Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (F)
Guardian Procedure Calls Reference Manual—522629-013
5-255
FP_IEEE_ENABLES_GET_ Procedure
Considerations
•
A constant named FP_IEEE_ALL_ENABLES is equivalent to a combination of the
mask bits to enable traps for all the exceptions.
•
In some cases, the conditions that cause a trap are slightly different from the
conditions that cause the corresponding exception flag to be set.
•
When a trap happens, a SIGFPE signal is raised, and the corresponding signal
handler is called. The
SIGFPE signal handler typically does a function frame trace
showing the point of failure, and then abends the process. The
SIGFPE signal is
not allowed to return to the point where the trap happened.
•
Trap handling is an optional part of the IEEE floating-point standard. See
FP_IEEE_EXCEPTIONS_GET_ Procedure
on page 5-261 and
FP_IEEE_EXCEPTIONS_SET_ Procedure
on page 5-264 for an alternative to
using traps.
•
The compiler optimizer might reorder operations within a local routine and cause
different results from the FP_ IEEE status procedures than intended. To work
around this, place arithmetic operations in a separate function. The compiler
cannot optimize across function boundaries, so the FP_IEEE status procedure will
be called in the intended order.