[turbofan] Support inlining of unguarded loops.

Also allow inlining of native functions.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/962963006

Cr-Commit-Position: refs/heads/master@{#26959}

src/compiler/js-inlining.cc

@@ -79,6 +79,11 @@ class Inlinee {
   Node* value_output() {
     return NodeProperties::GetValueInput(unique_return(), 0);
   }
+  // Return the control output of the graph,
+  // that is the control input of the return statement of the inlinee.
+  Node* control_output() {
+    return NodeProperties::GetControlInput(unique_return(), 0);
+  }
   // Return the unique return statement of the graph.
   Node* unique_return() {
     Node* unique_return = NodeProperties::GetControlInput(end_);
@@ -263,7 +268,19 @@ Reduction Inlinee::InlineAtCall(JSGraph* jsgraph, Node* call) {
     }
   }
 
-  NodeProperties::ReplaceWithValue(call, value_output(), effect_output());
+  for (Edge edge : call->use_edges()) {
+    if (NodeProperties::IsControlEdge(edge)) {
+      // TODO(turbofan): Handle kIfException uses.
+      DCHECK_EQ(IrOpcode::kIfSuccess, edge.from()->opcode());
+      edge.from()->ReplaceUses(control_output());
+      edge.UpdateTo(nullptr);
+    } else if (NodeProperties::IsEffectEdge(edge)) {
+      edge.UpdateTo(effect_output());
+    } else {
+      edge.UpdateTo(value_output());
+    }
+  }
+
   return Reducer::Replace(value_output());
 }
 
@@ -312,16 +329,6 @@ Reduction JSInliner::Reduce(Node* node) {
 
   Handle<JSFunction> function = match.Value().handle();
 
-  if (function->shared()->native()) {
-    if (FLAG_trace_turbo_inlining) {
-      SmartArrayPointer<char> name =
-          function->shared()->DebugName()->ToCString();
-      PrintF("Not Inlining %s into %s because inlinee is native\n", name.get(),
-             info_->shared_info()->DebugName()->ToCString().get());
-    }
-    return NoChange();
-  }
-
   CompilationInfoWithZone info(function);
 
   if (!Compiler::ParseAndAnalyze(&info)) return NoChange();

test/cctest/compiler/test-run-inlining.cc

@@ -320,6 +320,53 @@ TEST(InlineLoopGuardedTwice) {
 }
 
 
+TEST(InlineLoopUnguardedEmpty) {
+  FLAG_turbo_deoptimization = true;
+  FunctionTester T(
+      "(function () {"
+      "  function foo(s) { AssertInlineCount(2); while (s); return s; };"
+      "  function bar(s, t) { return foo(s); };"
+      "  return bar;"
+      "})();",
+      kInlineFlags);
+
+  InstallAssertInlineCountHelper(CcTest::isolate());
+  T.CheckCall(T.Val(0.0), T.Val(0.0), T.Val(4));
+}
+
+
+TEST(InlineLoopUnguardedOnce) {
+  FLAG_turbo_deoptimization = true;
+  FunctionTester T(
+      "(function () {"
+      "  function foo(s) { AssertInlineCount(2); while (s) {"
+      "                    s = s - 1; }; return s; };"
+      "  function bar(s, t) { return foo(s); };"
+      "  return bar;"
+      "})();",
+      kInlineFlags);
+
+  InstallAssertInlineCountHelper(CcTest::isolate());
+  T.CheckCall(T.Val(0.0), T.Val(0.0), T.Val(4));
+}
+
+
+TEST(InlineLoopUnguardedTwice) {
+  FLAG_turbo_deoptimization = true;
+  FunctionTester T(
+      "(function () {"
+      "  function foo(s) { AssertInlineCount(2); while (s > 0) {"
+      "                    s = s - 1; }; return s; };"
+      "  function bar(s,t) { return foo(foo(s,t),t); };"
+      "  return bar;"
+      "})();",
+      kInlineFlags);
+
+  InstallAssertInlineCountHelper(CcTest::isolate());
+  T.CheckCall(T.Val(0.0), T.Val(0.0), T.Val(4));
+}
+
+
 TEST(InlineStrictIntoNonStrict) {
   FLAG_turbo_deoptimization = true;
   FunctionTester T(