APPARATUS, SYSTEM, AND METHOD FOR COMPILING CODE FOR A PROCESSOR

Abstract

For example, a compiler may be configured to compile source code into target code configured for execution by a target processor in a plurality of execution cycles, including a first execution cycle, a second execution cycle after the first execution cycle, and a third execution cycle after the second execution cycle. For example, the target code may include one or more no-op instructions configured to keep a first variable live so that a value of the first variable is available in a register of the target processor on the first execution cycle and the third execution cycle.

Description

CROSS REFERENCEThis application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 415,303, entitled "APPARATUS, SYSTEM, AND METHOD OF COMPUTING CODE FOR A PROCESSOR," filed Oct. 12, 2022, the entire disclosure of which is incorporated herein by reference.BACKGROUNDA compiler may be configured to compile source code into target code configured for execution by a processor.It is necessary to provide a technical solution to support efficient processing functions.BRIEF DESCRIPTION OF THE DRAWINGSFor simplicity and clarity, the elements depicted in the figures are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to other elements to aid in clarity of illustration. Moreover, reference numerals may be repeated in the figures to indicate corresponding or analogous elements. The figures are listed below. FIG. 1 is a schematic block diagram representation of a system in accordance with some example aspects. FIG. 2 is a schematic illustration of a compiler in accordance with some example aspects. FIG. 3 is a schematic illustration of a vector processor in accordance with some example aspects. FIG. 4 is a schematic flow diagram illustration of a method for compiling code for a processor, in accordance with some example aspects. FIG. 5 is a schematic flow diagram illustration of a method for compiling code for a processor, in accordance with some example aspects. FIG. 6 is a schematic illustration of a product in accordance with some example aspects.DETAILED DESCRIPTIONIn the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of some aspects. However, those skilled in the art will understand that some aspects may be practiced without these specific details. In other instances, well-known methods, procedures, components, devices, and / or circuits have not been described in detail in order not to obscure the discussion.Some portions of the following detailed description are presented in terms of algorithms and symbolic representations of operations on data bits or binary digital signals in a memory. These algorithmic descriptions and representations may be the techniques used by those skilled in the data processing arts to convey the substance of their work to others skilled in the art.An algorithm is considered herein and generally as a self-consistent sequence of acts or acts that result in a desired result. This includes physical manipulations of physical quantities. Typically, but not necessarily, these quantities take the form of electrical or magnetic signals that can be stored, transmitted, combined, compared, and otherwise manipulated. It has sometimes been found convenient, especially for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. It should be understood, however, that all of these and similar terms are to be associated with the corresponding physical quantities and are merely convenient labels for those quantities.Terms such as "processing," "computing," "determining," "determining," "setting," "analyzing," "checking," or the like may refer to reference to the operation(s) and / or process(s) of a computer, computing platform, computing system, or other electronic computing device that manipulate and / or convert data represented as physical (e.g., electronic) quantities in the registers and / or memories of the computer into other data similarly represented as physical quantities in the registers and / or memories of the computer or other information storage medium that may store instructions for performing operations and / or processes.The terms "plurality" and "a plurality" as used herein include, for example, "multiple" or "two or more". For example, "a plurality of elements" includes two or more elements.References to "an aspect", "an aspect", "an example aspect", "various aspects", etc., indicate that the aspect(s) so described may / may include a particular feature, structure, or characteristic, but not every aspect necessarily includes the particular feature, structure, or characteristic. Further, repeated use of the phrase "in one aspect" does not necessarily refer to the same aspect, although this may be the case.As used herein, the use of the ordinal adjectives "first," "second," "third," etc., to describe a common object, unless otherwise indicated, merely indicates that different instances of similar objects are being referenced, and is not intended to imply that the objects so described must be in a particular sequence, whether temporal, spatial, ranking, or any other manner.Some aspects may take the form of, for example, a fully hardware-related aspect, a fully software-related aspect, or an aspect that includes both hardware and software elements. Some aspects may be implemented in software, including but not limited to firmware, resident software, microcode, or the like.Moreover, some aspects may take the form of a product in the form of a computer program accessible from a computer usable or computer readable medium and providing program code for use by or in connection with a computer or any instruction execution system. For example, a computer-usable or computer-readable medium may be, or include, a device that can contain, store, communicate, transmit, or transport the program for use by or in connection with the instruction execution system, device, or device.In some example aspects, the medium may be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or transmission medium.In some example aspects, a data processing system suitable for storing and / or executing program code may include at least one processor directly or indirectly coupled to memory elements, for example, via a system bus. The memory elements may include, for example, local memory used during actual execution of the program code, mass storage, and cache memories that may provide temporary storage of at least a portion of the program code to reduce the number of times code is retrieved from the mass storage during execution.In some example aspects, input / output or I / O devices (including, but not limited to, keyboards, display devices, pointing devices, etc.) may be coupled to the system either directly or via intervening I / O controllers. In some example aspects, network adapters may be coupled to the system to couple the data processing system to other data processing systems or remote printers or storage devices, for example, via intervening private