Avoid recursive sibcall's.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94946 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index c0ebade..e27d93c 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -2252,10 +2252,26 @@
// If -tailcallopt is specified, make fastcc functions tail-callable.
const Function *CallerF = DAG.getMachineFunction().getFunction();
- if (PerformTailCallOpt &&
- CalleeCC == CallingConv::Fast &&
- CallerF->getCallingConv() == CalleeCC)
- return true;
+ if (PerformTailCallOpt) {
+ if (CalleeCC == CallingConv::Fast &&
+ CallerF->getCallingConv() == CalleeCC)
+ return true;
+ return false;
+ }
+
+ // Do not tail call optimize vararg calls for now.
+ if (isVarArg)
+ return false;
+
+ // Don't tail call optimize recursive call.
+ GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee);
+ const Function *CalleeF = G ? cast<Function>(G->getGlobal()) : 0;
+ if (CallerF == CalleeF)
+ return false;
+ // If it's an indirect call, conversatively return false if the caller's
+ // address is taken.
+ if (!isa<ExternalSymbolSDNode>(Callee) && CallerF->hasAddressTaken())
+ return false;
// Look for obvious safe cases to perform tail call optimization.
// If the callee takes no arguments then go on to check the results of the
@@ -2279,9 +2295,7 @@
return true;
// If the return types match, then it's safe.
- GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee);
if (!G) return false; // FIXME: common external symbols?
- Function *CalleeF = cast<Function>(G->getGlobal());
const Type *CalleeRetTy = CalleeF->getReturnType();
return CallerRetTy == CalleeRetTy;
}