[Bug tree-optimization/52907] Underflowing floating point expressions wrongly folded to zero

[joseph at codesourcery dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52907

--- Comment #2 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2012-04-23 20:02:50 UTC ---
On Tue, 10 Apr 2012, rguenth at gcc dot gnu.org wrote:

> Does real.c even communicate this fact?

You can identify underflow from the result of multiplication or division 
being zero or subnormal (unless an operand is zero or infinite), just as 
overflow is identified from an infinite result.  Information about 
subnormal results may not be conveniently communicated by real.c, but 
simply handling zero results here would be enough for the use cases in 
glibc.