Math Library (libm)

Summary of Change

The HP-UX 11i v1.6 introduces new functions in the HP-UX namespace:

Details of Change

The reciprocal square root functions provide a combined square root and divide, which is common in some important performance critical applications, with about the execution time of a square root alone.The integer-exponent power functions provide a direct C translation of the Fortran real integer operations, and achieve better performance in some cases than the standard C pow functions.Users may call the new functions if they wish, but are not otherwise required to take any action. (See Compatibility below.)

Impact

No impact.

Compatibility

The names of the new functions expand the HP-UX namespace:

and further with the -fpwidetypes option:

If these names have been for other purposes, the pertinent code may need to be altered.

Declarations of the integer-exponent power functions, with names prefixed with an underscore, appeared in the HP-UX 11i v1.5 math.h header, though were not documented in the manpages. The underscore-prefix names are retained in the HP-UX 11i v1.6 math.h header (and the entry points are still in libm.a).

Performance

There is no impact to performance.

Obsolescence

Not applicable.

Documentation

The new rsqrt(3M) manpage describes the reciprocal square root functions.

The pow(3M) manpage is augmented to cover the integer-exponent power functions.The new functions are mentioned in the math library white paper, which is updated for HP-UX 11i v1.6 and can be found at:

http://docs.hp.com