Java example source code file (SPARCRegisterMap.java)

This example Java source code file (SPARCRegisterMap.java) 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

address, frame, object, observer, r_g_nums, r_i_nums, r_l_nums, r_lio_mask, r_o_nums, registerimpl\:\:number_of_registers, sp\,fp\,tls\,etc, sparcregistermap, util, younger

The SPARCRegisterMap.java Java example source code

/*
 * Copyright (c) 2000, 2005, 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.
 *
 */

package sun.jvm.hotspot.runtime.sparc;

import java.util.*;

import sun.jvm.hotspot.asm.sparc.*;
import sun.jvm.hotspot.debugger.*;
import sun.jvm.hotspot.runtime.*;
import sun.jvm.hotspot.types.*;
import sun.jvm.hotspot.utilities.*;

public class SPARCRegisterMap extends RegisterMap {
  /** Register window save area (for L and I regs) */
  private Address window;
  /** Previous save area (for O regs, if needed) */
  private Address youngerWindow;

  private static int registerImplNumberOfRegisters;

  // Unified register numbering scheme: each 32-bits counts as a register
  // number, so all the V9 registers take 2 slots.
  private static int[] R_L_nums = new int[] {0+040,2+040,4+040,6+040,8+040,10+040,12+040,14+040};
  private static int[] R_I_nums = new int[] {0+060,2+060,4+060,6+060,8+060,10+060,12+060,14+060};
  private static int[] R_O_nums = new int[] {0+020,2+020,4+020,6+020,8+020,10+020,12+020,14+020};
  private static int[] R_G_nums = new int[] {0+000,2+000,4+000,6+000,8+000,10+000,12+000,14+000};

  private static long badMask;
  private static long R_LIO_mask;

  private static int sizeofJint;

  static {
    VM.registerVMInitializedObserver(new Observer() {
        public void update(Observable o, Object data) {
          initialize(VM.getVM().getTypeDataBase());
        }
      });
  }

  private static void initialize(TypeDataBase db) {
    badMask = 0;
    R_LIO_mask = 0;

    sizeofJint = (int) db.lookupType("jint").getSize();
    registerImplNumberOfRegisters = db.lookupIntConstant("RegisterImpl::number_of_registers").intValue();

    for (int i = 0; i < 8; i++) {
      Assert.that(R_L_nums[i] < locationValidTypeSize, "in first chunk");
      Assert.that(R_I_nums[i] < locationValidTypeSize, "in first chunk");
      Assert.that(R_O_nums[i] < locationValidTypeSize, "in first chunk");
      Assert.that(R_G_nums[i] < locationValidTypeSize, "in first chunk");
    }

    badMask |= ((long) 1 << R_O_nums[6]); // SP
    badMask |= ((long) 1 << R_O_nums[7]); // cPC
    badMask |= ((long) 1 << R_I_nums[6]); // FP
    badMask |= ((long) 1 << R_I_nums[7]); // rPC
    badMask |= ((long) 1 << R_G_nums[2]); // TLS
    badMask |= ((long) 1 << R_G_nums[7]); // reserved by libthread

    for (int i = 0; i < 8; i++) {
      R_LIO_mask |= ((long) 1 << R_L_nums[i]);
      R_LIO_mask |= ((long) 1 << R_I_nums[i]);
      R_LIO_mask |= ((long) 1 << R_O_nums[i]);
    }
  }

