Fix simplifier issue with predicated ifield get

In cases where all targets of a HPredicatedInstanceFieldGet
instruction are known to not be null the simplifier would attempt to
replace the default value with a null instruction. This would cause a
null-pointer dereference. Correct the simplifier to handle this case
correctly.

Moved some LSE test helper functions to CommonCompilerTestHelper to
avoid duplicating code.

Fixed an incorrect (though until now unused) constructor for
HPredicatatedInstanceFieldGet (the default value and target we
swapped).

Test: ./test.py --host
Test: ./art/tools/compile_jars.py --profile-file bad-compile.txt ~/imgur.apk
Bug: 183942773
Change-Id: I66f4ce37d768d5e457047a3f80bd4cb9aa4546a3

1 files changed, 310 insertions, 0 deletions

diff --git a/compiler/optimizing/instruction_simplifier_test.cc b/compiler/optimizing/instruction_simplifier_test.cc
new file mode 100644
index 0000000000..7d93809be6
--- /dev/null
+++ b/compiler/optimizing/instruction_simplifier_test.cc
@@ -0,0 +1,310 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "instruction_simplifier.h"
+
+#include <initializer_list>
+#include <tuple>
+
+#include "gtest/gtest.h"
+#include "nodes.h"
+#include "optimizing/data_type.h"
+#include "optimizing_unit_test.h"
+
+namespace art {
+
+class InstructionSimplifierTest : public CommonCompilerTest, public OptimizingUnitTestHelper {
+ public:
+  void SetUp() override {
+    CommonCompilerTest::SetUp();
+    gLogVerbosity.compiler = true;
+  }
+
+  void TearDown() override {
+    CommonCompilerTest::TearDown();
+    gLogVerbosity.compiler = false;
+  }
+};
+
+// // ENTRY
+// switch (param) {
+// case 1:
+//   obj1 = param2; break;
+// case 2:
+//   obj1 = param3; break;
+// default:
+//   obj2 = new Obj();
+// }
+// val_phi = PHI[3,4,10]
+// target_phi = PHI[param2, param3, obj2]
+// return PredFieldGet[val_phi, target_phi] => PredFieldGet[val_phi, target_phi]
+TEST_F(InstructionSimplifierTest, SimplifyPredicatedFieldGetNoMerge) {
+  VariableSizedHandleScope vshs(Thread::Current());
+  CreateGraph(&vshs);
+  AdjacencyListGraph blks(SetupFromAdjacencyList("entry",
+                                                 "exit",
+                                                 {{"entry", "case1"},
+                                                  {"entry", "case2"},
+                                                  {"entry", "case3"},
+                                                  {"case1", "breturn"},
+                                                  {"case2", "breturn"},
+                                                  {"case3", "breturn"},
+                                                  {"breturn", "exit"}}));
+#define GET_BLOCK(name) HBasicBlock* name = blks.Get(#name)
+  GET_BLOCK(entry);
+  GET_BLOCK(exit);
+  GET_BLOCK(case1);
+  GET_BLOCK(case2);
+  GET_BLOCK(case3);
+  GET_BLOCK(breturn);
+#undef GET_BLOCK
+
+  HInstruction* bool_value = MakeParam(DataType::Type::kInt32);
+  HInstruction* obj1_param = MakeParam(DataType::Type::kReference);
+  HInstruction* obj2_param = MakeParam(DataType::Type::kReference);
+  HInstruction* c3 = graph_->GetIntConstant(3);
+  HInstruction* c4 = graph_->GetIntConstant(4);
+  HInstruction* c10 = graph_->GetIntConstant(10);
+
+  HInstruction* cls = MakeClassLoad();
+  HInstruction* switch_inst = new (GetAllocator()) HPackedSwitch(0, 2, bool_value);
+  entry->AddInstruction(cls);
+  entry->AddInstruction(switch_inst);
+  ManuallyBuildEnvFor(cls, {});
+
+  HInstruction* goto_c1 = new (GetAllocator()) HGoto();
+  case1->AddInstruction(goto_c1);
+
+  HInstruction* goto_c2 = new (GetAllocator()) HGoto();
+  case2->AddInstruction(goto_c2);
+
+  HInstruction* obj3 = MakeNewInstance(cls);
+  HInstruction* goto_c3 = new (GetAllocator()) HGoto();
+  case3->AddInstruction(obj3);
+  case3->AddInstruction(goto_c3);
+
+  HPhi* val_phi = MakePhi({c3, c4, c10});
+  HPhi* obj_phi = MakePhi({obj1_param, obj2_param, obj3});
+  HPredicatedInstanceFieldGet* read_end =
+      new (GetAllocator()) HPredicatedInstanceFieldGet(obj_phi,
+                                                       nullptr,
