forked from OSchip/llvm-project
71 lines
1.8 KiB
ReStructuredText
71 lines
1.8 KiB
ReStructuredText
Call may contain unknown parallel regions. Use `__attribute__((assume("omp_no_parallelism")))` to override. [OMP133]
|
|
====================================================================================================================
|
|
|
|
.. _omp133:
|
|
|
|
This analysis remark identifies calls that prevented :ref:`OMP131 <omp131>` from
|
|
providing the generic-mode kernel with a fully specialized state machine. This
|
|
remark will identify each call that may contain unknown parallel regions that
|
|
caused the kernel to require a fallback.
|
|
|
|
Examples
|
|
--------
|
|
|
|
This will occur for any generic-mode kernel that may contain unknown parallel
|
|
regions. This is typically coupled with the :ref:`OMP132 <omp132>` remark.
|
|
|
|
.. code-block:: c++
|
|
|
|
extern void setup();
|
|
|
|
void foo() {
|
|
#pragma omp target
|
|
{
|
|
setup();
|
|
#pragma omp parallel
|
|
{
|
|
work();
|
|
}
|
|
}
|
|
}
|
|
|
|
.. code-block:: console
|
|
|
|
$ clang++ -fopenmp -fopenmp-targets=nvptx64 -O2 -Rpass-analysis=openmp-opt omp133.cpp
|
|
omp133.cpp:6:5: remark: Call may contain unknown parallel regions. Use
|
|
`__attribute__((assume("omp_no_parallelism")))` to override. [OMP133]
|
|
setup();
|
|
^
|
|
|
|
The remark suggests marking the function with the assumption that it contains no
|
|
parallel regions. If this is done then the kernel will be rewritten with a fully
|
|
specialized state machine.
|
|
|
|
.. code-block:: c++
|
|
|
|
__attribute__((assume("omp_no_parallelism"))) extern void setup();
|
|
|
|
|
|
void foo() {
|
|
#pragma omp target
|
|
{
|
|
setup();
|
|
#pragma omp parallel
|
|
{
|
|
work();
|
|
}
|
|
}
|
|
}
|
|
|
|
.. code-block:: console
|
|
|
|
$ clang++ -fopenmp -fopenmp-targets=nvptx64 -O2 -Rpass=openmp-opt omp133.cpp
|
|
omp133.cpp:4:1: remark: Rewriting generic-mode kernel with a customized state machine. [OMP131]
|
|
#pragma omp target
|
|
^
|
|
|
|
Diagnostic Scope
|
|
----------------
|
|
|
|
OpenMP target offloading analysis remark.
|