src/hotspot/share/interpreter/abstractInterpreter.cpp

/*
 * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "asm/macroAssembler.hpp"
#include "asm/macroAssembler.inline.hpp"
#include "cds/metaspaceShared.hpp"
#include "compiler/disassembler.hpp"
#include "interpreter/bytecodeHistogram.hpp"
#include "interpreter/bytecodeStream.hpp"
#include "interpreter/interpreter.hpp"
#include "interpreter/interpreterRuntime.hpp"
#include "interpreter/interp_masm.hpp"
#include "interpreter/templateTable.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/resourceArea.hpp"
#include "oops/arrayOop.hpp"
#include "oops/constantPool.inline.hpp"
#include "oops/cpCache.inline.hpp"
#include "oops/methodData.hpp"
#include "oops/method.inline.hpp"
#include "oops/oop.inline.hpp"
#include "prims/jvmtiExport.hpp"
#include "prims/methodHandles.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/stubRoutines.hpp"
#include "runtime/timer.hpp"

# define __ _masm->

//------------------------------------------------------------------------------------------------------------------------
// Implementation of platform independent aspects of Interpreter

void AbstractInterpreter::initialize() {
  // make sure 'imported' classes are initialized
  if (CountBytecodes || TraceBytecodes || StopInterpreterAt) BytecodeCounter::reset();
  if (PrintBytecodeHistogram)                                BytecodeHistogram::reset();
  if (PrintBytecodePairHistogram)                            BytecodePairHistogram::reset();
}

void AbstractInterpreter::print() {
  tty->cr();
  tty->print_cr("----------------------------------------------------------------------");
  tty->print_cr("Interpreter");
  tty->cr();
  tty->print_cr("code size        = %6dK bytes", (int)_code->used_space()/1024);
  tty->print_cr("total space      = %6dK bytes", (int)_code->total_space()/1024);
  tty->print_cr("wasted space     = %6dK bytes", (int)_code->available_space()/1024);
  tty->cr();
  tty->print_cr("# of codelets    = %6d"      , _code->number_of_stubs());
  if (_code->number_of_stubs() != 0) {
    tty->print_cr("avg codelet size = %6d bytes", _code->used_space() / _code->number_of_stubs());
    tty->cr();
  }
  _should_print_instructions = PrintInterpreter;
  _code->print();
  _should_print_instructions = false;
  tty->print_cr("----------------------------------------------------------------------");
  tty->cr();
}


//------------------------------------------------------------------------------------------------------------------------
// Implementation of interpreter

StubQueue* AbstractInterpreter::_code                                       = nullptr;
bool       AbstractInterpreter::_notice_safepoints                          = false;
address    AbstractInterpreter::_rethrow_exception_entry                    = nullptr;

address    AbstractInterpreter::_slow_signature_handler;
address    AbstractInterpreter::_entry_table            [AbstractInterpreter::number_of_method_entries];
address    AbstractInterpreter::_native_abi_to_tosca    [AbstractInterpreter::number_of_result_handlers];

bool       AbstractInterpreter::_should_print_instructions = false;

//------------------------------------------------------------------------------------------------------------------------
// Generation of complete interpreter

AbstractInterpreterGenerator::AbstractInterpreterGenerator() {
  _masm                      = nullptr;
}


//------------------------------------------------------------------------------------------------------------------------
// Entry points

AbstractInterpreter::MethodKind AbstractInterpreter::method_kind(const methodHandle& m) {
  // Abstract method?
  if (m->is_abstract()) return abstract;

  // Method handle primitive?
  vmIntrinsics::ID iid = m->intrinsic_id();
  if (iid != vmIntrinsics::_none) {
    if (m->is_method_handle_intrinsic()) {
      assert(MethodHandles::is_signature_polymorphic(iid), "must match an intrinsic");
      MethodKind kind = (MethodKind)(method_handle_invoke_FIRST +
                                    vmIntrinsics::as_int(iid) -
                                    static_cast<int>(vmIntrinsics::FIRST_MH_SIG_POLY));
      assert(kind <= method_handle_invoke_LAST, "parallel enum ranges");
      return kind;
    }

