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89-527: The open source GCC compiler removed support for POWER1 (RIOS) and POWER2 (RIOS2) in the 4.5 release. Improvements over the POWER1 included enhancements to the POWER instruction set architecture (consisting of new user and system instructions and other system-related features), higher clock rates (55 to 71.5 MHz), an extra fixed point unit and floating point unit , a larger 32 KB instruction cache, and

178-550: A 68000 Unix system with only 64 KB, and concluded he would have to write a new compiler from scratch. None of the Pastel compiler code ended up in GCC, though Stallman did use the C front end he had written. GCC was first released March 22, 1987, available by FTP from MIT . Stallman was listed as the author but cited others for their contributions, including Tower for "parts of the parser, RTL generator, RTL definitions, and of

267-428: A negative or positive liberty . Due to their restrictions on distribution, not everyone considers copyleft licenses to be free. Conversely, a permissive license may provide an incentive to create non-free software by reducing the cost of developing restricted software. Since this is incompatible with the spirit of software freedom, many people consider permissive licenses to be less free than copyleft licenses. There

356-559: A solder ball connect (SBC) package instead of a MCM. POWER2 Super Chip (P2SC) was released in October 1996 as the successor of the POWER2. It was a single-chip implementation of the eight-chip POWER2, integrating 15 million transistors on a 335 mm die manufactured in IBM's 0.29 μm five-layer metal CMOS-6S process. The first version ran at 120 or 135 MHz, nearly twice as fast as

445-430: A C++ compiler is required that understands ISO/IEC C++03 standard. On May 18, 2020, GCC moved away from ISO/IEC C++03 standard to ISO/IEC C++11 standard (i.e. needed to compile, bootstrap, the compiler itself; by default it however compiles later versions of C++). Each front end uses a parser to produce the abstract syntax tree of a given source file . Due to the syntax tree abstraction, source files of any of

534-529: A copy of the free application itself. Fees are usually charged for distribution on compact discs and bootable USB drives, or for services of installing or maintaining the operation of free software. Development of large, commercially used free software is often funded by a combination of user donations, crowdfunding , corporate contributions, and tax money. The SELinux project at the United States National Security Agency

623-561: A fee. The Free Software Foundation encourages selling free software. As the Foundation has written, "distributing free software is an opportunity to raise funds for development. Don't waste it!". For example, the FSF's own recommended license (the GNU GPL ) states that "[you] may charge any price or no price for each copy that you convey, and you may offer support or warranty protection for

712-450: A fee." Microsoft CEO Steve Ballmer stated in 2001 that "open source is not available to commercial companies. The way the license is written, if you use any open-source software, you have to make the rest of your software open source." This misunderstanding is based on a requirement of copyleft licenses (like the GPL) that if one distributes modified versions of software, they must release

801-494: A for-profit, commercial activity or not. Some free software is developed by volunteer computer programmers while other is developed by corporations; or even by both. Although both definitions refer to almost equivalent corpora of programs, the Free Software Foundation recommends using the term "free software" rather than " open-source software " (an alternative, yet similar, concept coined in 1998), because

890-537: A front-end for CHILL due to a lack of maintenance. Before version 4.0 the Fortran front end was g77 , which only supported FORTRAN 77 , but later was dropped in favor of the new GNU Fortran front end that supports Fortran 95 and large parts of Fortran 2003 and Fortran 2008 as well. As of version 4.8, GCC is implemented in C++. Support for Cilk Plus existed from GCC 5 to GCC 7. GCC has been ported to

979-581: A higher combined price than the previous bundle, which led many of Sun's users to buy or download GCC instead of the vendor's tools. While Stallman considered GNU Emacs as his main project, by 1990 GCC supported thirteen computer architectures, was outperforming several vendor compilers, and was used commercially by several companies. As GCC was licensed under the GPL, programmers wanting to work in other directions—particularly those writing interfaces for languages other than C—were free to develop their own fork of

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1068-433: A language-specific driver program ( gcc for C, g++ for C++, etc.), which interprets command arguments , calls the actual compiler, runs the assembler on the output, and then optionally runs the linker to produce a complete executable binary. Each of the language compilers is a separate program that reads source code and outputs machine code . All have a common internal structure. A per-language front end parses

1157-542: A larger 128 or 256 KB data cache. The POWER2 was a multi-chip design consisting of six or eight semi-custom integrated circuits, depending on the amount of data cache (the 256 KB configuration required eight chips). The partitioning of the design was identical to that of the POWER1: an instruction cache unit chip, a fixed-point unit chip, a floating-point unit chip, a storage control unit chip, and two or four data cache unit chips. The eight-chip configuration contains

1246-446: A much more limited scope, and have less high-level information. Some of these optimizations performed at this level include dead-code elimination , partial-redundancy elimination , global value numbering , sparse conditional constant propagation , and scalar replacement of aggregates . Array dependence based optimizations such as automatic vectorization and automatic parallelization are also performed. Profile-guided optimization

1335-571: A significant part in the development of the Internet, the World Wide Web and the infrastructure of dot-com companies . Free software allows users to cooperate in enhancing and refining the programs they use; free software is a pure public good rather than a private good . Companies that contribute to free software increase commercial innovation . "We migrated key functions from Windows to Linux because we needed an operating system that

1424-498: A small set of licenses. The most popular of these licenses are: The Free Software Foundation and the Open Source Initiative both publish lists of licenses that they find to comply with their own definitions of free software and open-source software respectively: The FSF list is not prescriptive: free-software licenses can exist that the FSF has not heard about, or considered important enough to write about. So it

1513-440: A total of 23 million transistors and a total die area of 1,215 mm. The chips are manufactured by IBM in its 0.72 μm CMOS process, which features a 0.45 μm effective channel length; and one layer of polysilicon and four layers of metal interconnect. The chips are packaged in a ceramic multi-chip module (MCM) that measures 64 mm by 64 mm. An improved version of the POWER2 optimized for transaction processing

1602-602: A wide variety of instruction set architectures , and is widely deployed as a tool in the development of both free and proprietary software . GCC is also available for many embedded systems , including Symbian (called gcce ), ARM -based, and Power ISA -based chips. The compiler can target a wide variety of platforms, including video game consoles such as the PlayStation 2 , Cell SPE of PlayStation 3, and Dreamcast . It has been ported to more kinds of processors and operating systems than any other compiler. As of

1691-423: Is a simplified GENERIC, in which various constructs are lowered to multiple GIMPLE instructions. The C , C++ , and Java front ends produce GENERIC directly in the front end. Other front ends instead have different intermediate representations after parsing and convert these to GENERIC. In either case, the so-called "gimplifier" then converts this more complex form into the simpler SSA -based GIMPLE form that

1780-654: Is also possible. The GCC project includes an implementation of the C++ Standard Library called libstdc++, licensed under the GPLv3 License with an exception to link non-GPL applications when sources are built with GCC. Some features of GCC include: The primary supported (and best tested) processor families are 64- and 32-bit ARM, 64- and 32-bit x86_64 and x86 and 64-bit PowerPC and SPARC . GCC target processor families as of version 11.1 include: Lesser-known target processors supported in

1869-617: Is an example of a federally funded free-software project. Proprietary software, on the other hand, tends to use a different business model, where a customer of the proprietary application pays a fee for a license to legally access and use it. This license may grant the customer the ability to configure some or no parts of the software themselves. Often some level of support is included in the purchase of proprietary software, but additional support services (especially for enterprise applications) are usually available for an additional fee. Some proprietary software vendors will also customize software for

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1958-466: Is biased by counting more vulnerabilities for the free software systems, since their source code is accessible and their community is more forthcoming about what problems exist as a part of full disclosure , and proprietary software systems can have undisclosed societal drawbacks, such as disenfranchising less fortunate would-be users of free programs. As users can analyse and trace the source code, many more people with no commercial constraints can inspect

