Some IBM pSeries(TM) machines are capable of shared-memory parallel processing. You can compile with -qsmp to generate the threaded code needed to exploit this capability. The option implies an optimization level of at least -O2.
The following table lists the most commonly used suboptions. Descriptions and syntax of all the suboptions are provided in XL C/C++ Compiler Reference.
Table 11. Commonly used -qsmp suboptions
suboption | Behavior |
---|---|
auto | Instructs the compiler to automatically generate parallel code where possible without user assistance. This is the default setting if you do not specify any -qsmp suboptions, and it also implies the opt suboption. |
omp | Instructs the compiler to observe OpenMP language extensions for specifying explicit parallelism. Note that -qsmp=omp is currently incompatible with -qsmp=auto. |
opt | Instructs the compiler to optimize as well as parallelize. The optimization is equivalent to -O2 -qhot in the absence of other optimization options. |
fine_tuning | Other values for the suboption provide control over thread scheduling, nested parallelism, locking, etc. |
Here are some suggestions for using the -qsmp option: