diff options
| -rw-r--r-- | lib/Target/X86/X86ISelLowering.cpp | 13 | ||||
| -rw-r--r-- | lib/Target/X86/X86ISelLowering.h | 2 |
2 files changed, 12 insertions, 3 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index f75df6c8f8..9c40a7007f 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -1477,7 +1477,6 @@ X86TargetLowering::LowerFormalArguments(SDValue Chain, DebugLoc dl, SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) { - MachineFunction &MF = DAG.getMachineFunction(); X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>(); @@ -1779,7 +1778,8 @@ X86TargetLowering::LowerCall(SDValue Chain, SDValue Callee, if (isTailCall) { // Check if it's really possible to do a tail call. - isTailCall = IsEligibleForTailCallOptimization(Callee, CallConv, isVarArg, + isTailCall = IsEligibleForTailCallOptimization(Callee, CallConv, + isVarArg, IsStructRet, MF.getFunction()->hasStructRetAttr(), Outs, Ins, DAG); // Sibcalls are automatically detected tailcalls which do not require @@ -2297,6 +2297,8 @@ bool X86TargetLowering::IsEligibleForTailCallOptimization(SDValue Callee, CallingConv::ID CalleeCC, bool isVarArg, + bool isCalleeStructRet, + bool isCallerStructRet, const SmallVectorImpl<ISD::OutputArg> &Outs, const SmallVectorImpl<ISD::InputArg> &Ins, SelectionDAG& DAG) const { @@ -2316,10 +2318,15 @@ X86TargetLowering::IsEligibleForTailCallOptimization(SDValue Callee, // Look for obvious safe cases to perform tail call optimization that does not // requite ABI changes. This is what gcc calls sibcall. - // Do not tail call optimize vararg calls for now. + // Do not sibcall optimize vararg calls for now. if (isVarArg) return false; + // Also avoid sibcall optimization if either caller or callee uses struct + // return semantics. + if (isCalleeStructRet || isCallerStructRet) + return false; + // If the callee takes no arguments then go on to check the results of the // call. if (!Outs.empty()) { diff --git a/lib/Target/X86/X86ISelLowering.h b/lib/Target/X86/X86ISelLowering.h index 4c12fcc32f..5936975404 100644 --- a/lib/Target/X86/X86ISelLowering.h +++ b/lib/Target/X86/X86ISelLowering.h @@ -637,6 +637,8 @@ namespace llvm { bool IsEligibleForTailCallOptimization(SDValue Callee, CallingConv::ID CalleeCC, bool isVarArg, + bool isCalleeStructRet, + bool isCallerStructRet, const SmallVectorImpl<ISD::OutputArg> &Outs, const SmallVectorImpl<ISD::InputArg> &Ins, SelectionDAG& DAG) const; |