[TLS] New lower emutls pass, fix linkage bugs.

Previous implementation in http://reviews.llvm.org/D10522
created external references to __emutls_v.* variables.
Such references are inaccurate and cannot be handled by
all linkers, e.g. Android dynamic and gold linkers for aarch64.

Now a new LowerEmuTLS pass to go through all global variables,
and add emutls_v.* and emutls_t.* variables.
These __emutls* variables have the same linkage and
visibility as the associated user defined TLS variable.

Also removed old code that dump __emutls* variables in AsmPrinter.cpp,
and updated TLS unit tests.

Differential Revision: http://reviews.llvm.org/D15300

llvm-svn: 257718

1 files changed, 1 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index c64d882d69a..df0453394e8 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -3057,9 +3057,7 @@ SDValue TargetLowering::LowerToTLSEmulatedModel(const GlobalAddressSDNode *GA,
   Module *VariableModule = const_cast<Module*>(GA->getGlobal()->getParent());
   StringRef EmuTlsVarName(NameString);
   GlobalVariable *EmuTlsVar = VariableModule->getNamedGlobal(EmuTlsVarName);
-  if (!EmuTlsVar)
-    EmuTlsVar = dyn_cast_or_null<GlobalVariable>(
-        VariableModule->getOrInsertGlobal(EmuTlsVarName, VoidPtrType));
+  assert(EmuTlsVar && "Cannot find EmuTlsVar ");
   Entry.Node = DAG.getGlobalAddress(EmuTlsVar, dl, PtrVT);
   Entry.Ty = VoidPtrType;
   Args.push_back(Entry);