[PowerPC] Add r2 as an operand for all calls under both PPC64 ELF V1 and V2

Our PPC64 ELF V2 call lowering logic added r2 as an operand to all direct call
instructions in order to represent the dependency on the TOC base pointer
value. Restricting this to ELF V2, however, does not seem to make sense: calls
under ELF V1 have the same dependence, and indirect calls have an r2 dependence
just as direct ones. Make sure the dependence is noted for all calls under both
ELF V1 and ELF V2.

llvm-svn: 226432
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 2001e42..d1317b7 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -3823,8 +3823,9 @@
     Ops.push_back(DAG.getRegister(RegsToPass[i].first,
                                   RegsToPass[i].second.getValueType()));
 
-  // Direct calls in the ELFv2 ABI need the TOC register live into the call.
-  if (Callee.getNode() && isELFv2ABI && !IsPatchPoint)
+  // All calls, in both the ELF V1 and V2 ABIs, need the TOC register live
+  // into the call.
+  if (isSVR4ABI && isPPC64 && !IsPatchPoint)
     Ops.push_back(DAG.getRegister(PPC::X2, PtrVT));
 
   return CallOpc;
@@ -7368,8 +7369,19 @@
 PPCTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
                                                MachineBasicBlock *BB) const {
   if (MI->getOpcode() == TargetOpcode::STACKMAP ||
-      MI->getOpcode() == TargetOpcode::PATCHPOINT)
+      MI->getOpcode() == TargetOpcode::PATCHPOINT) {
+    if (Subtarget.isPPC64() && Subtarget.isSVR4ABI() &&
+        MI->getOpcode() == TargetOpcode::PATCHPOINT) {
+      // Call lowering should have added an r2 operand to indicate a dependence
+      // on the TOC base pointer value. It can't however, because there is no
+      // way to mark the dependence as implicit there, and so the stackmap code
+      // will confuse it with a regular operand. Instead, add the dependence
+      // here.
+      MI->addOperand(MachineOperand::CreateReg(PPC::X2, false, true));
+    }
+
     return emitPatchPoint(MI, BB);
+  }
 
   if (MI->getOpcode() == PPC::EH_SjLj_SetJmp32 ||
       MI->getOpcode() == PPC::EH_SjLj_SetJmp64) {