2047-471: Is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty , not price; all users are legally free to do what they want with their copies of a free software (including profiting from them) regardless of how much is paid to obtain the program. Computer programs are deemed "free" if they give end-users (not just

2136-545: Is consistent with the intended meaning unlike the term "Open Source". The loan adjective " libre " is often used to avoid the ambiguity of the word "free" in the English language , and the ambiguity with the older usage of "free software" as public-domain software. ( See Gratis versus libre . ) The first formal definition of free software was published by FSF in February 1986. That definition, written by Richard Stallman ,

2225-451: Is debate over the security of free software in comparison to proprietary software, with a major issue being security through obscurity . A popular quantitative test in computer security is to use relative counting of known unpatched security flaws. Generally, users of this method advise avoiding products that lack fixes for known security flaws, at least until a fix is available. Free software advocates strongly believe that this methodology

2314-463: Is like considering the practical advantages of not being handcuffed, in that it is not necessary for an individual to consider practical reasons in order to realize that being handcuffed is undesirable in itself. The FSF also notes that "Open Source" has exactly one specific meaning in common English, namely that "you can look at the source code." It states that while the term "Free Software" can lead to two different interpretations, at least one of them

2403-419: Is not covered by copyright law, such as software in the public domain , is free as long as the source code is also in the public domain, or otherwise available without restrictions. Proprietary software uses restrictive software licences or EULAs and usually does not provide users with the source code. Users are thus legally or technically prevented from changing the software, and this results in reliance on

2492-495: Is not endorsed by the FSF and does not use Linux-libre, it is also a popular distribution available without kernel blobs by default since 2011. The Linux community uses the term "blob" to refer to all nonfree firmware in a kernel whereas OpenBSD uses the term to refer to device drivers. The FSF does not consider OpenBSD to be blob free under the Linux community's definition of blob. Selling software under any free-software licence

2581-601: Is not in the IT sector choose free software for their Internet information and sales sites, due to the lower initial capital investment and ability to freely customize the application packages. Most companies in the software business include free software in their commercial products if the licenses allow that. Free software is generally available at no cost and can result in permanently lower TCO ( total cost of ownership ) compared to proprietary software . With free software, businesses can fit software to their specific needs by changing

2670-415: Is permissible, as is commercial use. This is true for licenses with or without copyleft . Since free software may be freely redistributed, it is generally available at little or no fee. Free software business models are usually based on adding value such as customization, accompanying hardware, support, training, integration, or certification. Exceptions exist however, where the user is charged to obtain

2759-521: Is possible for a license to be free and not in the FSF list. The OSI list only lists licenses that have been submitted, considered and approved. All open-source licenses must meet the Open Source Definition in order to be officially recognized as open source software. Free software, on the other hand, is a more informal classification that does not rely on official recognition. Nevertheless, software licensed under licenses that do not meet

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2848-644: Is still maintained today and states that software is free software if people who receive a copy of the software have the following four freedoms. The numbering begins with zero, not only as a spoof on the common usage of zero-based numbering in programming languages, but also because "Freedom 0" was not initially included in the list, but later added first in the list as it was considered very important. Freedoms 1 and 3 require source code to be available because studying and modifying software without its source code can range from highly impractical to nearly impossible. Thus, free software means that computer users have

2937-613: Is summarized at the Debian web site. It is rare that a license announced as being in-compliance with the FSF guidelines does not also meet the Open Source Definition , although the reverse is not necessarily true (for example, the NASA Open Source Agreement is an OSI-approved license, but non-free according to FSF). There are different categories of free software. Proponents of permissive and copyleft licenses disagree on whether software freedom should be viewed as

3026-442: Is the common language for a large number of powerful language- and architecture-independent global (function scope) optimizations. GENERIC is an intermediate representation language used as a "middle end" while compiling source code into executable binaries . A subset, called GIMPLE , is targeted by all the front ends of GCC. The middle stage of GCC does all of the code analysis and optimization , working independently of both

