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/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 8248c94..5219cb7 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -2673,11 +2673,15 @@
 SDValue
 PPCTargetLowering::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) {
+  if (isTailCall)
+    isTailCall = IsEligibleForTailCallOptimization(Callee, CallConv, isVarArg,
+                                                   Ins, DAG);
+
   if (PPCSubTarget.isSVR4ABI() && !PPCSubTarget.isPPC64()) {
     return LowerCall_SVR4(Chain, Callee, CallConv, isVarArg,
                           isTailCall, Outs, Ins,
@@ -2700,10 +2704,6 @@
   // See PPCTargetLowering::LowerFormalArguments_SVR4() for a description
   // of the 32-bit SVR4 ABI stack frame layout.
 
-  assert((!isTailCall ||
-          (CallConv == CallingConv::Fast && PerformTailCallOpt)) &&
-         "IsEligibleForTailCallOptimization missed a case!");
-
   assert((CallConv == CallingConv::C ||
           CallConv == CallingConv::Fast) && "Unknown calling convention!");