Re: OT (partially): about promotion of integers

[Walter Bright]

On 12/12/2012 4:51 AM, Araq wrote:

 From http://embed.cs.utah.edu/ioc/

" Examples of undefined integer overflows we have reported:

     An SQLite bug
     Some problems in SafeInt
     GNU MPC
     PHP
     Firefox
     GCC
     PostgreSQL
     LLVM
     Python

We also reported bugs to BIND and OpenSSL. Most of the SPEC CPU 2006 benchmarks
contain undefined overflows."

Thanks, this is interesting information.

So how does D improve on C's model? If signed integers are required to wrap
around in D (no undefined behaviour), you also prevent some otherwise possible
optimizations (there is a reason it's still undefined behaviour in C).

D requires 2's complement arithmetic, it does not support 1's complement as C 
does.