or public networks. In some example aspects, modems, cable modems, and Ethernet cards are example examples of types of network adaptors. Other suitable components may also be used.Some aspects may be used in connection with various devices and systems, e.g., a computing unit, a computer, a mobile computer, a non-mobile computer, a server computer, or the like.As used herein, the term "circuit" may be a reference to, part of, or inclusion of an application specific integrated circuit (ASIC), an integrated circuit, an electronic circuit, a processor (shared, dedicated, or in a group) and / or a memory (shared, dedicated, or in a group) that execute one or more software or firmware programs, a combinational logic circuit, and / or other suitable hardware components that provide the described functionality. In certain aspects, some functions associated with the circuitry may be implemented by one or more software or firmware modules. In certain aspects, circuitry may include logic that may be executed at least partially in hardware.The term "logic" may refer to, for example, the computational logic embedded in the circuitry of a computing device and / or the computational logic stored in a memory of a computing device. For example, a processor of the computing device may access the logic to execute the computing logic to perform computing functions and / or operations. For example, the logic may be embedded in various types of memory and / or firmware, e.g., silicon blocks of various chips and / or processors. Logic may be included in and / or implemented as part of various circuits, e.g., processor circuits, control circuits, and / or the like. In an example, the logic may be embedded in volatile memory and / or nonvolatile memory, including random access memory, read only memory, programmable memory, magnetic memory, flash memory, persistent memory, and the like. Logic may be executed by one or more processors using memory, e.g., registers, read-only memories, buffers, and / or the like, coupled to the one or more processors, e.g., as required to execute the logic.Referring to FIG. 1, which schematically illustrates a block diagram of a system 100, in accordance with some example aspects.As shown in FIG. 1, the system 100 may include a computing unit 102, in accordance with some example aspects.In some example aspects, device 102 may be implemented using suitable hardware components and / or software components, such as processors, controllers, storage units, storage units, input units, output units, communication units, operating systems, applications, or the like.In some example aspects, device 102 may include, for example, a computer, a mobile computing device, a non-mobile computing device, a laptop, a notebook, a tablet computer, a handheld computer, a personal computer (PC), or the like.In some example aspects, device 102 may include, for example, one or more processors 191, an input unit 192, an output unit 193, a storage unit 194, and / or a storage unit 195. Device 102 may optionally include other suitable hardware and / or software components. In some example aspects, some or all of the components of one or more devices 102 may be enclosed in a common housing or package and interconnected or connected in an operation via one or more wired or wireless connections. In other aspects, components of one or more devices 102 may be distributed among multiple or separate devices.In some example aspects, processor 191 may include, for example, a central processing unit (CPU), a digital signal processor (DSP), one or more processor cores, a single core processor, a dual core processor, a multi-core processor, a microprocessor, a host processor, a controller, a plurality of processors or controllers, a chip, a microchip, one or more circuits, circuitry, a logic unit, an integrated circuit (IC), an application specific IC (ASIC), or another suitable general purpose or special purpose processor or controller. Processor 191 may execute instructions, for example, from an operating system (OS) of device 102 and / or one or more suitable applications.In some example aspects, input unit 192 may include, for example, a keyboard, a keypad, a mouse, a touch screen, a touchpad, a trackball, a pen, a microphone, or another suitable pointing or input device. Output unit 193 may include, for example, a monitor, a screen, a touch screen, a flat panel display, a light emitting diode (LED) display, a liquid crystal display (LCD) display, a plasma display unit, one or more speakers or earphones, or other suitable output devices.In some example aspects, memory 194 includes, for example, random access memory (RAM), read only memory (ROM), dynamic RAM (DRAM), synchronous DRAM (SD-RAM), flash memory, volatile memory, non-volatile memory, cache memory, buffer, short term memory, long term memory, or other suitable storage devices. Storage unit 195 may include, for example, a hard disk, solid state drive (SSD), or other suitable removable or non-removable storage units. Storage unit 194 and / or storage unit 195 may store data processed by device 102, for example.In some example aspects, device 102 may be configured to communicate with one or more other devices via at least one network 103, e.g., a wireless and / or wired network.In some example aspects, the network 103 may include a wired network, a local area network (LAN), a wireless network, a wireless LAN (WLAN), a radio network, a cellular network, a WiFi network, an IR network, a Bluetooth network (BT), and the like.In some example aspects, device 102 may be configured to perform one or more operations, modules, processes, methods, and / or the like, e.g., as described herein.In some example aspects, device 102 may include a compiler 160 that may be configured to generate target code 115, for example, based on source code 112 as described below.In some example aspects, compiler 160 may be configured to translate source code 112 into target code 115, as described below.In some example aspects, compiler 160 may include, or be implemented as, software, a software module, an application, a program, a subroutine, instructions, an instruction set, computational code, words, values, symbols, and / or the like.In some example aspects, source code 112 may include computer code written in a source language.In some example aspects, the source language may include a programming language. For example, the source language may include a high-level programming language, such as C programming language, C++ programming language, and / or the like.In some example aspects, target code 115 may include computer code written in a target language.In some example aspects, the target language may include a low-level language, such as assembly language, object code, machine code, or the like.In some example aspects, target code 115 may include one or more object files, e.g., which may create and / or form an executable program.In some example aspects, the executable program may be configured to be executed on