Quelle vtableStubs_aarch64.cpp Sprache: C

/*
* Copyright (c) 2003, 2021, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2014, Red Hat Inc. 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 "precompiled.hpp"
#include "asm/assembler.inline.hpp"
#include "asm/macroAssembler.inline.hpp"
#include "code/vtableStubs.hpp"
#include "interp_masm_aarch64.hpp"
#include "memory/resourceArea.hpp"
#include "oops/compiledICHolder.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/klassVtable.hpp"
#include "runtime/sharedRuntime.hpp"
#include "vmreg_aarch64.inline.hpp"
#ifdef COMPILER2
#include "opto/runtime.hpp"
#endif

// machine-dependent part of VtableStubs: create VtableStub of correct size and
// initialize its code

#define __ masm->

#ifndef PRODUCT
extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index);
#endif

VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {
  // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.
  const int stub_code_length = code_size_limit(true);
  VtableStub* s = new(stub_code_length) VtableStub(true, vtable_index);
  // Can be NULL if there is no free space in the code cache.
  if (s == NULL) {
    return NULL;
  }

  // Count unused bytes in instruction sequences of variable size.
  // We add them to the computed buffer size in order to avoid
  // overflow in subsequently generated stubs.
  address   start_pc;
  int       slop_bytes = 0;
  int       slop_delta = 0;

  ResourceMark    rm;
  CodeBuffer      cb(s->entry_point(), stub_code_length);
  MacroAssembler* masm = new MacroAssembler(&cb);

#if (!defined(PRODUCT) && defined(COMPILER2))
  if (CountCompiledCalls) {
    __ lea(r16, ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
    __ increment(Address(r16));
  }
#endif

  // get receiver (need to skip return address on top of stack)
  assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");

  // get receiver klass
  address npe_addr = __ pc();
  __ load_klass(r16, j_rarg0);

#ifndef PRODUCT
  if (DebugVtables) {
    Label L;
    // TODO: find upper bound for this debug code.
    start_pc = __ pc();

    // check offset vs vtable length
    __ ldrw(rscratch1, Address(r16, Klass::vtable_length_offset()));
    __ cmpw(rscratch1, vtable_index * vtableEntry::size());
    __ br(Assembler::GT, L);
    __ enter();
    __ mov(r2, vtable_index);

    __ call_VM(noreg, CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), j_rarg0, r2);
    const ptrdiff_t estimate = 256;
    const ptrdiff_t codesize = __ pc() - start_pc;
    slop_delta  = estimate - codesize;  // call_VM varies in length, depending on data
    slop_bytes += slop_delta;
    assert(slop_delta >= 0, "vtable #%d: Code size estimate (%d) for DebugVtables too small, required: %d", vtable_index, (int)estimate, (int)codesize);

    __ leave();
    __ bind(L);
  }
#endif // PRODUCT

  start_pc = __ pc();
  __ lookup_virtual_method(r16, vtable_index, rmethod);
  slop_delta  = 8 - (int)(__ pc() - start_pc);
  slop_bytes += slop_delta;
  assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);

#ifndef PRODUCT
  if (DebugVtables) {
    Label L;
    __ cbz(rmethod, L);
    __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));
    __ cbnz(rscratch1, L);
    __ stop("Vtable entry is NULL");
    __ bind(L);
  }
#endif // PRODUCT

  // r0: receiver klass
  // rmethod: Method*
  // r2: receiver
  address ame_addr = __ pc();
  __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));
  __ br(rscratch1);

  masm->flush();
  bookkeeping(masm, tty, s, npe_addr, ame_addr, true, vtable_index, slop_bytes, 0);

  return s;
}

VtableStub* VtableStubs::create_itable_stub(int itable_index) {
  // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.
  const int stub_code_length = code_size_limit(false);
  VtableStub* s = new(stub_code_length) VtableStub(false, itable_index);
  // Can be NULL if there is no free space in the code cache.
  if (s == NULL) {
    return NULL;
  }