3115-604: Is widely deployed as a tool in the development of both free and proprietary software . GCC is also available for many embedded systems , including ARM -based and Power ISA -based chips. As well as being the official compiler of the GNU operating system , GCC has been adopted as the standard compiler by many other modern Unix-like computer operating systems , including most Linux distributions. Most BSD family operating systems also switched to GCC shortly after its release, although since then, FreeBSD and Apple macOS have moved to

3204-756: The Apache web server; and the Sendmail mail transport agent. Other influential examples include the Emacs text editor; the GIMP raster drawing and image editor; the X Window System graphical-display system; the LibreOffice office suite; and the TeX and LaTeX typesetting systems. From the 1950s up until the early 1970s, it was normal for computer users to have the software freedoms associated with free software, which

3293-657: The Clang compiler, largely due to licensing reasons. GCC can also compile code for Windows , Android , iOS , Solaris , HP-UX , AIX and DOS . In late 1983, in an effort to bootstrap the GNU operating system, Richard Stallman asked Andrew S. Tanenbaum , the author of the Amsterdam Compiler Kit (also known as the Free University Compiler Kit ) for permission to use that software for GNU. When Tanenbaum advised him that

3382-559: The GNU General Public License (GNU GPL). GCC is a key component of the GNU toolchain which is used for most projects related to GNU and the Linux kernel . With roughly 15 million lines of code in 2019, GCC is one of the largest free programs in existence. It has played an important role in the growth of free software , as both a tool and an example. When it was first released in 1987 by Richard Stallman , GCC 1.0

3471-458: The GNU Project : a collaborative effort to create a freedom-respecting operating system , and to revive the spirit of cooperation once prevalent among hackers during the early days of computing. Free software differs from: For software under the purview of copyright to be free, it must carry a software license whereby the author grants users the aforementioned rights. Software that

3560-727: The GNU operating system began in January 1984, and the Free Software Foundation (FSF) was founded in October 1985. He developed a free software definition and the concept of " copyleft ", designed to ensure software freedom for all. Some non-software industries are beginning to use techniques similar to those used in free software development for their research and development process; scientists, for example, are looking towards more open development processes, and hardware such as microchips are beginning to be developed with specifications released under copyleft licenses ( see

3649-693: The Linux kernel and other device drivers motivated some developers in Ireland to launch gNewSense , a Linux-based distribution with all the binary blobs removed. The project received support from the Free Software Foundation and stimulated the creation, headed by the Free Software Foundation Latin America , of the Linux-libre kernel. As of October 2012 , Trisquel is the most popular FSF endorsed Linux distribution ranked by Distrowatch (over 12 months). While Debian

POWER2 - Misplaced Pages Continue

3738-661: The OpenCores project, for instance ). Creative Commons and the free-culture movement have also been largely influenced by the free software movement. In 1983, Richard Stallman , longtime member of the hacker community at the MIT Artificial Intelligence Laboratory , announced the GNU Project, saying that he had become frustrated with the effects of the change in culture of the computer industry and its users. Software development for

3827-410: The source code was distributed to use these programs. Software was also shared and distributed as printed source code ( Type-in program ) in computer magazines (like Creative Computing , SoftSide , Compute! , Byte , etc.) and books, like the bestseller BASIC Computer Games . By the early 1970s, the picture changed: software costs were dramatically increasing, a growing software industry

3916-592: The 13.1 release, GCC includes front ends for C ( gcc ), C++ ( g++ ), Objective-C and Objective-C++ , Fortran ( gfortran ), Ada ( GNAT ), Go ( gccgo ), D ( gdc , since 9.1), and Modula-2 ( gm2 , since 13.1) programming languages, with the OpenMP and OpenACC parallel language extensions being supported since GCC 5.1. Versions prior to GCC 7 also supported Java ( gcj ), allowing compilation of Java to native machine code. Regarding language version support for C++ and C, since GCC 11.1

