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/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 76c6a27..59c198c 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -897,11 +897,13 @@
 SDValue
 ARMTargetLowering::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) {
+  // ARM target does not yet support tail call optimization.
+  isTailCall = false;
 
   // Analyze operands of the call, assigning locations to each operand.
   SmallVector<CCValAssign, 16> ArgLocs;