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| | Threaded code - Wikipedia, the free encyclopedia |
 | | Huffman threaded code is one of the most compact representations known for a computer program. | | | In computer science, the term threaded code refers to an implementation technique for programming languages that produces very compact code. | | | In systems with virtual memory (where memory is simulated with a mechanical disk drive), threaded code may be hundreds of times faster than a less-compact design that does not fit in the available physical memory, because disk drives tend to be roughly a thousand times slower than random-access memory (RAM). |
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http://en.wikipedia.org/wiki/Threaded_code
(1456 words)
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| | UTR#17: Character Encoding Model |
| | The input to SCSU and RCSU are code units, the output is a compressed stream of bytes. | | | A code unit is an integer occupying a specified binary width in a computer architecture, such as an 8-bit byte. | | | This difference does not matter for operations on code units in memory, but the byte order becomes important when code units are serialized to sequences of bytes using a particular CES. |
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http://www.unicode.org/reports/tr17
(6354 words)
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| | Byte Code Compiler |
| | A byte code compiler translates a complex high-level language like Lisp into a very simple language that can be interpreted by a very fast byte code interpreter, or virtual machine. | | | The internal representation of this simple language is a string of bytes, hence the name byte code. | | | The naive approach does indeed produce additional speedup of about a factor of two by eliminating the byte code interpretation component, but there is a significant cost: the resulting object code is huge. |
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http://www.cs.uiowa.edu/~luke/xls/interface98/paper/node3.html
(442 words)
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| | UTF-8C1 |
| | This is because, with the C1 control codes being reserved for single-byte codes, there are few bits available in lead bytes for a larger 2-byte code range while still encoding the BMP with up to 3 bytes and all of Unicode with up to 4. | | | Signature byte sequence: Like the other Unicode encodings, the byte sequence representing U+feff shall be used as a signature. | | | With UTF-EBCDIC, which uses the same number of byte values for single- and multi-byte-sequences, almost all of the CJK, Hangul, Yi, and compatibility areas of the BMP need 4 bytes per code point. |
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http://www.mindspring.com/~markus.scherer/unicode/utf-8c1.html
(669 words)
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| | WorkPackage3 < WorkPackage < TWiki |
| | Support for byte code level is needed to enable Proof Carrying Code, as only the byte code is available for checking by the code consumer. | | | We will develop a specification language and a program logic for single-threaded code at byte code level. | | | The scientific objective of this work package is to develop modular logical techniques for verifying security and functional properties of programs at the source and byte code level. |
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http://mobius.inria.fr/twiki/bin/view/WorkPackage/WorkPackage3
(648 words)
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| | [No title] |
| | byte codes; the former takes a single 8-bit number as input and returns the value of the corresponding global variable, while the latter writes its second input, a 16-bit number, to the global variable specified by its first input (an 8-bit number). | | | In the resulting instruction stream, the first byte of the procedure body is the number of inputs to the procedure. | | | This byte is followed by the procedure body code. |
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http://handyboard.com/cricket/tech/ckdirect.txt
(2018 words)
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| | Compressing XML—Part I, Writing WBXML |
| | Therefore all the content from bytes 6 to 30 in Table 1 is part of the attribute code space. | | | Therefore byte 5 in Table 1 is 0x7f (0x3F + 0x40). | | | For example the byte 7 is 0x55, which is the code for the id attribute. |
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http://www.devx.com/xml/Article/16754/0/page/2
(1081 words)
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| | Low Level Security in Java |
| | First, the bytes that make up the virtual instructions are broken up into a sequence of instructions, and the offset of the start of each instruction is kept in a bit table. | | | Since Java language compiled code is designed to be transported in binary format across networks, security is extremely important. | | | Otherwise, a devious piece of code could fool the verifier into thinking it had initialized an object when it had, in fact, initialized an object created in a previous pass through the loop. |
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http://java.sun.com/sfaq/verifier.html
(4464 words)
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| | BCEL - Byte Code Engineering Library (BCEL) |
| | are encoded as relative offsets in the array of byte codes. | | | The byte code instruction set currently consists of 212 instructions, 44 opcodes are marked as reserved and may be used for future extensions or intermediate optimizations within the Virtual Machine. | | | The table marks handlers, i.e., code chunks, to be responsible for exceptions of certain types that are raised within a given area of the byte code. |
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http://jakarta.apache.org/bcel/manual.html
(5482 words)
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| | HP-41C Synthetic Programming |
| | The characters for the byte codes are shown in the right side of each cell in the graphical byte code table. | | | The first is a graphic byte code table (~40K) similar to those published in many books. | | | These comments refer to the graphic byte code table and HTML byte code table. |
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http://www.hpmuseum.org/prog/synth41.htm
(4912 words)
