Profile-guided Optimization
In computer programming, profile-guided optimization (PGO, sometimes pronounced as ''pogo''), also known as profile-directed feedback (PDF) or feedback-directed optimization (FDO), is the compiler optimization technique of using prior analyses of software artifacts or behaviors (" profiling") to improve the expected runtime performance of the program. Method Optimization techniques based on static program analysis of the source code consider code performance improvements without actually executing the program. No dynamic program analysis is performed. For example, inferring or placing formal constraints on the number of iterations a loop is likely to execute is fundamentally useful when considering whether to unroll it or not, but such facts typically rely on complex runtime factors that are difficult to conclusively establish. Usually, static analysis will have incomplete information and only be able to approximate estimates of the eventual runtime conditions. The first high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Computer Programming
Computer programming or coding is the composition of sequences of instructions, called computer program, programs, that computers can follow to perform tasks. It involves designing and implementing algorithms, step-by-step specifications of procedures, by writing source code, code in one or more programming languages. Programmers typically use high-level programming languages that are more easily intelligible to humans than machine code, which is directly executed by the central processing unit. Proficient programming usually requires expertise in several different subjects, including knowledge of the Domain (software engineering), application domain, details of programming languages and generic code library (computing), libraries, specialized algorithms, and Logic#Formal logic, formal logic. Auxiliary tasks accompanying and related to programming include Requirements analysis, analyzing requirements, Software testing, testing, debugging (investigating and fixing problems), imple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Hardware Performance Counters
In computers, hardware performance counters (HPCs), or hardware counters are a set of special-purpose registers built into modern microprocessors to store the counts of hardware-related activities. Advanced users often rely on those counters to conduct low-level performance analysis or tuning. Implementations The number of available hardware counters in a processor is limited while each CPU model might have a lot of different events that a developer might like to measure. Each counter can be programmed with the index of an event type to be monitored, like a L1 cache miss or a branch misprediction. One of the first processors to implement a hardware counter and an associated instruction to access it (the RDPMC instruction) was the Intel Pentium, but they were not documented until Terje Mathisen wrote an article about reverse engineering them in ''Byte'' July 1994. The following table shows some examples of CPUs and the number of available hardware counters: Versus software te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oracle Solaris Studio
Oracle Developer Studio, formerly named Oracle Solaris Studio, Sun Studio, Sun WorkShop, Forte Developer, and SunPro Compilers, is the Oracle Corporation's flagship software development product for the Solaris and Linux operating systems. It includes optimizing C, C++, and Fortran compilers, libraries, and performance analysis and debugging tools, for Solaris on SPARC and x86 platforms, and Linux on x86/x64 platforms, including multi-core systems. Oracle Developer Studio is downloadable and usable at no charge; however, there are many security and functionality patch updates which are only available with a support contract from Oracle. Version 12.4 added partial support for the C++11 language standard. All C++11 features are supported except for concurrency and atomic operations, and user-defined literals. Version 12.6 supports the C++14 language standard. Languages * C * C++ * Fortran Supported architectures * SPARC * i86pc ( x86 and x86-64) Components The Oracle Devel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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GNU Compiler Collection
The GNU Compiler Collection (GCC) is a collection of compilers from the GNU Project that support various programming languages, Computer architecture, hardware architectures, and operating systems. The Free Software Foundation (FSF) distributes GCC as free software under 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 was named the GNU C Compiler since it only handled the C (programming language), C programming language. It was extended to compile C++ in December of that year. Compiler#Front end, Front ends were later developed for Objective-C, Objective-C++, Fortran, Ada (programming language), Ada, Go (programming la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Intel C++ Compiler
Intel oneAPI DPC++/C++ Compiler and Intel C++ Compiler Classic (deprecated icc and icl is in Intel OneAPI HPC toolkit) are Intel’s C, C++, SYCL, and Data Parallel C++ (DPC++) compilers for Intel processor-based systems, available for Windows, Linux, and macOS operating systems. Overview Intel oneAPI DPC++/C++ Compiler is available for Windows and Linux and supports compiling C, C++, SYCL, and Data Parallel C++ (DPC++) source, targeting Intel IA-32, Intel 64 (aka x86-64), Core, Xeon, and Xeon Scalable processors, as well as GPUs including Intel Processor Graphics Gen9 and above, Intel Xe architecture, and Intel Programmable Acceleration Card with Intel Arria 10 GX FPGA. Like Intel C++ Compiler Classic, it also supports the Microsoft Visual Studio and Eclipse IDE development environments, and supports threading via Intel oneAPI Threading Building Blocks, OpenMP, and native threads. DPC++ builds on the SYCL specification from The Khronos Group. It is designed to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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32-bit
