llvm-project/openmp/docs/remarks/OMP140.rst

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.. _omp140:
Could not internalize function. Some optimizations may not be possible. [OMP140]
====================================================================================================================
This analysis remark indicates that function internalization failed for the
given function. Internalization occurs when a call to a function that ordinarily
has external visibility is replaced with a call to a copy of that function with
only internal visibility. This allows the compiler to make strong static
assertions about the context a function is called in. Without internalization
this analysis would always be invalidated by the possibility of someone calling
the function in a different context outside of the current translation unit.
This is necessary for optimizations like :ref:`OMP111 <omp111>` and :ref:`OMP120
<omp120>`. If a function failed to be internalized it most likely has linkage
that cannot be copied. Internalization is currently only enabled by default for
OpenMP target offloading.
Examples
--------
This will occur for any function declaration that has incompatible linkage.
.. code-block:: c++
__attribute__((weak)) void setup();
void foo() {
#pragma omp target
{
setup();
#pragma omp parallel
{
work();
}
}
}
.. code-block:: console
$ clang++ -fopenmp -fopenmp-targets=nvptx64 -O1 -Rpass-analysis=openmp-opt omp140.cpp
omp140.cpp:1:1: remark: Could not internalize function. Some optimizations may not
be possible. [OMP140]
__attribute__((weak)) void setup() {
^
Diagnostic Scope
----------------
OpenMP analysis remark.