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| | CUMP Byte Code |
| | This is an attempt to define a byte code language for an embedded interpreter with a special bias to IO processing. | | | If the ASCII byte codes selected relate to the function the perform, a human could use them to carry on a "conversation" with the processor just as easily as another computer. | | | A byte code that starts a conditional jump would be assigned "?". |
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http://www.piclist.com/techref/piclist/cump/bytecode.htm
(2048 words)
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| | Byte Code Enhancement vs. Class Mutilation |
| | Byte code enhancement, class mutliation, source code enhancement --- it all sounds like a hack job to me. A technically pure JDO implementation would not make any requirements regarding source code changes or class file changes. | | | The positives of byte code enhancement are clear. | | | Finally, JDO doesn't prescribe a byte code enhancer. |
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http://www.oreillynet.com/cs/user/view/cs_msg/12128
(589 words)
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| | 18.10.1 Python Byte Code Instructions |
| | This is used in the code for a class definition: After the class body is evaluated, the locals are passed to the class definition. | | | If the code object has N free variables, the next N items on the stack are the cells for these variables. | | | An argument is two bytes, with the more significant byte last. |
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http://www.python.org/doc/current/lib/bytecodes.html
(875 words)
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| | BCEL - |
| | The Byte Code Engineering Library is intended to give users a convenient possibility to analyze, create, and manipulate (binary) Java class files (those ending with.class). | | | The Byte Code Engineering Library (BCEL) may be also useful if you want to learn about the Java Virtual Machine (JVM) and the format of Java.class files. | | | Classes are represented by objects which contain all the symbolic information of the given class: methods, fields and byte code instructions, in particular. |
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http://jakarta.apache.org/bcel
(160 words)
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| | Decoding Instructions |
| | Each instruction in the computer is translated to machine code. | | | Since this is a mov of a byte from memory to a register the code is 10001010 (reference 5). | | | The beginning of every instruction in machine code is an opcode that tells the machine whether you are doing an add, multiiply, mov, etc. Unfortunately, in the Intel architecture, each name such as "add" corresponds to several operation codes. |
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http://www.wiu.edu/users/mflll/310/Decode.html
(1567 words)
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| | Deviant Byte Code: A Fundamental Threat to Java Security |
| | Each byte of the code array is either a legal Java opcode, of which there are 201 at the present time, or an operand of an opcode. | | | After inspecting Beginner.class, the author wrote Attacker.java, which inserted 3 bytes of code into Beginner.class at the end of its finally block: goto followed by the 2-byte offset necessary to return control to the beginning of the program. | | | To insert some code, for instance, one need only append entries to the constant_pool, append the appropriate opcodes to a suitable method's code array, and use the goto instruction (167 or 0xa7) to jump to and from the inserted code. |
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http://www.cigital.com/hostile-applets/deviant2.html
(3660 words)
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| | UTN #6: BOCU-1 |
| | As a single/lead byte, byte value FF is used as a special “reset-state-only” command. | | | Proper input of supplementary code points (e.g., matched surrogate pairs in UTF-16) must be encoded by code points. | | | Byte values for single-byte codes and lead bytes overlap with trail bytes. |
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http://www.unicode.org/notes/tn6
(1422 words)
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| | The Parrot Bytecode (PBC) Format - |
| | All segments are aligned at a 16 byte boundary. | | | FloatType 0 is IEEE 754 8 byte double, FloatType 1 is i386 little endian 12 byte long double. | | | << integer constants are represented as manifest constants in the byte code stream currently, limiting them to 32 bit values. |
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http://www.parrotcode.org/docs/parrotbyte.html
(751 words)
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| | bytecode.nw |
| | The simple byte code used so far does not allow for flow control or variable assignments or calling arbitrary functions, or anything else that would be useful--it is very primitive. | | | A byte coded version of the constant-folded version of the sample function is constructed by | | | The overhead of the evaluation process can be further reduced by moving to a byte code representation of the code. |
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http://www.stat.uiowa.edu/~luke/R/bytecode.html
(1715 words)
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| | Administration Guide |
| | The available characters depend on the code page in use and if you are using the database in a multiple code page environment, you must ensure that all code pages support any alphabetics you plan on using from the extended character set. | | | The coding of SQL statements is not language dependent. | | | Within each implied DBCS code page, there are 256 code points available as the second byte for each valid first byte. |
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http://www.pdc.kth.se/doc/SP/manuals/db2-5.0/html/db2d0/db2d0240.htm
(521 words)
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| | UTF-8: What is It and Why is It Important |
| | UTF-8 is a multi-byte encoding in which each character can be encoded in as little as 1 byte and as many as 4 bytes. | | | The problem was that trail bytes could also be lead bytes in some encodings. | | | The encoding distributes a Unicode code value’s bit pattern across 1, 2, 3, or even 4 bytes. |
