Commit 25e67eda authored by Tanya Lattner's avatar Tanya Lattner
Browse files

Merge 99620 from mainline. 

Do not sibcall if stack needs to be dynamically aligned.

llvm-svn: 99955
parent 1df1d40e

llvm/lib/Target/X86/X86ISelLowering.cpp

+6 −0
Original line number Diff line number Diff line
@@ -2307,6 +2307,7 @@ X86TargetLowering::IsEligibleForTailCallOptimization(SDValue Callee, 
    return false;



  // If -tailcallopt is specified, make fastcc functions tail-callable.

  const MachineFunction &MF = DAG.getMachineFunction();

  const Function *CallerF = DAG.getMachineFunction().getFunction();

  if (GuaranteedTailCallOpt) {

    if (IsTailCallConvention(CalleeCC) &&
@@ -2318,6 +2319,11 @@ 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.



  // Can't do sibcall if stack needs to be dynamically re-aligned. PEI needs to

  // emit a special epilogue.

  if (RegInfo->needsStackRealignment(MF))

    return false;



  // Do not sibcall optimize vararg calls for now.

  if (isVarArg)

    return false;

llvm/test/CodeGen/X86/sibcall.ll

+13 −0
Original line number Diff line number Diff line
@@ -216,3 +216,16 @@ entry: 
}



declare fastcc %struct.ns* @foo7(%struct.cp* byval align 4, i8 signext) nounwind ssp







define void @t19() alignstack(32) nounwind {

entry:

; CHECK: t19:

; CHECK: andl $-32

; CHECK: call {{_?}}foo

  tail call void @foo() nounwind

  ret void

}



declare void @foo()