In computer architecture, 32-bit computing refers to computer systems with a processor, memory, and other major system components that operate on data in a maximum of 32- bit units. Compared to smaller bit widths, 32-bit computers can perform large calculations more efficiently and process more data per clock cycle. Typical 32-bit personal computers also have a 32-bit address bus, permitting up to 4 GiB of RAM to be accessed, far more than previous generations of system architecture allowed. 32-bit designs have been used since the earliest days of electronic computing, in experimental systems and then in large mainframe and minicomputer systems. The first hybrid 16/32-bit microprocessor, the Motorola 68000, was introduced in the late 1970s and used in systems such as the original Apple Macintosh. Fully 32-bit microprocessors such as the HP FOCUS, Motorola 68020 and Intel 80386 were launched in the early to mid 1980s and became dominant by the early 1990s. This gener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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64-bit
In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit central processing units (CPU) and arithmetic logic units (ALU) are those that are based on processor registers, address buses, or data buses of that size. A computer that uses such a processor is a 64-bit computer. From the software perspective, 64-bit computing means the use of machine code with 64-bit virtual memory addresses. However, not all 64-bit instruction sets support full 64-bit virtual memory addresses; x86-64 and AArch64, for example, support only 48 bits of virtual address, with the remaining 16 bits of the virtual address required to be all zeros (000...) or all ones (111...), and several 64-bit instruction sets support fewer than 64 bits of physical memory address. The term ''64-bit'' also describes a generation of computers in which 64-bit processors are the norm. 64 bits is a word size that defines certain classes of computer archi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Google Chrome
Google Chrome is a web browser developed by Google. It was first released in 2008 for Microsoft Windows, built with free software components from Apple WebKit and Mozilla Firefox. Versions were later released for Linux, macOS, iOS, iPadOS, and also for Android (operating system), Android, where it is the default browser. The browser is also the main component of ChromeOS, where it serves as the platform for web applications. Most of Chrome's source code comes from Google's free and open-source software project Chromium (web browser), Chromium, but Chrome is licensed as proprietary freeware. WebKit was the original Browser engine, rendering engine, but Google eventually Fork (software development), forked it to create the Blink (browser engine), Blink engine; all Chrome variants except iOS used Blink as of 2017. , StatCounter estimates that Chrome has a 65% worldwide usage share of web browsers, browser market share (after peaking at 72.38% in November 2018) on personal comput ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Microsoft Windows
Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sectors of the computing industry – Windows (unqualified) for a consumer or corporate workstation, Windows Server for a Server (computing), server and Windows IoT for an embedded system. Windows is sold as either a consumer retail product or licensed to Original equipment manufacturer, third-party hardware manufacturers who sell products Software bundles, bundled with Windows. The first version of Windows, Windows 1.0, was released on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces (GUIs). The name "Windows" is a reference to the windowing system in GUIs. The 1990 release of Windows 3.0 catapulted its market success and led to various other product families ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Recompilation
In computer science, dynamic recompilation is a feature of some emulators and virtual machines, where the system may recompile some part of a program during execution. By compiling during execution, the system can tailor the generated code to reflect the program's run-time environment, and potentially produce more efficient code by exploiting information that is not available to a traditional static compiler. Uses Most dynamic recompilers are used to convert machine code between architectures at runtime. This is a task often needed in the emulation of legacy gaming platforms. In other cases, a system may employ dynamic recompilation as part of an adaptive optimization strategy to execute a portable program representation such as Java or .NET Common Language Runtime bytecodes. Full-speed debuggers also utilize dynamic recompilation to reduce the space overhead incurred in most deoptimization techniques, and other features such as dynamic thread migration. Tasks The main task ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Adaptive Optimization
Adaptive optimization is a technique in computer science that performs dynamic recompilation of portions of a program based on the current execution profile. With a simple implementation, an adaptive optimizer may simply make a trade-off between just-in-time compilation and interpreting instructions. At another level, adaptive optimization may take advantage of local data conditions to optimize away branches and to use inline expansion to decrease the cost of procedure calls. Consider a hypothetical banking application that handles transactions one after another. These transactions may be checks, deposits, and a large number of more obscure transactions. When the program executes, the actual data may consist of clearing tens of thousands of checks without processing a single deposit and without processing a single check with a fraudulent account number. An adaptive optimizer would compile assembly code to optimize for this common case. If the system then started processing tens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |