Determine whether one floating-point number is less than another
Synopsis:
#include <math.h>
#define isless( x, y  ) ...
 
Arguments:
- x, y
 
- The floating-point numbers that you want to compare.
 
 
Library:
- libm
 
- The general-purpose math library.
 
- libm-sve
 
- (QNX Neutrino 7.1 or later)
  A library that optimizes the code for ARMv8.2 chips that have Scalable Vector Extension hardware.
 
Your system requirements will determine how you should work with these libraries:
- If you want only selected processes to run with the SVE version, you can include both libraries in your OS image
  and use the -l m or -l m-sve option to
  qcc
  to link explicitly against the appropriate one.
 
- If you want all processes to use the SVE version, include libm-sve.so in your OS image
  and set up a symbolic link from libm.so to libm-sve.so.
  Use the -l m option to
  qcc
  to link against the library.
 
Note: 
Compile your program with the -fno-builtin option to prevent the compiler from using a
  built-in version of the function.
 
Description:
The isless() macro determines whether x is less than y.
It's the same as (x) < (y) but doesn't raise the
invalid floating-point exception if x and y are unordered.
 
Returns:
The value of (x) < (y).
If x or y is NaN, this function returns 0.
 
Classification:
C11,
POSIX 1003.1
| Safety: | 
  | 
| Cancellation point | 
No | 
| Interrupt handler | 
Yes | 
| Signal handler | 
Yes | 
| Thread | 
Yes |