[StripGCRelocates] New pass to remove gc.relocates added by RS4GC

Summary:
Utility pass to remove gc.relocates created by rewrite statepoints for GC.
With respect to safepoint verification, the IR generated would be incorrect, and cannot run
as such.

This would be a single transformation on the final optimized IR.
The benefit of the pass is for easy analysis when the IRs are 'polluted' by too
many gc.relocates.
Added tests.

test run: All RS4GC tests with -verify option. Local downstream tests on large
IR files. This also works when the pointer being gc.relocated is another
gc.relocate.

Reviewers: sanjoy, reames

Subscribers: beanz, mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D25096

llvm-svn: 284855

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Utils/Utils.cpp b/llvm/lib/Transforms/Utils/Utils.cpp
index 8dc9c35..cfd8551 100644
--- a/llvm/lib/Transforms/Utils/Utils.cpp
+++ b/llvm/lib/Transforms/Utils/Utils.cpp
@@ -36,6 +36,7 @@ void llvm::initializeTransformUtils(PassRegistry &Registry) {
   initializeMetaRenamerPass(Registry);
   initializeMemorySSAWrapperPassPass(Registry);
   initializeMemorySSAPrinterLegacyPassPass(Registry);
+  initializeStripGCRelocatesPass(Registry);
 }
 
 /// LLVMInitializeTransformUtils - C binding for initializeTransformUtilsPasses.