Encode interpreter::SourcePositionTable as variable-length ints.

src/interpreter/bytecode-array-builder.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/interpreter/bytecode-array-builder.h"
 #include "src/compiler.h"
 
 namespace v8 {
 namespace internal {
 namespace interpreter {
@@ skipping 106 matching lines @@
 Handle<BytecodeArray> BytecodeArrayBuilder::ToBytecodeArray() {
   DCHECK_EQ(bytecode_generated_, false);
   DCHECK(exit_seen_in_block_);
 
   int bytecode_size = static_cast<int>(bytecodes_.size());
   int register_count =
       fixed_and_temporary_register_count() + translation_register_count();
   int frame_size = register_count * kPointerSize;
   Handle<FixedArray> constant_pool = constant_array_builder()->ToFixedArray();
   Handle<FixedArray> handler_table = handler_table_builder()->ToHandlerTable();
-  Handle<FixedArray> source_position_table =
-      source_position_table_builder()->ToFixedArray();
+  Handle<ByteArray> source_position_table =
+      source_position_table_builder()->ToSourcePositionTable();
   Handle<BytecodeArray> output = isolate_->factory()->NewBytecodeArray(
       bytecode_size, &bytecodes_.front(), frame_size, parameter_count(),
       constant_pool);
   output->set_handler_table(*handler_table);
   output->set_source_position_table(*source_position_table);
   bytecode_generated_ = true;
   return output;
 }
 
 
 template <size_t N>
 void BytecodeArrayBuilder::Output(Bytecode bytecode, uint32_t(&operands)[N]) {
   // Don't output dead code.
-  if (exit_seen_in_block_) {
-    source_position_table_builder_.RevertPosition(bytecodes()->size());
-    return;
-  }
+  if (exit_seen_in_block_) return;
 
   int operand_count = static_cast<int>(N);
   DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode), operand_count);
 
   int register_operand_count = Bytecodes::NumberOfRegisterOperands(bytecode);
   if (register_operand_count > 0) {
     register_translator()->TranslateInputRegisters(bytecode, operands,
                                                    operand_count);
   }
 
@@ skipping 47 matching lines @@
 
 
 void BytecodeArrayBuilder::Output(Bytecode bytecode, uint32_t operand0) {
   uint32_t operands[] = {operand0};
   Output(bytecode, operands);
 }
 
 
 void BytecodeArrayBuilder::Output(Bytecode bytecode) {
   // Don't output dead code.
-  if (exit_seen_in_block_) {
-    source_position_table_builder_.RevertPosition(bytecodes()->size());
-    return;
-  }
+  if (exit_seen_in_block_) return;
 
   DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode), 0);
   last_bytecode_start_ = bytecodes()->size();
   bytecodes()->push_back(Bytecodes::ToByte(bytecode));
 }
 
 BytecodeArrayBuilder& BytecodeArrayBuilder::BinaryOperation(Token::Value op,
                                                             Register reg) {
   Output(BytecodeForBinaryOperation(op), reg.ToRawOperand());
   return *this;
@@ skipping 626 matching lines @@
     case OperandSize::kNone:
       UNREACHABLE();
   }
   unbound_jumps_--;
 }
 
 
 BytecodeArrayBuilder& BytecodeArrayBuilder::OutputJump(Bytecode jump_bytecode,
                                                        BytecodeLabel* label) {
   // Don't emit dead code.
-  if (exit_seen_in_block_) {
-    source_position_table_builder_.RevertPosition(bytecodes()->size());
-    return *this;
-  }
+  if (exit_seen_in_block_) return *this;
 
   // Check if the value in accumulator is boolean, if not choose an
   // appropriate JumpIfToBoolean bytecode.
   if (NeedToBooleanCast()) {
     jump_bytecode = GetJumpWithToBoolean(jump_bytecode);
   }
 
   if (label->is_bound()) {
     // Label has been bound already so this is a backwards jump.
     CHECK_GE(bytecodes()->size(), label->offset());
@@ skipping 173 matching lines @@
   last_block_end_ = bytecodes()->size();
   exit_seen_in_block_ = false;
 }
 
 void BytecodeArrayBuilder::EnsureReturn(FunctionLiteral* literal) {
   if (!exit_seen_in_block_) {
     LoadUndefined();
     SetReturnPosition(literal);
     Return();
   }
+  DCHECK(exit_seen_in_block_);
 }
 
 BytecodeArrayBuilder& BytecodeArrayBuilder::CallIC(
     Register callable, Register receiver_args, size_t receiver_args_count,
     int feedback_slot, TailCallMode tail_call_mode) {
   Bytecode bytecode = BytecodeForCallIC(tail_call_mode);
   if (FitsInReg8Operand(callable) && FitsInReg8Operand(receiver_args) &&
       FitsInIdx8Operand(receiver_args_count) &&
       FitsInIdx8Operand(feedback_slot)) {
     Output(bytecode, callable.ToRawOperand(), receiver_args.ToRawOperand(),
@@ skipping 126 matching lines @@
   Output(BytecodeForDelete(language_mode), object.ToRawOperand());
   return *this;
 }
 
 
 size_t BytecodeArrayBuilder::GetConstantPoolEntry(Handle<Object> object) {
   return constant_array_builder()->Insert(object);
 }
 
 void BytecodeArrayBuilder::SetReturnPosition(FunctionLiteral* fun) {
+  // Don't emit dead code.
+  if (exit_seen_in_block_) return;
+
   int pos = std::max(fun->start_position(), fun->end_position() - 1);
   source_position_table_builder_.AddStatementPosition(bytecodes_.size(), pos);
 }
 
 void BytecodeArrayBuilder::SetStatementPosition(Statement* stmt) {
   if (stmt->position() == RelocInfo::kNoPosition) return;
+  if (exit_seen_in_block_) return;
   source_position_table_builder_.AddStatementPosition(bytecodes_.size(),
                                                       stmt->position());
 }
 
 void BytecodeArrayBuilder::SetExpressionPosition(Expression* expr) {
   if (expr->position() == RelocInfo::kNoPosition) return;
+  if (exit_seen_in_block_) return;
   source_position_table_builder_.AddExpressionPosition(bytecodes_.size(),
                                                        expr->position());
 }
 
 bool BytecodeArrayBuilder::TemporaryRegisterIsLive(Register reg) const {
   return temporary_register_allocator()->RegisterIsLive(reg);
 }
 
 bool BytecodeArrayBuilder::OperandIsValid(Bytecode bytecode, int operand_index,
                                           uint32_t operand_value) const {
@@ skipping 436 matching lines @@
 }
 
 // static
 bool BytecodeArrayBuilder::FitsInReg16OperandUntranslated(Register value) {
   return value.is_short_operand();
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8