+                                                       val_phi,
+                                                       val_phi->GetType(),
+                                                       MemberOffset(10),
+                                                       false,
+                                                       42,
+                                                       0,
+                                                       graph_->GetDexFile(),
+                                                       0);
+  HInstruction* return_exit = new (GetAllocator()) HReturn(read_end);
+  breturn->AddPhi(val_phi);
+  breturn->AddPhi(obj_phi);
+  breturn->AddInstruction(read_end);
+  breturn->AddInstruction(return_exit);
+
+  SetupExit(exit);
+
+  LOG(INFO) << "Pre simplification " << blks;
+  graph_->ClearDominanceInformation();
+  graph_->BuildDominatorTree();
+  InstructionSimplifier simp(graph_, /*codegen=*/nullptr);
+  simp.Run();
+
+  LOG(INFO) << "Post simplify " << blks;
+
+  EXPECT_INS_RETAINED(read_end);
+
+  EXPECT_INS_EQ(read_end->GetTarget(), obj_phi);
+  EXPECT_INS_EQ(read_end->GetDefaultValue(), val_phi);
+}
+
+// // ENTRY
+// switch (param) {
+// case 1:
+//   obj1 = param2; break;
+// case 2:
+//   obj1 = param3; break;
+// default:
+//   obj2 = new Obj();
+// }
+// val_phi = PHI[3,3,10]
+// target_phi = PHI[param2, param3, obj2]
+// return PredFieldGet[val_phi, target_phi] => PredFieldGet[3, target_phi]
+TEST_F(InstructionSimplifierTest, SimplifyPredicatedFieldGetMerge) {
+  VariableSizedHandleScope vshs(Thread::Current());
+  CreateGraph(&vshs);
+  AdjacencyListGraph blks(SetupFromAdjacencyList("entry",
+                                                 "exit",
+                                                 {{"entry", "case1"},
+                                                  {"entry", "case2"},
+                                                  {"entry", "case3"},
+                                                  {"case1", "breturn"},
+                                                  {"case2", "breturn"},
+                                                  {"case3", "breturn"},
+                                                  {"breturn", "exit"}}));
+#define GET_BLOCK(name) HBasicBlock* name = blks.Get(#name)
+  GET_BLOCK(entry);
+  GET_BLOCK(exit);
+  GET_BLOCK(case1);
+  GET_BLOCK(case2);
+  GET_BLOCK(case3);
+  GET_BLOCK(breturn);
+#undef GET_BLOCK
+
+  HInstruction* bool_value = MakeParam(DataType::Type::kInt32);
+  HInstruction* obj1_param = MakeParam(DataType::Type::kReference);
+  HInstruction* obj2_param = MakeParam(DataType::Type::kReference);
+  HInstruction* c3 = graph_->GetIntConstant(3);
+  HInstruction* c10 = graph_->GetIntConstant(10);
+
+  HInstruction* cls = MakeClassLoad();
+  HInstruction* switch_inst = new (GetAllocator()) HPackedSwitch(0, 2, bool_value);
+  entry->AddInstruction(cls);
+  entry->AddInstruction(switch_inst);
+  ManuallyBuildEnvFor(cls, {});
+
+  HInstruction* goto_c1 = new (GetAllocator()) HGoto();
+  case1->AddInstruction(goto_c1);
+
+  HInstruction* goto_c2 = new (GetAllocator()) HGoto();
+  case2->AddInstruction(goto_c2);
+
+  HInstruction* obj3 = MakeNewInstance(cls);
+  HInstruction* goto_c3 = new (GetAllocator()) HGoto();
+  case3->AddInstruction(obj3);
+  case3->AddInstruction(goto_c3);
+
+  HPhi* val_phi = MakePhi({c3, c3, c10});
+  HPhi* obj_phi = MakePhi({obj1_param, obj2_param, obj3});
+  HPredicatedInstanceFieldGet* read_end =
+      new (GetAllocator()) HPredicatedInstanceFieldGet(obj_phi,
+                                                       nullptr,
+                                                       val_phi,
+                                                       val_phi->GetType(),
+                                                       MemberOffset(10),
+                                                       false,
+                                                       42,
+                                                       0,
+                                                       graph_->GetDexFile(),
+                                                       0);
