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Java example source code file (c1_FpuStackSim_x86.cpp)

This example Java source code file (c1_FpuStackSim_x86.cpp) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bailout_, empty, fpu-pop, fpu\-push, fpustacksim, fpustacksim\:\:clear, fpustacksim\:\:dec_stack_size, fpustacksim\:\:get_slot, fpustacksim\:\:is_empty, fpustacksim\:\:pop, fpustacksim\:\:regs_at, fpustacksim\:\:set_slot, framemap::nof_fpu_regs, tracefpustack

The c1_FpuStackSim_x86.cpp Java example source code

/*
 * Copyright (c) 2005, 2010, 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_FpuStackSim.hpp"
#include "c1/c1_FrameMap.hpp"
#include "utilities/array.hpp"
#include "utilities/ostream.hpp"

//--------------------------------------------------------
//               FpuStackSim
//--------------------------------------------------------

// This class maps the FPU registers to their stack locations; it computes
// the offsets between individual registers and simulates the FPU stack.

const int EMPTY = -1;

int FpuStackSim::regs_at(int i) const {
  assert(i >= 0 && i < FrameMap::nof_fpu_regs, "out of bounds");
  return _regs[i];
}

void FpuStackSim::set_regs_at(int i, int val) {
  assert(i >= 0 && i < FrameMap::nof_fpu_regs, "out of bounds");
  _regs[i] = val;
}

void FpuStackSim::dec_stack_size() {
  _stack_size--;
  assert(_stack_size >= 0, "FPU stack underflow");
}

void FpuStackSim::inc_stack_size() {
  _stack_size++;
  assert(_stack_size <= FrameMap::nof_fpu_regs, "FPU stack overflow");
}

FpuStackSim::FpuStackSim(Compilation* compilation)
 : _compilation(compilation)
{
  _stack_size = 0;
  for (int i = 0; i < FrameMap::nof_fpu_regs; i++) {
    set_regs_at(i, EMPTY);
  }
}


void FpuStackSim::pop() {
  if (TraceFPUStack) { tty->print("FPU-pop "); print(); tty->cr(); }
  set_regs_at(tos_index(), EMPTY);
  dec_stack_size();
}

void FpuStackSim::pop(int rnr) {
  if (TraceFPUStack) { tty->print("FPU-pop %d", rnr); print(); tty->cr(); }
  assert(regs_at(tos_index()) == rnr, "rnr is not on TOS");
  set_regs_at(tos_index(), EMPTY);
  dec_stack_size();
}


void FpuStackSim::push(int rnr) {
  if (TraceFPUStack) { tty->print("FPU-push %d", rnr); print(); tty->cr(); }
  assert(regs_at(stack_size()) == EMPTY, "should be empty");
  set_regs_at(stack_size(), rnr);
  inc_stack_size();
}


void FpuStackSim::swap(int offset) {
  if (TraceFPUStack) { tty->print("FPU-swap %d", offset); print(); tty->cr(); }
  int t = regs_at(tos_index() - offset);
  set_regs_at(tos_index() - offset, regs_at(tos_index()));
  set_regs_at(tos_index(), t);
}


int FpuStackSim::offset_from_tos(int rnr) const {
  for (int i = tos_index(); i >= 0; i--) {
    if (regs_at(i) == rnr) {
      return tos_index() - i;
    }
  }
  assert(false, "FpuStackSim: register not found");
  BAILOUT_("FpuStackSim: register not found", 0);
}


int FpuStackSim::get_slot(int tos_offset) const {
  return regs_at(tos_index() - tos_offset);
}

void FpuStackSim::set_slot(int tos_offset, int rnr) {
  set_regs_at(tos_index() - tos_offset, rnr);
}

void FpuStackSim::rename(int old_rnr, int new_rnr) {
  if (TraceFPUStack) { tty->print("FPU-rename %d %d", old_rnr, new_rnr); print(); tty->cr(); }
  if (old_rnr == new_rnr)
    return;
  bool found = false;
  for (int i = 0; i < stack_size(); i++) {
    assert(regs_at(i) != new_rnr, "should not see old occurrences of new_rnr on the stack");
    if (regs_at(i) == old_rnr) {
      set_regs_at(i, new_rnr);
      found = true;
    }
  }
  assert(found, "should have found at least one instance of old_rnr");
}


bool FpuStackSim::contains(int rnr) {
  for (int i = 0; i < stack_size(); i++) {
    if (regs_at(i) == rnr) {
      return true;
    }
  }
  return false;
}

bool FpuStackSim::is_empty() {
#ifdef ASSERT
  if (stack_size() == 0) {
    for (int i = 0; i < FrameMap::nof_fpu_regs; i++) {
      assert(regs_at(i) == EMPTY, "must be empty");
    }
  }
#endif
  return stack_size() == 0;
}


bool FpuStackSim::slot_is_empty(int tos_offset) {
  return (regs_at(tos_index() - tos_offset) == EMPTY);
}


void FpuStackSim::clear() {
  if (TraceFPUStack) { tty->print("FPU-clear"); print(); tty->cr(); }
  for (int i = tos_index(); i >= 0; i--) {
    set_regs_at(i, EMPTY);
  }
  _stack_size = 0;
}


intArray* FpuStackSim::write_state() {
  intArray* res = new intArray(1 + FrameMap::nof_fpu_regs);
  (*res)[0] = stack_size();
  for (int i = 0; i < FrameMap::nof_fpu_regs; i++) {
    (*res)[1 + i] = regs_at(i);
  }
  return res;
}


void FpuStackSim::read_state(intArray* fpu_stack_state) {
  _stack_size = (*fpu_stack_state)[0];
  for (int i = 0; i < FrameMap::nof_fpu_regs; i++) {
    set_regs_at(i, (*fpu_stack_state)[1 + i]);
  }
}


#ifndef PRODUCT
void FpuStackSim::print() {
  tty->print(" N=%d[", stack_size());\
  for (int i = 0; i < stack_size(); i++) {
    int reg = regs_at(i);
    if (reg != EMPTY) {
      tty->print("%d", reg);
    } else {
      tty->print("_");
    }
  };
  tty->print(" ]");
}
#endif

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