[OpenMP] Create COMDAT group for OpenMP offload registration code to avoid multiple copies
Thanks to Sergey Dmitriev for submitting the patch.
Differential Revision: https://reviews.llvm.org/D33509
llvm-svn: 304056
diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index 601d662..0644d1b 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -2903,6 +2903,19 @@
Desc);
CGM.getCXXABI().registerGlobalDtor(CGF, RegUnregVar, UnRegFn, Desc);
});
+ if (CGM.supportsCOMDAT()) {
+ // It is sufficient to call registration function only once, so create a
+ // COMDAT group for registration/unregistration functions and associated
+ // data. That would reduce startup time and code size. Registration
+ // function serves as a COMDAT group key.
+ auto ComdatKey = M.getOrInsertComdat(RegFn->getName());
+ RegFn->setLinkage(llvm::GlobalValue::LinkOnceAnyLinkage);
+ RegFn->setVisibility(llvm::GlobalValue::HiddenVisibility);
+ RegFn->setComdat(ComdatKey);
+ UnRegFn->setComdat(ComdatKey);
+ DeviceImages->setComdat(ComdatKey);
+ Desc->setComdat(ComdatKey);
+ }
return RegFn;
}