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Loop Unswitching
Loop unswitching is a compiler optimization. It moves a conditional inside a loop outside of it by duplicating the loop's body, and placing a version of it inside each of the if and else clauses of the conditional. This can improve the parallelization of the loop. Since modern processors can operate quickly on vectors, this improvement increases the speed of the program. Here is a simple example. Suppose we want to add the two arrays ''x'' and ''y'' and also do something depending on the variable ''w''. We have the following C code: int i, w, x000 y000 for (i = 0; i < 1000; i++) The conditional inside this loop makes it difficult to safely parallelize this loop. When we unswitch the loop, this becomes: |
Compiler Optimization
In computing, an optimizing compiler is a compiler that tries to minimize or maximize some attributes of an executable computer program. Common requirements are to minimize a program's execution time, memory footprint, storage size, and power consumption (the last three being popular for portable computers). Compiler optimization is generally implemented using a sequence of ''optimizing transformations'', algorithms which take a program and transform it to produce a semantically equivalent output program that uses fewer resources or executes faster. It has been shown that some code optimization problems are NP-complete, or even undecidable. In practice, factors such as the programmer's willingness to wait for the compiler to complete its task place upper limits on the optimizations that a compiler might provide. Optimization is generally a very CPU- and memory-intensive process. In the past, computer memory limitations were also a major factor in limiting which optimizations co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C (programming Language)
C (''pronounced like the letter c'') is a General-purpose language, general-purpose computer programming language. It was created in the 1970s by Dennis Ritchie, and remains very widely used and influential. By design, C's features cleanly reflect the capabilities of the targeted CPUs. It has found lasting use in operating systems, device drivers, protocol stacks, though decreasingly for application software. C is commonly used on computer architectures that range from the largest supercomputers to the smallest microcontrollers and embedded systems. A successor to the programming language B (programming language), B, C was originally developed at Bell Labs by Ritchie between 1972 and 1973 to construct utilities running on Unix. It was applied to re-implementing the kernel of the Unix operating system. During the 1980s, C gradually gained popularity. It has become one of the measuring programming language popularity, most widely used programming languages, with C compilers avail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automatic Parallelization
Automatic may refer to: Music Bands * Automatic (band), Australian rock band * Automatic (American band), American rock band * The Automatic, a Welsh alternative rock band Albums * ''Automatic'' (Jack Bruce album), a 1983 electronic rock album * ''Automatic'' (Sharpe & Numan album), a 1989 synthpop album * ''Automatic'' (The Jesus and Mary Chain album), a 1989 alternative rock album * ''Automatic'', a 1997 electronic album by Le Car * ''Automatic'' (Dweezil Zappa album), a 2000 hard rock album, or the title song * ''Automatic'', a 2003 punk rock album by The Turbo A.C.'s * ''Automatic'' (Stitches album), a 2006 punk rock album, or the title song * ''Automatic'' (VNV Nation album), a 2011 futurepop album * ''Automatic'', a 2013 reggae-rock album by Iration * ''Automatic'' (Don Broco album), a 2015 rock album * ''Automatic'' (Kaskade album), 2015 album by Kaskade * ''Automatic'' (Mildlife album), 2020 album by Mildlife Songs * "Automatic" (Danny Fernandes song) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Compiler Collection
The GNU Compiler Collection (GCC) is an optimizing compiler produced by the GNU Project supporting various programming languages, 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 and the standard compiler for most projects related to GNU and the Linux kernel. With roughly 15 million lines of code in 2019, GCC is one of the biggest 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. It was extended to compile C++ in December of that year. Front ends were later developed for Objective-C, Objective-C++, Fortran, Ada, D and Go, among others. The OpenMP and OpenACC specifications are also supported in the C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