4005-601: The 30-node IBM Deep Blue supercomputer that beat world champion Garry Kasparov at chess in 1997. However, the computer's chess-playing capabilities were a result of its expert system running on custom VLSI chips, rather than the P2SCs. GNU Compiler Collection The GNU Compiler Collection ( GCC ) is a collection of compilers from the GNU Project that support various programming languages , hardware architectures and operating systems . The Free Software Foundation (FSF) distributes GCC as free software under

4094-571: The FSF officially halted development on their GCC 2.x compiler, blessed EGCS as the official version of GCC, and appointed the EGCS project as the GCC maintainers in April 1999. With the release of GCC 2.95 in July 1999 the two projects were once again united. GCC has since been maintained by a varied group of programmers from around the world under the direction of a steering committee. GCC 3 (2002) removed

4183-557: The Free Software Definition cannot rightly be considered free software. Apart from these two organizations, the Debian project is seen by some to provide useful advice on whether particular licenses comply with their Debian Free Software Guidelines . Debian does not publish a list of approved licenses, so its judgments have to be tracked by checking what software they have allowed into their software archives. That

4272-443: The GCC steering committee decided to allow use of a C++ compiler to compile GCC. The compiler was intended to be written mostly in C plus a subset of features from C++. In particular, this was decided so that GCC's developers could use the destructors and generics features of C++. In August 2012, the GCC steering committee announced that GCC now uses C++ as its implementation language. This means that to build GCC from sources,

4361-521: The GCC versions developed for various Texas Instruments, Hewlett Packard, Sharp, and Casio programmable graphing calculators. GCC is licensed under the GNU General Public License version 3. The GCC runtime exception permits compilation of proprietary programs (in addition to free software) with GCC headers and runtime libraries. This does not impact the license terms of GCC source code. Free software Free software , libre software , libreware sometimes known as freedom-respecting software

4450-631: The GNU operating system began in January 1984, and the Free Software Foundation (FSF) was founded in October 1985. An article outlining the project and its goals was published in March 1985 titled the GNU Manifesto . The manifesto included significant explanation of the GNU philosophy, Free Software Definition and " copyleft " ideas. The Linux kernel , started by Linus Torvalds , was released as freely modifiable source code in 1991. The first licence

4539-525: The Internet. Users can easily download and install those applications via a package manager that comes included with most Linux distributions . The Free Software Directory maintains a large database of free-software packages. Some of the best-known examples include Linux-libre , Linux-based operating systems, the GNU Compiler Collection and C library ; the MySQL relational database;

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4628-653: The L1 data cache and data translation lookaside buffer (TLB) capacities were halved to 128 KB and 256 entries, respectively, and a rarely used feature that locked entries in the TLB was not implemented in order to fit the original design onto a single die. The P2SC was succeeded by the POWER3 as IBM's flagship microprocessor on the RS/6000 line in 1998. A notable use of the P2SC was

4717-471: The POWER2 at 71.5 MHz, with the memory and I/O buses running at half speed to support the higher clock frequency. IBM claimed that the performance of this version was 5.5 SPECint95_base and 14.5 SPECfp95_base. A faster 160 MHz part fabricated in the 0.25 μm CMOS-6S2 process was announced at the Microprocessor Forum in October 1997. The P2SC was not a complete copy of the POWER2,

4806-454: The Vax machine description", Jack Davidson and Christopher W. Fraser for the idea of using RTL as an intermediate language, and Paul Rubin for writing most of the preprocessor. Described as the "first free software hit" by Peter H. Salus , the GNU compiler arrived just at the time when Sun Microsystems was unbundling its development tools from its operating system , selling them separately at

4895-588: The code and find bugs and loopholes than a corporation would find practicable. According to Richard Stallman, user access to the source code makes deploying free software with undesirable hidden spyware functionality far more difficult than for proprietary software. Some quantitative studies have been done on the subject. In 2006, OpenBSD started the first campaign against the use of binary blobs in kernels . Blobs are usually freely distributable device drivers for hardware from vendors that do not reveal driver source code to users or developers. This restricts

