/*

 * Copyright (c) 2008, 2018, 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"

#include "asm/macroAssembler.inline.hpp"

#include "c1/c1_Defs.hpp"

#include "c1/c1_LIRAssembler.hpp"

#include "c1/c1_MacroAssembler.hpp"

#include "c1/c1_Runtime1.hpp"

#include "ci/ciUtilities.hpp"

#include "gc/shared/cardTable.hpp"

#include "gc/shared/cardTableBarrierSet.hpp"

#include "interpreter/interpreter.hpp"

#include "nativeInst_arm.hpp"

#include "oops/compiledICHolder.hpp"

#include "oops/oop.inline.hpp"

#include "prims/jvmtiExport.hpp"

#include "register_arm.hpp"

#include "runtime/sharedRuntime.hpp"

#include "runtime/signature.hpp"

#include "runtime/vframeArray.hpp"

#include "utilities/align.hpp"

#include "vmreg_arm.inline.hpp"

// Note: Rtemp usage is this file should not impact C2 and should be

// correct as long as it is not implicitly used in lower layers (the

// arm [macro]assembler) and used with care in the other C1 specific

// files.

// Implementation of StubAssembler

int StubAssembler::call_RT(Register oop_result1, Register metadata_result, address entry, int args_size) {

  mov(R0, Rthread);

  int call_offset = set_last_Java_frame(SP, FP, false, Rtemp);

  call(entry);

  if (call_offset == -1) { // PC not saved

    call_offset = offset();

  }

  reset_last_Java_frame(Rtemp);

  assert(frame_size() != no_frame_size, "frame must be fixed");

  if (_stub_id != Runtime1::forward_exception_id) {

    ldr(R3, Address(Rthread, Thread::pending_exception_offset()));

  }

  if (oop_result1->is_valid()) {

    assert_different_registers(oop_result1, R3, Rtemp);

    get_vm_result(oop_result1, Rtemp);

  }

  if (metadata_result->is_valid()) {

    assert_different_registers(metadata_result, R3, Rtemp);

    get_vm_result_2(metadata_result, Rtemp);

  }

  // Check for pending exception

  // unpack_with_exception_in_tls path is taken through

  // Runtime1::exception_handler_for_pc

  if (_stub_id != Runtime1::forward_exception_id) {

    assert(frame_size() != no_frame_size, "cannot directly call forward_exception_id");

#ifdef AARCH64

    Label skip;

    cbz(R3, skip);

    jump(Runtime1::entry_for(Runtime1::forward_exception_id), relocInfo::runtime_call_type, Rtemp);

    bind(skip);

#else

    cmp(R3, 0);

    jump(Runtime1::entry_for(Runtime1::forward_exception_id), relocInfo::runtime_call_type, Rtemp, ne);

#endif // AARCH64

  } else {

#ifdef ASSERT

    // Should not have pending exception in forward_exception stub

    ldr(R3, Address(Rthread, Thread::pending_exception_offset()));

    cmp(R3, 0);

    breakpoint(ne);

#endif // ASSERT

  }

  return call_offset;

}

int StubAssembler::call_RT(Register oop_result1, Register metadata_result, address entry, Register arg1) {

  if (arg1 != R1) {

    mov(R1, arg1);

  }

  return call_RT(oop_result1, metadata_result, entry, 1);

}

int StubAssembler::call_RT(Register oop_result1, Register metadata_result, address entry, Register arg1, Register arg2) {

  assert(arg1 == R1 && arg2 == R2, "cannot handle otherwise");

  return call_RT(oop_result1, metadata_result, entry, 2);

}

int StubAssembler::call_RT(Register oop_result1, Register metadata_result, address entry, Register arg1, Register arg2, Register arg3) {

  assert(arg1 == R1 && arg2 == R2 && arg3 == R3, "cannot handle otherwise");

  return call_RT(oop_result1, metadata_result, entry, 3);

}

#define __ sasm->

// TODO: ARM - does this duplicate RegisterSaver in SharedRuntime?

#ifdef AARCH64

  //

  // On AArch64 registers save area has the following layout:

  //

  // |---------------------|

  // | return address (LR) |

  // | FP                  |

  // |---------------------|

  // | D31                 |

  // | ...                 |

  // | D0                  |

  // |---------------------|

  // | padding             |

  // |---------------------|

  // | R28                 |

  // | ...                 |

  // | R0                  |

  // |---------------------| <-- SP

  //

enum RegisterLayout {

  number_of_saved_gprs = 29,

  number_of_saved_fprs = FloatRegisterImpl::number_of_registers,

  R0_offset  = 0,

  D0_offset  = R0_offset + number_of_saved_gprs + 1,

  FP_offset  = D0_offset + number_of_saved_fprs,

  LR_offset  = FP_offset + 1,

  reg_save_size = LR_offset + 1,

  arg1_offset = reg_save_size * wordSize,

  arg2_offset = (reg_save_size + 1) * wordSize

};

#else

enum RegisterLayout {

  fpu_save_size = pd_nof_fpu_regs_reg_alloc,

#ifndef __SOFTFP__

  D0_offset = 0,

#endif

  R0_offset = fpu_save_size,

  R1_offset,

  R2_offset,

  R3_offset,

  R4_offset,

  R5_offset,

  R6_offset,

#if (FP_REG_NUM != 7)

  R7_offset,

#endif

  R8_offset,

  R9_offset,

  R10_offset,

#if (FP_REG_NUM != 11)

  R11_offset,

#endif

  R12_offset,

  FP_offset,

  LR_offset,

  reg_save_size,

  arg1_offset = reg_save_size * wordSize,

  arg2_offset = (reg_save_size + 1) * wordSize

};

#endif // AARCH64

static OopMap* generate_oop_map(StubAssembler* sasm, bool save_fpu_registers = HaveVFP) {

  sasm->set_frame_size(reg_save_size /* in words */);

  // Record saved value locations in an OopMap.

  // Locations are offsets from sp after runtime call.

  OopMap* map = new OopMap(VMRegImpl::slots_per_word * reg_save_size, 0);

#ifdef AARCH64

  for (int i = 0; i < number_of_saved_gprs; i++) {

    map->set_callee_saved(VMRegImpl::stack2reg((R0_offset + i) * VMRegImpl::slots_per_word), as_Register(i)->as_VMReg());

  }

  map->set_callee_saved(VMRegImpl::stack2reg(FP_offset * VMRegImpl::slots_per_word), FP->as_VMReg());

  map->set_callee_saved(VMRegImpl::stack2reg(LR_offset * VMRegImpl::slots_per_word), LR->as_VMReg());

  if (save_fpu_registers) {

    for (int i = 0; i < number_of_saved_fprs; i++) {

      map->set_callee_saved(VMRegImpl::stack2reg((D0_offset + i) * VMRegImpl::slots_per_word), as_FloatRegister(i)->as_VMReg());

    }

  }

#else

  int j=0;

  for (int i = R0_offset; i < R10_offset; i++) {

    if (j == FP_REG_NUM) {

      // skip the FP register, saved below

      j++;

    }

    map->set_callee_saved(VMRegImpl::stack2reg(i), as_Register(j)->as_VMReg());

    j++;

  }

  assert(j == R10->encoding(), "must be");

#if (FP_REG_NUM != 11)

  // add R11, if not saved as FP

  map->set_callee_saved(VMRegImpl::stack2reg(R11_offset), R11->as_VMReg());

#endif

  map->set_callee_saved(VMRegImpl::stack2reg(FP_offset), FP->as_VMReg());

  map->set_callee_saved(VMRegImpl::stack2reg(LR_offset), LR->as_VMReg());

  if (save_fpu_registers) {

    for (int i = 0; i < fpu_save_size; i++) {

      map->set_callee_saved(VMRegImpl::stack2reg(i), as_FloatRegister(i)->as_VMReg());

    }

  }

#endif // AARCH64

  return map;

}

static OopMap* save_live_registers(StubAssembler* sasm, bool save_fpu_registers = HaveVFP) {

  __ block_comment("save_live_registers");

  sasm->set_frame_size(reg_save_size /* in words */);

#ifdef AARCH64

  assert((reg_save_size * wordSize) % StackAlignmentInBytes == 0, "SP should be aligned");

  __ raw_push(FP, LR);

  __ sub(SP, SP, (reg_save_size - 2) * wordSize);

  for (int i = 0; i < align_down((int)number_of_saved_gprs, 2); i += 2) {

    __ stp(as_Register(i), as_Register(i+1), Address(SP, (R0_offset + i) * wordSize));

  }

  if (is_odd(number_of_saved_gprs)) {

    int i = number_of_saved_gprs - 1;

