From cf2e2e88e12149c62b7cfdb01066b96cde9f5a19 Mon Sep 17 00:00:00 2001
From: Teagan Strickland <sstrickl@google.com>
Date: Tue, 4 Jun 2019 16:51:36 +0000
Subject: [PATCH] [vm/compiler] Fix receiver redefinition type for poly
 inlining.

In cases where the same target function is used for multiple
CID ranges, we only perform the inlining once. However, if the
CID range used for the initial inlining is a single CID, we will
set the type of the redefinition to that CID.

Detect this case and clear the concrete type associated with
the redefinition if it was given one.

Change-Id: I3c27c46c71e10e71624ce3b969cb741eb9b2915f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/104781
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
---
 runtime/vm/compiler/backend/inliner.cc      |  5 ++
 runtime/vm/compiler/backend/inliner_test.cc | 83 +++++++++++++++++++++
 runtime/vm/compiler/compiler_sources.gni    |  1 +
 3 files changed, 89 insertions(+)
 create mode 100644 runtime/vm/compiler/backend/inliner_test.cc

diff --git a/runtime/vm/compiler/backend/inliner.cc b/runtime/vm/compiler/backend/inliner.cc
index 7be5d0ec0f91..9c17bb46404a 100644
--- a/runtime/vm/compiler/backend/inliner.cc
+++ b/runtime/vm/compiler/backend/inliner.cc
@@ -1731,6 +1731,11 @@ bool PolymorphicInliner::CheckInlinedDuplicate(const Function& target) {
           BlockEntryInstr* block = old_target->dominated_blocks()[j];
           new_join->AddDominatedBlock(block);
         }
+        // Since we are reusing the same inlined body across multiple cids,
+        // reset the type information on the redefinition of the receiver
+        // in case it was originally given a concrete type.
+        ASSERT(new_join->next()->IsRedefinition());
+        new_join->next()->AsRedefinition()->UpdateType(CompileType::Dynamic());
         // Create a new target with the join as unconditional successor.
         TargetEntryInstr* new_target = new TargetEntryInstr(
             AllocateBlockId(), old_target->try_index(), DeoptId::kNone);
diff --git a/runtime/vm/compiler/backend/inliner_test.cc b/runtime/vm/compiler/backend/inliner_test.cc
new file mode 100644
index 000000000000..9c98b1d4c83e
--- /dev/null
+++ b/runtime/vm/compiler/backend/inliner_test.cc
@@ -0,0 +1,83 @@
+// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "vm/compiler/backend/inliner.h"
+
+#include "vm/compiler/backend/il_printer.h"
+#include "vm/compiler/backend/il_test_helper.h"
+#include "vm/compiler/compiler_pass.h"
+#include "vm/object.h"
+#include "vm/unit_test.h"
+
+namespace dart {
+
+// Test that the redefinition for an inlined polymorphic function used with
+// multiple receiver cids does not have a concrete type.
+ISOLATE_UNIT_TEST_CASE(Inliner_PolyInliningRedefinition) {
+  const char* kScript = R"(
+    class A {
+      String toInline() { return "A"; }
+    }
+
+    class B extends A {
+      @override
+      String toInline() { return "B"; }
+    }
+    class C extends A {}
+    class D extends A {
+      @override
+      String toInline() { return "D";}
+    }
+    class E extends A {}
+
+    testInlining(A arg) {
+      arg.toInline();
+    }
+
+    main() {
+      for (var i = 0; i < 10; i++) {
+        testInlining(B());
+        testInlining(C());
+        testInlining(D());
+        testInlining(E());
+      }
+    }
+  )";
+
+  const auto& root_library = Library::Handle(LoadTestScript(kScript));
+  const auto& function =
+      Function::Handle(GetFunction(root_library, "testInlining"));
+
+  Invoke(root_library, "main");
+
+  TestPipeline pipeline(function, CompilerPass::kJIT);
+  FlowGraph* flow_graph = pipeline.RunPasses({
+      CompilerPass::kComputeSSA,
+      CompilerPass::kApplyICData,
+      CompilerPass::kTryOptimizePatterns,
+      CompilerPass::kSetOuterInliningId,
+      CompilerPass::kTypePropagation,
+      CompilerPass::kApplyClassIds,
+      CompilerPass::kInlining,
+  });
+
+  auto entry = flow_graph->graph_entry()->normal_entry();
+  EXPECT(entry != nullptr);
+
+  RedefinitionInstr* redefn = nullptr;
+
+  ILMatcher cursor(flow_graph, entry);
+  RELEASE_ASSERT(cursor.TryMatch(
+      {
+          kMatchAndMoveBranchFalse,
+          kMatchAndMoveBranchTrue,
+          {kMatchAndMoveRedefinition, &redefn},
+          kMatchReturn,
+      },
+      /*insert_before=*/kMoveGlob));
+
+  EXPECT(redefn->Type()->ToCid() == kDynamicCid);
+}
+
+}  // namespace dart
diff --git a/runtime/vm/compiler/compiler_sources.gni b/runtime/vm/compiler/compiler_sources.gni
index 632e5b40c096..bac526c10f12 100644
--- a/runtime/vm/compiler/compiler_sources.gni
+++ b/runtime/vm/compiler/compiler_sources.gni
@@ -168,6 +168,7 @@ compiler_sources_tests = [
   "backend/il_test.cc",
   "backend/il_test_helper.h",
   "backend/il_test_helper.cc",
+  "backend/inliner_test.cc",
   "backend/locations_helpers_test.cc",
   "backend/loops_test.cc",
   "backend/range_analysis_test.cc",