Implement target independent TLS compatible with glibc's emutls.c.

The 'common' section TLS is not implemented.
Current C/C++ TLS variables are not placed in common section.
DWARF debug info to get the address of TLS variables is not generated yet.

clang and driver changes in http://reviews.llvm.org/D10524

  Added -femulated-tls flag to select the emulated TLS model,
  which will be used for old targets like Android that do not
  support ELF TLS models.

Added TargetLowering::LowerToTLSEmulatedModel as a target-independent
function to convert a SDNode of TLS variable address to a function call
to __emutls_get_address.

Added into lib/Target/*/*ISelLowering.cpp to call LowerToTLSEmulatedModel
for TLSModel::Emulated. Although all targets supporting ELF TLS models are
enhanced, emulated TLS model has been tested only for Android ELF targets.
Modified AsmPrinter.cpp to print the emutls_v.* and emutls_t.* variables for
emulated TLS variables.
Modified DwarfCompileUnit.cpp to skip some DIE for emulated TLS variabls.

TODO: Add proper DIE for emulated TLS variables.
      Added new unit tests with emulated TLS.

Differential Revision: http://reviews.llvm.org/D10522

llvm-svn: 243438

7 files changed, 19 insertions, 0 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index d42f26f1b7b..be8696b25a9 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -3404,6 +3404,10 @@ AArch64TargetLowering::LowerELFGlobalTLSAddress(SDValue Op,
   const GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
 
   TLSModel::Model Model = getTargetMachine().getTLSModel(GA->getGlobal());
+
+  if (DAG.getTarget().Options.EmulatedTLS)
+    return LowerToTLSEmulatedModel(GA, DAG);
+
   if (!EnableAArch64ELFLocalDynamicTLSGeneration) {
     if (Model == TLSModel::LocalDynamic)
       Model = TLSModel::GeneralDynamic;
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index afc6ee8ad0e..e01d26a67d8 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -2583,6 +2583,8 @@ ARMTargetLowering::LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const {
   assert(Subtarget->isTargetELF() &&
          "TLS not implemented for non-ELF targets");
   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
+  if (DAG.getTarget().Options.EmulatedTLS)
+    return LowerToTLSEmulatedModel(GA, DAG);
 
   TLSModel::Model model = getTargetMachine().getTLSModel(GA->getGlobal());
 
diff --git a/llvm/lib/Target/Mips/MipsISelLowering.cpp b/llvm/lib/Target/Mips/MipsISelLowering.cpp
index fc886be8aec..f40cf0d0338 100644
--- a/llvm/lib/Target/Mips/MipsISelLowering.cpp
+++ b/llvm/lib/Target/Mips/MipsISelLowering.cpp
@@ -1723,6 +1723,9 @@ lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const
   // Local Exec TLS Model.
 
   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
+  if (DAG.getTarget().Options.EmulatedTLS)
+    return LowerToTLSEmulatedModel(GA, DAG);
+
   SDLoc DL(GA);
   const GlobalValue *GV = GA->getGlobal();
   EVT PtrVT = getPointerTy(DAG.getDataLayout());
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index c56f72525e7..ea5a663a5a1 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -2085,6 +2085,9 @@ SDValue PPCTargetLowering::LowerGlobalTLSAddress(SDValue Op,
   // large models could be added if users need it, at the cost of
   // additional complexity.
   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
+  if (DAG.getTarget().Options.EmulatedTLS)
+    return LowerToTLSEmulatedModel(GA, DAG);
+
   SDLoc dl(GA);
   const GlobalValue *GV = GA->getGlobal();
   EVT PtrVT = getPointerTy(DAG.getDataLayout());
diff --git a/llvm/lib/Target/Sparc/SparcISelLowering.cpp b/llvm/lib/Target/Sparc/SparcISelLowering.cpp
index 67918a7c319..c7c5d27dab6 100644
--- a/llvm/lib/Target/Sparc/SparcISelLowering.cpp
+++ b/llvm/lib/Target/Sparc/SparcISelLowering.cpp
@@ -1872,6 +1872,9 @@ SDValue SparcTargetLowering::LowerGlobalTLSAddress(SDValue Op,
                                                    SelectionDAG &DAG) const {
 
   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
+  if (DAG.getTarget().Options.EmulatedTLS)
+    return LowerToTLSEmulatedModel(GA, DAG);
+
   SDLoc DL(GA);
   const GlobalValue *GV = GA->getGlobal();
   EVT PtrVT = getPointerTy(DAG.getDataLayout());
diff --git a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
index 3c5d185ffe8..dfe42345173 100644
--- a/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
@@ -2485,6 +2485,8 @@ SDValue SystemZTargetLowering::lowerTLSGetOffset(GlobalAddressSDNode *Node,
 
 SDValue SystemZTargetLowering::lowerGlobalTLSAddress(GlobalAddressSDNode *Node,
 						     SelectionDAG &DAG) const {
+  if (DAG.getTarget().Options.EmulatedTLS)
+    return LowerToTLSEmulatedModel(Node, DAG);
   SDLoc DL(Node);
   const GlobalValue *GV = Node->getGlobal();
   EVT PtrVT = getPointerTy(DAG.getDataLayout());
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index b3672c3216d..a99cc206451 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -11645,6 +11645,8 @@ X86TargetLowering::LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const {
   auto PtrVT = getPointerTy(DAG.getDataLayout());
 
   if (Subtarget->isTargetELF()) {
+    if (DAG.getTarget().Options.EmulatedTLS)
+      return LowerToTLSEmulatedModel(GA, DAG);
     TLSModel::Model model = DAG.getTarget().getTLSModel(GV);
     switch (model) {
       case TLSModel::GeneralDynamic: