Guardian Procedure Calls Reference Manual

FP_IEEE_ENV_CLEAR_ Procedure
Summary
Syntax for C Programmers
Syntax for TAL Programmers
Returned Value
Considerations
Examples
Summary
The FP_IEEE_ENV_CLEAR_ procedure sets the floating-point environment (consisting of the rounding
mode, the exception flags, the trap enables, and the denormalization mode) back to its initial
values. The initial values are as follows:
Round to nearest or nearest even valueRounding mode
No exceptions encountered (zeroes)Exception flags
All floating-point traps disabledTrap enables
Denormalized enabledDenormalization
NOTE: This procedure is supported in all J-series and H-series RVUs and in G-series RVUs
beginning with G06.06. IEEE floating-point is available on all NB-Series and NS-Series systems,
and on all S-Series systems, except S70000 servers with NSR-G processors.
Syntax for C Programmers
#include <kpieee.h>
fp_ieee_env FP_IEEE_ENV_CLEAR_ ( void );
Syntax for TAL Programmers
?SOURCE $SYSTEM.SYSTEM.KFPIEEE
savedEnv := FP_IEEE_ENV_CLEAR_;
Returned Value
INT(32)
The current floating-point environment (prior to being cleared), in an internal format. This value
must be passed unmodified to the FP_IEEE_ENV_RESUME_ procedure to undo the effect of the
clear and any intervening FP_IEEE_..._SET_ calls.
Considerations
FP_IEEE_ENV_CLEAR_ and FP_IEEE_ENV_RESUME_ are for use by a process, such as a signal
handler, a clean-up routine, or a procedure that needs to tolerate being called with any possible
values in the floating-point status and control. They are not for use by interrupt handlers.
FP_IEEE_ENV_CLEAR_ Procedure 643