.TH "dlaisnan.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME dlaisnan.f \- .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "logical function \fBdlaisnan\fP (DIN1, DIN2)" .br .RI "\fI\fBDLAISNAN\fP tests input for NaN by comparing two arguments for inequality\&. \fP" .in -1c .SH "Function/Subroutine Documentation" .PP .SS "logical function dlaisnan (double precisionDIN1, double precisionDIN2)" .PP \fBDLAISNAN\fP tests input for NaN by comparing two arguments for inequality\&. .PP \fBPurpose: \fP .RS 4 .PP .nf This routine is not for general use. It exists solely to avoid over-optimization in DISNAN. DLAISNAN checks for NaNs by comparing its two arguments for inequality. NaN is the only floating-point value where NaN != NaN returns .TRUE. To check for NaNs, pass the same variable as both arguments. A compiler must assume that the two arguments are not the same variable, and the test will not be optimized away. Interprocedural or whole-program optimization may delete this test. The ISNAN functions will be replaced by the correct Fortran 03 intrinsic once the intrinsic is widely available. .fi .PP .RE .PP \fBParameters:\fP .RS 4 \fIDIN1\fP .PP .nf DIN1 is DOUBLE PRECISION .fi .PP .br \fIDIN2\fP .PP .nf DIN2 is DOUBLE PRECISION Two numbers to compare for inequality. .fi .PP .RE .PP \fBAuthor:\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP \fBDate:\fP .RS 4 September 2012 .RE .PP .PP Definition at line 75 of file dlaisnan\&.f\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.