On Mon, 2006-03-06 at 11:39 -0700, Jeffrey A Law wrote: > if Side = Right or else Side = Both then > while High >= Low and then Source (High) = Wide_Space loop > High := High - 1; > end loop; > end if; > > > side is an enumerated type with the following values > > > Symbolic name Integer value > left 0 > right 1 > both 2 > > The min/max values associated with the type specify that side > should have the values [0, 2]. > > Note carefully that the expression (side - 1) will produce a value > outside the defined min/max values for side's type [0, 2] when side > has the value "left". > > Not surprisingly, we turn the .original code into this gimple code: > > D.5765 = side - 1; > if (D.5765 <= 1)
Side is read-only in the code at the Ada level (an "in" parameter, so considered constant in the function code), it's likely that it's not the front-end that decided to generate "side - 1" somewhere in the code but some combination of middle end transformations not preserving type information correctly and then vrp-like optimisations. > I think it's time to hand this one to the Ada guys :-0 May be not :). Laurent