a target computer. For example, the target computer may include particular computer hardware, machine, and / or operating system.In some example aspects, the executable program may be configured to execute on a processor 180, as described below.In some example aspects, processor 180 may include a vector processor 180, e.g., as described below. In other aspects, processor 180 may include any other type of processor.Some example aspects are described herein with respect to a compiler, e.g., compiler 160 configured to compile source code 112 into target code 115 configured to be executed by a vector processor 180, as described below. In other aspects, a compiler, e.g., compiler 160, is configured to compile source code 112 into target code 115 configured to be executed by any other type of processor 180.In some example aspects, processor 180 may be implemented as part of device 102.In other aspects, processor 180 may be implemented as part of any other device, e.g., separate from device 102.In some example aspects, vector processor 180 (also referred to as an "array processor") may include a processor that may be configured to process an entire vector into an instruction, e.g., as described below.In other aspects, the executable program may be configured to execute on any other additional or alternative processor type.In some example aspects, vector processor 180 may be designed to support high performance image and / or vector processing. For example, vector processor 180 may be configured to process 1 / 2 / 3 / 4D arrays of fixed-point data and / or floating-point arrays, e.g., very quickly and / or efficiently.In some example aspects, vector processor 180 may be configured to process any data, e.g., structures with pointers to structures. For example, vector processor 180 may include a scalar processor to calculate the non-vector data, e.g., assuming that the non-vector data is minimal.In some example aspects, compiler 160 may be implemented as a local application executed by device 102. For example, the storage unit 194 and / or the storage unit 195 may store instructions that lead to compiler 160 and / or the processor 191 may be configured to execute the instructions that lead to compiler 160 and / or perform one or more computations and / or processes of compiler 160, e.g., as described below.In other aspects, compiler 160 may include a remote application that is executed by any suitable computer system, e.g., server 170.In some example aspects, server 170 may include at least one remote server, a web-based server, a cloud server, and / or any other server.In some example aspects, server 170 may include a suitable storage and / or storage unit 174 storing instructions that lead to compiler 160 and a suitable processor 171 to execute the instructions, e.g., as described below.In some example aspects, compiler 160 may include a combination of a remote application and a local application.In an example, the compiler 160 may be downloaded and / or received by the user of the device 102 from another computer system, e.g., a server 170, such that the compiler 160 may be executed locally by users of the device 102. For example, the instructions may be received and stored, e.g., temporarily in a memory or suitable short-term memory or buffer of the device 102, e.g., before being executed by the processor 191 of the device 102.In another example, compiler 160 may include a client module that is executed locally by device 102 and a server module that is executed by server 170. For example, the client module may include and / or be implemented as a local application, a web application, a web site, a web client, e.g., a hypertext markup language (HTML) web application, or the like.For example, one or more first operations of compiler 160 may be performed locally, such as by device 102, and / or one or more second operations of compiler 160 may be performed remotely, such as by server 170.In other aspects, compiler 160 may include, or be implemented by, any other suitable arrangement and / or scheme of computing units.In some example aspects, system 100 may include an interface 110, e.g., a user interface, to interface between a user of device 102 and one or more elements of system 100, e.g., compiler 160.In some example aspects, interface 110 may be implemented using any suitable hardware and / or software components, such as processors, controllers, memory units, storage units, input units, output units, communication units, operating systems, and / or applications.In some example aspects, the interface 110 may be implemented as part of a suitable module, system, device, or component of the system 100.In other aspects, the interface 110 may be implemented as a separate element of the system 100.In some example aspects, interface 110 may be implemented as part of device 102. For example, the interface 110 may be connected to and / or included as part of the device 102.For example, the interface 110 may be implemented as middleware and / or as part of any suitable application of the device 102. For example, the interface 110 may be implemented as part of the compiler 160 and / or as part of an operating system of the device 102.In some example aspects, the interface 110 may be implemented as part of the server 170. For example, the interface 110 may be connected to and / or included as part of the server 170.In an example, the interface 110 may include or be a part of a web-based application, a web site, a web page, a plug-in, an ActiveX controller, a rich content component, e.g., a flash or shockwave component, or the like.In some example aspects, interface 110 may be connected to and / or include, for example, a gateway (GW) 113 and / or an application programming interface (API) 114, for example, to communicate information and / or communications between elements of system 100 and / or to one or more other, e.g., internal or external, parties, users, applications, and / or systems.In some example aspects, the interface 110 may include any suitable graphical user interface (GUI) 116 and / or any other suitable interface.In some example aspects, the interface 110 may be configured to receive the source code 112 from, for example, a user of the device 102, e.g., via the GUI 116 and / or the API 114.In some example aspects, the interface 110 may be configured to transmit the source code 112 to, for example, the compiler 160 to generate, for example, the target code 115, as described below.Referring to FIG. 2, which schematically illustrates a compiler 200 in accordance with some example aspects. For example, compiler 160 (FIG. 1 ) may implement one or more elements of compiler 200 and / or perform one or more operations and / or functionalities of compiler 200.In some example aspects, as shown in FIG. 2, compiler 200 may be configured to generate target code 233 by, for example, compiling source code 212 in a source language.In some example aspects, as shown in FIG. 2, compiler 200 may include a front end 210 configured to