/*

 * 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/assembler.inline.hpp"

#include "asm/codeBuffer.hpp"

#include "code/codeCache.hpp"

#include "runtime/handles.inline.hpp"

inline void MacroAssembler::pd_patch_instruction(address branch, address target, const char* file, int line) {

  int instr = *(int*)branch;

  int new_offset = (int)(target - branch - 8);

  assert((new_offset & 3) == 0, "bad alignment");

  if ((instr & 0x0e000000) == 0x0a000000) {

    // B or BL instruction

    assert(new_offset < 0x2000000 && new_offset > -0x2000000, "encoding constraint");

    *(int*)branch = (instr & 0xff000000) | ((unsigned int)new_offset << 6 >> 8);

  } else if((unsigned int)instr == address_placeholder_instruction) {

    // address

    *(int*)branch = (int)target;

  } else if ((instr & 0x0fff0000) == 0x028f0000 || ((instr & 0x0fff0000) == 0x024f0000)) {

    // ADR

    int encoding = 0x8 << 20; // ADD

    if (new_offset < 0) {

      encoding = 0x4 << 20; // SUB

      new_offset = -new_offset;

    }

    AsmOperand o(new_offset);

    *(int*)branch = (instr & 0xff0ff000) | encoding | o.encoding();

  } else {

    // LDR Rd, [PC, offset] instruction

    assert((instr & 0x0f7f0000) == 0x051f0000, "Must be ldr_literal");

    assert(new_offset < 4096 && new_offset > -4096, "encoding constraint");

    if (new_offset >= 0) {

      *(int*)branch = (instr & 0xff0ff000) | 9 << 20 | new_offset;

    } else {

      *(int*)branch = (instr & 0xff0ff000) | 1 << 20 | -new_offset;

    }

  }

}