LAPACK
3.6.1
LAPACK: Linear Algebra PACKage

logical function slaisnan  (  real  SIN1, 
real  SIN2  
) 
SLAISNAN tests input for NaN by comparing two arguments for inequality.
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This routine is not for general use. It exists solely to avoid overoptimization in SISNAN. SLAISNAN checks for NaNs by comparing its two arguments for inequality. NaN is the only floatingpoint 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 wholeprogram optimization may delete this test. The ISNAN functions will be replaced by the correct Fortran 03 intrinsic once the intrinsic is widely available.
[in]  SIN1  SIN1 is REAL 
[in]  SIN2  SIN2 is REAL Two numbers to compare for inequality. 
Definition at line 76 of file slaisnan.f.