    switch (iid) {
#ifndef ZERO
      // Use optimized stub code for CRC32 native methods.
      case vmIntrinsics::_updateCRC32:       return java_util_zip_CRC32_update;
      case vmIntrinsics::_updateBytesCRC32:  return java_util_zip_CRC32_updateBytes;
      case vmIntrinsics::_updateByteBufferCRC32: return java_util_zip_CRC32_updateByteBuffer;
      // Use optimized stub code for CRC32C methods.
      case vmIntrinsics::_updateBytesCRC32C: return java_util_zip_CRC32C_updateBytes;
      case vmIntrinsics::_updateDirectByteBufferCRC32C: return java_util_zip_CRC32C_updateDirectByteBuffer;
      case vmIntrinsics::_float16ToFloat:    return java_lang_Float_float16ToFloat;
      case vmIntrinsics::_floatToFloat16:    return java_lang_Float_floatToFloat16;
      case vmIntrinsics::_currentThread:     return java_lang_Thread_currentThread;
#endif // ZERO
      case vmIntrinsics::_dsin:              return java_lang_math_sin;
      case vmIntrinsics::_dcos:              return java_lang_math_cos;
      case vmIntrinsics::_dtan:              return java_lang_math_tan;
      case vmIntrinsics::_dtanh:             return java_lang_math_tanh;
      case vmIntrinsics::_dcbrt:             return java_lang_math_cbrt;
      case vmIntrinsics::_dabs:              return java_lang_math_abs;
      case vmIntrinsics::_dlog:              return java_lang_math_log;
      case vmIntrinsics::_dlog10:            return java_lang_math_log10;
      case vmIntrinsics::_dpow:              return java_lang_math_pow;
      case vmIntrinsics::_dexp:              return java_lang_math_exp;
      case vmIntrinsics::_fmaD:              return java_lang_math_fmaD;
      case vmIntrinsics::_fmaF:              return java_lang_math_fmaF;
      case vmIntrinsics::_dsqrt:             return java_lang_math_sqrt;
      case vmIntrinsics::_dsqrt_strict:      return java_lang_math_sqrt_strict;
      case vmIntrinsics::_Reference_get:     return java_lang_ref_reference_get;
      case vmIntrinsics::_Object_init:
        if (m->code_size() == 1) {
          // We need to execute the special return bytecode to check for
          // finalizer registration so create a normal frame.
          return zerolocals;
        }
        break;
      default: break;
    }
  }

  // Native method?
  if (m->is_native()) {
    if (m->is_continuation_native_intrinsic()) {
      // This entry will never be called.  The real entry gets generated later, like for MH intrinsics.
      return abstract;
    }
    assert(!m->is_method_handle_intrinsic(), "overlapping bits here, watch out");
    return m->is_synchronized() ? native_synchronized : native;
  }

  // Synchronized?
  if (m->is_synchronized()) {
    return zerolocals_synchronized;
  }

  // Empty method?
  if (m->is_empty_method()) {
    return empty;
  }

  // Getter method?
  if (m->is_getter()) {
    return getter;
  }

  // Setter method?
  if (m->is_setter()) {
    return setter;
  }

  // Note: for now: zero locals for all non-empty methods
  return zerolocals;
}

vmIntrinsics::ID AbstractInterpreter::method_intrinsic(MethodKind kind) {
  switch (kind) {
  case java_lang_math_sin         : return vmIntrinsics::_dsin;
  case java_lang_math_cos         : return vmIntrinsics::_dcos;
  case java_lang_math_tan         : return vmIntrinsics::_dtan;
  case java_lang_math_tanh        : return vmIntrinsics::_dtanh;
  case java_lang_math_cbrt        : return vmIntrinsics::_dcbrt;
  case java_lang_math_abs         : return vmIntrinsics::_dabs;
  case java_lang_math_log         : return vmIntrinsics::_dlog;
  case java_lang_math_log10       : return vmIntrinsics::_dlog10;
  case java_lang_math_sqrt        : return vmIntrinsics::_dsqrt;
  case java_lang_math_sqrt_strict : return vmIntrinsics::_dsqrt_strict;
  case java_lang_math_pow         : return vmIntrinsics::_dpow;
  case java_lang_math_exp         : return vmIntrinsics::_dexp;
  case java_lang_math_fmaD        : return vmIntrinsics::_fmaD;
  case java_lang_math_fmaF        : return vmIntrinsics::_fmaF;
  case java_lang_ref_reference_get: return vmIntrinsics::_Reference_get;
  case java_util_zip_CRC32_update : return vmIntrinsics::_updateCRC32;
  case java_util_zip_CRC32_updateBytes
                                  : return vmIntrinsics::_updateBytesCRC32;
  case java_util_zip_CRC32_updateByteBuffer
                                  : return vmIntrinsics::_updateByteBufferCRC32;
  case java_util_zip_CRC32C_updateBytes
                                  : return vmIntrinsics::_updateBytesCRC32C;
  case java_util_zip_CRC32C_updateDirectByteBuffer
                                  : return vmIntrinsics::_updateDirectByteBufferCRC32C;
  case java_lang_Thread_currentThread
                                  : return vmIntrinsics::_currentThread;
  case java_lang_Float_float16ToFloat
                                  : return vmIntrinsics::_float16ToFloat;
  case java_lang_Float_floatToFloat16
                                  : return vmIntrinsics::_floatToFloat16;

  default:
    fatal("unexpected method intrinsic kind: %d", kind);
    break;
  }
  return vmIntrinsics::_none;
}

void AbstractInterpreter::set_entry_for_kind(MethodKind kind, address entry) {
  assert(kind >= method_handle_invoke_FIRST &&
         kind <= method_handle_invoke_LAST, "late initialization only for MH entry points");
  assert(_entry_table[kind] == _entry_table[abstract], "previous value must be AME entry");
  _entry_table[kind] = entry;
}

// Return true if the interpreter can prove that the given bytecode has
// not yet been executed (in Java semantics, not in actual operation).
bool AbstractInterpreter::is_not_reached(const methodHandle& method, int bci) {
  BytecodeStream s(method, bci);
  Bytecodes::Code code = s.next();

  if (Bytecodes::is_invoke(code)) {
    assert(!Bytecodes::must_rewrite(code), "invokes aren't rewritten");
    ConstantPool* cpool = method()->constants();

    Bytecode invoke_bc(s.bytecode());

    switch (code) {
      case Bytecodes::_invokedynamic: {
        assert(invoke_bc.has_index_u4(code), "sanity");
        int method_index = invoke_bc.get_index_u4(code);
        return cpool->resolved_indy_entry_at(method_index)->is_resolved();
      }
      case Bytecodes::_invokevirtual:   // fall-through
      case Bytecodes::_invokeinterface: // fall-through
      case Bytecodes::_invokespecial:   // fall-through
      case Bytecodes::_invokestatic: {
        if (cpool->has_preresolution()) {
          return false; // might have been reached
        }
        assert(!invoke_bc.has_index_u4(code), "sanity");
        int method_index = invoke_bc.get_index_u2(code);
        constantPoolHandle cp(Thread::current(), cpool);
        Method* resolved_method = ConstantPool::method_at_if_loaded(cp, method_index);
        return (resolved_method == nullptr);
      }
      default: ShouldNotReachHere();
    }
  } else if (!Bytecodes::must_rewrite(code)) {
    // might have been reached
    return false;
  }

  // the bytecode might not be rewritten if the method is an accessor, etc.
  address ientry = method->interpreter_entry();
  if (ientry != entry_for_kind(AbstractInterpreter::zerolocals) &&
      ientry != entry_for_kind(AbstractInterpreter::zerolocals_synchronized))
    return false;  // interpreter does not run this method!

  // otherwise, we can be sure this bytecode has never been executed
  return true;
}


