root / src / lapack / double / dlaisnan.f @ 9
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LOGICAL FUNCTION DLAISNAN( DIN1, DIN2 ) |
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* |
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* -- LAPACK auxiliary routine (version 3.2.2) -- |
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* -- LAPACK is a software package provided by Univ. of Tennessee, -- |
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* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
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* June 2010 |
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* |
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* .. Scalar Arguments .. |
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DOUBLE PRECISION DIN1, DIN2 |
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* .. |
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* |
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* Purpose |
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* ======= |
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* |
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* This routine is not for general use. It exists solely to avoid |
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* over-optimization in DISNAN. |
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* |
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* DLAISNAN checks for NaNs by comparing its two arguments for |
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* inequality. NaN is the only floating-point value where NaN != NaN |
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* returns .TRUE. To check for NaNs, pass the same variable as both |
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* arguments. |
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* |
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* A compiler must assume that the two arguments are |
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* not the same variable, and the test will not be optimized away. |
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* Interprocedural or whole-program optimization may delete this |
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* test. The ISNAN functions will be replaced by the correct |
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* Fortran 03 intrinsic once the intrinsic is widely available. |
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* |
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* Arguments |
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* ========= |
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* |
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* DIN1 (input) DOUBLE PRECISION |
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* |
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* DIN2 (input) DOUBLE PRECISION |
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* Two numbers to compare for inequality. |
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* |
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* ===================================================================== |
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* |
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* .. Executable Statements .. |
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DLAISNAN = (DIN1.NE.DIN2) |
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RETURN |
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END |