This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]

Re: basic_block index negative?


Daniel Egger wrote:-

> I think it would be really nice to mostly unsigned variables; this
> makes it easy to prevent nasty sideeffects when dealing with them
> and quite frankly I don't like the just of casts in the code. Maybe
> gcc could also create better code but this is just a speculation
> for recent versions, it worked on older versions though.

I think you'll always get better code - some mathematical operations
are genuinely more tricky on signed quantities.  For example, a
division by 4 that would be a bitshift if unsinged suddenly has to
incorporate a jump if signed (on x86 if you don't want to use the idiv
instruction at least).

Neil.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]