XL Fortran Enterprise Edition for AIX : User's Guide - IBM

Rules
v If you specify -qsmp more than once, the previous settings of all suboptions are
preserved, unless overridden by the subsequent suboption setting. The compiler
does not override previous suboptions that you specify. The same is true for the
version of -qsmp without suboptions; the default options are saved.
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Specifying the omp suboption always implies noauto, unless you specify -qsmp
or -qsmp=auto on the command line.
Specifying the noomp suboption always implies auto.
The omp and noomp suboptions only appear in the compiler listing if you
explicitly set them.
If -qsmp is specified without any suboptions, -qsmp=opt becomes the default
setting. If -qsmp is specified after the -qsmp=noopt suboption has been set, the
-qsmp=noopt setting will always be ignored.
If the option -qsmp with no suboptions follows the suboption-qsmp=noopt on a
command line, the -qsmp=opt and -qsmp=auto options are enabled.
Specifying the -qsmp=noopt suboption implies that -qsmp=noauto. It also
implies -qnoopt. This option overrides performance options such as -O2, -O3,
-qhot, anywhere on the command line unless -qsmp appears after -qsmp=noopt.
Object files generated with the -qsmp=opt option can be linked with object files
generated with -qsmp=noopt. The visibility within the debugger of the variables
in each object file will not be affected by linking.
Restrictions
The -qsmp=noopt suboption may affect the performance of the program.
Within the same -qsmp specification, you cannot specify the omp suboption before
or after certain suboptions. The compiler issues warning messages if you attempt
to specify them with omp:
auto
This suboption controls automatic parallelization, but omp turns off
automatic parallelization.
nested_par
Note that the implementation of the nested_par suboption does not
comply with the OpenMP Fortran API. If you specify this suboption, the
run-time library uses the same threads for the nested PARALLEL DO and
PARALLEL SECTIONS constructs that it used for the enclosing
PARALLEL constructs.
rec_locks
This suboption specifies a behaviour for CRITICAL constructs that is
inconsistent with the OpenMP Fortran API.
schedule=affinity=n
The affinity scheduling type does not appear in the OpenMP Fortran API
standard.
Examples
The -qsmp=noopt suboption overrides performance optimization options
anywhere on the command line unless -qsmp appears after -qsmp=noopt. The
following examples illustrate that all optimization options that appear after
-qsmp=noopt are processed according to the normal rules of scope and
precedence.
Example 1
XL Fortran Compiler-Option Reference 237