/*

 * Copyright (c) 2016, 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 "c1/c1_CodeStubs.hpp"

#include "c1/c1_FrameMap.hpp"

#include "c1/c1_LIRAssembler.hpp"

#include "c1/c1_MacroAssembler.hpp"

#include "c1/c1_Runtime1.hpp"

#include "nativeInst_s390.hpp"

#include "runtime/sharedRuntime.hpp"

#include "utilities/align.hpp"

#include "utilities/macros.hpp"

#include "vmreg_s390.inline.hpp"

#define __ ce->masm()->

#undef  CHECK_BAILOUT

#define CHECK_BAILOUT() { if (ce->compilation()->bailed_out()) return; }

  assert(info != NULL, "must have info");

  _info = new CodeEmitInfo(info);

}

void RangeCheckStub::emit_code(LIR_Assembler* ce) {

  __ bind(_entry);

  if (_info->deoptimize_on_exception()) {

    address a = Runtime1::entry_for (Runtime1::predicate_failed_trap_id);

    ce->emit_call_c(a);

    CHECK_BAILOUT();

    ce->add_call_info_here(_info);

    ce->verify_oop_map(_info);

    debug_only(__ should_not_reach_here());

    return;

  }

  // Pass the array index in Z_R1_scratch which is not managed by linear scan.

  if (_index->is_cpu_register()) {

    __ lgr_if_needed(Z_R1_scratch, _index->as_register());

  } else {

    __ load_const_optimized(Z_R1_scratch, _index->as_jint());

  }

  Runtime1::StubID stub_id;

  if (_throw_index_out_of_bounds_exception) {

    stub_id = Runtime1::throw_index_exception_id;

  } else {

    stub_id = Runtime1::throw_range_check_failed_id;

  }

  ce->emit_call_c(Runtime1::entry_for (stub_id));

  CHECK_BAILOUT();

  ce->add_call_info_here(_info);

  ce->verify_oop_map(_info);

  debug_only(__ should_not_reach_here());

}

PredicateFailedStub::PredicateFailedStub(CodeEmitInfo* info) {

  _info = new CodeEmitInfo(info);

}

void PredicateFailedStub::emit_code(LIR_Assembler* ce) {

  __ bind(_entry);

  address a = Runtime1::entry_for (Runtime1::predicate_failed_trap_id);

  ce->emit_call_c(a);

  CHECK_BAILOUT();

  ce->add_call_info_here(_info);

  ce->verify_oop_map(_info);

  debug_only(__ should_not_reach_here());

}

void CounterOverflowStub::emit_code(LIR_Assembler* ce) {

  __ bind(_entry);

  Metadata *m = _method->as_constant_ptr()->as_metadata();

  bool success = __ set_metadata_constant(m, Z_R1_scratch);

  if (!success) {

    ce->compilation()->bailout("const section overflow");

    return;

  }

  ce->store_parameter(/*_method->as_register()*/ Z_R1_scratch, 1);

  ce->store_parameter(_bci, 0);

  ce->emit_call_c(Runtime1::entry_for (Runtime1::counter_overflow_id));

  CHECK_BAILOUT();

  ce->add_call_info_here(_info);

  ce->verify_oop_map(_info);

  __ branch_optimized(Assembler::bcondAlways, _continuation);

}

void DivByZeroStub::emit_code(LIR_Assembler* ce) {

  if (_offset != -1) {

    ce->compilation()->implicit_exception_table()->append(_offset, __ offset());

  }

  __ bind(_entry);

  ce->emit_call_c(Runtime1::entry_for (Runtime1::throw_div0_exception_id));

  CHECK_BAILOUT();

  ce->add_call_info_here(_info);

  debug_only(__ should_not_reach_here());

}

void ImplicitNullCheckStub::emit_code(LIR_Assembler* ce) {

  address a;

  if (_info->deoptimize_on_exception()) {

    // Deoptimize, do not throw the exception, because it is probably wrong to do it here.

    a = Runtime1::entry_for (Runtime1::predicate_failed_trap_id);

  } else {

    a = Runtime1::entry_for (Runtime1::throw_null_pointer_exception_id);

  }

  ce->compilation()->implicit_exception_table()->append(_offset, __ offset());

  __ bind(_entry);

  ce->emit_call_c(a);

  CHECK_BAILOUT();

  ce->add_call_info_here(_info);

  ce->verify_oop_map(_info);

  debug_only(__ should_not_reach_here());

