Undo changes mistakenly made in revision 128750.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128751 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 59 insertions, 27 deletions

diff --git a/lib/Target/Mips/MipsISelDAGToDAG.cpp b/lib/Target/Mips/MipsISelDAGToDAG.cpp
index 0382964fe9..3749009112 100644
--- a/lib/Target/Mips/MipsISelDAGToDAG.cpp
+++ b/lib/Target/Mips/MipsISelDAGToDAG.cpp
@@ -122,8 +122,7 @@ SelectAddr(SDValue Addr, SDValue &Offset, SDValue &Base) {
     if ((Addr.getOpcode() == ISD::TargetGlobalAddress) ||
         (Addr.getOpcode() == ISD::TargetConstantPool) ||
         (Addr.getOpcode() == ISD::TargetJumpTable) ||
-        (Addr.getOpcode() == ISD::TargetBlockAddress) ||
-        (Addr.getOpcode() == ISD::TargetExternalSymbol)) {
+        (Addr.getOpcode() == ISD::TargetBlockAddress)) {
       Base   = CurDAG->getRegister(Mips::GP, MVT::i32);
       Offset = Addr;
       return true;
@@ -445,6 +444,61 @@ SDNode* MipsDAGToDAGISel::Select(SDNode *Node) {
         return ResNode;
       // Other cases are autogenerated.
       break;
+
+    /// Handle direct and indirect calls when using PIC. On PIC, when
+    /// GOT is smaller than about 64k (small code) the GA target is
+    /// loaded with only one instruction. Otherwise GA's target must
+    /// be loaded with 3 instructions.
+    case MipsISD::JmpLink: {
+      if (TM.getRelocationModel() == Reloc::PIC_) {
+        unsigned LastOpNum = Node->getNumOperands()-1;
+
+        SDValue Chain  = Node->getOperand(0);
+        SDValue Callee = Node->getOperand(1);
+        SDValue InFlag;
+
+        // Skip the incomming flag if present
+        if (Node->getOperand(LastOpNum).getValueType() == MVT::Glue)
+          LastOpNum--;
+
+        if ( (isa<GlobalAddressSDNode>(Callee)) ||
+             (isa<ExternalSymbolSDNode>(Callee)) )
+        {
+          /// Direct call for global addresses and external symbols
+          SDValue GPReg = CurDAG->getRegister(Mips::GP, MVT::i32);
+
+          // Use load to get GOT target
+          SDValue Ops[] = { Callee, GPReg, Chain };
+          SDValue Load = SDValue(CurDAG->getMachineNode(Mips::LW, dl, MVT::i32,
+                                     MVT::Other, Ops, 3), 0);
+          Chain = Load.getValue(1);
+
+          // Call target must be on T9
+          Chain = CurDAG->getCopyToReg(Chain, dl, Mips::T9, Load, InFlag);
+        } else
+          /// Indirect call
+          Chain = CurDAG->getCopyToReg(Chain, dl, Mips::T9, Callee, InFlag);
+
+        // Map the JmpLink operands to JALR
+        SDVTList NodeTys = CurDAG->getVTList(MVT::Other, MVT::Glue);
+        SmallVector<SDValue, 8> Ops;
+        Ops.push_back(CurDAG->getRegister(Mips::T9, MVT::i32));
+
+        for (unsigned i = 2, e = LastOpNum+1; i != e; ++i)
+          Ops.push_back(Node->getOperand(i));
+        Ops.push_back(Chain);
+        Ops.push_back(Chain.getValue(1));
+
+        // Emit Jump and Link Register
+        SDNode *ResNode = CurDAG->getMachineNode(Mips::JALR, dl, NodeTys,
+                                  &Ops[0], Ops.size());
+
+        // Replace Chain and InFlag
+        ReplaceUses(SDValue(Node, 0), SDValue(ResNode, 0));
+        ReplaceUses(SDValue(Node, 1), SDValue(ResNode, 1));
+        return ResNode;
+      }
+    }
   }
 
   // Select the default instruction
diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index 20df9c8632..59ad81b5a7 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -1201,34 +1201,12 @@ MipsTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
   // node so that legalize doesn't hack it.
   unsigned char OpFlag = IsPIC ? MipsII::MO_GOT_CALL : MipsII::MO_NO_FLAG;
-  bool LoadSymAddr = false;
-
-  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
+  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
     Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl,
-                                        getPointerTy(), 0, OpFlag);
-    LoadSymAddr = true;
-  }
-  else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
+                                getPointerTy(), 0, OpFlag);
+  else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee))
     Callee = DAG.getTargetExternalSymbol(S->getSymbol(),
                                 getPointerTy(), OpFlag);
-    LoadSymAddr = true;
-  }
-
-  // Create nodes that load address of callee and copy it to T9
-  if (IsPIC) {
-    if (LoadSymAddr) {
-      // load callee address
-      Callee = DAG.getLoad(MVT::i32, dl, Chain, Callee,
-                           MachinePointerInfo::getGOT(),
-                           false, false, 0);
-      Chain = Callee.getValue(1);
-    }
-
-    // copy to T9
-    Chain = DAG.getCopyToReg(Chain, dl, Mips::T9, Callee, SDValue(0, 0));
-    InFlag = Chain.getValue(1);
-    Callee = DAG.getRegister(Mips::T9, MVT::i32);
-  }
 
   // MipsJmpLink = #chain, #target_address, #opt_in_flags...
   //             = Chain, Callee, Reg#1, Reg#2, ...