[turbofan] Remove support for LazyBailout operators.

The LazyBailout operator (modelled as a nop-call) was introduced for
placing a deoptimization point into exception handlers. Now that we are
no longer re-entering lazy deoptimized code, the support can be removed.

R=jarin@chromium.org
BUG=v8:4195
LOG=n

Review URL: https://codereview.chromium.org/1697503002

Cr-Commit-Position: refs/heads/master@{#34020}

src/ast/ast-numbering.cc

@@ -306,7 +306,6 @@ void AstNumberingVisitor::VisitWhileStatement(WhileStatement* node) {
 void AstNumberingVisitor::VisitTryCatchStatement(TryCatchStatement* node) {
   IncrementNodeCount();
   DisableOptimization(kTryCatchStatement);
-  node->set_base_id(ReserveIdRange(TryCatchStatement::num_ids()));
   Visit(node->try_block());
   Visit(node->catch_block());
 }
@@ -315,7 +314,6 @@ void AstNumberingVisitor::VisitTryCatchStatement(TryCatchStatement* node) {
 void AstNumberingVisitor::VisitTryFinallyStatement(TryFinallyStatement* node) {
   IncrementNodeCount();
   DisableOptimization(kTryFinallyStatement);
-  node->set_base_id(ReserveIdRange(TryFinallyStatement::num_ids()));
   Visit(node->try_block());
   Visit(node->finally_block());
 }

src/ast/ast.h

@@ -1183,27 +1183,12 @@ class TryStatement : public Statement {
   Block* try_block() const { return try_block_; }
   void set_try_block(Block* b) { try_block_ = b; }
 
-  void set_base_id(int id) { base_id_ = id; }
-  static int num_ids() { return parent_num_ids() + 1; }
-  BailoutId HandlerId() const { return BailoutId(local_id(0)); }
-
  protected:
   TryStatement(Zone* zone, Block* try_block, int pos)
-      : Statement(zone, pos),
-        try_block_(try_block),
-        base_id_(BailoutId::None().ToInt()) {}
-  static int parent_num_ids() { return 0; }
-
-  int base_id() const {
-    DCHECK(!BailoutId(base_id_).IsNone());
-    return base_id_;
-  }
+      : Statement(zone, pos), try_block_(try_block) {}
 
  private:
-  int local_id(int n) const { return base_id() + parent_num_ids() + n; }
-
   Block* try_block_;
-  int base_id_;
 };
 
 

src/compiler/arm/code-generator-arm.cc

@@ -473,11 +473,6 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       frame_access_state()->ClearSPDelta();
       break;
     }
-    case kArchLazyBailout: {
-      EnsureSpaceForLazyDeopt();
-      RecordCallPosition(instr);
-      break;
-    }
     case kArchPrepareCallCFunction: {
       int const num_parameters = MiscField::decode(instr->opcode());
       __ PrepareCallCFunction(num_parameters, kScratchReg);

src/compiler/arm64/code-generator-arm64.cc

@@ -573,11 +573,6 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       frame_access_state()->ClearSPDelta();
       break;
     }
-    case kArchLazyBailout: {
-      EnsureSpaceForLazyDeopt();
-      RecordCallPosition(instr);
-      break;
-    }
     case kArchPrepareCallCFunction:
       // We don't need kArchPrepareCallCFunction on arm64 as the instruction
       // selector already perform a Claim to reserve space on the stack and

src/compiler/ast-graph-builder.cc

@@ -1449,14 +1449,6 @@ void AstGraphBuilder::VisitTryCatchStatement(TryCatchStatement* stmt) {
   }
   try_control.EndTry();
 
-  // Insert lazy bailout point.
-  // TODO(mstarzinger): We are only using a 'call' to get a lazy bailout
-  // point. Ideally, we whould not re-enter optimized code when deoptimized
-  // lazily. Tracked by issue v8:4195.
-  NewNode(common()->LazyBailout(),
-          jsgraph()->ZeroConstant(),                      // dummy target.
-          environment()->Checkpoint(stmt->HandlerId()));  // frame state.
-
   // Clear message object as we enter the catch block.
   Node* the_hole = jsgraph()->TheHoleConstant();
   NewNode(javascript()->StoreMessage(), the_hole);
@@ -1501,14 +1493,6 @@ void AstGraphBuilder::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
   }
   try_control.EndTry(commands->GetFallThroughToken(), fallthrough_result);
 
-  // Insert lazy bailout point.
-  // TODO(mstarzinger): We are only using a 'call' to get a lazy bailout
-  // point. Ideally, we whould not re-enter optimized code when deoptimized
-  // lazily. Tracked by issue v8:4195.
-  NewNode(common()->LazyBailout(),
-          jsgraph()->ZeroConstant(),                      // dummy target.
-          environment()->Checkpoint(stmt->HandlerId()));  // frame state.
-
   // The result value semantics depend on how the block was entered:
   //  - ReturnStatement: It represents the return value being returned.
   //  - ThrowStatement: It represents the exception being thrown.

