filter unwated cflags? (-ffast-math)

[Bernd Buschinski]

hi, 

I am not sure how do deal with unwanted cflags(cxxflags), so I ask here :)

For kjs for example -ffast-math is known to cause problems, as we stricly rely 
on IEEE compatible floating point, NaN, Inf, signed Zero and all the stuff.

So the question should I filter them? or leave it to the user to 
optimize(break) his system?

If you say yes to filter, it also involves
-fno-math-errno
-funsafe-math-optimizations
-ffinite-math-only
-fno-rounding-math
-fno-signaling-nans
-fcx-limited-range
and I have no clue if there are msvc (or other compiler) versions of them.

If you are against filter, how should I deal with bugreport caused by XYZ 
cflag?