    __ str(as_Register(i), Address(SP, (R0_offset + i) * wordSize));

  }

  if (save_fpu_registers) {

    assert (is_even(number_of_saved_fprs), "adjust this code");

    for (int i = 0; i < number_of_saved_fprs; i += 2) {

      __ stp_d(as_FloatRegister(i), as_FloatRegister(i+1), Address(SP, (D0_offset + i) * wordSize));

    }

  }

#else

  __ push(RegisterSet(FP) | RegisterSet(LR));

  __ push(RegisterSet(R0, R6) | RegisterSet(R8, R10) | R12 | altFP_7_11);

  if (save_fpu_registers) {

    __ fstmdbd(SP, FloatRegisterSet(D0, fpu_save_size / 2), writeback);

  } else {

    __ sub(SP, SP, fpu_save_size * wordSize);

  }

#endif // AARCH64

  return generate_oop_map(sasm, save_fpu_registers);

}

static void restore_live_registers(StubAssembler* sasm,

                                   bool restore_R0,

                                   bool restore_FP_LR,

                                   bool do_return,

                                   bool restore_fpu_registers = HaveVFP) {

  __ block_comment("restore_live_registers");

#ifdef AARCH64

  if (restore_R0) {

    __ ldr(R0, Address(SP, R0_offset * wordSize));

  }

  assert(is_odd(number_of_saved_gprs), "adjust this code");

  for (int i = 1; i < number_of_saved_gprs; i += 2) {

    __ ldp(as_Register(i), as_Register(i+1), Address(SP, (R0_offset + i) * wordSize));

  }

  if (restore_fpu_registers) {

    assert (is_even(number_of_saved_fprs), "adjust this code");

    for (int i = 0; i < number_of_saved_fprs; i += 2) {

      __ ldp_d(as_FloatRegister(i), as_FloatRegister(i+1), Address(SP, (D0_offset + i) * wordSize));

    }

  }

  __ add(SP, SP, (reg_save_size - 2) * wordSize);

  if (restore_FP_LR) {

    __ raw_pop(FP, LR);

    if (do_return) {

      __ ret();

    }

  } else {

    assert (!do_return, "return without restoring FP/LR");

  }

#else

  if (restore_fpu_registers) {

    __ fldmiad(SP, FloatRegisterSet(D0, fpu_save_size / 2), writeback);

    if (!restore_R0) {

      __ add(SP, SP, (R1_offset - fpu_save_size) * wordSize);

    }

  } else {

    __ add(SP, SP, (restore_R0 ? fpu_save_size : R1_offset) * wordSize);

  }

  __ pop(RegisterSet((restore_R0 ? R0 : R1), R6) | RegisterSet(R8, R10) | R12 | altFP_7_11);

  if (restore_FP_LR) {

    __ pop(RegisterSet(FP) | RegisterSet(do_return ? PC : LR));

  } else {

    assert (!do_return, "return without restoring FP/LR");

  }

#endif // AARCH64

}

static void restore_live_registers_except_R0(StubAssembler* sasm, bool restore_fpu_registers = HaveVFP) {

  restore_live_registers(sasm, false, true, true, restore_fpu_registers);

}

static void restore_live_registers(StubAssembler* sasm, bool restore_fpu_registers = HaveVFP) {

  restore_live_registers(sasm, true, true, true, restore_fpu_registers);

}

#ifndef AARCH64

static void restore_live_registers_except_FP_LR(StubAssembler* sasm, bool restore_fpu_registers = HaveVFP) {

  restore_live_registers(sasm, true, false, false, restore_fpu_registers);

}

#endif // !AARCH64

static void restore_live_registers_without_return(StubAssembler* sasm, bool restore_fpu_registers = HaveVFP) {

  restore_live_registers(sasm, true, true, false, restore_fpu_registers);

}

void StubAssembler::save_live_registers() {

  ::save_live_registers(this);

}

void StubAssembler::restore_live_registers_without_return() {

  ::restore_live_registers_without_return(this);

}

void Runtime1::initialize_pd() {

}

OopMapSet* Runtime1::generate_exception_throw(StubAssembler* sasm, address target, bool has_argument) {

  OopMap* oop_map = save_live_registers(sasm);

  int call_offset;

  if (has_argument) {

    __ ldr(R1, Address(SP, arg1_offset));

    __ ldr(R2, Address(SP, arg2_offset));

    call_offset = __ call_RT(noreg, noreg, target, R1, R2);

  } else {

    call_offset = __ call_RT(noreg, noreg, target);

  }

  OopMapSet* oop_maps = new OopMapSet();

  oop_maps->add_gc_map(call_offset, oop_map);

  DEBUG_ONLY(STOP("generate_exception_throw");)  // Should not reach here

  return oop_maps;

}

static void restore_sp_for_method_handle(StubAssembler* sasm) {

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

  __ ldr_s32(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 // AARCH64

}

OopMapSet* Runtime1::generate_handle_exception(StubID id, StubAssembler* sasm) {

  __ block_comment("generate_handle_exception");

  bool save_fpu_registers = false;

  // Save registers, if required.