4984-461: The code. These work on multiple representations, mostly the architecture-independent GIMPLE representation and the architecture-dependent RTL representation. Finally, machine code is produced using architecture-specific pattern matching originally based on an algorithm of Jack Davidson and Chris Fraser. GCC was written primarily in C except for parts of the Ada front end. The distribution includes

5073-482: The compiled language and the target architecture, starting from the GENERIC representation and expanding it to register transfer language (RTL). The GENERIC representation contains only the subset of the imperative programming constructs optimized by the middle end. In transforming the source code to GIMPLE, complex expressions are split into a three-address code using temporary variables . This representation

5162-423: The compiler is the "middle end." The exact set of GCC optimizations varies from release to release as it develops, but includes the standard algorithms, such as loop optimization , jump threading , common subexpression elimination , instruction scheduling , and so forth. The RTL optimizations are of less importance with the addition of global SSA-based optimizations on GIMPLE trees, as RTL optimizations have

5251-479: The compiler was not free, and that only the university was free, Stallman decided to work on a different compiler. His initial plan was to rewrite an existing compiler from Lawrence Livermore National Laboratory from Pastel to C with some help from Len Tower and others. Stallman wrote a new C front end for the Livermore compiler, but then realized that it required megabytes of stack space, an impossibility on

5340-438: The compiler, provided they meet the GPL's terms, including its requirements to distribute source code . Multiple forks proved inefficient and unwieldy, however, and the difficulty in getting work accepted by the official GCC project was greatly frustrating for many, as the project favored stability over new features. The FSF kept such close control on what was added to the official version of GCC 2.x (developed since 1992) that GCC

5429-578: The default target is gnu++17 , a superset of C++17 , and gnu11 , a superset of C11 , with strict standard support also available. GCC also provides experimental support for C++20 and C++23 . Third-party front ends exist for many languages, such as Pascal ( gpc ), Modula-3 , and VHDL ( GHDL ). A few experimental branches exist to support additional languages, such as the GCC UPC compiler for Unified Parallel C or Rust . GCC's external interface follows Unix conventions. Users invoke

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5518-435: The developer) ultimate control over the software and, subsequently, over their devices. The right to study and modify a computer program entails that the source code —the preferred format for making changes—be made available to users of that program. While this is often called "access to source code" or "public availability", the Free Software Foundation (FSF) recommends against thinking in those terms, because it might give

5607-410: The different supported languages can be processed by the same back end . GCC started out using LALR parsers generated with Bison , but gradually switched to hand-written recursive-descent parsers for C++ in 2004, and for C and Objective-C in 2006. As of 2021 all front ends use hand-written recursive-descent parsers. Until GCC 4.0 the tree representation of the program was not fully independent of

5696-423: The freedom to cooperate with whom they choose, and to control the software they use. To summarize this into a remark distinguishing libre (freedom) software from gratis (zero price) software, the Free Software Foundation says: "Free software is a matter of liberty, not price. To understand the concept, you should think of 'free' as in ' free speech ', not as in 'free beer ' ". ( See Gratis versus libre . ) In

5785-412: The goals and messaging are quite dissimilar. According to the Free Software Foundation, "Open source" and its associated campaign mostly focus on the technicalities of the public development model and marketing free software to businesses, while taking the ethical issue of user rights very lightly or even antagonistically. Stallman has also stated that considering the practical advantages of free software

5874-409: The government charged that bundled software was anti-competitive . While some software might always be free, there would henceforth be a growing amount of software produced primarily for sale. In the 1970s and early 1980s, the software industry began using technical measures (such as only distributing binary copies of computer programs ) to prevent computer users from being able to study or adapt

5963-513: The impression that users have an obligation (as opposed to a right) to give non-users a copy of the program. Although the term "free software" had already been used loosely in the past and other permissive software like the Berkeley Software Distribution released in 1978 existed, Richard Stallman is credited with tying it to the sense under discussion and starting the free software movement in 1983, when he launched

