Original Patch and summary by Philip Reames.
RewriteStatepointsForGC tries to rewrite a function in a manner where
the optimizer can't end up using a pointer value after it might have
been relocated by a safepoint. This pass checks the invariant that
RSForGC is supposed to establish and that (if we constructed semantics
correctly) later passes must preserve.
This has been a really useful diagnostic tool when initially developing
the rewriting scheme and has found numerous bugs.
Differential Revision: https://reviews.llvm.org/D15940
Reviewed by: swaroop.sridhar, mjacob
Subscribers: llvm-commits
llvm-svn: 307112
Anna Thomas