In the following program, the subexpression "i < 0" is side-effect-free and
appears in a context in which its value is not required.

    public class Bug {
        public static void main(String args[]) {
            int i = 1;
            boolean b = i < 0 || true;
        }
    }

When compiled with javac (1.1.3), the following code results:

    public class Bug {
     // Compiled from Bug.java
// Compiler version 3.45;


    public static Method main:"([Ljava/lang/String;)V"
   stack 1 locals 2
    {
   iconst_1;
istore_1;
iload_1;
iflt L9;
goto L9;
L9: iconst_1;
pop;
return;
    }

    public Method <init>:"()V"
stack 1 locals 1
    {
aload_0;
invokespecial Method java/lang/Object.<init>:"()V";
return;
    }

    } // end Class Bug

Examination of the compiler code, e.g, Expression.simplify, Expression.inline,
and Expression.inlineValue, reveals that expressions are not always re-examined
for further simplifications enabled by previous simplifications. In the
case illustrated, the CommaExpression introduced during the simplification
of 'i < 0 || true' to '(i < 0, true)' is not further simplified, which would
allow the expression 'i < 0' to be discarded.

While the only observed effects are on code quality, it is possible that
the correctness of the compiler may be impacted, as the compile-time
simplification machinery is also used to evaluate constant expressions as
defined in the JLS. Such expressions must simplify to a literal constant.