C++ User's Guide

Warnings

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

Use the -ftrap=inexact trap with caution. Use of -ftrap=inexact results in the trap being issued whenever a floating-point value cannot be represented exactly. For example, the following statement generates this condition:

x = 1.0 / 3.0;

This option is effective only if used when compiling the main program. Be cautious when using this option. If you wish to enable the IEEE traps, use -ftrap=common.