#ifndef PRODUCT
void AbstractInterpreter::print_method_kind(MethodKind kind) {
  switch (kind) {
    case zerolocals             : tty->print("zerolocals"             ); break;
    case zerolocals_synchronized: tty->print("zerolocals_synchronized"); break;
    case native                 : tty->print("native"                 ); break;
    case native_synchronized    : tty->print("native_synchronized"    ); break;
    case empty                  : tty->print("empty"                  ); break;
    case getter                 : tty->print("getter"                 ); break;
    case setter                 : tty->print("setter"                 ); break;
    case abstract               : tty->print("abstract"               ); break;
    case java_lang_math_sin     : tty->print("java_lang_math_sin"     ); break;
    case java_lang_math_cos     : tty->print("java_lang_math_cos"     ); break;
    case java_lang_math_tan     : tty->print("java_lang_math_tan"     ); break;
    case java_lang_math_tanh    : tty->print("java_lang_math_tanh"    ); break;
    case java_lang_math_cbrt    : tty->print("java_lang_math_cbrt"    ); break;
    case java_lang_math_abs     : tty->print("java_lang_math_abs"     ); break;
    case java_lang_math_log     : tty->print("java_lang_math_log"     ); break;
    case java_lang_math_log10   : tty->print("java_lang_math_log10"   ); break;
    case java_lang_math_pow     : tty->print("java_lang_math_pow"     ); break;
    case java_lang_math_exp     : tty->print("java_lang_math_exp"     ); break;
    case java_lang_math_fmaD    : tty->print("java_lang_math_fmaD"    ); break;
    case java_lang_math_fmaF    : tty->print("java_lang_math_fmaF"    ); break;
    case java_lang_math_sqrt    : tty->print("java_lang_math_sqrt"    ); break;
    case java_lang_math_sqrt_strict           : tty->print("java_lang_math_sqrt_strict"); break;
    case java_util_zip_CRC32_update           : tty->print("java_util_zip_CRC32_update"); break;
    case java_util_zip_CRC32_updateBytes      : tty->print("java_util_zip_CRC32_updateBytes"); break;
    case java_util_zip_CRC32_updateByteBuffer : tty->print("java_util_zip_CRC32_updateByteBuffer"); break;
    case java_util_zip_CRC32C_updateBytes     : tty->print("java_util_zip_CRC32C_updateBytes"); break;
    case java_util_zip_CRC32C_updateDirectByteBuffer: tty->print("java_util_zip_CRC32C_updateDirectByteByffer"); break;
    case java_lang_ref_reference_get          : tty->print("java_lang_ref_reference_get"); break;
    case java_lang_Thread_currentThread       : tty->print("java_lang_Thread_currentThread"); break;
    case java_lang_Float_float16ToFloat       : tty->print("java_lang_Float_float16ToFloat"); break;
    case java_lang_Float_floatToFloat16       : tty->print("java_lang_Float_floatToFloat16"); break;
    default:
      if (kind >= method_handle_invoke_FIRST &&
          kind <= method_handle_invoke_LAST) {
        const char* kind_name = vmIntrinsics::name_at(method_handle_intrinsic(kind));
        if (kind_name[0] == '_')  kind_name = &kind_name[1];  // '_invokeExact' => 'invokeExact'
        tty->print("method_handle_%s", kind_name);
        break;
      }
      ShouldNotReachHere();
      break;
  }
}
#endif // PRODUCT


//------------------------------------------------------------------------------------------------------------------------
// Deoptimization support

/**
 * If a deoptimization happens, this function returns the point of next bytecode to continue execution.
 */
address AbstractInterpreter::deopt_continue_after_entry(Method* method, address bcp, int callee_parameters, bool is_top_frame) {
  assert(method->contains(bcp), "just checkin'");

  // Get the original and rewritten bytecode.
  Bytecodes::Code code = Bytecodes::java_code_at(method, bcp);
  assert(!Interpreter::bytecode_should_reexecute(code), "should not reexecute");

  const int bci = method->bci_from(bcp);

  // compute continuation length
  const int length = Bytecodes::length_at(method, bcp);

  // compute result type
  BasicType type = T_ILLEGAL;

  switch (code) {
    case Bytecodes::_invokevirtual  :
    case Bytecodes::_invokespecial  :
    case Bytecodes::_invokestatic   :
    case Bytecodes::_invokeinterface: {
      Thread *thread = Thread::current();
      ResourceMark rm(thread);
      methodHandle mh(thread, method);
      type = Bytecode_invoke(mh, bci).result_type();
      // since the cache entry might not be initialized:
      // (NOT needed for the old calling convention)
      if (!is_top_frame) {
        int index = Bytes::get_native_u2(bcp+1);
        method->constants()->cache()->resolved_method_entry_at(index)->set_num_parameters(callee_parameters);
      }
      break;
    }

