DeadArgElim: Don't mark swifterror arguments as unused
Replacing swifterror arguments with undef creates invalid IR.
rdar://28300490
llvm-svn: 282075
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());
}
diff --git a/llvm/test/Transforms/DeadArgElim/deadexternal.ll b/llvm/test/Transforms/DeadArgElim/deadexternal.ll
index 21cbc37..1b098c6f 100644
--- a/llvm/test/Transforms/DeadArgElim/deadexternal.ll
+++ b/llvm/test/Transforms/DeadArgElim/deadexternal.ll
@@ -50,3 +50,18 @@
ret void
}
+%swift_error = type opaque
+
+define void @unused_swifterror_arg(%swift_error** swifterror %dead_arg) {
+ tail call void @sideeffect() nounwind
+ ret void
+}
+
+; CHECK-LABEL: @dont_replace_by_undef
+; CHECK-NOT: call void @unused_swifterror_arg({{.*}}undef)
+define void @dont_replace_by_undef() {
+ %error_ptr_ref = alloca swifterror %swift_error*
+ store %swift_error* null, %swift_error** %error_ptr_ref
+ call void @unused_swifterror_arg(%swift_error** %error_ptr_ref)
+ ret void
+}