6052-421: The late 1990s, other groups published their own definitions that describe an almost identical set of software. The most notable are Debian Free Software Guidelines published in 1997, and The Open Source Definition , published in 1998. The BSD -based operating systems, such as FreeBSD , OpenBSD , and NetBSD , do not have their own formal definitions of free software. Users of these systems generally find

6141-417: The processor being targeted. The meaning of a tree was somewhat different for different language front ends, and front ends could provide their own tree codes. This was simplified with the introduction of GENERIC and GIMPLE, two new forms of language-independent trees that were introduced with the advent of GCC 4.0. GENERIC is more complex, based on the GCC 3.x Java front end's intermediate representation. GIMPLE

6230-468: The publisher to provide updates, help, and support. ( See also vendor lock-in and abandonware ). Users often may not reverse engineer , modify, or redistribute proprietary software. Beyond copyright law, contracts and a lack of source code, there can exist additional obstacles keeping users from exercising freedom over a piece of software, such as software patents and digital rights management (more specifically, tivoization ). Free software can be

6319-511: The same set of software to be acceptable, but sometimes see copyleft as restrictive. They generally advocate permissive free software licenses , which allow others to use the software as they wish, without being legally forced to provide the source code. Their view is that this permissive approach is more free. The Kerberos , X11 , and Apache software licenses are substantially similar in intent and implementation. There are thousands of free applications and many operating systems available on

6408-435: The shift in climate surrounding the computer world and its users. In his initial declaration of the project and its purpose, he specifically cited as a motivation his opposition to being asked to agree to non-disclosure agreements and restrictive licenses which prohibited the free sharing of potentially profitable in-development software, a prohibition directly contrary to the traditional hacker ethic . Software development for

6497-461: The software applications as they saw fit. In 1980, copyright law was extended to computer programs. In 1983, Richard Stallman , one of the original authors of the popular Emacs program and a longtime member of the hacker community at the MIT Artificial Intelligence Laboratory , announced the GNU Project , the purpose of which was to produce a completely non-proprietary Unix-compatible operating system, saying that he had become frustrated with

6586-443: The software themselves or by hiring programmers to modify it for them. Free software often has no warranty, and more importantly, generally does not assign legal liability to anyone. However, warranties are permitted between any two parties upon the condition of the software and its usage. Such an agreement is made separately from the free software license. A report by Standish Group estimates that adoption of free software has caused

6675-411: The source and use the same license. This requirement does not extend to other software from the same developer. The claim of incompatibility between commercial companies and free software is also a misunderstanding. There are several large companies, e.g. Red Hat and IBM (IBM acquired RedHat in 2019), which do substantial commercial business in the development of free software. Free software played

6764-446: The source code in that language and produces an abstract syntax tree ("tree" for short). These are, if necessary, converted to the middle end's input representation, called GENERIC form; the middle end then gradually transforms the program towards its final form. Compiler optimizations and static code analysis techniques (such as FORTIFY_SOURCE, a compiler directive that attempts to discover some buffer overflows ) are applied to

6853-811: The standard libraries for Ada and C++ whose code is mostly written in those languages. On some platforms, the distribution also includes a low-level runtime library, libgcc , written in a combination of machine-independent C and processor-specific machine code , designed primarily to handle arithmetic operations that the target processor cannot perform directly. GCC uses many additional tools in its build, many of which are installed by default by many Unix and Linux distributions (but which, normally, aren't present in Windows installations), including Perl , Flex , Bison , and other common tools. In addition, it currently requires three additional libraries to be present in order to build: GMP , MPC , and MPFR . In May 2010,

6942-464: The standard release have included: Additional processors have been supported by GCC versions maintained separately from the FSF version: The GCJ Java compiler can target either a native machine language architecture or the Java virtual machine 's Java bytecode . When retargeting GCC to a new platform, bootstrapping is often used. Motorola 68000, Zilog Z80, and other processors are also targeted in

7031-495: The users' freedom effectively to modify the software and distribute modified versions. Also, since the blobs are undocumented and may have bugs , they pose a security risk to any operating system whose kernel includes them. The proclaimed aim of the campaign against blobs is to collect hardware documentation that allows developers to write free software drivers for that hardware, ultimately enabling all free operating systems to become or remain blob-free. The issue of binary blobs in

