/*

 * Copyright (c) 2008, 2016, 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 "precompiled.hpp"

#ifdef COMPILER2

#include "asm/assembler.hpp"

#include "assembler_arm.inline.hpp"

#include "classfile/systemDictionary.hpp"

#include "code/vmreg.hpp"

#include "interpreter/interpreter.hpp"

#include "memory/resourceArea.hpp"

#include "nativeInst_arm.hpp"

#include "opto/runtime.hpp"

#include "runtime/interfaceSupport.hpp"

#include "runtime/sharedRuntime.hpp"

#include "runtime/stubRoutines.hpp"

#include "runtime/vframeArray.hpp"

#include "utilities/globalDefinitions.hpp"

#include "vmreg_arm.inline.hpp"

#endif

#define __ masm->

//------------------------------ generate_exception_blob ---------------------------

// creates exception blob at the end

// Using exception blob, this code is jumped from a compiled method.

// (see emit_exception_handler in sparc.ad file)

//

// Given an exception pc at a call we call into the runtime for the

// handler in this method. This handler might merely restore state

// (i.e. callee save registers) unwind the frame and jump to the

// exception handler for the nmethod if there is no Java level handler

// for the nmethod.

//

// This code is entered with a jmp.

//

// Arguments:

//   Rexception_obj (R4/R19): exception oop

//   Rexception_pc  (R5/R20): exception pc

//

// Results:

//   Rexception_obj (R4/R19): exception oop

//   O1: exception pc in caller or ???

//   destination: exception handler of caller

//

// Note: the exception pc MUST be at a call (precise debug information)

//

void OptoRuntime::generate_exception_blob() {

  // allocate space for code

  ResourceMark rm;

  int pad = VerifyThread ? 256 : 0;// Extra slop space for more verify code

  // setup code generation tools

  // Measured 8/7/03 at 256 in 32bit debug build (no VerifyThread)

  // Measured 8/7/03 at 528 in 32bit debug build (VerifyThread)

  CodeBuffer buffer("exception_blob", 600+pad, 512);

  MacroAssembler* masm     = new MacroAssembler(&buffer);

  int framesize_in_words = 2; // FP + LR

  int framesize_in_bytes = framesize_in_words * wordSize;

  int framesize_in_slots = framesize_in_bytes / sizeof(jint);

  int start = __ offset();

  __ str(Rexception_obj, Address(Rthread, JavaThread::exception_oop_offset()));

  __ str(Rexception_pc, Address(Rthread, JavaThread::exception_pc_offset()));

  // This call does all the hard work. It checks if an exception catch

  // exists in the method.

  // If so, it returns the handler address.

  // If the nmethod has been deoptimized and it had a handler the handler

  // address is the deopt blob unpack_with_exception entry.

  //

  // If no handler exists it prepares for stack-unwinding, restoring the callee-save

  // registers of the frame being removed.

  //

  __ mov(LR, Rexception_pc);

  __ raw_push(FP, LR);

  int pc_offset = __ set_last_Java_frame(SP, FP, false, Rtemp);

  __ mov(R0, Rthread);

  // This call can block at exit and nmethod can be deoptimized at that

  // point. If the nmethod had a catch point we would jump to the

  // now deoptimized catch point and fall thru the vanilla deopt

  // path and lose the exception

  // Sure would be simpler if this call didn't block!

  __ call(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C));

  if (pc_offset == -1) {

    pc_offset = __ offset();

  }

  // Set an oopmap for the call site.  This oopmap will only be used if we

  // are unwinding the stack.  Hence, all locations will be dead.

  // Callee-saved registers will be the same as the frame above (i.e.,

  // handle_exception_stub), since they were restored when we got the

  // exception.

  OopMapSet *oop_maps = new OopMapSet();

  oop_maps->add_gc_map(pc_offset - start, new OopMap(framesize_in_slots, 0));

  __ reset_last_Java_frame(Rtemp);

  __ raw_pop(FP, LR);

  // Restore SP from its saved reg (FP) if the exception PC is a MethodHandle call site.

  __ ldr(Rtemp, Address(Rthread, JavaThread::is_method_handle_return_offset()));

#ifdef AARCH64

  Label skip;

  __ cbz(Rtemp, skip);

  __ mov(SP, Rmh_SP_save);

  __ bind(skip);

#else

  __ cmp(Rtemp, 0);

  __ mov(SP, Rmh_SP_save, ne);

#endif

  // R0 contains handler address

  // Since this may be the deopt blob we must set R5 to look like we returned

  // from the original pc that threw the exception

  __ ldr(Rexception_pc,  Address(Rthread, JavaThread::exception_pc_offset()));  // R5/R20

  __ ldr(Rexception_obj, Address(Rthread, JavaThread::exception_oop_offset())); // R4/R19

  __ mov(Rtemp, 0);

#ifdef ASSERT

  __ str(Rtemp, Address(Rthread, JavaThread::exception_handler_pc_offset()));

  __ str(Rtemp, Address(Rthread, JavaThread::exception_pc_offset()));

#endif

  // Clear the exception oop so GC no longer processes it as a root.

  __ str(Rtemp, Address(Rthread, JavaThread::exception_oop_offset()));

  __ jump(R0);

  // -------------

  // make sure all code is generated

  masm->flush();

  _exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize_in_words);

}