[PowerPC] Add secure plt support for TLS symbols

This patch supports secure plt mode for TLS symbols.

Differential Revision: https://reviews.llvm.org/D45520

llvm-svn: 355513

3 files changed, 34 insertions, 6 deletions

diff --git a/llvm/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp b/llvm/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
index 77206494990..251385e95f3 100644
--- a/llvm/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
@@ -444,13 +444,22 @@ void PPCInstPrinter::printTLSCall(const MCInst *MI, unsigned OpNo,
   // On PPC64, VariantKind is VK_None, but on PPC32, it's VK_PLT, and it must
   // come at the _end_ of the expression.
   const MCOperand &Op = MI->getOperand(OpNo);
-  const MCSymbolRefExpr &refExp = cast<MCSymbolRefExpr>(*Op.getExpr());
-  O << refExp.getSymbol().getName();
+  const MCSymbolRefExpr *RefExp = nullptr;
+  const MCConstantExpr *ConstExp = nullptr;
+  if (const MCBinaryExpr *BinExpr = dyn_cast<MCBinaryExpr>(Op.getExpr())) {
+    RefExp = cast<MCSymbolRefExpr>(BinExpr->getLHS());
+    ConstExp = cast<MCConstantExpr>(BinExpr->getRHS());
+  } else
+    RefExp = cast<MCSymbolRefExpr>(Op.getExpr());
+
+  O << RefExp->getSymbol().getName();
   O << '(';
   printOperand(MI, OpNo+1, O);
   O << ')';
-  if (refExp.getKind() != MCSymbolRefExpr::VK_None)
-    O << '@' << MCSymbolRefExpr::getVariantKindName(refExp.getKind());
+  if (RefExp->getKind() != MCSymbolRefExpr::VK_None)
+    O << '@' << MCSymbolRefExpr::getVariantKindName(RefExp->getKind());
+  if (ConstExp != nullptr)
+    O << '+' << ConstExp->getValue();
 }
 
 /// showRegistersWithPercentPrefix - Check if this register name should be
diff --git a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
index f4ef95caebd..a8d4303939a 100644
--- a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -472,8 +472,14 @@ void PPCAsmPrinter::EmitTlsCall(const MachineInstr *MI,
   if (!Subtarget->isPPC64() && !Subtarget->isDarwin() &&
       isPositionIndependent())
     Kind = MCSymbolRefExpr::VK_PLT;
-  const MCSymbolRefExpr *TlsRef =
+  const MCExpr *TlsRef =
     MCSymbolRefExpr::create(TlsGetAddr, Kind, OutContext);
+
+  // Add 32768 offset to the symbol so we follow up the latest GOT/PLT ABI.
+  if (Kind == MCSymbolRefExpr::VK_PLT && Subtarget->isSecurePlt())
+    TlsRef = MCBinaryExpr::createAdd(TlsRef,
+                                     MCConstantExpr::create(32768, OutContext),
+                                     OutContext);
   const MachineOperand &MO = MI->getOperand(2);
   const GlobalValue *GValue = MO.getGlobal();
   MCSymbol *MOSymbol = getSymbol(GValue);
diff --git a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
index 08a5003e697..196a98aea0c 100644
--- a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
@@ -4353,7 +4353,20 @@ void PPCDAGToDAGISel::Select(SDNode *N) {
     if (trySETCC(N))
       return;
     break;
-
+  // These nodes will be transformed into GETtlsADDR32 node, which
+  // later becomes BL_TLS __tls_get_addr(sym at tlsgd)@PLT
+  case PPCISD::ADDI_TLSLD_L_ADDR:
+  case PPCISD::ADDI_TLSGD_L_ADDR: {
+    const Module *Mod = MF->getFunction().getParent();
+    if (PPCLowering->getPointerTy(CurDAG->getDataLayout()) != MVT::i32 ||
+        !PPCSubTarget->isSecurePlt() || !PPCSubTarget->isTargetELF() ||
+        Mod->getPICLevel() == PICLevel::SmallPIC)
+      break;
+      // Attach global base pointer on GETtlsADDR32 node in order to
+      // generate secure plt code for TLS symbols.
+      getGlobalBaseReg();
+  }
+    break;
   case PPCISD::CALL: {
     const Module *M = MF->getFunction().getParent();