Intel® Fortran Libraries Reference

2 Intel Fortran Libraries ReferenceThe defaults for the floating-point control word are 53-bit precision, round to nearest, and thedenormal, underflow and inexact precision exceptions disabled. An exception is disabled if its flagis set to 1 and enabled if its flag is cleared to 0. Exceptions can be disabled by setting the flags to 1with SETCONTROLFPQQ.If an exception is disabled, it does not cause an interrupt when it occurs. Instead, floating-pointprocesses generate an appropriate special value (NaN or signed infinity), but the programcontinues.You can find out which exceptions (if any) occurred by calling GETSTATUSFPQQ. If errors onfloating-point exceptions are enabled (by clearing the flags to 0 with SETCONTROLFPQQ), theoperating system generates an interrupt when the exception occurs. By default, these interruptscause run-time errors, but you can capture the interrupts with SIGNALQQ and branch to your ownerror-handling routines.You can use GETCONTROLFPQQ to retrieve the current control word andSETCONTROLFPQQ to change the control word. Most users do not need to change the defaultsettings. For a full discussion of the floating-point control word, exceptions, and error handling,see "The Floating-Point Environment" in your user’s guide.CompatibilityCONSOLE STANDARD GRAPHICS QUICKWIN GRAPHICS WINDOWS LIBSee Also: “SETCONTROLFPQQ”, “GETSTATUSFPQQ”, “SIGNALQQ”,“CLEARSTATUSFPQQ”ExampleUSE IFPORTINTEGER(2) controlCALL GETCONTROLFPQQ (control)!if not rounding downIF (IAND(control, FPCW$DOWN) .NE. FPCW$DOWN) THENcontrol = IAND(control, NOT(FPCW$MCW_RC)) ! clear all! roundingcontrol = IOR(control, FPCW$DOWN)! set to! round downCALL SETCONTROLFPQQ(control)END IFEND2-108