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http://www.joconner.com/javai18n/articles/UTF8.html
(1579 words)
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| | RCX Internals |
| | Additionally, user programs are downloaded to the RCX as byte code and are stored in a 6K region of memory. | | | The table in this section gives a brief overview of the opcodes that make up the RCX byte code and is an index into the RCX Opcode Reference, where more information about the opcodes can be found. | | | Messages consist of four parts: a header, an opcode, optional data bytes, and a checksum. |
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http://graphics.stanford.edu/~kekoa/rcx
(2302 words)
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| | LtU Classic Archives |
| | The current approach is to reduce the stack-based JVM code to an expression tree format so that the reordering can be done in the translator rather than the generated code (although this changes the semantics of the Java source code wrt parameter evaluation order). | | | The Byte Code Engineering Library (formerly known as JavaClass) is intended to give users a convenient possibility to analyze, create, and manipulate (binary) Java class files (those ending with.class). | | | Classes are represented by objects which contain all the symbolic information of the given class: methods, fields and byte code instructions, in particular. |
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http://lambda-the-ultimate.org/classic/message6008.html
(725 words)
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| | The Open Group Releases High Performance Java Byte Code Compiler for HP |
| | Developers and users still enjoy the Java paradigm of 'develop once and run everywhere' because the compiler is operating on byte code as distributed on the net. | | | "It translates Java byte code (not Java source code) into native machine code, using up-to-date, complex optimizations that produce highly optimized code and can be saved as executable files or dynamically loadable shared libraries. | | | On some tests, performance increases of up to 100 times the byte code interpreter speed have been measured. |
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http://www.opengroup.org/press/2dec97.htm
(717 words)
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| | CodeShield(tm) Java Byte Code Obfuscator |
| | Rearranges byte code instructions so that decompilation to structured code is virtually impossible by decompilers. | | | A command line byte code obfuscator that works with your build environment | | | Allows user defined base package names on obfuscated code to add flexibility to your build environment. |
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http://www.codingart.com/codeshield.html
(447 words)
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| | Byte code instrumentation (US6314558) |
| | Instrumenting a computer program to provide instrumented byte code includes examining the byte code, selecting portions of the byte code for instrumentation, and instrumenting the portions to provide instrumented byte code. | | | (a) examining the initial byte code to determine an identifier associated with at least one block of code included in the initial byte code; | | | A method of instrumenting an initial byte code computer program, comprising: |
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http://www.delphion.com/details?pn=US06314558__
(557 words)
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| | BYTE.com |
| | Th is lets you boost the speed of a commonly used function or hook Python byte-code files to large, already-made binaries such as imaging libraries or to platform-specific APIs like Microsoft Foundation Classes (MFC) or the Mac OS Toolbox. | | | The interpreter performs automatic version checks against the source code file's modification date and fetches the most recently generated byte-code file. | | | My approach to software engineering is far more pragmatic than it is theoretical--and no language better exemplifies this than C++. |
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http://www.byte.com/art/9702/sec5/art4.htm#027proa0
(1708 words)
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| | Native compilation of Emacs byte-code |
| | The speedup over byte code is available, but in most cases it will be over-shadowed by the time spent in primitives. | | | An attempt to speed up Emacs by compiling byte-code functions into native code. | | | The CCL part has been solved by Unicode additions to Emacs. |
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http://www.mundell.ukfsn.org/native
(295 words)
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| | GNU Emacs Lisp Reference Manual - Compilation Functions |
| | Only the byte compiler knows how to generate valid calls to this function. | | | All comments are discarded when the input file is read. | | | These report usage in your program that suggest a problem, but are not necessarily erroneous. |
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http://www.tac.nyc.ny.us/manuals/elisp/elisp_168.html
(550 words)
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| | NewtonScript Byte Code Specification |
| | This instruction is used internally as part of the coding of for loops. | | | If the low three bits of the first byte in the sequence are all 1 then the following two bytes are also part of the instruction, otherwise it is a single byte instruction. | | | instructions is a block of bytecode bytes, the meaning of which we will get to a little later. |
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http://www.0x1.org/d/stuff/newton/vm
(3718 words)
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| | [No title] |
| | It fully encrypts the byte code so that from JVM's point of view, the encrypted code is no longer a valid Java byte-code. | | | Java developers do not need to do anything when they are developing their code. | | | It transparently encrypts Java class files and at run-time decrypts the code, so that the JVM can interpret the class file as a valid Java byte-code. |
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http://www.jbitsoftware.com/JBitSoftware/jlockinfo.html
(283 words)
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| | Cracking Java byte-code encryption |
