LOGICAL FUNCTION SLAISNAN(SIN1,SIN2) * * -- LAPACK auxiliary routine (version 3.1) -- * Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. * November 2006 * * .. Scalar Arguments .. REAL 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. * * Strictly speaking, Fortran does not allow aliasing of function * arguments. So 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) REAL * SIN2 (input) REAL * Two numbers to compare for inequality. * * ===================================================================== * * .. Executable Statements .. SLAISNAN = (SIN1.NE.SIN2) RETURN END