7120-413: Was write-through . The cache tags were contained on the storage control unit chip. The POWER2+ has a narrower 64- or 128-bit memory bus and a smaller 64 or 128 KB data cache. As there is less cache, the data cache unit chips are smaller as a result, and the revised storage control unit chip is also smaller. A goal for the six-chip configuration was to reduce cost, and therefore the chips are packaged in

7209-541: Was a proprietary software licence. However, with version 0.12 in February 1992, he relicensed the project under the GNU General Public License . Much like Unix, Torvalds' kernel attracted the attention of volunteer programmers. FreeBSD and NetBSD (both derived from 386BSD ) were released as free software when the USL v. BSDi lawsuit was settled out of court in 1993. OpenBSD forked from NetBSD in 1995. Also in 1995, The Apache HTTP Server , commonly referred to as Apache,

7298-402: Was competing with the hardware manufacturer's bundled software products (free in that the cost was included in the hardware cost), leased machines required software support while providing no revenue for software, and some customers able to better meet their own needs did not want the costs of "free" software bundled with hardware product costs. In United States vs. IBM , filed January 17, 1969,

7387-562: Was inspired by the SIMPLE representation proposed in the McCAT compiler by Laurie J. Hendren for simplifying the analysis and optimization of imperative programs . Optimization can occur during any phase of compilation; however, the bulk of optimizations are performed after the syntax and semantic analysis of the front end and before the code generation of the back end; thus a common, though somewhat self-contradictory, name for this part of

7476-522: Was introduced in May 1994 as the POWER2+. Transaction processing workloads benefited from the addition of a L2 cache with capacities of 512 KB, 1 MB and 2 MB. This cache was implemented off-package with industry-standard burst SRAMs. The cache was connected to the POWER2+ via a 64- (for low-end systems) or 128-bit bus (for high-end systems). The cache was direct-mapped , had a 128-byte line size, and

7565-522: Was named the GNU C Compiler since it only handled the C programming language . It was extended to compile C++ in December of that year. Front ends were later developed for Objective-C , Objective-C++ , Fortran , Ada , D , Go and Rust , among others. The OpenMP and OpenACC specifications are also supported in the C and C++ compilers. GCC has been ported to more platforms and instruction set architectures than any other compiler, and

7654-476: Was released under the Apache License 1.0 . All free-software licenses must grant users all the freedoms discussed above. However, unless the applications' licenses are compatible, combining programs by mixing source code or directly linking binaries is problematic, because of license technicalities . Programs indirectly connected together may avoid this problem. The majority of free software falls under

7743-679: Was stable and reliable – one that would give us in-house control. So if we needed to patch, adjust, or adapt, we could." Official statement of the United Space Alliance , which manages the computer systems for the International Space Station (ISS), regarding their May 2013 decision to migrate ISS computer systems from Windows to Linux The economic viability of free software has been recognized by large corporations such as IBM , Red Hat , and Sun Microsystems . Many companies whose core business

7832-407: Was typically public-domain software . Software was commonly shared by individuals who used computers and by hardware manufacturers who welcomed the fact that people were making software that made their hardware useful. Organizations of users and suppliers, for example, SHARE , were formed to facilitate exchange of software. As software was often written in an interpreted language such as BASIC ,

7921-887: Was used as one example of the "cathedral" development model in Eric S. Raymond 's essay The Cathedral and the Bazaar . In 1997, a group of developers formed the Experimental/Enhanced GNU Compiler System (EGCS) to merge several experimental forks into a single project. The basis of the merger was a development snapshot of GCC (taken around the 2.7.2 and later followed up to 2.8.1 release). Mergers included g77 (Fortran), PGCC ( P5 Pentium -optimized GCC), many C++ improvements, and many new architectures and operating system variants. While both projects followed each other's changes closely, EGCS development proved considerably more vigorous, so much so that

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