The following floating-point exceptions are signalling

Dear fluka experts,

My program terminated unexpectedly,there is a sentence in the .log file “Note: The following floating-point exceptions are signalling: IEEE_UNDERFLOW_FLAG IEEE_DENORMAL”
I will upload my input file,please take a look for me if you have time.

remix.inp (6.0 KB)


Hello Li,

Can you try whether reducing the number of bins in your USRBINs lifts the stop?



Dear Li,

the IEEE_UNDERFLOW_FLAG and IEEE_DENORMAL messages are normal, and can be ignored.

The meaning of the message is explained on Wikipedia:

In a normal floating-point value, there are no leading zeros in the significand; rather, leading zeros are removed by adjusting the exponent (for example, the number 0.0123 would be written as 1.23 × 10−2). Denormal numbers are numbers where this representation would result in an exponent that is below the smallest representable exponent (the exponent usually having a limited range). Such numbers are represented using leading zeros in the significand.

The unexpected STOP of FLUKA is unrelated to these messages.

As @cesc pointed out, and possibly the error message at the end of the .out file suggests, you run out of the memory usable for scoring.


Thanks for your reply,it works.

I run out of the memory usable for scoring with a certain capacity,so should I reduce the number of scoring cards or the number of bins of every scoring cards?

Dear Li,

it is completely up to your needs. At the end what matters is it the total number of bins across all scoring cards.