/*

 * Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved.

 * Copyright 2008, 2009, 2010 Red Hat, Inc.

 * 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 "shark/llvmHeaders.hpp"

#include "shark/sharkFunction.hpp"

#include "shark/sharkNativeWrapper.hpp"

#include "shark/sharkStack.hpp"

#include "shark/sharkType.hpp"

using namespace llvm;

void SharkStack::initialize(Value* method) {

  bool setup_sp_and_method = (method != NULL);

  int locals_words  = max_locals();

  int extra_locals  = locals_words - arg_size();

  int header_words  = SharkFrame::header_words;

  int monitor_words = max_monitors()*frame::interpreter_frame_monitor_size();

  int stack_words   = max_stack();

  int frame_words   = header_words + monitor_words + stack_words;

  _extended_frame_size = frame_words + locals_words;

  // Update the stack pointer

  Value *stack_pointer = builder()->CreateSub(

    CreateLoadStackPointer(),

    LLVMValue::intptr_constant((frame_words + extra_locals) * wordSize));

  CreateStackOverflowCheck(stack_pointer);

  if (setup_sp_and_method)

    CreateStoreStackPointer(stack_pointer);

  // Create the frame

  _frame = builder()->CreateIntToPtr(

    stack_pointer,

    PointerType::getUnqual(

      ArrayType::get(SharkType::intptr_type(), extended_frame_size())),

    "frame");

  int offset = 0;

  // Expression stack

  _stack_slots_offset = offset;

  offset += stack_words;

  // Monitors

  _monitors_slots_offset = offset;

  offset += monitor_words;

  // Temporary oop slot

  _oop_tmp_slot_offset = offset++;

  // Method pointer

  _method_slot_offset = offset++;

  if (setup_sp_and_method) {

    builder()->CreateStore(

      method, slot_addr(method_slot_offset(), SharkType::Method_type()));

  }

  // Unextended SP

  builder()->CreateStore(stack_pointer, slot_addr(offset++));

  // PC

  _pc_slot_offset = offset++;

  // Frame header

  builder()->CreateStore(

    LLVMValue::intptr_constant(ZeroFrame::SHARK_FRAME), slot_addr(offset++));

  Value *fp = slot_addr(offset++);

  // Local variables

  _locals_slots_offset = offset;

  offset += locals_words;

  // Push the frame

  assert(offset == extended_frame_size(), "should do");

  builder()->CreateStore(CreateLoadFramePointer(), fp);

  CreateStoreFramePointer(

    builder()->CreatePtrToInt(fp, SharkType::intptr_type()));

}

// This function should match ZeroStack::overflow_check

void SharkStack::CreateStackOverflowCheck(Value* sp) {

  BasicBlock *zero_ok  = CreateBlock("zero_stack_ok");

  BasicBlock *overflow = CreateBlock("stack_overflow");

  BasicBlock *abi_ok   = CreateBlock("abi_stack_ok");

  // Check the Zero stack

  builder()->CreateCondBr(

    builder()->CreateICmpULT(sp, stack_base()),

    overflow, zero_ok);

  // Check the ABI stack

  builder()->SetInsertPoint(zero_ok);

  Value *stack_top = builder()->CreateSub(

    builder()->CreateValueOfStructEntry(

      thread(),

      Thread::stack_base_offset(),

      SharkType::intptr_type(),

      "abi_base"),

    builder()->CreateValueOfStructEntry(

      thread(),

      Thread::stack_size_offset(),

      SharkType::intptr_type(),

      "abi_size"));

  Value *free_stack = builder()->CreateSub(

    builder()->CreatePtrToInt(

      builder()->CreateGetFrameAddress(),

      SharkType::intptr_type(),

      "abi_sp"),

    stack_top);

  builder()->CreateCondBr(

    builder()->CreateICmpULT(

      free_stack,

      LLVMValue::intptr_constant(StackShadowPages * os::vm_page_size())),

    overflow, abi_ok);

  // Handle overflows

  builder()->SetInsertPoint(overflow);

  builder()->CreateCall(builder()->throw_StackOverflowError(), thread());

  builder()->CreateRet(LLVMValue::jint_constant(0));

  builder()->SetInsertPoint(abi_ok);