receive and analyze source code 212 in the source language.In some example aspects, front end 210 may be configured to generate intermediate code 213, for example, based on source code 212.In some example aspects, intermediate code 213 may include a lowered representation of source code 212.In some example aspects, front end 210 may be configured to perform, for example, lexical analysis, syntax analysis, semantic analysis, and / or other additional or alternative manner of analyzing source code 212.In some example aspects, front end 210 may be configured to identify errors and / or problems with a result of analyzing source code 212. For example, front end 210 may be configured to generate fault information, e.g., including fault and / or warning messages, which may identify, for example, a location in source code 212 where a fault or problem is detected.In some example aspects, as shown in FIG. 2, compiler 200 may include a middle end 220 configured to receive and process intermediate code 213 and generate an adjusted, e.g., optimized, intermediate code 223.In some example aspects, the middle end 220 may be configured to perform one or more adjustments, e.g., optimizations, to the intermediate code 213 to generate the adjusted intermediate code 223, for example.In some example aspects, the middle end 220 may be configured to perform one or more optimizations on the intermediate code 213, for example, regardless of the type of the target computer, to execute the target code 233.In some example aspects, the middle end 220 may be implemented to support use of the optimized intermediate code 223, for example, for different machine types.In some example aspects, the middle end 220 may be configured to optimize the intermediate representation of the intermediate code 223, for example to improve the performance and / or quality of the generated target code 233.In some example aspects, the one or more optimizations of intermediate code 213 may include, for example, inline expansion, dead code elimination, constant transmission, loop conversion, parallelization, and / or the like.In some example aspects, as shown in FIG. 2, compiler 200 may include a back end 230 configured to receive and process adjusted intermediate code 213 and generate target code 233 based on adjusted intermediate code 213.In some example aspects, the back end 230 may be configured to perform one or more operations and / or processes that may be specific to the target computer to execute the target code 233. For example, back end 230 may be configured to process optimized intermediate code 213 by applying analysis, conversion, and / or optimization operations to adjusted intermediate code 213, which may be configured, for example, based on the target computer, to execute target code 233.In some example aspects, the one or more analysis, conversion, and / or optimization operations applied to the adjusted intermediate code 213 may include, for example, resource and storage decisions, e.g., register allocation, instruction scheduling, and / or the like.In some example aspects, the target code 233 may include target dependent assembler code, which may be specific to the target computer and / or a target operating system of the target computer to execute the target code 233.In some example aspects, target code 233 may include target dependent assembler code for a processor, e.g., vector processor 180 (FIG. 1 ).In some example aspects, compiler 200 may include a Vector Micro-Code Processor (VMP) compiler for Open Computing Language (OpenCL), e.g., as described below. In other aspects, compiler 200 may include, or be implemented as part of, any other vector processor compiler.In some example aspects, the VMP OpenCL compiler may include a low level virtual machine (LLVM)-based (LLVM-based) compiler that may be configured in accordance with an LLVM-based compilation scheme, for example, to lower OpenCL C code to VMP accelerator assembly code suitable, for example, for execution by vector processor 180 (FIG. 1 ).In some example aspects, compiler 200 may include one or more technologies that may be required to compile code into a format suitable for a VMP architecture, e.g., in addition to open-source LLVM compiler passes.In some example aspects, FE 210 may be configured to analyze and translate the OpenCL C code, e.g., by an abstract syntax tree (AST), for example, into an LLVM intermediate representation (IR).In some example aspects, compiler 200 may include a dedicated API, for example, to recognize a correct pattern for compiler pattern matching that is suitable for the VMP, for example. For example, the VMP may be configured as a complex instruction set machine (CISC) implementing a very complex instruction set architecture (ISA) that may be difficult to respond from standard C code. According to this case, the compiler pattern matching may not easily recognize the proper pattern, and in this case, the compiler may need a dedicated API.In some example aspects, FE 210 may implement one or more integrated vendor extensions that may, for example, target VMP-specific ISA, in addition to the standard OpenCL integrators that may be optimized for a VMP engine.In some example aspects, FE 210 may be configured to implement OpenCL structures and / or work element functions.In some example aspects, ME 220 may be configured to process LLVM IR code, which may be, for example, general and target independent, although it may include one or more hooks for particular target architectures.In some example aspects, ME 220 may execute one or more user-defined passes, for example to support the VMP architecture, as described below.In some example aspects, ME 220 may be configured to perform one or more operations of control flow graph (CFG) linearization, as described below.In some example aspects, CFG linearization may be configured to linearize the code, for example, by converting if instructions to selection patterns if the VMP vector code does not support the default control flow.In one example, ME 220 may obtain a particular code, e.g., as follows: If(x>0){A=A+; } else{B=B*2; }According to this example, ME 220 may be configured to apply the CFG linearization to the given code, e.g., as follows:tmpA=A+;tmpB=B*2;mask=x>0;A=Select mask, tmpA, AB=Select not mask, tmpB, BExample (1)In some example aspects, ME 220 may be configured to perform one or more operations of auto-vectoring analysis, e.g., as described below.In some example aspects, auto-vectoring analysis may be configured to vector a given code, e.g., automatically vectoring, to take advantage of the vector capabilities of the VMP.In some example aspects, ME 220 may be configured to perform auto-vectoring analysis, e.g., to vector code in scalar form. For example, some or all of the operations of auto-vectoring analysis may not be performed, e.g., if the code is already provided in vectoring form.In some example aspects, e.g., in some use cases and / or scenarios, a compiler may not always be able to automatically vector