SLAISNAN(3) MathKeisan LAPACK routine SLAISNAN(3)
NAME
SLAISNAN - i not for general use
SYNOPSIS
LOGICAL FUNCTION SLAISNAN(SIN1,SIN2)
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 X != X returns .TRUE. To
check for NaNs, pass the same variable as both arguments.
Strictly speaking, Fortran does not allow aliasing of function argu-
ments. So a compiler must assume that the two arguments are not the
same variable, and the test will not be optimized away. Interprocedu-
ral 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.
LAPACK auxiliary routine (versionNo3v.e1m)ber 2006 SLAISNAN(3)