| | Unfortunately, both approaches must actually change the code the JVM will run, and many users are afraid (rightfully so) that this transformation may add new bugs to their applications. | | | And guess what, the byte array must contain the unencrypted class definition in a well-documented format (see the class file format specification). | | | data to make the byte code either harder to read when decompiled or harder to decompile into valid Java code (or both). |
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http://www.javaworld.com/javaworld/javaqa/2003-05/01-qa-0509-jcrypt.html
(1852 words)
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| | Standalone byte code |
| | One perceived problem is that delivering GHC > itself in that form would be intolerably slow; rough > measurements show interpreted code at least 10 times slower > than native code. | | | and particularly how to > do register allocation on the virtual code in such a way that > the jitter is very simple -- meaning doesn't do register allocation > -- yet gives good code. | | | I've also been playing with dynamic > code generation on x86s recently for other purposes. |
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http://www.haskell.org/pipermail/cvs-all/2001-May/012462.html
(782 words)
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| | NeoBasic,java like byte-code scripting langua - visual basic, vb, vbscript |
| | Virus note:All files are scanned once-a-day by Planet Source Code for viruses,but new viruses come out every day, so no prevention program can catch 100% of them. | | | NOTICE: The author of this code has been kind enough to share it with you. | | | Afterdownloading it, you will need a program like Winzip to decompress it. |
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http://www.planetsourcecode.com/vb/scripts/ShowCode.asp?txtCodeId=43417&lngWId=1
(577 words)
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| | The Java Language Environment |
| | The bytecode verifier traverses the bytecodes, constructs the type state information, and verifies the types of the parameters to all the bytecode instructions. | | | While all this checking appears excruciatingly detailed, by the time the bytecode verifier has done its work, the Java interpreter can proceed, knowing that the code will run securely. | | | Knowing these properties makes the Java interpreter much faster, because it doesn't have to check anything. |
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http://java.sun.com/docs/white/langenv/Security.doc3.html
(490 words)
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| | Microsoft Security Bulletin (MS99-022) |
| | As a result, the file is simply delivered as text to the browser, thereby allowing the source code to be viewed. | | | Microsoft has released a patch that eliminates a vulnerability in Microsoft® Internet Information Server that could allow a web site visitor to view the source code for selected files on the server, if the server's default language is set to Chinese, Japanese or Korean. | | | Patch Available for "Double Byte Code Page" Vulnerability |
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http://www.microsoft.com/technet/security/bulletin/MS99-022.mspx
(439 words)
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| | CMUCL: Different compilers |
| | The assembly code is slightly optimized, then assembled to machine code, and finally emitted to the FASL file. | | | This document provides more information on the differences between these parts of CMUCL. | | | code from a file without first compiling it using |
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http://www.cons.org/cmucl/doc/different-compilers.html
(478 words)
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| | Hardware-based Byte-code Interpreters: Are they all they are cracked up to be? |
| | For an earlier analysis, see this Byte article: http://www.byte.com/art/9611/sec6/art2.htm. | | | I don't know if these checks can be optimized using hardware execution instead of JITing. | | | I was under the impression that having hardware with these capabilities would unquestionably make Java's speed a force to be reckoned with. |
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http://weblogs.asp.net/sibrahim/archive/2004/03/10/87717.aspx
(647 words)
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| | Eclipse - Omondo - The Live UML Company |
| | Reverse engineering at project level is the only way to analyse all in-going and out-going information. | | | Working at project level allows EclipseUML to analyse the Main class, which could be anywhere in the project, and brings the information on element types into the Company collection. | | | The project information will then be available in Java code and the tags. |
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http://www.tutorial-omondo.com/reverse
(362 words)
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| | Mobile Code Security Through Java Byte Code Modification |
| | This project is about modification of java bytecode to make mobile Java code more secure. | | | The bytecode modification techniques used by our group at Stanford.(refer paper and code above) | | | Mobile Code Security Through Java Byte Code Modification |
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http://theory.stanford.edu/~vganesh/project.html
(772 words)
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| | 5.9 Byte Coded Compilation |
| | Produce a normal fasl file, but byte compile any functions for which the | | | Python supports byte compilation to reduce the size of Lisp programs by allowing functions to be compiled more compactly. | | | Large Lisp systems (such as CMU Common Lisp itself) often have large amounts of user-interface code, compile-time (macro) code, debugging code, or rarely executed special-case code. |
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http://www.ifi.uio.no/~kt-lab/lambdalab/doc/CMUCL/node159.html
(270 words)
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| | Comp.compilers: Re: What is byte-code ? |
| | simple VM instructions, each with 1-3 lines of code, and the speedup | | | 20-100 lines of code, and the speedup is small on many | | | their death during a forward pass through the code, whereas with most |
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http://compilers.iecc.com/comparch/article/05-03-120
(691 words)
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