  OopMapSet* oop_maps = new OopMapSet();

  OopMap* oop_map = NULL;

  switch (id) {

  case forward_exception_id: {

    save_fpu_registers = HaveVFP;

    oop_map = generate_oop_map(sasm);

    __ ldr(Rexception_obj, Address(Rthread, Thread::pending_exception_offset()));

    __ ldr(Rexception_pc, Address(SP, LR_offset * wordSize));

    Register zero = __ zero_register(Rtemp);

    __ str(zero, Address(Rthread, Thread::pending_exception_offset()));

    break;

  }

  case handle_exception_id:

    save_fpu_registers = HaveVFP;

    // fall-through

  case handle_exception_nofpu_id:

    // At this point all registers MAY be live.

    oop_map = save_live_registers(sasm, save_fpu_registers);

    break;

  case handle_exception_from_callee_id:

    // At this point all registers except exception oop (R4/R19) and

    // exception pc (R5/R20) are dead.

    oop_map = save_live_registers(sasm);  // TODO it's not required to save all registers

    break;

  default:  ShouldNotReachHere();

  }

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

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

  __ str(Rexception_pc, Address(SP, LR_offset * wordSize)); // patch throwing pc into return address

  int call_offset = __ call_RT(noreg, noreg, CAST_FROM_FN_PTR(address, exception_handler_for_pc));

  oop_maps->add_gc_map(call_offset, oop_map);

  // Exception handler found

  __ str(R0, Address(SP, LR_offset * wordSize)); // patch the return address

  // Restore the registers that were saved at the beginning, remove

  // frame and jump to the exception handler.

  switch (id) {

  case forward_exception_id:

  case handle_exception_nofpu_id:

  case handle_exception_id:

    restore_live_registers(sasm, save_fpu_registers);

    // Note: the restore live registers includes the jump to LR (patched to R0)

    break;

  case handle_exception_from_callee_id:

    restore_live_registers_without_return(sasm); // must not jump immediatly to handler

    restore_sp_for_method_handle(sasm);

    __ ret();

    break;

  default:  ShouldNotReachHere();

  }

  DEBUG_ONLY(STOP("generate_handle_exception");)  // Should not reach here

  return oop_maps;

}

void Runtime1::generate_unwind_exception(StubAssembler* sasm) {

  // FP no longer used to find the frame start

  // on entry, remove_frame() has already been called (restoring FP and LR)

  // search the exception handler address of the caller (using the return address)

  __ mov(c_rarg0, Rthread);

  __ mov(Rexception_pc, LR);

  __ mov(c_rarg1, LR);

  __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::exception_handler_for_return_address), c_rarg0, c_rarg1);

  // Exception oop should be still in Rexception_obj and pc in Rexception_pc

  // Jump to handler

  __ verify_not_null_oop(Rexception_obj);

  // JSR292 extension

  restore_sp_for_method_handle(sasm);

  __ jump(R0);

}

OopMapSet* Runtime1::generate_patching(StubAssembler* sasm, address target) {

  OopMap* oop_map = save_live_registers(sasm);

  // call the runtime patching routine, returns non-zero if nmethod got deopted.

  int call_offset = __ call_RT(noreg, noreg, target);

  OopMapSet* oop_maps = new OopMapSet();

  oop_maps->add_gc_map(call_offset, oop_map);

  DeoptimizationBlob* deopt_blob = SharedRuntime::deopt_blob();

  assert(deopt_blob != NULL, "deoptimization blob must have been created");

  __ cmp_32(R0, 0);

#ifdef AARCH64

  Label call_deopt;

  restore_live_registers_without_return(sasm);

  __ b(call_deopt, ne);

  __ ret();

  __ bind(call_deopt);

#else

  restore_live_registers_except_FP_LR(sasm);

  __ pop(RegisterSet(FP) | RegisterSet(PC), eq);

  // Deoptimization needed

  // TODO: ARM - no need to restore FP & LR because unpack_with_reexecution() stores them back

  __ pop(RegisterSet(FP) | RegisterSet(LR));

#endif // AARCH64

  __ jump(deopt_blob->unpack_with_reexecution(), relocInfo::runtime_call_type, Rtemp);

  DEBUG_ONLY(STOP("generate_patching");)  // Should not reach here

  return oop_maps;

}