commit f62ba1031fc88b76db2dc19960fd8da7ed5aefac
author Arnold Schwaighofer <aschwaighofer@apple.com> Wed Sep 21 15:29:08 2016 +0000
committer Arnold Schwaighofer <aschwaighofer@apple.com> Wed Sep 21 15:29:08 2016 +0000
tree c04001d0208e1e6f4863e194e640931ce44d5db2
parent 62ba446223d5ed6abd3563d8527eda988cf885a7

DeadArgElim: Don't mark swifterror arguments as unused

Replacing swifterror arguments with undef creates invalid IR.

rdar://28300490

llvm-svn: 282075

llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp

diff --git a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
index c8c895b..c294d64 100644
--- a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -270,7 +270,7 @@
 
   SmallVector<unsigned, 8> UnusedArgs;
   for (Argument &Arg : Fn.args()) {
-    if (Arg.use_empty() && !Arg.hasByValOrInAllocaAttr())
+    if (!Arg.hasSwiftErrorAttr() && Arg.use_empty() && !Arg.hasByValOrInAllocaAttr())
       UnusedArgs.push_back(Arg.getArgNo());
   }