}

Value* SharkStack::CreatePopFrame(int result_slots) {

  assert(result_slots >= 0 && result_slots <= 2, "should be");

  int locals_to_pop = max_locals() - result_slots;

  Value *fp = CreateLoadFramePointer();

  Value *sp = builder()->CreateAdd(

    fp,

    LLVMValue::intptr_constant((1 + locals_to_pop) * wordSize));

  CreateStoreStackPointer(sp);

  CreateStoreFramePointer(

    builder()->CreateLoad(

      builder()->CreateIntToPtr(

        fp, PointerType::getUnqual(SharkType::intptr_type()))));

  return sp;

}

Value* SharkStack::slot_addr(int         offset,

                             Type* type,

                             const char* name) const {

  bool needs_cast = type && type != SharkType::intptr_type();

  Value* result = builder()->CreateStructGEP(

    _frame, offset, needs_cast ? "" : name);

  if (needs_cast) {

    result = builder()->CreateBitCast(

      result, PointerType::getUnqual(type), name);

  }

  return result;

}

// The bits that differentiate stacks with normal and native frames on top

SharkStack* SharkStack::CreateBuildAndPushFrame(SharkFunction* function,

                                                Value*         method) {

  return new SharkStackWithNormalFrame(function, method);

}

SharkStack* SharkStack::CreateBuildAndPushFrame(SharkNativeWrapper* wrapper,

                                                Value*              method) {

  return new SharkStackWithNativeFrame(wrapper, method);

}

SharkStackWithNormalFrame::SharkStackWithNormalFrame(SharkFunction* function,

                                                     Value*         method)

  : SharkStack(function), _function(function) {

  // For normal frames, the stack pointer and the method slot will

  // be set during each decache, so it is not necessary to do them

  // at the time the frame is created.  However, we set them for

  // non-PRODUCT builds to make crash dumps easier to understand.

  initialize(PRODUCT_ONLY(NULL) NOT_PRODUCT(method));

}

SharkStackWithNativeFrame::SharkStackWithNativeFrame(SharkNativeWrapper* wrp,

                                                     Value*              method)

  : SharkStack(wrp), _wrapper(wrp) {

  initialize(method);

}

int SharkStackWithNormalFrame::arg_size() const {

  return function()->arg_size();

}

int SharkStackWithNativeFrame::arg_size() const {

  return wrapper()->arg_size();

}

int SharkStackWithNormalFrame::max_locals() const {

  return function()->max_locals();

}

int SharkStackWithNativeFrame::max_locals() const {

  return wrapper()->arg_size();

}

int SharkStackWithNormalFrame::max_stack() const {

  return function()->max_stack();

}

int SharkStackWithNativeFrame::max_stack() const {

  return 0;

}

int SharkStackWithNormalFrame::max_monitors() const {

  return function()->max_monitors();

}

int SharkStackWithNativeFrame::max_monitors() const {

  return wrapper()->is_synchronized() ? 1 : 0;

}

BasicBlock* SharkStackWithNormalFrame::CreateBlock(const char* name) const {

  return function()->CreateBlock(name);

}

BasicBlock* SharkStackWithNativeFrame::CreateBlock(const char* name) const {

  return wrapper()->CreateBlock(name);

}

address SharkStackWithNormalFrame::interpreter_entry_point() const {

  return (address) CppInterpreter::normal_entry;

}

address SharkStackWithNativeFrame::interpreter_entry_point() const {

  return (address) CppInterpreter::native_entry;

}

#ifndef PRODUCT

void SharkStack::CreateAssertLastJavaSPIsNull() const {

#ifdef ASSERT

  BasicBlock *fail = CreateBlock("assert_failed");

  BasicBlock *pass = CreateBlock("assert_ok");

  builder()->CreateCondBr(

    builder()->CreateICmpEQ(

      builder()->CreateLoad(last_Java_sp_addr()),

      LLVMValue::intptr_constant(0)),

    pass, fail);

  builder()->SetInsertPoint(fail);

  builder()->CreateShouldNotReachHere(__FILE__, __LINE__);

  builder()->CreateUnreachable();

  builder()->SetInsertPoint(pass);

#endif // ASSERT

}

#endif // !PRODUCT