HP aC++/HP C A.06.25 Programmer's Guide

The +Oautopar option enables automatic parallelization of loops that are deemed safe
and profitable by the loop transformer.
Usage:
This optimization allows applications to exploit otherwise idle resources on multicore
or multiprocessor systems by automatically transforming serial loops into multithreaded
parallel code. When the +Oautopar option is used at optimization levels +O3 and
above, the compiler automatically parallelizes those loops that are deemed safe and
profitable by the loop transformer.
Automatic parallelization can be combined with manual parallelization through the
use of OpenMP directives and the +Oopenmp option. When both +Oopenmp and
+Oautopar options are specified, then any existing OpenMP directives take precedence,
and the compiler will only consider auto-parallelizing other loops that are not controlled
by those directives.
Programs compiled with the +Oautopar option require the libcps, libomp, and
libpthreads runtime support libraries to be present at both compilation and runtime.
When linking with the HP-UX B.11.61 linker, compiling with the +Oautoparoption
causes them to be automatically included. Older linkers require those libraries to be
specified explicitly or by compiling with +Oopenmp.
The +Oautopar option is supported when compiling C, C++, or Fortran files. Specifying
+Oautopar implies the -mt option.
The default is +Onoautopar, which disables automatic parallelization of loops.
+O[no]report
+O[no]report[=report_type]
The +O[no]report option causes the compiler to display[not to display] various
optimization reports.
Usage:
The value of report_type determines which report is displayed, as described below:
loop
Produces the Loop Report that gives information on optimizations
performed on loops and calls. +Oreport is equivalent to +Oreport=loop.
private
Produces the loop report and privatization table, that provide information
on loop variables that are privatized by the compiler.
all
Produces all reports.
The +Onoreport option does not accept any of the report_type values and turns
off all reporting. The +Oreport[=report_type] option is active only at optimization
levels 3 and above.
The default is +Onoreport.
See Parallel Programming Guide for HP-UX Systems for more information.
Parallel Processing Options 91