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Avoid sibcall optimization if either caller or callee is using sret semantics. 

llvm-svn: 98561
This commit is contained in:
Evan Cheng 2010-03-15 18:54:48 +00:00
parent e01bec9791
commit ae5edee6c8
2 changed files with 12 additions and 3 deletions
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13
llvm/lib/Target/X86/X86ISelLowering.cpp
View File

@ -1524,7 +1524,6 @@ X86TargetLowering::LowerFormalArguments(SDValue Chain,
DebugLoc dl, DebugLoc dl,
SelectionDAG &DAG, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) { SmallVectorImpl<SDValue> &InVals) {
MachineFunction &MF = DAG.getMachineFunction(); MachineFunction &MF = DAG.getMachineFunction();
X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>(); X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
@ -1826,7 +1825,8 @@ X86TargetLowering::LowerCall(SDValue Chain, SDValue Callee,
if (isTailCall) { if (isTailCall) {
// Check if it's really possible to do a tail call. // 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); Outs, Ins, DAG);
// Sibcalls are automatically detected tailcalls which do not require // Sibcalls are automatically detected tailcalls which do not require
@ -2324,6 +2324,8 @@ bool
X86TargetLowering::IsEligibleForTailCallOptimization(SDValue Callee, X86TargetLowering::IsEligibleForTailCallOptimization(SDValue Callee,
CallingConv::ID CalleeCC, CallingConv::ID CalleeCC,
bool isVarArg, bool isVarArg,
bool isCalleeStructRet,
bool isCallerStructRet,
const SmallVectorImpl<ISD::OutputArg> &Outs, const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<ISD::InputArg> &Ins, const SmallVectorImpl<ISD::InputArg> &Ins,
SelectionDAG& DAG) const { SelectionDAG& DAG) const {
@ -2343,10 +2345,15 @@ X86TargetLowering::IsEligibleForTailCallOptimization(SDValue Callee,
// Look for obvious safe cases to perform tail call optimization that does not // Look for obvious safe cases to perform tail call optimization that does not
// requite ABI changes. This is what gcc calls sibcall. // 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) if (isVarArg)
return false; 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 // If the callee takes no arguments then go on to check the results of the
// call. // call.
if (!Outs.empty()) { if (!Outs.empty()) {

2
llvm/lib/Target/X86/X86ISelLowering.h
View File

@ -630,6 +630,8 @@ namespace llvm {
bool IsEligibleForTailCallOptimization(SDValue Callee, bool IsEligibleForTailCallOptimization(SDValue Callee,
CallingConv::ID CalleeCC, CallingConv::ID CalleeCC,
bool isVarArg, bool isVarArg,
bool isCalleeStructRet,
bool isCallerStructRet,
const SmallVectorImpl<ISD::OutputArg> &Outs, const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<ISD::InputArg> &Ins, const SmallVectorImpl<ISD::InputArg> &Ins,
SelectionDAG& DAG) const; SelectionDAG& DAG) const;