[PATCH] [og10] libgomp, Fortran: Fix OpenACC "gang reduction on an orphan loop" error message

[Frederik Harwath]

Hi,
This patch fixes the check for reductions on orphaned gang loops in
the Fortran frontend which (in contrast to the C, C++ frontends)
erroneously rejects reductions on gang loops that are contained in
"kernels" constructs and which hence are not orphaned.

According to the OpenACC standard version 2.5 and later, reductions on
orphaned gang loops are explicitly disallowed (cf.  section "Changes
from Version 2.0 to 2.5").  Remember that a loop is "orphaned" if it is
not lexically contained in a compute construct (cf. section "Loop
construct" of the OpenACC standard), i.e. in either a "parallel", a
"serial", or a "kernels" construct.

The patch has been tested by running the GCC and libgomp testsuites.
The latter tests ran with offloading to nvptx although that should not
be important here unless there was some very subtle reason for
forbidding the gang reductions on kernels loops. As expect, there seems
to be no such reason, i.e. I observed no regressions with the patch.

Can I include the patch in OG10?

Best regards,
Frederik

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