}

// Note: pass object in Z_R1_scratch

void SimpleExceptionStub::emit_code(LIR_Assembler* ce) {

  __ bind(_entry);

  if (_obj->is_valid()) {

    __ z_lgr(Z_R1_scratch, _obj->as_register()); // _obj contains the optional argument to the stub

  }

  address a = Runtime1::entry_for (_stub);

  ce->emit_call_c(a);

  CHECK_BAILOUT();

  ce->add_call_info_here(_info);

  debug_only(__ should_not_reach_here());

}

NewInstanceStub::NewInstanceStub(LIR_Opr klass_reg, LIR_Opr result, ciInstanceKlass* klass, CodeEmitInfo* info, Runtime1::StubID stub_id) {

  _result = result;

  _klass = klass;

  _klass_reg = klass_reg;

  _info = new CodeEmitInfo(info);

  assert(stub_id == Runtime1::new_instance_id                 ||

         stub_id == Runtime1::fast_new_instance_id            ||

         stub_id == Runtime1::fast_new_instance_init_check_id,

         "need new_instance id");

  _stub_id = stub_id;

}

void NewInstanceStub::emit_code(LIR_Assembler* ce) {

  __ bind(_entry);

  assert(_klass_reg->as_register() == Z_R11, "call target expects klass in Z_R11");

  address a = Runtime1::entry_for (_stub_id);

  ce->emit_call_c(a);

  CHECK_BAILOUT();

  ce->add_call_info_here(_info);

  ce->verify_oop_map(_info);

  assert(_result->as_register() == Z_R2, "callee returns result in Z_R2,");

  __ z_brul(_continuation);

}

NewTypeArrayStub::NewTypeArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {

  _klass_reg = klass_reg;

  _length = length;

  _result = result;

  _info = new CodeEmitInfo(info);

}

void NewTypeArrayStub::emit_code(LIR_Assembler* ce) {

  __ bind(_entry);

  assert(_klass_reg->as_register() == Z_R11, "call target expects klass in Z_R11");

  __ lgr_if_needed(Z_R13, _length->as_register());

  address a = Runtime1::entry_for (Runtime1::new_type_array_id);

  ce->emit_call_c(a);

  CHECK_BAILOUT();

  ce->add_call_info_here(_info);

  ce->verify_oop_map(_info);

  assert(_result->as_register() == Z_R2, "callee returns result in Z_R2,");

  __ z_brul(_continuation);

}

NewObjectArrayStub::NewObjectArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info) {

  _klass_reg = klass_reg;

  _length = length;

  _result = result;

  _info = new CodeEmitInfo(info);

}

void NewObjectArrayStub::emit_code(LIR_Assembler* ce) {

  __ bind(_entry);

  assert(_klass_reg->as_register() == Z_R11, "call target expects klass in Z_R11");

  __ lgr_if_needed(Z_R13, _length->as_register());

  address a = Runtime1::entry_for (Runtime1::new_object_array_id);

  ce->emit_call_c(a);

  CHECK_BAILOUT();

  ce->add_call_info_here(_info);

  ce->verify_oop_map(_info);

  assert(_result->as_register() == Z_R2, "callee returns result in Z_R2,");

  __ z_brul(_continuation);

}

MonitorEnterStub::MonitorEnterStub(LIR_Opr obj_reg, LIR_Opr lock_reg, CodeEmitInfo* info)

  : MonitorAccessStub(obj_reg, lock_reg) {

  _info = new CodeEmitInfo(info);

}

void MonitorEnterStub::emit_code(LIR_Assembler* ce) {

  __ bind(_entry);

  Runtime1::StubID enter_id;

  if (ce->compilation()->has_fpu_code()) {

    enter_id = Runtime1::monitorenter_id;

  } else {

    enter_id = Runtime1::monitorenter_nofpu_id;

  }

  __ lgr_if_needed(Z_R1_scratch, _obj_reg->as_register());

  __ lgr_if_needed(Z_R13, _lock_reg->as_register()); // See LIRGenerator::syncTempOpr().

  ce->emit_call_c(Runtime1::entry_for (enter_id));

  CHECK_BAILOUT();

  ce->add_call_info_here(_info);

  ce->verify_oop_map(_info);

  __ branch_optimized(Assembler::bcondAlways, _continuation);

}

void MonitorExitStub::emit_code(LIR_Assembler* ce) {

  __ bind(_entry);

  // Move address of the BasicObjectLock into Z_R1_scratch.

  if (_compute_lock) {

    // Lock_reg was destroyed by fast unlocking attempt => recompute it.

    ce->monitor_address(_monitor_ix, FrameMap::as_opr(Z_R1_scratch));

  } else {

    __ lgr_if_needed(Z_R1_scratch, _lock_reg->as_register());

  }

  // Note: non-blocking leaf routine => no call info needed.