code, e.g., due to data dependencies between loop iterations.In one example, ME 220 may obtain a particular code, e.g., as follows: char* a,b,c; for (int i=0; i<20448; i++){a[i]=b[i]+c[i ]; }According to this example, ME 220 may be configured such that the CFG autovectorization analysis is performed by applying a first conversion, e.g., as follows: char* a,b,c; for (inti=0;i<2048;i+=32){a[i.i+31]=b[i...i+31]+c[i...i+31], }Example (2a)For example, ME 220 may be configured such that the CFG autovectorization analysis is performed by applying a second conversion, e.g., after the first conversion, e.g., as follows: char32* a,b,c; for (int i=0; i<64; i++){a[i]=b[i]+c[i ]; }Example (2b)In some example aspects, ME 220 may be configured to perform one or more acts of scratch pad memory loop access analysis (SPMLAA), e.g., as described below.In some example aspects, the SPMLAA may define processing blocks (PB), e.g., those that should be outlined and compiled later for VMP.In some example aspects, the processing blocks may include accelerated loops that may be executed by the vector unit of the VMP.In some example aspects, a PB, e.g., each PB, may include memory references. For example, some or all memory accesses may refer to local memory banks.In some example aspects, the VMP may enable access to memory banks via AGUs, e.g., AGUs 320 as described below with reference to FIG. 3, and scatter-gel units (SG).In some example aspects, the AGUs may be preconfigured, e.g., prior to execution of a loop. For example, the number of loop passes may be calculated, e.g., before executing a processing block.In some example aspects, at this stage, image references, e.g., some or all of the image references, may be created and steps and offsets may be calculated, e.g., per dimension, for each reference.In some example aspects, ME 220 may be configured to perform one or more operations of an AGU scheduler analysis, e.g., as described below.In some example aspects, AGU scheduler analysis may include an iterator assignment that may cover image references, e.g., all image references, from the entire processing block.In some example aspects, an iterator may cover a single reference or a group of references.In some example aspects, one or more references to memory may be merged and / or the same access reused by shuffle instructions and / or values read from previous iterations may be stored.In some example aspects, other references to memory, e.g., those without linear access patterns, may be processed using a scatter-gel unit (SG), but this may result in performance degradations, as indices and / or masks may need to be maintained.In some example aspects, a plan may be configured as an array of iterators in a processing block. For example, a processing block may have multiple plans, e.g., theoretically.In some example aspects, the AGU scheduler analysis may be configured to create all possible schedules for all PBs and select a combination, e.g., a best combination, e.g., from all valid combinations.In some example aspects, the total number of iterators in a valid combination may be constrained, e.g., so as not to exceed the number of available AGUs on a VMP.In some example aspects, one or more parameters, e.g., including pitch, width, and / or base, may be defined for an iterator, e.g., for each iterator as part of the AGU scheduler analysis. For example, min-max ranges for the iterators may be defined in one dimension, e.g., in each dimension, for example as part of the AGU Planner Analysis.In some example aspects, the AGU scheduler analysis may be configured to track and evaluate a reference to the memory, e.g., any reference to the memory, to an image, e.g., to understand its access pattern.In an example according to Examples 2a / 2b, the image "a", which is the base address, may be accessed with steps of 32 bytes for 64 iterations.In some example aspects, the LLVM may include a scalar evaluation analysis (SCEV) that may calculate an access pattern, e.g., to understand any reference to images.In some example aspects, ME 220 may utilize masking capabilities of the AGUs, e.g., to avoid maintaining an induction variable that may be a performance penalty.In some example aspects, ME 220 may be configured to perform one or more operations of a rewrite analysis, e.g., as described below.In some example aspects, the rewrite analysis may be configured to convert the code of a processing block, e.g., while iterators are set and / or memory access instructions are changed.In some example aspects, the setting of the iterators, e.g., all iterators, in IR may be implemented in target specific intrinsic functions. For example, the setting of the iterators may be in an outmost loop pre-header.In some example aspects, the rewrite analysis may include loop perfection analysis, as described below.In some example aspects, the code may be compiled to the end that substantially all computations should be performed within the innermost loop.For example, the loop perfection analysis may raise commands, e.g., to move an operation performed after a last iteration of the loop into a loop.For example, the loop infection analysis may lower commands, e.g., to move an operation performed before a first iteration of the loop into a loop.For example, loop perfecting analysis may raise commands and / or lower commands, e.g., such that substantially all commands are moved from outer loops to the innermost loops.For example, the loop perfection analysis may be configured to provide a technical solution to support VMP iterators, e.g., to operate with only perfectly nested loops.For example, loop infection analysis may result in a situation where there are no commands between the "for" statements making up the loop, e.g., to support VMP iterators that cannot emulate such cases.In some example aspects, loop infection analysis may be configured to convert an nested loop into a single merged loop.In one example, ME 220 may obtain a particular code, e.g., as follows: for (int i=0; i<N; i++){int sum=0; for (intj=0;j<M;j++) sum+=a[j+stride*i]; res[i]=sum; }According to this example, ME 220 may be configured such that the loop infection analysis is performed to summarize the nested loop in code into a single merged loop, e.g., as follows: for (intk=0;k<N*M;k++){sum=(k%M==0?0:sum); sum+=a[k%M+stride*(k / M)];res[k / M]=sum; }Example (3)In some example aspects, ME 220 may be configured to perform one or more operations of vector loop contour analysis, as described below.In some example aspects, vector loop contour analysis may be configured to split code between a scalar subsystem and a vector subsystem, e.g., vector processing block 310 (FIG. 3 ) and scalar processor 330 (FIG. 3 ), as described below with reference to FIG. 3.In some example aspects, the VMP accelerator may include the scalar and / or vector subsystems, e.g., as described below. For example, each of the subsystems may have different computational units / processors. Accordingly, scalar code may be compiled on a scalar