Hi Nathan! Merging back your trunk r230169 into gomp-4_0-branch, for the new libgomp/testsuite/libgomp.oacc-c-c++-common/firstprivate-2.c test, I'm seeing the compiler diagnose as follows (compile with "-Wall -O2"): source-gcc/libgomp/testsuite/libgomp.oacc-c-c++-common/firstprivate-2.c: In function 'main._omp_fn.1': source-gcc/libgomp/testsuite/libgomp.oacc-c-c++-common/firstprivate-2.c:20:17: warning: 'val' is used uninitialized in this function [-Wuninitialized] ok = val == 7; ^ source-gcc/libgomp/testsuite/libgomp.oacc-c-c++-common/firstprivate-2.c:9:7: note: 'val' was declared here int val = 2; ^ ..., and execution fails ("return 1" from main), so I XFAILed the execution in the merge commit r230214 on gomp-4_0-branch. (..., and I still think that it's a good idea to change the libgomp testsuite to run with -Wall enabled...) Do you have an idea what's going on? Given your preparatory "[gomp4] Rework gimplifyier region flags", (thanks!), the merge commit r230214 on gomp-4_0-branch didn't contain any changes to gcc/gimplify.c, so that can't be it. It also can't be the possibly inconsistent usage of gcc/omp-low.c:is_reference vs. "TREE_CODE (TREE_TYPE ([...])) == REFERENCE_TYPE" in gcc/omp-low.c, because that doesn't matter for C code anyway (no artificial REFERENCE_TYPEs generated), right? So it must be some other change installed on gomp-4_0-branch but not on trunk. Grüße Thomas