   case Bytecodes::_invokedynamic: {
      Thread *thread = Thread::current();
      ResourceMark rm(thread);
      methodHandle mh(thread, method);
      type = Bytecode_invoke(mh, bci).result_type();
      // since the cache entry might not be initialized:
      // (NOT needed for the old calling convention)
      if (!is_top_frame) {
        int index = Bytes::get_native_u4(bcp+1);
        method->constants()->resolved_indy_entry_at(index)->set_num_parameters(callee_parameters);
      }
      break;
    }

    case Bytecodes::_ldc   :
    case Bytecodes::_ldc_w : // fall through
    case Bytecodes::_ldc2_w:
      {
        Thread *thread = Thread::current();
        ResourceMark rm(thread);
        methodHandle mh(thread, method);
        type = Bytecode_loadconstant(mh, bci).result_type();
        break;
      }

    default:
      type = Bytecodes::result_type(code);
      break;
  }

  // return entry point for computed continuation state & bytecode length
  return
    is_top_frame
    ? Interpreter::deopt_entry (as_TosState(type), length)
    : Interpreter::return_entry(as_TosState(type), length, code);
}

// If deoptimization happens, this function returns the point where the interpreter reexecutes
// the bytecode.
// Note: Bytecodes::_athrow is a special case in that it does not return
//       Interpreter::deopt_entry(vtos, 0) like others
address AbstractInterpreter::deopt_reexecute_entry(Method* method, address bcp) {
  assert(method->contains(bcp), "just checkin'");
  Bytecodes::Code code   = Bytecodes::java_code_at(method, bcp);
#if defined(COMPILER1) || INCLUDE_JVMCI
  if(code == Bytecodes::_athrow ) {
    return Interpreter::rethrow_exception_entry();
  }
#endif /* COMPILER1 || INCLUDE_JVMCI */
  return Interpreter::deopt_entry(vtos, 0);
}

// If deoptimization happens, the interpreter should reexecute these bytecodes.
// This function mainly helps the compilers to set up the reexecute bit.
bool AbstractInterpreter::bytecode_should_reexecute(Bytecodes::Code code) {
  switch (code) {
    case Bytecodes::_lookupswitch:
    case Bytecodes::_tableswitch:
    case Bytecodes::_fast_binaryswitch:
    case Bytecodes::_fast_linearswitch:
    // recompute conditional expression folded into _if<cond>
    case Bytecodes::_lcmp      :
    case Bytecodes::_fcmpl     :
    case Bytecodes::_fcmpg     :
    case Bytecodes::_dcmpl     :
    case Bytecodes::_dcmpg     :
    case Bytecodes::_ifnull    :
    case Bytecodes::_ifnonnull :
    case Bytecodes::_goto      :
    case Bytecodes::_goto_w    :
    case Bytecodes::_ifeq      :
    case Bytecodes::_ifne      :
    case Bytecodes::_iflt      :
    case Bytecodes::_ifge      :
    case Bytecodes::_ifgt      :
    case Bytecodes::_ifle      :
    case Bytecodes::_if_icmpeq :
    case Bytecodes::_if_icmpne :
    case Bytecodes::_if_icmplt :
    case Bytecodes::_if_icmpge :
    case Bytecodes::_if_icmpgt :
    case Bytecodes::_if_icmple :
    case Bytecodes::_if_acmpeq :
    case Bytecodes::_if_acmpne :
    // special cases
    case Bytecodes::_getfield  :
    case Bytecodes::_putfield  :
    case Bytecodes::_getstatic :
    case Bytecodes::_putstatic :
    case Bytecodes::_aastore   :
#ifdef COMPILER1
    //special case of reexecution
    case Bytecodes::_athrow    :
#endif
      return true;

    default:
      return false;
  }
}

void AbstractInterpreter::initialize_method_handle_entries() {
  // method handle entry kinds are generated later in MethodHandlesAdapterGenerator::generate:
  for (int i = method_handle_invoke_FIRST; i <= method_handle_invoke_LAST; i++) {
    MethodKind kind = (MethodKind) i;
    _entry_table[kind] = _entry_table[Interpreter::abstract];
  }
}