LAPACK
3.6.1
LAPACK: Linear Algebra PACKage
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logical function dlaisnan | ( | double precision | DIN1, |
double precision | DIN2 | ||
) |
DLAISNAN tests input for NaN by comparing two arguments for inequality.
Download DLAISNAN + dependencies [TGZ] [ZIP] [TXT]
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.
[in] | DIN1 | DIN1 is DOUBLE PRECISION |
[in] | DIN2 | DIN2 is DOUBLE PRECISION Two numbers to compare for inequality. |
Definition at line 76 of file dlaisnan.f.