compiler, e.g., an SSC compiler, and / or accelerated vector code may be executed on the VMP vector processor.In some example aspects, the vector loop contour analysis may be configured to generate a separate function for a loop body of the accelerated vector code. These functions may be marked for the VMP, for example, and / or may continue to the VMP backend, while the rest of the code may be compiled by the SSC compiler.In some example aspects, one or more portions of a vector loop, e.g., vector unit configuration and / or vector register initialization, may be performed by a scalar unit. However, these portions may be executed at a later stage, e.g., by backpatching into scalar code, as the scalar code may still be in LLVM IR prior to processing by the SSC compiler.In some example aspects, BE 230 may be configured to translate the LLVM IR into machine instructions. For example, BE 230 may not be target independent and familiar with target specific architecture and optimizations, e.g., as compared to ME 220, which may be agnostic to a target specific architecture.In some example aspects, BE 230 may be configured to perform one or more analyses that may be specific to a target computer, e.g., a VMP computer to which code is lowered, although BE 230 may use the common LLVM.In some example aspects, BE 230 may be configured to perform one or more operations of a command descent analysis, e.g., as described below.In some example aspects, the instruction descent analysis may be configured to translate LLVM IR into Machine IR (MIR) targeted instructions, for example, by translating the LLVM IR into a Directed Acyclic Graph (DAG).In some example aspects, the DAG may undergo a legislization process of instructions, for example, based on the data types and / or VMP instructions that may be supported by a VMP HW.In some example aspects, the command sink analysis may be configured to perform a process of pattern matching, e.g., after the instruction legization process, to sink, for example, a node, e.g., each node, in the DAG, e.g., into a VMP-specific machine command.In some example aspects, the command descent analysis may be configured to generate the MIR, e.g., after the process of pattern matching.In some example aspects, the instruction de-assertion analysis may be configured to de-assert the instruction according to the machine application binary interface (ABI) and / or the calling conventions.In some example aspects, BE 230 may be configured to perform one or more operations of a unit balancing analysis, e.g., as described below.In some example aspects, the unit balancing analysis may be configured to balance instructions between VMP compute units, e.g., computing units 316 (FIG. 3 ), as described below with reference to FIG. 3.In some example aspects, the unit balancing analysis may be familiar with some or all available arithmetic transformations and / or perform transformations according to an optimal algorithm.In some example aspects, BE 230 may be configured to perform one or more modulo scheduler (pipelined) analysis operations, e.g., as described below.In some example aspects, the pipeliner may be configured to schedule the instructions according to one or more restrictions, e.g., data dependency, resource bottleneck, and / or other restrictions, for example, using swing modulo scheduling (SMS) heuristics and / or other additional and / or alternative heuristics.In some example aspects, the pipeliner may be configured to schedule a group of very long instruction word (VLIW) instructions, e.g., an initiation interval (II), that the program traverses during a steady state, for example.In some example aspects, a performance metric that may be based on a number of cycles that a typical loop may perform may be measured, e.g., as follows:(Size of input data in bytes) * II / (bytes consumed / generated per iteration)In some example aspects, the pipeliner may attempt to minimize II, e.g., as far as possible, to improve performance.In some example aspects, the pipeliner may be configured to calculate a minimum of II and generate a corresponding schedule. For example, if the pipeliner fails to meet the schedule, it may attempt to increase the II and retry the schedule, e.g., until a predefined II threshold is exceeded.In some example aspects, BE 230 may be configured to perform one or more operations of register mapping analysis, e.g., as described below.In some example aspects, the register mapping analysis may be configured to attempt to assign a register in an efficient, e.g., optimal, manner.In some example aspects, the register mapping analysis may assign values to bypass vector registers, general purpose vector registers, and / or scalar registers.In some example aspects, the values may include private variables, constants, and / or values that are rotated across iterations.In some example aspects, register mapping analysis may implement optimal heuristics that fit one or more VMP register file constraints (regfile). For example, register mapping analysis may not use standard LLVM register mapping in some applications.In some example aspects, the register mapping analysis may fail in some cases, which may mean that the loop cannot be compiled. In this case, the register allocation analysis may implement a retry mechanism that returns to the modulo scheduler and attempts to reschedule the loop, e.g., with an increased initiation interval. For example, increasing the initiation interval may decrease register pressure and / or may assist in compiling the vector loop, e.g., in many cases.In some example aspects, BE 230 may be configured to perform one or more operations of SSC configuration analysis, e.g., as described below.In some example aspects, the SSC configuration analysis may be configured to specify a configuration for executing the kernel, e.g., the AGU configuration.In some example aspects, the SSC configuration analysis may be performed at a late stage, for example due to configurations calculated after legization, register mapping analysis, and / or modulo scheduling analysis.In some example aspects, the SSC configuration analysis may include a zero overhead loop mechanism (ZOL) in the vector loop. For example, the ZOL mechanism may configure a loop execution count based on an access pattern of references to memory in the loop, for example, to avoid executing instructions that check the loop output condition at each iteration.In some example aspects, a VMP compilation flow may include one or more steps, e.g., some steps that may be invoked during the compilation flow in a test library (testlib), e.g., a wrapper script for compilation, execution, and / or program tests. These steps may be performed, for example, outside the LLVM compiler.In some example aspects, a PHDL (Hardware Description Language) simulator may be implemented to perform one or more roles of an assembler, encoder, and / or linker.In some example aspects, compiler 200 may be configured to provide a technical solution to support robustness