001 /*
002 * This file is part of the Jikes RVM project (http://jikesrvm.org).
003 *
004 * This file is licensed to You under the Eclipse Public License (EPL);
005 * You may not use this file except in compliance with the License. You
006 * may obtain a copy of the License at
007 *
008 * http://www.opensource.org/licenses/eclipse-1.0.php
009 *
010 * See the COPYRIGHT.txt file distributed with this work for information
011 * regarding copyright ownership.
012 */
013 package org.jikesrvm.mm.mminterface;
014
015 import org.jikesrvm.Constants;
016 import org.jikesrvm.classloader.RVMType;
017 import org.jikesrvm.objectmodel.JavaHeader;
018 import org.jikesrvm.objectmodel.ObjectModel;
019 import org.mmtk.plan.TransitiveClosure;
020 import org.vmmagic.pragma.Inline;
021 import org.vmmagic.pragma.Uninterruptible;
022
023 /**
024 * Supply and interpretation of values to be alignment-encoded into
025 * the TIB pointer of an object.
026 */
027 public class HandInlinedScanning {
028
029 public static final int AE_FALLBACK = (1<<AlignmentEncoding.FIELD_WIDTH)-1;
030 public static final int AE_REFARRAY = AE_FALLBACK - 1;
031
032 public static final int AE_PATTERN_0x0 = 0;
033 public static final int AE_PATTERN_0x1 = 1;
034 public static final int AE_PATTERN_0x7 = 2;
035 public static final int AE_PATTERN_0x3F = 3;
036 public static final int AE_PATTERN_0x3 = 4;
037 public static final int AE_PATTERN_0x3D = 5;
038
039 private static final int FIELD0_OFFSET =
040 JavaHeader.objectStartOffset(RVMType.JavaLangObjectType) +
041 ObjectModel.computeScalarHeaderSize(RVMType.JavaLangObjectType);
042
043 private static final int FIELD1_OFFSET = FIELD0_OFFSET + Constants.BYTES_IN_ADDRESS;
044 private static final int FIELD2_OFFSET = FIELD1_OFFSET + Constants.BYTES_IN_ADDRESS;
045 private static final int FIELD3_OFFSET = FIELD2_OFFSET + Constants.BYTES_IN_ADDRESS;
046 private static final int FIELD4_OFFSET = FIELD3_OFFSET + Constants.BYTES_IN_ADDRESS;
047 private static final int FIELD5_OFFSET = FIELD4_OFFSET + Constants.BYTES_IN_ADDRESS;
048
049 /** Master switch */
050 public static final boolean ENABLED = true;
051
052 public static int referenceArray() {
053 if (!ENABLED)
054 return AlignmentEncoding.ALIGN_CODE_NONE;
055 return AE_REFARRAY;
056 }
057
058 public static int primitiveArray() {
059 if (!ENABLED)
060 return AlignmentEncoding.ALIGN_CODE_NONE;
061 return AE_PATTERN_0x0;
062 }
063
064 public static int fallback() {
065 if (!ENABLED)
066 return AlignmentEncoding.ALIGN_CODE_NONE;
067 return AE_FALLBACK;
068 }
069
070 public static int scalar(int[] offsets) {
071 if (!ENABLED)
072 return AlignmentEncoding.ALIGN_CODE_NONE;
073 if (offsets.length == 0) {
074 return AE_PATTERN_0x0;
075 }
076 if (offsets.length == 1) {
077 if (offsets[0] == FIELD0_OFFSET)
078 return AE_PATTERN_0x1;
079 }
080 // if (offsets.length == 2) {
081 // if (offsets[0] == FIELD0_OFFSET &&
082 // offsets[1] == FIELD1_OFFSET)
083 // return AE_PATTERN_0x3;
084 // }
085 if (offsets.length == 3) {
086 if (offsets[0] == FIELD0_OFFSET &&
087 offsets[1] == FIELD1_OFFSET &&
088 offsets[2] == FIELD2_OFFSET)
089 return AE_PATTERN_0x7;
090 }
091 // if (offsets.length == 5) {
092 // if (offsets[0] == FIELD0_OFFSET &&
093 // offsets[1] == FIELD2_OFFSET &&
094 // offsets[2] == FIELD3_OFFSET &&
095 // offsets[3] == FIELD4_OFFSET &&
096 // offsets[4] == FIELD5_OFFSET)
097 // return AE_PATTERN_0x3D;
098 // }
099 if (offsets.length == 6) {
100 if (offsets[0] == FIELD0_OFFSET &&
101 offsets[1] == FIELD1_OFFSET &&
102 offsets[2] == FIELD2_OFFSET &&
103 offsets[3] == FIELD3_OFFSET &&
104 offsets[4] == FIELD4_OFFSET &&
105 offsets[5] == FIELD5_OFFSET)
106 return AE_PATTERN_0x3F;
107 }
108 return AE_FALLBACK;
109 }
110
111 /**
112 * Hand-inlined scanning of objects. The cases of the conditional
113 * are ordered in descending frequency of patterns.
114 *
115 * This entry point falls back to specialized scanning if it is enabled.
116 */
117 @Inline
118 @Uninterruptible
119 public static void scanObject(int code, int id, Object object, TransitiveClosure trace) {
120 scanObject(code, id, object, trace, SpecializedScanMethod.ENABLED);
121 }
122
123 /**
124 * Hand-inlined scanning of objects. The cases of the conditional
125 * are ordered in descending frequency of patterns.
126 * <p>
127 * This entry point does not fall back to specialized scanning.
128 */
129 @Inline
130 @Uninterruptible
131 public static void scanObject(int code, Object object, TransitiveClosure trace) {
132 scanObject(code, 0, object, trace, false);
133 }
134
135 @Inline
136 @Uninterruptible
137 private static void scanObject(int code, int id, Object object, TransitiveClosure trace, boolean specialize) {
138 if (code == AE_PATTERN_0x0) {
139 ;
140 } else if (code == AE_PATTERN_0x1) {
141 SpecializedScanMethod.pattern(0x1,object,trace);
142 } else if (code == AE_PATTERN_0x7) {
143 SpecializedScanMethod.pattern(0x7,object,trace);
144 } else if (code == AE_PATTERN_0x3F) {
145 SpecializedScanMethod.pattern(0x3F,object,trace);
146 } else if (code == AE_FALLBACK) {
147 if (specialize) {
148 SpecializedScanMethod.invoke(id, object,trace);
149 } else {
150 SpecializedScanMethod.fallback(object, trace);
151 }
152 } else if (code == AE_REFARRAY) {
153 SpecializedScanMethod.referenceArray(object,trace);
154 } else if (code == AE_PATTERN_0x3) {
155 SpecializedScanMethod.pattern(0x3,object,trace);
156 } else if (code == AE_PATTERN_0x3D) {
157 SpecializedScanMethod.pattern(0x3D,object,trace);
158 }
159 }
160 }