SLAISNAN(3) LAPACK routine of NEC Numeric Library Collection SLAISNAN(3) NAME SLAISNAN SYNOPSIS LOGICAL FUNCTION SLAISNAN (SIN1, SIN2) PURPOSE This routine is not for general use. It exists solely to avoid over-optimization in SISNAN. SLAISNAN 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. ARGUMENTS SIN1 (input) SIN1 is REAL SIN2 (input) SIN2 is REAL Two numbers to compare for inequality. LAPACK routine 31 October 2017 SLAISNAN(3)