Index: lib/Transforms/Scalar/PlaceSafepoints.cpp
===================================================================
--- lib/Transforms/Scalar/PlaceSafepoints.cpp
+++ lib/Transforms/Scalar/PlaceSafepoints.cpp
@@ -738,7 +738,8 @@
   // different type inserted previously
   Function *F =
       dyn_cast<Function>(M->getOrInsertFunction("gc.safepoint_poll", ftype));
-  assert(F && !F->empty() && "definition must exist");
+  assert(F && "void @gc.safepoint_poll() must be defined");
+  assert(!F->empty() && "gc.safepoint_poll must be a non-empty function");
   CallInst *poll = CallInst::Create(F, "", term);
 
   // Record some information about the call site we're replacing
@@ -861,7 +862,7 @@
   IRBuilder<> Builder(insertBefore);
   // First, create the statepoint (with all live ptrs as arguments).
   std::vector<llvm::Value *> args;
-  // target, #args, unused, args
+  // target, #call args, unused, call parameters, #deopt args, deopt parameters
   Value *Target = CS.getCalledValue();
   args.push_back(Target);
   int callArgSize = CS.arg_size();
@@ -869,6 +870,8 @@
       ConstantInt::get(Type::getInt32Ty(M->getContext()), callArgSize));
   // TODO: add a 'Needs GC-rewrite' later flag
   args.push_back(ConstantInt::get(Type::getInt32Ty(M->getContext()), 0));
+  // deopt: unused
+  args.push_back(ConstantInt::get(Type::getInt32Ty(M->getContext()), 0));
 
   // Copy all the arguments of the original call
   args.insert(args.end(), CS.arg_begin(), CS.arg_end());
Index: test/Transforms/Safepoint/place.ll
===================================================================
--- /dev/null
+++ test/Transforms/Safepoint/place.ll
@@ -0,0 +1,17 @@
+; RUN: opt %s -place-safepoints -S | FileCheck %s
+
+declare zeroext i1 @return_i1()
+
+define void @gc.safepoint_poll() {
+  ret void
+}
+
+define i1 @test_basic() gc "statepoint-example" {
+; CHECK-LABEL: test_basic
+; This is just checking that a statepoint is inserted
+; CHECK: gc.statepoint.p0f_isVoidf
+; CHECK: gc.statepoint.p0f_i1f
+entry:
+  %call1 = tail call i1 ()* @return_i1()
+  ret i1 %call1
+}