[OpenMP] Enable HeapToStack conversion in OpenMPOpt for new RTL globalization…

Authored by jhuber6 on Jun 7 2021, 10:24 AM.


[OpenMP] Enable HeapToStack conversion in OpenMPOpt for new RTL globalization calls

The changes to globalization introduced in D97680 introduce a large amount of overhead by default. The old globalization method would always ignore globalization code if executing in SPMD mode. This wasn't strictly correct as data sharing is still possible in SPMD mode. The new interface is correct but introduces globalization code even when unnecessary. This optimization will use the existing HeapToStack transformation in the attributor to allow for unneeded globalization to be replaced with thread-private stack memory. This is done using the newly introduced library instances for the RTL functions added in D102087.

Depends on D97818

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D102197