Revert "Revert "Deoptimization-based bce.""

This reverts commit 0ba627337274ccfb8c9cb9bf23fffb1e1b9d1430.

Change-Id: I1ca10d15bbb49897a0cf541ab160431ec180a006
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index 03d3445..ee04b3a 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -352,6 +352,26 @@
   DISALLOW_COPY_AND_ASSIGN(TypeCheckSlowPathARM64);
 };
 
+class DeoptimizationSlowPathARM64 : public SlowPathCodeARM64 {
+ public:
+  explicit DeoptimizationSlowPathARM64(HInstruction* instruction)
+    : instruction_(instruction) {}
+
+  void EmitNativeCode(CodeGenerator* codegen) OVERRIDE {
+    __ Bind(GetEntryLabel());
+    SaveLiveRegisters(codegen, instruction_->GetLocations());
+    DCHECK(instruction_->IsDeoptimize());
+    HDeoptimize* deoptimize = instruction_->AsDeoptimize();
+    uint32_t dex_pc = deoptimize->GetDexPc();
+    CodeGeneratorARM64* arm64_codegen = down_cast<CodeGeneratorARM64*>(codegen);
+    arm64_codegen->InvokeRuntime(QUICK_ENTRY_POINT(pDeoptimize), instruction_, dex_pc, this);
+  }
+
+ private:
+  HInstruction* const instruction_;
+  DISALLOW_COPY_AND_ASSIGN(DeoptimizationSlowPathARM64);
+};
+
 #undef __
 
 Location InvokeDexCallingConventionVisitor::GetNextLocation(Primitive::Type type) {
@@ -1615,25 +1635,18 @@
   }
 }
 
-void LocationsBuilderARM64::VisitIf(HIf* if_instr) {
-  LocationSummary* locations = new (GetGraph()->GetArena()) LocationSummary(if_instr);
-  HInstruction* cond = if_instr->InputAt(0);
-  if (!cond->IsCondition() || cond->AsCondition()->NeedsMaterialization()) {
-    locations->SetInAt(0, Location::RequiresRegister());
-  }
-}
-
-void InstructionCodeGeneratorARM64::VisitIf(HIf* if_instr) {
-  HInstruction* cond = if_instr->InputAt(0);
+void InstructionCodeGeneratorARM64::GenerateTestAndBranch(HInstruction* instruction,
+                                                          vixl::Label* true_target,
+                                                          vixl::Label* false_target,
+                                                          vixl::Label* always_true_target) {
+  HInstruction* cond = instruction->InputAt(0);
   HCondition* condition = cond->AsCondition();
-  vixl::Label* true_target = codegen_->GetLabelOf(if_instr->IfTrueSuccessor());
-  vixl::Label* false_target = codegen_->GetLabelOf(if_instr->IfFalseSuccessor());
 
   if (cond->IsIntConstant()) {
     int32_t cond_value = cond->AsIntConstant()->GetValue();
     if (cond_value == 1) {
-      if (!codegen_->GoesToNextBlock(if_instr->GetBlock(), if_instr->IfTrueSuccessor())) {
-        __ B(true_target);
+      if (always_true_target != nullptr) {
+        __ B(always_true_target);
       }
       return;
     } else {
@@ -1641,9 +1654,9 @@
     }
   } else if (!cond->IsCondition() || condition->NeedsMaterialization()) {
     // The condition instruction has been materialized, compare the output to 0.
-    Location cond_val = if_instr->GetLocations()->InAt(0);
+    Location cond_val = instruction->GetLocations()->InAt(0);
     DCHECK(cond_val.IsRegister());
-    __ Cbnz(InputRegisterAt(if_instr, 0), true_target);
+    __ Cbnz(InputRegisterAt(instruction, 0), true_target);
   } else {
     // The condition instruction has not been materialized, use its inputs as
     // the comparison and its condition as the branch condition.
@@ -1661,11 +1674,52 @@
       __ B(arm64_cond, true_target);
     }
   }
-  if (!codegen_->GoesToNextBlock(if_instr->GetBlock(), if_instr->IfFalseSuccessor())) {
+  if (false_target != nullptr) {
     __ B(false_target);
   }
 }
 
+void LocationsBuilderARM64::VisitIf(HIf* if_instr) {
+  LocationSummary* locations = new (GetGraph()->GetArena()) LocationSummary(if_instr);
+  HInstruction* cond = if_instr->InputAt(0);
+  if (!cond->IsCondition() || cond->AsCondition()->NeedsMaterialization()) {
+    locations->SetInAt(0, Location::RequiresRegister());
+  }
+}
+
+void InstructionCodeGeneratorARM64::VisitIf(HIf* if_instr) {
+  vixl::Label* true_target = codegen_->GetLabelOf(if_instr->IfTrueSuccessor());
+  vixl::Label* false_target = codegen_->GetLabelOf(if_instr->IfFalseSuccessor());
+  vixl::Label* always_true_target = true_target;
+  if (codegen_->GoesToNextBlock(if_instr->GetBlock(),
+                                if_instr->IfTrueSuccessor())) {
+    always_true_target = nullptr;
+  }
+  if (codegen_->GoesToNextBlock(if_instr->GetBlock(),
+                                if_instr->IfFalseSuccessor())) {
+    false_target = nullptr;
+  }
+  GenerateTestAndBranch(if_instr, true_target, false_target, always_true_target);
+}
+
+void LocationsBuilderARM64::VisitDeoptimize(HDeoptimize* deoptimize) {
+  LocationSummary* locations = new (GetGraph()->GetArena())
+      LocationSummary(deoptimize, LocationSummary::kCallOnSlowPath);
+  HInstruction* cond = deoptimize->InputAt(0);
+  DCHECK(cond->IsCondition());
+  if (cond->AsCondition()->NeedsMaterialization()) {
+    locations->SetInAt(0, Location::RequiresRegister());
+  }
+}
+
+void InstructionCodeGeneratorARM64::VisitDeoptimize(HDeoptimize* deoptimize) {
+  SlowPathCodeARM64* slow_path = new (GetGraph()->GetArena())
+      DeoptimizationSlowPathARM64(deoptimize);
+  codegen_->AddSlowPath(slow_path);
+  vixl::Label* slow_path_entry = slow_path->GetEntryLabel();
+  GenerateTestAndBranch(deoptimize, slow_path_entry, nullptr, slow_path_entry);
+}
+
 void LocationsBuilderARM64::VisitInstanceFieldGet(HInstanceFieldGet* instruction) {
   LocationSummary* locations =
       new (GetGraph()->GetArena()) LocationSummary(instruction, LocationSummary::kNoCall);