src/hotspot/cpu/arm/relocInfo_arm.cpp

/*
 * Copyright (c) 2008, 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.
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 */

#include "asm/assembler.inline.hpp"
#include "code/relocInfo.hpp"
#include "nativeInst_arm.hpp"
#include "oops/compressedOops.inline.hpp"
#include "oops/oop.hpp"
#include "runtime/safepoint.hpp"

void Relocation::pd_set_data_value(address x, bool verify_only) {

  NativeMovConstReg* ni = nativeMovConstReg_at(addr());
  if (verify_only) {
    guarantee(ni->data() == (intptr_t)x, "instructions must match");
  } else {
    ni->set_data((intptr_t)x);
  }
}

address Relocation::pd_call_destination(address orig_addr) {
  address pc = addr();

  int adj = 0;
  if (orig_addr != nullptr) {
    // We just moved this call instruction from orig_addr to addr().
    // This means that, when relative, its target will appear to have grown by addr() - orig_addr.
    adj = orig_addr - pc;
  }

  RawNativeInstruction* ni = rawNativeInstruction_at(pc);

  if (ni->is_add_lr()) {
    // Skip the optional 'add LR, PC, #offset'
    // (Allowing the jump support code to handle fat_call)
    pc = ni->next_raw_instruction_address();
    ni = nativeInstruction_at(pc);
  }

  if (ni->is_bl()) {
    // Fat_call are handled by is_jump for the new 'ni',
    // requiring only to support is_bl.
    return rawNativeCall_at(pc)->destination(adj);
  }

  if (ni->is_jump()) {
    return rawNativeJump_at(pc)->jump_destination(adj);
  }
  ShouldNotReachHere();
  return nullptr;
}

void Relocation::pd_set_call_destination(address x) {
  address pc = addr();
  NativeInstruction* ni = nativeInstruction_at(pc);

  if (ni->is_add_lr()) {
    // Skip the optional 'add LR, PC, #offset'
    // (Allowing the jump support code to handle fat_call)
    pc = ni->next_raw_instruction_address();
    ni = nativeInstruction_at(pc);
  }

  if (ni->is_bl()) {
    // Fat_call are handled by is_jump for the new 'ni',
    // requiring only to support is_bl.
    rawNativeCall_at(pc)->set_destination(x);
    return;
  }

  if (ni->is_jump()) { // raw jump
    rawNativeJump_at(pc)->set_jump_destination(x);
    return;
  }
  ShouldNotReachHere();
}


address* Relocation::pd_address_in_code() {
  return (address*)addr();
}

address Relocation::pd_get_address_from_code() {
  return *pd_address_in_code();
}

void poll_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {
}

void metadata_Relocation::pd_fix_value(address x) {
  assert(! addr_in_const(), "Do not use");
  if (!VM_Version::supports_movw()) {
    set_value(x);
#ifdef ASSERT
  } else {
    // the movw/movt data should be correct
    NativeMovConstReg* ni = nativeMovConstReg_at(addr());
    assert(ni->is_movw(), "not a movw");
    // The following assert should be correct but the shared code
    // currently 'fixes' the metadata instructions before the
    // metadata_table is copied in the new method (see
    // JDK-8042845). This means that 'x' (which comes from the table)
    // does not match the value inlined in the code (which is
    // correct). Failure can be temporarily ignored since the code is
    // correct and the table is copied shortly afterward.
    //
    // assert(ni->data() == (int)x, "metadata relocation mismatch");
#endif
  }
}