+O[no]rotating_fpregs

+O[no]rotating_fpregs

The +O[no]rotating_fpregs option specifies whether the compiler is allowed [not allowed] to make use of the rotating subset of the floating-point register file.

The default is +Orotating_fpregs.

+O[no]sumreduction

+O[no]sumreduction

This option enables [disables] sum reduction optimization. It allows the compiler to compute partial sums to allow faster computations. It is not technically legal to do this in C or C++ because of floating-point accuracy issues. This option is useful if an application cannot use the +Onofltacc option but wants sum reduction to be performed.

When sum reduction optimization is enabled, the compiler may evaluate intermediate partial sums of float or double precision terms using (wider) extended precision, which reduces variation in the result caused by different optimization strategies and generally produces a more accurate result.

Header File Options

Following are the command-line options you can use for header files:

-H

cc -H file

The -Hoption causes HP aC++/HP C to print the order and hierarchy of included files. The -Hoption dumps the include heirarchy to stderr so that the preprocessed compiler output indicates the include file nesting.

+hdr_create

aCC progname -c +hdr_create headername

This option extracts the header from a program file and saves it as a precompiled header file.

Example:

aCC ApplicTemplate.C -c +hdr_create ApplicHeader

+hdr_use

aCC progname +hdr_use headerfile -c

This option adds a precompiled header file to a program when the program is compiled.

Example:

aCC Applic.C +hdr_use ApplicHeader -c

-I directory

-Idirectory

directory is the HP-UX directory where the compiler looks for header files.

During the compile phase, this option adds directory to the directories to be searched for #include files during preprocessing. During the link phase, this option adds directory to the directories to be searched for #include files by the link-time template processor.

For #include files that are enclosed in double quotes (" ") within a source file and do not begin with a /, the preprocessor searches in the following order:

Header File Options 45