that enables compiling a wide range of loops with hardware constraints. For example, compiler 200 may be configured to support a technical solution that does not generate verification errors.In some example aspects, compiler 200 may be configured to provide a technical solution that supports the programmableity such that a user may express code in various ways that may be compiled correctly for the VMP architecture.In some example aspects, compiler 200 may be configured to provide a technical solution to support enhanced user experience that may allow the user to debug and / or profile code. For example, the enhanced user experience may provide informative error messages, reporting tools, and / or a profiler.In some example aspects, compiler 200 may be configured to provide a technical solution to support improved performance, e.g., to optimize VMP assembler code and / or iterator accesses, which may result in faster execution. For example, improved performance can be achieved by a high load on the computing units and the use of their complex CISC.Referring to FIG. 3, which schematically illustrates a vector processor 300 in accordance with some example aspects. For example, vector processor 180 (FIG. 1 ) may implement one or more elements of vector processor 300 and / or perform one or more operations and / or functionalities of vector processor 300.In some example aspects, vector processor 300 may include a vector microprocessor (VMP).In some example aspects, vector processor 300 may include a wide vector machine (WVM) that supports very long instruction word (VLIW) architectures and / or single instruction / multiple data (SIMD) architectures, for example.In some example aspects, vector processor 300 may be configured to provide a technical solution to support high performance for short integer types, which may be common in machine vision and / or deep learning algorithms, for example.In other aspects, vector processor 300 may include any other type of vector processor and / or may be configured to support other additional or alternative functionalities.In some example aspects, as shown in FIG. 3, vector processor 300 may include a vector processing block (vector processor) 310, a scalar processor 330, and a direct memory access (DMA) 340, as described below.In some example aspects, as shown in FIG. 3, vector processing block 310 may be configured to efficiently process image data and / or vector data, for example. For example, vector processing block 310 may be configured to use vector computing units to speed up computations, for example.In some example aspects, scalar processor 330 may be configured to perform scalar calculations. For example, scalar processor 330 may be used as "glue logic" for programs that include vector computations. For example, some, e.g., even most, computations of the programs may be performed by the vector processing block 310. However, multiple tasks, for example, some essential tasks, e.g., scalar calculations, may be performed by the scalar processor 330.In some example aspects, DMA 340 may be configured to connect to one or more memory in a chip including vector processor 300.In some example aspects, DMA 340 may be configured to read inputs from main memory and / or write outputs to main memory.In some example aspects, scalar processor 330 and vector processing block 310 may use corresponding local memories to process data.In some example aspects, as shown in FIG. 3, vector processor 300 may include a fetch and decode unit 350, which may be configured to control scalar processor 330 and / or vector processing block 310.In some example aspects, operations of scalar processor 330 and / or vector processing block 310 may be triggered by instructions stored in program memory 352.In some example aspects, DMA 340 may be configured to transfer data, for example, in parallel with execution of the program instructions in memory 352.In some example aspects, DMA 340 may be controlled by software, e.g., via configuration registers, rather than instructions, and accordingly may be considered a second "thread of execution" in vector processor 300.In some example aspects, scalar processor 330, vector processing block 310, and / or DMA 340 may include one or more computing devices, such as a set of computing devices, as described below.In some example aspects, the computing devices may include hardware configured to perform computations, e.g., an arithmetic logic unit (ALU).In one example, a computing device may be configured to add numbers and / or store the numbers in a memory.In some example aspects, the computing devices may be controlled by instructions encoded in, e.g., program memory 352 and / or configuration registers. For example, the configuration registers may be allocated as memory and described by the memory-memory instructions of the scalar processor 330.In some example aspects, scalar processor 330, vector processing block 310, and / or DMA 340 may include a state configuration including a set of registers and memories, as described below.In some example aspects, as shown in FIG. 3, vector processor block 310 may include a set of vector memories 312, which may be configured to store data to be processed by vector processor block 310, for example.In some example aspects, as shown in FIG. 3, vector processor block 310 may include a set of vector registers 314 that may be configured for use in data processing by vector processor block 310, for example.In some example aspects, scalar processor 330, vector processing block 310, and / or DMA 340 may be coupled to a set of memory allocations.In some example aspects, a memory map may include a set of addresses that may be accessed by a computing device that may load and / or store data from and to registers and memories.In some example aspects, as shown in FIG. 3, the vector processing block 310 may include a plurality of address generation units (AGUs) 320 that may include addresses accessible to them, e.g., in one or more memories 312.In some example aspects, as shown in FIG. 3, vector processor block 310 may include a plurality of computing devices 316, e.g., as described below.In some example aspects, computing devices 316 may be configured to process instructions, e.g., include multiple numbers simultaneously. In one example, an instruction may include 8 numbers. In another example, an instruction may include 4 numbers, 16 numbers, or any other number of numbers.In some example aspects, two or more computing devices 316 may be used simultaneously. In one example, computing devices 316 may process and execute a variety of different instructions, e.g., 3 different instructions, including, for example, 8 numbers, during a single cycle.In some example aspects, computing devices 316 may be asymmetric. For example, first and second computing devices 316 may support different commands. For example, a first computing device 316 may perform an addition and / or a second computing device 316 may perform a multiplication. For example, both