-ftrap=t

Sets the IEEE 754 trapping mode in effect at startup.

t is a comma-separated list that consists of one or more of the following: %all, %none, common, [no%]invalid, [no%]overflow, [no%]underflow, [no%]division, [no%]inexact.

The default is -ftrap=%none.

This option sets the IEEE 754 trapping modes that are established at program initialization. Processing is left-to-right. The common exceptions, by definition, are invalid, division by zero, and overflow.

Example: -ftrap=%all,no%inexact means set all traps, except inexact.

The meanings are the same as for the ieee_flags subroutine, except that:

• %all turns on all the trapping modes.

• %none, the default, turns off all trapping modes.

• A no% prefix turns off that specific trapping mode.

If you compile one routine with -ftrap=t, compile all routines of the program with the same -ftrap=t option; otherwise, you can get unexpected results.