[OpenMP] Encode offload target triples into comdat key for offload initialization code

Encoding offload target triples onto comdat group key for offload initialization
code guarantees that it will be executed once per each unique combination of
offload targets.

Differential Revision: https://reviews.llvm.org/D50218

llvm-svn: 338916

1 files changed, 13 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index fa850155df4..4d9f495c16e 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -3818,7 +3818,19 @@ CGOpenMPRuntime::createOffloadingBinaryDescriptorRegistration() {
     CGF.disableDebugInfo();
     const auto &FI = CGM.getTypes().arrangeNullaryFunction();
     llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(FI);
-    std::string Descriptor = getName({"omp_offloading", "descriptor_reg"});
+
+    // Encode offload target triples into the registration function name. It
+    // will serve as a comdat key for the registration/unregistration code for
+    // this particular combination of offloading targets.
+    SmallVector<StringRef, 4U> RegFnNameParts(Devices.size() + 2U);
+    RegFnNameParts[0] = "omp_offloading";
+    RegFnNameParts[1] = "descriptor_reg";
+    llvm::transform(Devices, std::next(RegFnNameParts.begin(), 2),
+                    [](const llvm::Triple &T) -> const std::string& {
+                      return T.getTriple();
+                    });
+    llvm::sort(std::next(RegFnNameParts.begin(), 2), RegFnNameParts.end());
+    std::string Descriptor = getName(RegFnNameParts);
     RegFn = CGM.CreateGlobalInitOrDestructFunction(FTy, Descriptor, FI);
     CGF.StartFunction(GlobalDecl(), C.VoidTy, RegFn, FI, FunctionArgList());
     CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__tgt_register_lib), Desc);