Warning! Compiler Bug (DecSt.3100)

[Chris Anderson]

The following program, when compiled on the DecStation 3100,
produces d=0, when it should be d=1:

    unsigned a = 2, d;
    int b = 1, c = 1;

    d = (c >= (b - a + 1));

What happens is that the whole expression is promoted to unsigned as expected,
but then the comparison is changed to ">" and the +1 operation is
"optimized" out. (Note, this happens even without -O). Voila! Bad code.

Beware of unsigned IFs with +1 in them somewhere...

Chris Anderson     (contex!chris at uunet.uu.net)
Xyvision, Inc.