1 /*
   2  * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package org.graalvm.compiler.lir.stackslotalloc;
  24 
  25 import org.graalvm.compiler.lir.VirtualStackSlot;
  26 
  27 import jdk.vm.ci.code.StackSlot;
  28 import jdk.vm.ci.meta.ValueKind;
  29 
  30 public final class StackInterval {
  31 
  32     private static final int INVALID_START = Integer.MAX_VALUE;
  33     private static final int INVALID_END = Integer.MIN_VALUE;
  34     private final VirtualStackSlot operand;
  35     private StackInterval hint;
  36     private final ValueKind<?> kind;
  37     private int from = INVALID_START;
  38     private int to = INVALID_END;
  39     private StackSlot location;
  40 
  41     public StackInterval(VirtualStackSlot operand, ValueKind<?> kind) {
  42         this.operand = operand;
  43         this.kind = kind;
  44     }
  45 
  46     public boolean verify(int maxOpId) {
  47         // maxOpId + 1 is the last position in the last block (i.e. the "write position")
  48         assert 0 <= from && from <= to && to <= maxOpId + 1 : String.format("from %d, to %d, maxOpId %d", from, to, maxOpId);
  49         return true;
  50     }
  51 
  52     public VirtualStackSlot getOperand() {
  53         return operand;
  54     }
  55 
  56     public void addTo(int opId) {
  57         if (opId >= to) {
  58             to = opId;
  59         }
  60     }
  61 
  62     protected void addFrom(int opId) {
  63         if (from > opId) {
  64             from = opId;
  65             // set opId also as to if it has not yet been set
  66             if (to == INVALID_END) {
  67                 to = opId;
  68             }
  69         }
  70     }
  71 
  72     public ValueKind<?> kind() {
  73         return kind;
  74     }
  75 
  76     public StackSlot location() {
  77         return location;
  78     }
  79 
  80     public void setLocation(StackSlot location) {
  81         this.location = location;
  82     }
  83 
  84     public int from() {
  85         return from;
  86     }
  87 
  88     public int to() {
  89         return to;
  90     }
  91 
  92     public void fixFrom() {
  93         if (from == INVALID_START) {
  94             from = 0;
  95         }
  96     }
  97 
  98     public boolean isFixed() {
  99         return from == 0;
 100     }
 101 
 102     @Override
 103     public String toString() {
 104         return String.format("SI[%d-%d] k=%s o=%s l=%s h=%s", from, to, kind, operand, location, hint != null ? hint.getOperand() : "null");
 105     }
 106 
 107     public void setLocationHint(StackInterval locationHint) {
 108         hint = locationHint;
 109     }
 110 
 111     public StackInterval locationHint() {
 112         return hint;
 113     }
 114 
 115 }