Mercurial > hg > truffle
annotate agent/src/share/classes/sun/jvm/hotspot/code/CompressedStream.java @ 1913:3b2dea75431e
6984311: JSR 292 needs optional bootstrap method parameters
Summary: Allow CONSTANT_InvokeDynamic nodes to have any number of extra operands.
Reviewed-by: twisti
| author | jrose |
|---|---|
| date | Sat, 30 Oct 2010 13:08:23 -0700 |
| parents | c18cbe5936b8 |
| children |
| rev | line source |
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| 0 | 1 /* |
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2 * Copyright (c) 2000, 2005, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
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6941466: Oracle rebranding changes for Hotspot repositories
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
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20 * or visit www.oracle.com if you need additional information or have any |
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c18cbe5936b8
6941466: Oracle rebranding changes for Hotspot repositories
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 25 package sun.jvm.hotspot.code; | |
| 26 | |
| 27 import sun.jvm.hotspot.debugger.*; | |
| 28 | |
| 29 /** NOTE that this class takes the address of a buffer. This means | |
| 30 that it can read previously-generated debug information directly | |
| 31 from the target VM. However, it also means that you can't create a | |
| 32 "wrapper" object for a CompressedStream down in the VM. It looks | |
| 33 like these are only kept persistently in OopMaps, and the code has | |
| 34 been special-cased in OopMap.java to handle this. */ | |
| 35 | |
| 36 public class CompressedStream { | |
| 37 protected Address buffer; | |
| 38 protected int position; | |
| 39 | |
| 40 /** Equivalent to CompressedStream(buffer, 0) */ | |
| 41 public CompressedStream(Address buffer) { | |
| 42 this(buffer, 0); | |
| 43 } | |
| 44 | |
| 45 public CompressedStream(Address buffer, int position) { | |
| 46 this.buffer = buffer; | |
| 47 this.position = position; | |
| 48 } | |
| 49 | |
| 50 public Address getBuffer() { | |
| 51 return buffer; | |
| 52 } | |
| 53 | |
| 54 public static final int LogBitsPerByte = 3; | |
| 55 public static final int BitsPerByte = 1 << 3; | |
| 56 | |
| 57 // Constants for UNSIGNED5 coding of Pack200 | |
| 58 public static final int lg_H = 6; | |
| 59 public static final int H = 1<<lg_H; // number of high codes (64) | |
| 60 public static final int L = (1<<BitsPerByte) - H; // number of low codes (192) | |
| 61 public static final int MAX_i = 4; // bytes are numbered in (0..4) | |
| 62 | |
| 63 // Positioning | |
| 64 public int getPosition() { | |
| 65 return position; | |
| 66 } | |
| 67 public void setPosition(int position) { | |
| 68 this.position = position; | |
| 69 } | |
| 70 | |
| 71 // 32-bit one-to-one sign encoding taken from Pack200 | |
| 72 // converts leading sign bits into leading zeros with trailing sign bit | |
| 73 public int encodeSign(int value) { | |
| 74 return (value << 1) ^ (value >> 31); | |
| 75 } | |
| 76 | |
| 77 public int decodeSign(int value) { | |
| 78 return (value >>> 1) ^ -(value & 1); | |
| 79 } | |
| 80 | |
| 81 // 32-bit self-inverse encoding of float bits | |
| 82 // converts trailing zeros (common in floats) to leading zeros | |
| 83 public int reverseInt(int i) { | |
| 84 // Hacker's Delight, Figure 7-1 | |
| 85 i = (i & 0x55555555) << 1 | (i >>> 1) & 0x55555555; | |
| 86 i = (i & 0x33333333) << 3 | (i >>> 2) & 0x33333333; | |
| 87 i = (i & 0x0f0f0f0f) << 4 | (i >>> 4) & 0x0f0f0f0f; | |
| 88 i = (i << 24) | ((i & 0xff00) << 8) | ((i >>> 8) & 0xff00) | (i >>> 24); | |
| 89 return i; | |
| 90 } | |
| 91 } |