Optimizer optimizing away too much?

Thomas Aeby aeby@graeff.com
Tue Aug 10 20:27:00 GMT 2004


Hello

Great oops for me: I just found out, that GCJ (3.4.0), using
with "-O" optimizes away something like

    ...
    public synchronized void increment() {
        value++;
    }

I assume the optimizer thinks "value++" is just an unused value
and does not respect that this also changes the value of value.

If I add a System.out after value++ like

   public ...
   {
	value++;
	System.out( "value of value: " + value );
   }

or change value++ into value = value + 1 everything wroks well.

I was kind of surprised :-)

Am I expecting something totally silly, shouldn't one ever use
optimization? What is your experience with GCJ and optimization?

Best regards,
Tom
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