[Bug tree-optimization/24021] VRP does not work with floating points

[vincent-gcc at vinc17 dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24021

--- Comment #10 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> ---
(In reply to Vincent Lefèvre from comment #9)
> Subnormals might also need to be considered as special cases: "Whether and
> in what cases subnormal numbers are treated as zeros is implementation
> defined." will be added to C23 (some behaviors are dictated by the hardware,
> e.g. ARM in some non-IEEE configurations), but I've asked for clarification
> in the CFP mailing-list.

Some details in http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2797.htm