Mercurial > hg > graal-compiler
comparison graal/com.oracle.max.criutils/src/com/oracle/max/criutils/TypeCheckHints.java @ 5369:2e9a5365dfb0
moved conversion of type profiles into hints for type check instructions from front end to lowering phase
author | Doug Simon <doug.simon@oracle.com> |
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date | Wed, 09 May 2012 22:21:58 +0200 |
parents | |
children | dc71b06d09f8 |
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5368:a4218dd1b157 | 5369:2e9a5365dfb0 |
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1 /* | |
2 * Copyright (c) 2012, 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 com.oracle.max.criutils; | |
24 | |
25 import java.lang.reflect.*; | |
26 import java.util.*; | |
27 | |
28 import com.oracle.max.cri.ci.*; | |
29 import com.oracle.max.cri.ri.*; | |
30 import com.oracle.max.cri.ri.RiTypeProfile.ProfiledType; | |
31 | |
32 /** | |
33 * Utility for deriving hint types for a type check instruction (e.g. checkcast or instanceof) | |
34 * based on the target type of the check and any profiling information available for the instruction. | |
35 */ | |
36 public class TypeCheckHints { | |
37 | |
38 private static final RiResolvedType[] NO_TYPES = {}; | |
39 | |
40 /** | |
41 * If true, then {@link #types} contains the only possible type that could pass the type check | |
42 * because the target of the type check is a final class or has been speculated to be a final class. | |
43 */ | |
44 public final boolean exact; | |
45 | |
46 /** | |
47 * The most likely types that the type check instruction will see. | |
48 */ | |
49 public final RiResolvedType[] types; | |
50 | |
51 /** | |
52 * Derives hint information for use when generating the code for a type check instruction. | |
53 * | |
54 * @param type the target type of the type check | |
55 * @param profile the profiling information available for the instruction (if any) | |
56 * @param assumptions the object in which speculations are recorded. This is null if speculations are not supported. | |
57 * @param minHintHitProbability if the probability that the type check will hit one the profiled types (up to | |
58 * {@code maxHints}) is below this value, then {@link #types} will be null | |
59 * @param maxHints the maximum length of {@link #types} | |
60 */ | |
61 public TypeCheckHints(RiResolvedType type, RiTypeProfile profile, CiAssumptions assumptions, double minHintHitProbability, int maxHints) { | |
62 if (type != null && isFinalClass(type)) { | |
63 types = new RiResolvedType[] {type}; | |
64 exact = true; | |
65 } else { | |
66 RiResolvedType uniqueSubtype = type == null ? null : type.uniqueConcreteSubtype(); | |
67 if (uniqueSubtype != null) { | |
68 types = new RiResolvedType[] {uniqueSubtype}; | |
69 if (assumptions != null) { | |
70 assumptions.recordConcreteSubtype(type, uniqueSubtype); | |
71 exact = true; | |
72 } else { | |
73 exact = false; | |
74 } | |
75 } else { | |
76 exact = false; | |
77 RiResolvedType[] hintTypes = NO_TYPES; | |
78 RiTypeProfile typeProfile = profile; | |
79 if (typeProfile != null) { | |
80 double notRecordedTypes = typeProfile.getNotRecordedProbability(); | |
81 ProfiledType[] ptypes = typeProfile.getTypes(); | |
82 if (notRecordedTypes < (1D - minHintHitProbability) && ptypes != null && ptypes.length > 0) { | |
83 hintTypes = new RiResolvedType[ptypes.length]; | |
84 int hintCount = 0; | |
85 double totalHintProbability = 0.0d; | |
86 for (ProfiledType ptype : ptypes) { | |
87 RiResolvedType hint = ptype.type; | |
88 if (type != null && hint.isSubtypeOf(type)) { | |
89 hintTypes[hintCount++] = hint; | |
90 totalHintProbability += ptype.probability; | |
91 } | |
92 } | |
93 if (totalHintProbability >= minHintHitProbability) { | |
94 if (hintTypes.length != hintCount || hintCount > maxHints) { | |
95 hintTypes = Arrays.copyOf(hintTypes, Math.min(maxHints, hintCount)); | |
96 } | |
97 } else { | |
98 hintTypes = NO_TYPES; | |
99 } | |
100 | |
101 } | |
102 } | |
103 this.types = hintTypes; | |
104 } | |
105 } | |
106 } | |
107 | |
108 public static boolean isFinalClass(RiResolvedType type) { | |
109 return Modifier.isFinal(type.accessFlags()) || (type.isArrayClass() && Modifier.isFinal(type.componentType().accessFlags())); | |
110 } | |
111 } |