On February 10, 2025, Sandra Loosemore wrote:
The "begin declare variant" has different rules for determining
whether a context selector cannot match for purposes of code elision
than we normally use; it excludes the case of a constant false
"condition" selector for the "user" set.
Namely: "If the context selector of a begin declare_variant
directive contains traits in the 'device' or 'implementation' set
that are known never to be compatible with an OpenMP context
... the preprocessed code ... is elided."
[Which in turn means that 'target_device', 'user' and 'construct'
won't be elided. Construct depends on the call side and cannot
be elided, the others sometimes could. In particular, if the
condition expression is a constant expression/constexpr evaluating
to false, it could. Why it has been excluded is unclear, given that
it can be useful at times. But as it has, let's honor it.]
gcc/ChangeLog
* omp-general.cc (omp_context_selector_matches): Add an optional
bool argument for the code elision case.
* omp-general.h (omp_context_selector_matches): Likewise.
LGTM.
Thanks,
Tobias
