Intel® Fortran Libraries Reference

Descriptions of the Library Routines 2Parameter name Hex value DescriptionFPCW$CHOP Z'0C00' TruncateFPCW$UP Z'0800' Round upFPCW$DOWN Z'0400' Round downFPCW$NEAR Z'0000' Round to nearestFPCW$MCW_EM Z'003F' Exception maskFPCW$INVALID Z'0001' Allow invalid numbersFPCW$DENORMAL Z'0002' Allow denormals (very small numbers)FPCW$ZERODIVIDE Z'0004' Allow divide by zeroFPCW$OVERFLOW Z'0008' Allow overflowFPCW$UNDERFLOW Z'0010' Allow underflowFPCW$INEXACT Z'0020' Allow inexact precisionThe 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.Setting the floating-point precision and rounding mechanism can be useful if you are reusing oldcode that is sensitive to the floating-point precision standard used and you want to get the sameresults as on the old machine.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. If you need to change the control word, always use SETCONTROLFPQQ to make surethat special routines handling floating-point stack exceptions and abnormal propagation workcorrectly.For a full discussion of the floating-point control word, exceptions, and error handling, see "TheFloating-Point Environment" in your user’s guide.NOTE. The Intel® Visual Fortran exception handler allows for softwaremasking of invalid operations, but does not allow the math chip to mask them.If you choose to use the software masking, be aware that this can affectprogram performance if you compile code written for Visual Fortran withanother compiler.CompatibilityCONSOLE STANDARD GRAPHICS QUICKWIN GRAPHICS WINDOWS DLL LIB2-395