+  HInstruction* return_exit = new (GetAllocator()) HReturn(read_end);
+  breturn->AddPhi(val_phi);
+  breturn->AddPhi(obj_phi);
+  breturn->AddInstruction(read_end);
+  breturn->AddInstruction(return_exit);
+
+  SetupExit(exit);
+
+  LOG(INFO) << "Pre simplification " << blks;
+  graph_->ClearDominanceInformation();
+  graph_->BuildDominatorTree();
+  InstructionSimplifier simp(graph_, /*codegen=*/nullptr);
+  simp.Run();
+
+  LOG(INFO) << "Post simplify " << blks;
+
+  EXPECT_FALSE(obj3->CanBeNull());
+  EXPECT_INS_RETAINED(read_end);
+
+  EXPECT_INS_EQ(read_end->GetTarget(), obj_phi);
+  EXPECT_INS_EQ(read_end->GetDefaultValue(), c3);
+}
+
+// // ENTRY
+// if (param) {
+//   obj1 = new Obj();
+// } else {
+//   obj2 = new Obj();
+// }
+// val_phi = PHI[3,10]
+// target_phi = PHI[obj1, obj2]
+// return PredFieldGet[val_phi, target_phi] => FieldGet[target_phi]
+TEST_F(InstructionSimplifierTest, SimplifyPredicatedFieldGetNoNull) {
+  VariableSizedHandleScope vshs(Thread::Current());
+  CreateGraph(&vshs);
+  AdjacencyListGraph blks(SetupFromAdjacencyList("entry",
+                                                 "exit",
+                                                 {{"entry", "left"},
+                                                  {"entry", "right"},
+                                                  {"left", "breturn"},
+                                                  {"right", "breturn"},
+                                                  {"breturn", "exit"}}));
+#define GET_BLOCK(name) HBasicBlock* name = blks.Get(#name)
+  GET_BLOCK(entry);
+  GET_BLOCK(exit);
+  GET_BLOCK(left);
+  GET_BLOCK(right);
+  GET_BLOCK(breturn);
+#undef GET_BLOCK
+
+  HInstruction* bool_value = MakeParam(DataType::Type::kBool);
+  HInstruction* c3 = graph_->GetIntConstant(3);
+  HInstruction* c10 = graph_->GetIntConstant(10);
+
+  HInstruction* cls = MakeClassLoad();
+  HInstruction* if_inst = new (GetAllocator()) HIf(bool_value);
+  entry->AddInstruction(cls);
+  entry->AddInstruction(if_inst);
+  ManuallyBuildEnvFor(cls, {});
+
+  HInstruction* obj1 = MakeNewInstance(cls);
+  HInstruction* goto_left = new (GetAllocator()) HGoto();
+  left->AddInstruction(obj1);
+  left->AddInstruction(goto_left);
+
+  HInstruction* obj2 = MakeNewInstance(cls);
+  HInstruction* goto_right = new (GetAllocator()) HGoto();
+  right->AddInstruction(obj2);
+  right->AddInstruction(goto_right);
+
+  HPhi* val_phi = MakePhi({c3, c10});
+  HPhi* obj_phi = MakePhi({obj1, obj2});
+  HInstruction* read_end = new (GetAllocator()) HPredicatedInstanceFieldGet(obj_phi,
+                                                                            nullptr,
+                                                                            val_phi,
+                                                                            val_phi->GetType(),
+                                                                            MemberOffset(10),
+                                                                            false,
+                                                                            42,
+                                                                            0,
+                                                                            graph_->GetDexFile(),
+                                                                            0);
+  HInstruction* return_exit = new (GetAllocator()) HReturn(read_end);
+  breturn->AddPhi(val_phi);
+  breturn->AddPhi(obj_phi);
+  breturn->AddInstruction(read_end);
+  breturn->AddInstruction(return_exit);
+
+  SetupExit(exit);
+
+  LOG(INFO) << "Pre simplification " << blks;
+  graph_->ClearDominanceInformation();
+  graph_->BuildDominatorTree();
+  InstructionSimplifier simp(graph_, /*codegen=*/nullptr);
+  simp.Run();
+
+  LOG(INFO) << "Post simplify " << blks;
+
+  EXPECT_FALSE(obj1->CanBeNull());
+  EXPECT_FALSE(obj2->CanBeNull());
+  EXPECT_INS_REMOVED(read_end);
+
+  HInstanceFieldGet* ifget = FindSingleInstruction<HInstanceFieldGet>(graph_, breturn);
+  ASSERT_NE(ifget, nullptr);
+  EXPECT_INS_EQ(ifget->InputAt(0), obj_phi);
+}
+
+}  // namespace art