On Sat, Feb 27, 2016 at 10:39:59AM +0000, Andrew Haley wrote:
> On 26/02/16 21:28, Bradley Lucier wrote:
> > Any advice on how to proceed? I'd be willing to write and test the few
> > lines of code myself if I knew where to put them.
>
> The best thing, rather than warning, would be to define this
> conversion as a GCC extension and implement it consistently
> everywhere. Then we wouldn't need a warning, and there'd be
> one fewer trap.
I disagree. That would slow down most of uses that use it when they know
the floating point value must be non-negative, for the benefit
of the few that invoke implementation defined behavior.
Just use -fsanitize=float-cast-overflow and you will be notified at runtime
when you run into this.
E.g.
(/lib64/libubsan.so.0+0x9202): runtime error: value -2 is outside the range of
representable values of type 'unsigned int'
Jakub
