[mips] Do not copy GOT address to register $gp if the function being called has
internal linkage.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170092 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index 65b33c1..f9a4d4a 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -2849,12 +2849,14 @@
   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
   // node so that legalize doesn't hack it.
   bool IsPICCall = (IsN64 || IsPIC); // true if calls are translated to jalr $25
-  bool GlobalOrExternal = false;
+  bool GlobalOrExternal = false, InternalLinkage = false;
   SDValue CalleeLo;
 
   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
     if (IsPICCall) {
-      if (G->getGlobal()->hasInternalLinkage())
+      InternalLinkage = G->getGlobal()->hasInternalLinkage();
+
+      if (InternalLinkage)
         Callee = getAddrLocal(Callee, DAG, HasMips64);
       else if (LargeGOT)
         Callee = getAddrGlobalLargeGOT(Callee, DAG, MipsII::MO_CALL_HI16,
@@ -2901,8 +2903,11 @@
   }
 
   // Insert node "GP copy globalreg" before call to function.
-  // Lazy-binding stubs require GP to point to the GOT.
-  if (IsPICCall) {
+  //
+  // R_MIPS_CALL* operators (emitted when non-internal functions are called
+  // in PIC mode) allow symbols to be resolved via lazy binding.
+  // The lazy binding stub requires GP to point to the GOT.
+  if (IsPICCall && !InternalLinkage) {
     unsigned GPReg = IsN64 ? Mips::GP_64 : Mips::GP;
     EVT Ty = IsN64 ? MVT::i64 : MVT::i32;
     RegsToPass.push_back(std::make_pair(GPReg, GetGlobalReg(DAG, Ty)));