Multiple f-flags: joined or last in series?

[Thompson, Matt (GSFC-610.1)[SCIENCE SYSTEMS AND APPLICATIONS INC] via fortran]

Dear gfortran gurus,

A question about flag parsing in gfortran. Namely, in my code's make 
flags I have in my options:

   -ffpe-trap=zero,overflow

What I'm wondering is whether:

   -ffpe-trap=zero -ffpe-trap=overflow

is the same or is the behavior like -O where the last one wins? Same for 
something like:

   -fcheck=all,no-array-temps

I tried reading the gfortran manpage but "multiple" doesn't even appear 
in it. And in the gcc page, some flags seem to add up and some the last 
wins (I note that most of the multiple-allowed are mainly 
linker-focused, so I'm guessing they need to be comma-joined in one flag.)

Thanks,
Matt


-- 
Matt Thompson, SSAI, Sr Scientific Programmer/Analyst
NASA GSFC,    Global Modeling and Assimilation Office
Code 610.1,  8800 Greenbelt Rd,  Greenbelt,  MD 20771
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