SPEC Flag Description for the Clang/Flang Compiler

Sections

Selecting one of the following will take you directly to that section:


Optimization Flags


Portability Flags


Compiler Flags


Shell, Environment, and Other Software Settings

OMP_STACKSIZE
Specify stack size to be allocated for each thread.
OMP_SCHEDULE
For loops running with OpenMP schedule "static", this results in (#iterations/#threads) iterations--rounded to the next lower integer--being allocated to most threads, with at most one additional iteration being allocated to some threads. Although the largest number of iterations assigned to any thread remains the same, this results in a more even sharing of iterations between threads, which may sometimes lead to a performance improvement relative to the default static thread distribution.
OMP_DYNAMIC
OMP_DYNAMIC=[ 1 | 0 ] Enables (1) or disables (0) the dynamic adjustment of the number of threads.
OMP_NESTED
Enables (TRUE) or disables (FALSE) nested parallelism.
OMP_LIBRARY
Selects the OpenMP run-time library.
Set stack size to unlimited
The command "ulimit -s unlimited" is used to set the stack size limit to unlimited.