Eliminate target hook IsEligibleForTailCallOptimization.

Target independent isel should always pass along the "tail call" property. Change
target hook LowerCall's parameter "isTailCall" into a refernce. If the target
decides it's impossible to honor the tail call request, it should set isTailCall
to false to make target independent isel happy.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94626 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PIC16/PIC16ISelLowering.cpp b/lib/Target/PIC16/PIC16ISelLowering.cpp
index 9f093e8..7754a4f 100644
--- a/lib/Target/PIC16/PIC16ISelLowering.cpp
+++ b/lib/Target/PIC16/PIC16ISelLowering.cpp
@@ -1355,11 +1355,13 @@
 SDValue
 PIC16TargetLowering::LowerCall(SDValue Chain, SDValue Callee,
                                CallingConv::ID CallConv, bool isVarArg,
-                               bool isTailCall,
+                               bool &isTailCall,
                                const SmallVectorImpl<ISD::OutputArg> &Outs,
                                const SmallVectorImpl<ISD::InputArg> &Ins,
                                DebugLoc dl, SelectionDAG &DAG,
                                SmallVectorImpl<SDValue> &InVals) {
+    // PIC16 target does not yet support tail call optimization.
+    isTailCall = false;
 
     assert(Callee.getValueType() == MVT::i16 &&
            "Don't know how to legalize this call node!!!");