Move the TLSModel information into the TargetMachine rather than hiding
in TargetLowering. There was already a FIXME about this location being
odd. The interface is simplified as a consequence. This will also make
it easier to change TLS models when compiling with PIE.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154292 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/TargetMachine.cpp b/lib/Target/TargetMachine.cpp
index 6eae385..b8e7f15 100644
--- a/lib/Target/TargetMachine.cpp
+++ b/lib/Target/TargetMachine.cpp
@@ -11,6 +11,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/GlobalValue.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCCodeGenInfo.h"
 #include "llvm/Target/TargetMachine.h"
@@ -74,6 +75,26 @@
   return CodeGenInfo->getCodeModel();
 }
 
+TLSModel::Model TargetMachine::getTLSModel(const GlobalValue *GV) const {
+  bool isLocal = GV->hasLocalLinkage();
+  bool isDeclaration = GV->isDeclaration();
+  // FIXME: what should we do for protected and internal visibility?
+  // For variables, is internal different from hidden?
+  bool isHidden = GV->hasHiddenVisibility();
+
+  if (getRelocationModel() == Reloc::PIC_) {
+    if (isLocal || isHidden)
+      return TLSModel::LocalDynamic;
+    else
+      return TLSModel::GeneralDynamic;
+  } else {
+    if (!isDeclaration || isHidden)
+      return TLSModel::LocalExec;
+    else
+      return TLSModel::InitialExec;
+  }
+}
+
 /// getOptLevel - Returns the optimization level: None, Less,
 /// Default, or Aggressive.
 CodeGenOpt::Level TargetMachine::getOptLevel() const {