src/compiler/common-operator.cc

@@ -803,11 +803,6 @@ const Operator* CommonOperatorBuilder::Call(const CallDescriptor* descriptor) {
 }
 
 
-const Operator* CommonOperatorBuilder::LazyBailout() {
-  return Call(Linkage::GetLazyBailoutDescriptor(zone()));
-}
-
-
 const Operator* CommonOperatorBuilder::TailCall(
     const CallDescriptor* descriptor) {
   class TailCallOperator final : public Operator1<const CallDescriptor*> {

src/compiler/common-operator.h

@@ -170,7 +170,6 @@ class CommonOperatorBuilder final : public ZoneObject {
   const Operator* Call(const CallDescriptor* descriptor);
   const Operator* TailCall(const CallDescriptor* descriptor);
   const Operator* Projection(size_t index);
-  const Operator* LazyBailout();
 
   // Constructs a new merge or phi operator with the same opcode as {op}, but
   // with {size} inputs.

src/compiler/ia32/code-generator-ia32.cc

@@ -413,11 +413,6 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       frame_access_state()->ClearSPDelta();
       break;
     }
-    case kArchLazyBailout: {
-      EnsureSpaceForLazyDeopt();
-      RecordCallPosition(instr);
-      break;
-    }
     case kArchPrepareCallCFunction: {
       // Frame alignment requires using FP-relative frame addressing.
       frame_access_state()->SetFrameAccessToFP();

src/compiler/instruction-codes.h

@@ -47,7 +47,6 @@ enum class RecordWriteMode { kValueIsMap, kValueIsPointer, kValueIsAny };
   V(ArchPrepareCallCFunction)      \
   V(ArchCallCFunction)             \
   V(ArchPrepareTailCall)           \
-  V(ArchLazyBailout)               \
   V(ArchJmp)                       \
   V(ArchLookupSwitch)              \
   V(ArchTableSwitch)               \

src/compiler/instruction-scheduler.cc

@@ -184,7 +184,6 @@ int InstructionScheduler::GetInstructionFlags(const Instruction* instr) const {
     case kArchCallCFunction:
     case kArchCallCodeObject:
     case kArchCallJSFunction:
-    case kArchLazyBailout:
       return kHasSideEffect;
 
     case kArchTailCallCodeObject:

src/compiler/instruction-selector.cc

@@ -568,10 +568,6 @@ void InstructionSelector::InitializeCallBuffer(Node* call, CallBuffer* buffer,
           g.UseLocation(callee, buffer->descriptor->GetInputLocation(0),
                         buffer->descriptor->GetInputType(0).representation()));
       break;
-    case CallDescriptor::kLazyBailout:
-      // The target is ignored, but we still need to pass a value here.
-      buffer->instruction_args.push_back(g.UseImmediate(callee));
-      break;
   }
   DCHECK_EQ(1u, buffer->instruction_args.size());
 
@@ -1459,9 +1455,6 @@ void InstructionSelector::VisitCall(Node* node, BasicBlock* handler) {
     case CallDescriptor::kCallJSFunction:
       opcode = kArchCallJSFunction | MiscField::encode(flags);
       break;
-    case CallDescriptor::kLazyBailout:
-      opcode = kArchLazyBailout | MiscField::encode(flags);
-      break;
   }
 
   // Emit the call instruction.

src/compiler/linkage.cc

@@ -63,9 +63,6 @@ std::ostream& operator<<(std::ostream& os, const CallDescriptor::Kind& k) {
     case CallDescriptor::kCallAddress:
       os << "Addr";
       break;
-    case CallDescriptor::kLazyBailout:
-      os << "LazyBail";
-      break;
   }
   return os;
 }
@@ -282,31 +279,6 @@ CallDescriptor* Linkage::GetRuntimeCallDescriptor(
 }
 
 
-CallDescriptor* Linkage::GetLazyBailoutDescriptor(Zone* zone) {
-  const size_t return_count = 0;
-  const size_t parameter_count = 0;
-
-  LocationSignature::Builder locations(zone, return_count, parameter_count);
-  MachineSignature::Builder types(zone, return_count, parameter_count);
-
-  // The target is ignored, but we need to give some values here.
-  MachineType target_type = MachineType::AnyTagged();
-  LinkageLocation target_loc = regloc(kJSFunctionRegister);
-  return new (zone) CallDescriptor(      // --
-      CallDescriptor::kLazyBailout,      // kind
-      target_type,                       // target MachineType
-      target_loc,                        // target location
-      types.Build(),                     // machine_sig
-      locations.Build(),                 // location_sig
-      0,                                 // stack_parameter_count
-      Operator::kNoThrow,                // properties
-      kNoCalleeSaved,                    // callee-saved
-      kNoCalleeSaved,                    // callee-saved fp
-      CallDescriptor::kNeedsFrameState,  // flags
-      "lazy-bailout");
-}
-
-
 CallDescriptor* Linkage::GetJSCallDescriptor(Zone* zone, bool is_osr,
                                              int js_parameter_count,
                                              CallDescriptor::Flags flags) {

