Floating Point Exceptions

• A fp status register flag is set when fpu is has an illegal condition:

  • division by zero
  • overflow
  • underflow
  • invalid
  • inexact

• By default, all exceptions are ignored!

• (e.g. for 1/0 NaN value is set and execution continues)

• The status register can be programmed to raise a Floating Point Exception.

• If an FPE occurs, the system can take a specified action:

  • abort
  • ignore the exception
  • repair the illegal condition

• You can manipulate the status register to select action:

  • with calls to the FPE library, link with -lfpe
  • with environment variable TRAP_FPE

• see man handle_sigfpes

Previous slide

Next slide

Back to first slide

View graphic version