  Runtime1::StubID exit_id;

  if (ce->compilation()->has_fpu_code()) {

    exit_id = Runtime1::monitorexit_id;

  } else {

    exit_id = Runtime1::monitorexit_nofpu_id;

  }

  ce->emit_call_c(Runtime1::entry_for (exit_id));

  CHECK_BAILOUT();

  __ branch_optimized(Assembler::bcondAlways, _continuation);

}

// Implementation of patching:

// - Copy the code at given offset to an inlined buffer (first the bytes, then the number of bytes).

// - Replace original code with a call to the stub.

// At Runtime:

// - call to stub, jump to runtime.

// - in runtime: Preserve all registers (especially objects, i.e., source and destination object).

// - in runtime: After initializing class, restore original code, reexecute instruction.

int PatchingStub::_patch_info_offset = - (12 /* load const */ + 2 /*BASR*/);

void PatchingStub::align_patch_site(MacroAssembler* masm) {

#ifndef PRODUCT

  const char* bc;

  switch (_id) {

  case access_field_id: bc = "patch site (access_field)"; break;

  case load_klass_id: bc = "patch site (load_klass)"; break;

  case load_mirror_id: bc = "patch site (load_mirror)"; break;

  case load_appendix_id: bc = "patch site (load_appendix)"; break;

  default: bc = "patch site (unknown patch id)"; break;

  }

  masm->block_comment(bc);

#endif

  masm->align(align_up((int)NativeGeneralJump::instruction_size, wordSize));

}

void PatchingStub::emit_code(LIR_Assembler* ce) {

  // Copy original code here.

  assert(NativeGeneralJump::instruction_size <= _bytes_to_copy && _bytes_to_copy <= 0xFF,

         "not enough room for call");

  NearLabel call_patch;

  int being_initialized_entry = __ offset();

  if (_id == load_klass_id) {

    // Produce a copy of the load klass instruction for use by the case being initialized.

#ifdef ASSERT

    address start = __ pc();

#endif

    AddressLiteral addrlit((intptr_t)0, metadata_Relocation::spec(_index));

    __ load_const(_obj, addrlit);

#ifdef ASSERT

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

      address ptr = (address)(_pc_start + i);

      int a_byte = (*ptr) & 0xFF;

      assert(a_byte == *start++, "should be the same code");

    }

#endif

  } else if (_id == load_mirror_id || _id == load_appendix_id) {

    // Produce a copy of the load mirror instruction for use by the case being initialized.

#ifdef ASSERT

    address start = __ pc();

#endif

    AddressLiteral addrlit((intptr_t)0, oop_Relocation::spec(_index));

    __ load_const(_obj, addrlit);

#ifdef ASSERT

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

      address ptr = (address)(_pc_start + i);

      int a_byte = (*ptr) & 0xFF;

      assert(a_byte == *start++, "should be the same code");

    }

#endif

  } else {

    // Make a copy the code which is going to be patched.

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

      address ptr = (address)(_pc_start + i);

      int a_byte = (*ptr) & 0xFF;

      __ emit_int8 (a_byte);

    }

  }

  address end_of_patch = __ pc();

  int bytes_to_skip = 0;

  if (_id == load_mirror_id) {

    int offset = __ offset();

    if (CommentedAssembly) {

      __ block_comment(" being_initialized check");

    }

    // Static field accesses have special semantics while the class

    // initializer is being run, so we emit a test which can be used to

    // check that this code is being executed by the initializing

    // thread.

    assert(_obj != noreg, "must be a valid register");

    assert(_index >= 0, "must have oop index");

    __ z_lg(Z_R1_scratch, java_lang_Class::klass_offset_in_bytes(), _obj);

    __ z_cg(Z_thread, Address(Z_R1_scratch, InstanceKlass::init_thread_offset()));

    __ branch_optimized(Assembler::bcondNotEqual, call_patch);

    // Load_klass patches may execute the patched code before it's

    // copied back into place so we need to jump back into the main

    // code of the nmethod to continue execution.

