Handle arguments passed in through the va_arg area
llvm-svn: 6769
diff --git a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
index f1599c3..ad4e0e2 100644
--- a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -79,7 +79,13 @@
Function *Callee = CS.getCalledFunction();
if (!Callee) return Alive;
- // FIXME: check to see if it's passed through a va_arg area
+ // Check to see if it's passed through a va_arg area: if so, we cannot
+ // remove it.
+ unsigned NumFixedArgs = Callee->getFunctionType()->getNumParams();
+ for (CallSite::arg_iterator AI = CS.arg_begin()+NumFixedArgs;
+ AI != CS.arg_end(); ++AI)
+ if (AI->get() == &A) // If passed through va_arg area, we cannot remove it
+ return Alive;
}
return MaybeLive; // It must be used, but only as argument to a function