  // Count unused bytes in instruction sequences of variable size.
  // We add them to the computed buffer size in order to avoid
  // overflow in subsequently generated stubs.
  address   start_pc;
  int       slop_bytes = 0;
  int       slop_delta = 0;

  ResourceMark    rm;
  CodeBuffer      cb(s->entry_point(), stub_code_length);
  MacroAssembler* masm = new MacroAssembler(&cb);

#if (!defined(PRODUCT) && defined(COMPILER2))
  if (CountCompiledCalls) {
    __ lea(r10, ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));
    __ increment(Address(r10));
  }
#endif

  // get receiver (need to skip return address on top of stack)
  assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");

  // Entry arguments:
  //  rscratch2: CompiledICHolder
  //  j_rarg0: Receiver

  // This stub is called from compiled code which has no callee-saved registers,
  // so all registers except arguments are free at this point.
  const Register recv_klass_reg     = r10;
  const Register holder_klass_reg   = r16; // declaring interface klass (DECC)
  const Register resolved_klass_reg = rmethod; // resolved interface klass (REFC)
  const Register temp_reg           = r11;
  const Register temp_reg2          = r15;
  const Register icholder_reg       = rscratch2;

  Label L_no_such_interface;

  __ ldr(resolved_klass_reg, Address(icholder_reg, CompiledICHolder::holder_klass_offset()));
  __ ldr(holder_klass_reg,   Address(icholder_reg, CompiledICHolder::holder_metadata_offset()));

  start_pc = __ pc();

  // get receiver klass (also an implicit null-check)
  address npe_addr = __ pc();
  __ load_klass(recv_klass_reg, j_rarg0);

  // Receiver subtype check against REFC.
  __ lookup_interface_method(// inputs: rec. class, interface
                             recv_klass_reg, resolved_klass_reg, noreg,
                             // outputs:  scan temp. reg1, scan temp. reg2
                             temp_reg2, temp_reg,
                             L_no_such_interface,
                             /*return_method=*/false);

  const ptrdiff_t  typecheckSize = __ pc() - start_pc;
  start_pc = __ pc();

  // Get selected method from declaring class and itable index
  __ lookup_interface_method(// inputs: rec. class, interface, itable index
                             recv_klass_reg, holder_klass_reg, itable_index,
                             // outputs: method, scan temp. reg
                             rmethod, temp_reg,
                             L_no_such_interface);

  const ptrdiff_t lookupSize = __ pc() - start_pc;

  // Reduce "estimate" such that "padding" does not drop below 8.
  const ptrdiff_t estimate = 124;
  const ptrdiff_t codesize = typecheckSize + lookupSize;
  slop_delta  = (int)(estimate - codesize);
  slop_bytes += slop_delta;
  assert(slop_delta >= 0, "itable #%d: Code size estimate (%d) for lookup_interface_method too small, required: %d", itable_index, (int)estimate, (int)codesize);

#ifdef ASSERT
  if (DebugVtables) {
    Label L2;
    __ cbz(rmethod, L2);
    __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));
    __ cbnz(rscratch1, L2);
    __ stop("compiler entrypoint is null");
    __ bind(L2);
  }
#endif // ASSERT

  // rmethod: Method*
  // j_rarg0: receiver
  address ame_addr = __ pc();
  __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));
  __ br(rscratch1);

  __ bind(L_no_such_interface);
  // Handle IncompatibleClassChangeError in itable stubs.
  // More detailed error message.
  // We force resolving of the call site by jumping to the "handle
  // wrong method" stub, and so let the interpreter runtime do all the
  // dirty work.
  assert(SharedRuntime::get_handle_wrong_method_stub() != NULL, "check initialization order");
  __ far_jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub()));

  masm->flush();
  bookkeeping(masm, tty, s, npe_addr, ame_addr, false, itable_index, slop_bytes, 0);

  return s;
}

int VtableStub::pd_code_alignment() {
  // aarch64 cache line size is not an architected constant. We just align on 4 bytes (instruction size).
  const unsigned int icache_line_size = 4;
  return icache_line_size;
}

quality95%

¤ Dauer der Verarbeitung: 0.4 Sekunden ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.