    __ branch_optimized(Assembler::bcondAlways, _patch_site_continuation);

    // Make sure this extra code gets skipped.

    bytes_to_skip += __ offset() - offset;

  }

  // Now emit the patch record telling the runtime how to find the

  // pieces of the patch. We only need 3 bytes but to help the disassembler

  // we make the data look like a the following add instruction:

  //   A R1, D2(X2, B2)

  // which requires 4 bytes.

  int sizeof_patch_record = 4;

  bytes_to_skip += sizeof_patch_record;

  // Emit the offsets needed to find the code to patch.

  int being_initialized_entry_offset = __ offset() - being_initialized_entry + sizeof_patch_record;

  // Emit the patch record: opcode of the add followed by 3 bytes patch record data.

  __ emit_int8((int8_t)(A_ZOPC>>24));

  __ emit_int8(being_initialized_entry_offset);

  __ emit_int8(bytes_to_skip);

  __ emit_int8(_bytes_to_copy);

  address patch_info_pc = __ pc();

  assert(patch_info_pc - end_of_patch == bytes_to_skip, "incorrect patch info");

  address entry = __ pc();

  NativeGeneralJump::insert_unconditional((address)_pc_start, entry);

  address target = NULL;

  relocInfo::relocType reloc_type = relocInfo::none;

  switch (_id) {

    case access_field_id:  target = Runtime1::entry_for (Runtime1::access_field_patching_id); break;

    case load_klass_id:    target = Runtime1::entry_for (Runtime1::load_klass_patching_id); reloc_type = relocInfo::metadata_type; break;

    case load_mirror_id:   target = Runtime1::entry_for (Runtime1::load_mirror_patching_id); reloc_type = relocInfo::oop_type; break;

    case load_appendix_id: target = Runtime1::entry_for (Runtime1::load_appendix_patching_id); reloc_type = relocInfo::oop_type; break;

    default: ShouldNotReachHere();

  }

  __ bind(call_patch);

  if (CommentedAssembly) {

    __ block_comment("patch entry point");

  }

  // Cannot use call_c_opt() because its size is not constant.

  __ load_const(Z_R1_scratch, target); // Must not optimize in order to keep constant _patch_info_offset constant.

  __ z_basr(Z_R14, Z_R1_scratch);

  assert(_patch_info_offset == (patch_info_pc - __ pc()), "must not change");

  ce->add_call_info_here(_info);

  __ z_brcl(Assembler::bcondAlways, _patch_site_entry);

  if (_id == load_klass_id || _id == load_mirror_id || _id == load_appendix_id) {

    CodeSection* cs = __ code_section();

    address pc = (address)_pc_start;

    RelocIterator iter(cs, pc, pc + 1);

    relocInfo::change_reloc_info_for_address(&iter, (address) pc, reloc_type, relocInfo::none);

  }

}

void DeoptimizeStub::emit_code(LIR_Assembler* ce) {

  __ bind(_entry);

  __ load_const_optimized(Z_R1_scratch, _trap_request); // Pass trap request in Z_R1_scratch.

  ce->emit_call_c(Runtime1::entry_for (Runtime1::deoptimize_id));

  CHECK_BAILOUT();

  ce->add_call_info_here(_info);

  DEBUG_ONLY(__ should_not_reach_here());

}

void ArrayCopyStub::emit_code(LIR_Assembler* ce) {

  // Slow case: call to native.

  __ bind(_entry);

  __ lgr_if_needed(Z_ARG1, src()->as_register());

  __ lgr_if_needed(Z_ARG2, src_pos()->as_register());

  __ lgr_if_needed(Z_ARG3, dst()->as_register());

  __ lgr_if_needed(Z_ARG4, dst_pos()->as_register());

  __ lgr_if_needed(Z_ARG5, length()->as_register());

  // Must align calls sites, otherwise they can't be updated atomically on MP hardware.

  ce->align_call(lir_static_call);

  assert((__ offset() + NativeCall::call_far_pcrelative_displacement_offset) % NativeCall::call_far_pcrelative_displacement_alignment == 0,

         "must be aligned");

  ce->emit_static_call_stub();

  // Prepend each BRASL with a nop.

  __ relocate(relocInfo::static_call_type);

  __ z_nop();

  __ z_brasl(Z_R14, SharedRuntime::get_resolve_static_call_stub());

  ce->add_call_info_here(info());

  ce->verify_oop_map(info());

#ifndef PRODUCT

  __ load_const_optimized(Z_R1_scratch, (address)&Runtime1::_arraycopy_slowcase_cnt);

  __ add2mem_32(Address(Z_R1_scratch), 1, Z_R0_scratch);

#endif

  __ branch_optimized(Assembler::bcondAlways, _continuation);

}

#undef __