src/compiler/linkage.h

@@ -146,8 +146,7 @@ class CallDescriptor final : public ZoneObject {
   enum Kind {
     kCallCodeObject,  // target is a Code object
     kCallJSFunction,  // target is a JSFunction object
-    kCallAddress,     // target is a machine pointer
-    kLazyBailout      // the call is no-op, only used for lazy bailout
+    kCallAddress      // target is a machine pointer
   };
 
   enum Flag {
@@ -325,8 +324,6 @@ class Linkage : public ZoneObject {
       Zone* zone, Runtime::FunctionId function, int parameter_count,
       Operator::Properties properties, CallDescriptor::Flags flags);
 
-  static CallDescriptor* GetLazyBailoutDescriptor(Zone* zone);
-
   static CallDescriptor* GetStubCallDescriptor(
       Isolate* isolate, Zone* zone, const CallInterfaceDescriptor& descriptor,
       int stack_parameter_count, CallDescriptor::Flags flags,

src/compiler/mips/code-generator-mips.cc

@@ -551,11 +551,6 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       frame_access_state()->ClearSPDelta();
       break;
     }
-    case kArchLazyBailout: {
-      EnsureSpaceForLazyDeopt();
-      RecordCallPosition(instr);
-      break;
-    }
     case kArchPrepareCallCFunction: {
       int const num_parameters = MiscField::decode(instr->opcode());
       __ PrepareCallCFunction(num_parameters, kScratchReg);

src/compiler/mips64/code-generator-mips64.cc

@@ -561,11 +561,6 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       frame_access_state()->ClearSPDelta();
       break;
     }
-    case kArchLazyBailout: {
-      EnsureSpaceForLazyDeopt();
-      RecordCallPosition(instr);
-      break;
-    }
     case kArchPrepareCallCFunction: {
       int const num_parameters = MiscField::decode(instr->opcode());
       __ PrepareCallCFunction(num_parameters, kScratchReg);

src/compiler/ppc/code-generator-ppc.cc

@@ -761,13 +761,6 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       frame_access_state()->ClearSPDelta();
       break;
     }
-    case kArchLazyBailout: {
-      v8::internal::Assembler::BlockTrampolinePoolScope block_trampoline_pool(
-          masm());
-      EnsureSpaceForLazyDeopt();
-      RecordCallPosition(instr);
-      break;
-    }
     case kArchPrepareCallCFunction: {
       int const num_parameters = MiscField::decode(instr->opcode());
       __ PrepareCallCFunction(num_parameters, kScratchReg);

src/compiler/x64/code-generator-x64.cc

@@ -654,11 +654,6 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       frame_access_state()->ClearSPDelta();
       break;
     }
-    case kArchLazyBailout: {
-      EnsureSpaceForLazyDeopt();
-      RecordCallPosition(instr);
-      break;
-    }
     case kArchPrepareCallCFunction: {
       // Frame alignment requires using FP-relative frame addressing.
       frame_access_state()->SetFrameAccessToFP();

src/compiler/x87/code-generator-x87.cc

@@ -485,14 +485,6 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
       frame_access_state()->ClearSPDelta();
       break;
     }
-    case kArchLazyBailout: {
-      DoEnsureSpaceForLazyDeopt(info(), masm(), last_lazy_deopt_pc_);
-      RecordCallPosition(instr);
-      // Lazy Bailout entry, need to re-initialize FPU state.
-      __ fninit();
-      __ fld1();
-      break;
-    }
     case kArchPrepareCallCFunction: {
       // Frame alignment requires using FP-relative frame addressing.
       frame_access_state()->SetFrameAccessToFP();

src/full-codegen/full-codegen.cc

@@ -1168,7 +1168,6 @@ void FullCodeGenerator::VisitTryCatchStatement(TryCatchStatement* stmt) {
   Label try_entry, handler_entry, exit;
   __ jmp(&try_entry);
   __ bind(&handler_entry);
-  PrepareForBailoutForId(stmt->HandlerId(), NO_REGISTERS);
   ClearPendingMessage();
 
   // Exception handler code, the exception is in the result register.
@@ -1237,7 +1236,6 @@ void FullCodeGenerator::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
   // Jump to try-handler setup and try-block code.
   __ jmp(&try_entry);
   __ bind(&handler_entry);
-  PrepareForBailoutForId(stmt->HandlerId(), NO_REGISTERS);
 
   // Exception handler code.  This code is only executed when an exception
   // is thrown.  Record the continuation and jump to the finally block.