Commit Graph

2 Commits

Author SHA1 Message Date
Anna Thomas cace053fb5 [SafepointIRVerifier] Avoid false positives in GC verifier for compare between pointers
Today the safepoint IR verifier catches some unrelocated uses of base
pointers that are actually valid.

With this change, we narrow down the set of false positives.
Specifically, the verifier knows about compares to null and compares
between 2 unrelocated pointers.

Reviewed by: skatkov

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D35057

llvm-svn: 307392
2017-07-07 13:02:29 +00:00
Anna Thomas 740f529dba [SafepointIRVerifier] Add verifier pass for finding GC relocation bugs
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
2017-07-05 01:16:29 +00:00