  /** This is the only public constructor, and is only called by
      SolarisSPARCJavaThread */
  public SPARCRegisterMap(JavaThread thread, boolean updateMap) {
    super(thread, updateMap);
  }

  protected SPARCRegisterMap(RegisterMap map) {
    super(map);
  }

  public Object clone() {
    SPARCRegisterMap retval = new SPARCRegisterMap(this);
    return retval;
  }

  protected void clearPD() {
    if (thread.hasLastJavaFrame()) {
      Frame fr = thread.getLastFrame();
      window = fr.getSP();
    } else {
      window = null;
      if (VM.getVM().isDebugging()) {
        Frame fr = thread.getCurrentFrameGuess();
        if (fr != null) {
          window = fr.getSP();
        }
      }
    }
    youngerWindow = null;
  }

  protected Address getLocationPD(VMReg vmreg) {
    VM vm = VM.getVM();
    int regname = vmreg.getValue();
    if (Assert.ASSERTS_ENABLED) {
       Assert.that(0 <= regname && regname < regCount, "sanity check");
    }

    // Only the GPRs get handled this way
    if (regname >= (registerImplNumberOfRegisters << 1)) {
       return null;
    }

    // don't talk about bad registers
    if ((badMask & ((long) 1 << regname)) != 0) {
      return null;
    }

    // Convert to a GPR
    int secondWord = 0;
    // 32-bit registers for in, out and local
    if (!isEven(regname)) {
      if (vm.isLP64()) {
        secondWord = sizeofJint;
      } else {
        return null;
      }
    }

    SPARCRegister reg = new SPARCRegister(regname >> 1);
    if (reg.isOut()) {
      if (Assert.ASSERTS_ENABLED) {
         Assert.that(youngerWindow != null, "Younger window should be available");
      }
      return youngerWindow.addOffsetTo(reg.afterSave().spOffsetInSavedWindow() + secondWord);
    }
    if (reg.isLocal() || reg.isIn()) {
      if (Assert.ASSERTS_ENABLED) {
        Assert.that(window != null, "Window should be available");
      }
      return window.addOffsetTo(reg.spOffsetInSavedWindow() + secondWord);
    }

    // Only the window'd GPRs get handled this way; not the globals.
    return null;
  }

  protected void initializePD() {
    window        = null;
    youngerWindow = null;
    // avoid the shift_individual_registers game
    makeIntegerRegsUnsaved();
  }

  protected void initializeFromPD(RegisterMap map) {
    SPARCRegisterMap srm = (SPARCRegisterMap) map;
    window        = srm.window;
    youngerWindow = srm.youngerWindow;
    // avoid the shift_individual_registers game
    makeIntegerRegsUnsaved();
  }

  public void shiftWindow(Address sp, Address youngerSP) {
    window        = sp;
    youngerWindow = youngerSP;
    // Throw away locations for %i, %o, and %l registers:
    // But do not throw away %g register locs.
    if (locationValid[0] != 0) {
      shiftIndividualRegisters();
    }
  }

  /** When popping out of compiled frames, we make all IRegs disappear. */
  public void makeIntegerRegsUnsaved() {
    locationValid[0] = 0;
  }

  //--------------------------------------------------------------------------------
  // Internals only below this point
  //

  private void shiftIndividualRegisters() {
    if (!getUpdateMap()) {
      return;
    }

    checkLocationValid();

    long lv = locationValid[0];
    long lv0 = lv;

    lv &= ~R_LIO_mask;  // clear %l, %o, %i regs

    // if we cleared some non-%g locations, we may have to do some shifting
    if (lv != lv0) {
      // copy %i0-%i5 to %o0-%o5, if they have special locations
      // This can happen in within stubs which spill argument registers
      // around a dynamic link operation, such as resolve_opt_virtual_call.
      for (int i = 0; i < 8; i++) {
        if ((lv0 & ((long) 1 << R_I_nums[i])) != 0) {
          location[R_O_nums[i]] = location[R_I_nums[i]];
          lv |= ((long) 1 << R_O_nums[i]);
        }
      }
    }

    locationValid[0] = lv;
    checkLocationValid();
  }

  private boolean isEven(int i) {
    return (i & 1) == 0;
  }

  private void checkLocationValid() {
    if (Assert.ASSERTS_ENABLED) {
      Assert.that((locationValid[0] & badMask) == 0, "cannot have special locations for SP,FP,TLS,etc.");
    }
  }
}