[cfe-dev] floating point division by 0.0 and -ftrapv

[Sean McBride]

Hi all,

I know that integer div by 0 is undefined behaviour, but is fp div by zero also undefined?  I've STFW a lot but find conflicting info.

CERT says:

<https://www.securecoding.cert.org/confluence/display/seccode/FLP03-C.+Detect+and+handle+floating+point+errors>

"Floating-point division by zero also results in undefined behavior" but then their "Compliant Solution" example does it anyway and then tests with fetestexcept().

Mind you, building their example also says: "warning: pragma STDC FENV_ACCESS ON is not supported, ignoring pragma".

I'm asking because clang with -ftrapv dies upon fp div by 0.  Is this correct or not?

Thanks,

-- 
____________________________________________________________
Sean McBride, B. Eng                 sean at rogue-research.com
Rogue Research                        www.rogue-research.com 
Mac Software Developer              Montréal, Québec, Canada