Allow trivial sibcall of vararg callee when no arguments are being passed.
llvm-svn: 99598
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 75e6f50..d08dfc4 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -2301,8 +2301,9 @@
// Look for obvious safe cases to perform tail call optimization that does not
// requite ABI changes. This is what gcc calls sibcall.
- // Do not sibcall optimize vararg calls for now.
- if (isVarArg)
+ // Do not sibcall optimize vararg calls unless the call site is not passing any
+ // arguments.
+ if (isVarArg && !Outs.empty())
return false;
// Also avoid sibcall optimization if either caller or callee uses struct