On 10 Apr 2007, at 00:04, Chris Ferrall wrote:
P.S. I've already received the following response from Frank.
[snip]
So the bugfix might be to make subrange types signed when the range allows (which would always be the case in valid ISO programs). Frank
Note that doing this may cause problems with packed arrays and records, like we had in FPC. If you treat 0..3 as signed, then you can no longer pack it in 2 bits using the current format used by FPC and GPC. The reason is that if a type is signed, both compilers treat the uppermost bit of a packed value as the sign bit. So 2 and 3 would be interpreted as -2 and -1, respectively.
Of course, it is possible to change the format of packed values (e.g., always store them as unsigned, with a bias of -lower_bound in case of signed types), but this may cause backward compatibility issues.
Jonas