp.hasValues();
+            return returnedStamp;
         }
         return this;
     }
@@ -1605,7 +1612,10 @@
                             long newUpMask = stamp.upMask() & defaultMask;
                             long newLowerBound = CodeUtil.signExtend((lowerBound | newDownMask) & newUpMask, resultBits);
                             long newUpperBound = CodeUtil.signExtend((upperBound | newDownMask) & newUpMask, resultBits);
-                            return new IntegerStamp(resultBits, newLowerBound, newUpperBound, newDownMask, newUpMask);
+
+                            IntegerStamp result = new IntegerStamp(resultBits, newLowerBound, newUpperBound, newDownMask, newUpMask);
+                            assert result.hasValues();
+                            return result;
                         }
                     },