operations may be performed by one or more additional other computing devices 316.In some example aspects, computing devices 316 may be configured to support arithmetic operations for many combinations of input and output data types.In some example aspects, computing devices 316 may be configured to support one or more operations that may be less common. For example, processing units 316 may support operations that operate on a look-up table (LUT) of a vector processor 300 and / or any other operations.In some example aspects, computing devices 316 may be configured to support efficient computation of non-linear functions, histograms, and / or random data access, which may be useful for implementing algorithms such as image scaling, Hough transforms, and / or other algorithms, for example.In some example aspects, vector memories 312 may include, for example, memory banks of 16K or other size that may be accessed in the same cycle.In one example, a maximum memory access size may be 64 bits. According to this example, a peak throughput may be 256 bits, e.g., 64x4=256. For example, a high bandwidth of memory may be implemented to take advantage of the computational capabilities of the computing devices 316.In one example, two computing devices 316 may support 16 8-bit multiply-accumulate operations (MACs) per cycle. According to this example, the two computing devices 316 may not be useful, e.g., if the input numbers are not retrieved at that speed and / or there are not exactly 256 bits of input, e.g., 16x8x2= 256.In some example aspects, AGUs 320 may be configured to perform operations associated with memory, e.g., loading and storing data from / into vector memory 314.In some example aspects, AGUs 320 may be configured to compute addresses of input and output data elements, for example, to process I / O and utilize computing devices 316, e.g., when the clean bandwidth is insufficient.In some example aspects, AGUs 320 may be configured to calculate the addresses of the input and / or output data elements, for example, based on configuration registers written by scalar processor 330, for example, before a block of vector instructions, e.g., a loop, is input.For example, AGUs 320 may be configured to write a frame base pointer, width, height, and / or step to the configuration registers to traverse an image, for example.In some example aspects, AGUs 320 may be configured to take over addressing, e.g., all addressing, to provide a technical solution in which computing devices 316 do not have the load to increment pointers or counters in a loop, and / or have the load to check for end-of-line conditions, e.g., to set a counter in the loop to zero.In some example aspects, as shown in FIG. 3, AGUs 320 may include 4 AGUs, and accordingly four memories 312 may be accessed in one cycle. In other aspects, any other number of AGUs 32 may be implemented.In some example aspects, AGUs 320 may not be "tied" to memory banks 312. For example, an AGU 320, e.g., each AGU 320, may access a memory 312, e.g., each memory 312, as long as two or more AGUs 320 are not attempting to access the same memory 312 in the same cycle.In some example aspects, vector registers 314 may be configured to support communication between computing devices 316 and AGUs 320.In one example, the total number of vector registers 314 may be 28 that may be divided into multiple subsets, e.g., based on their function. For example, a first subset of the vector registers 314 may be used to input / output all of the computing devices 316 and / or AGUs 320; and / or a second subset of the vector registers 314 may not be used to output some operations, e.g., most operations, and may be used for one or more other operations, e.g., to store loop-invariant inputs.In some example aspects, a computing device 316, e.g., each computing device 316, may include one or more registers to host an output of a last-executed operation, which may be input to other computing devices 316, for example. For example, these registers may "bypass" the vector registers 314 and operate faster than when these outputs are written to the first set of vector registers 314.In some example aspects, fetch and decode unit 350 may be configured to support low-overhead vector loops, e.g., very low-overhead vector loops (also referred to as "zero-overhead vector loops"). In such cases, it may not be necessary, for example, to check an abort condition during execution of the vector loop.For example, a condition for termination (output) may be signaled by an AGU 320, such as when the AGU 320 has completed iteration through a configured memory.For example, fetch and decode unit 350 may exit the loop, such as when AGU 320 signals the condition for termination.For example, the scalar processor 330 may be used to configure the loop parameters, e.g., first and last instructions and / or the initial condition.In one example, vector loops may be used, for example, along with high bandwidth of memory and / or inexpensive addressing to solve, for example, a control and data flow issue, for example, to provide a technical solution that allows computing devices 316 to process data, e.g., without substantial additional overhead.In some example aspects, scalar processor 330 may be configured to provide one or more functionalities that may be complementary to those of vector processing block 310. For example, a large portion, e.g., most of, of the work may be performed in a vector program by the computing devices 316. For example, scalar processor 330 may be used to "glue" the various blocks of the vector code of the vector program, for example.In some example aspects, scalar processor 330 may be implemented separately from vector processing block 310. In other aspects, scalar processor 330 may be configured to share one or more components and / or functionalities with vector processing block 310.In some example aspects, scalar processor 330 may be configured to perform operations not suitable for execution in vector processing block 310.For example, scalar processor 330 may be used to execute 32-bit C programs. For example, scalar processor 330 may be configured to support 1-, 2- and / or 4-byte data types of C code and / or some or all arithmetic operators of C code.For example, scalar processor 330 may be configured to provide a technical solution to perform operations that cannot be performed in vector processing block 310, for example, without using a full CPU.In some example aspects, scalar processor 330 may include a scalar memory 332, which may be, e.g., 16K or other size, and may be configured to store data, e.g., variables used by the scalar portions of a program.For example, scalar processor 330 may store local and / or global variables declared by portable C code that may be assigned to scalar data storage by a compiler, e.g., compiler 200 (FIG. 2 ).In some example aspects, as shown in FIG. 3, scalar processor 330 may include or be connected to a set of vector registers 334, which may be used in a process of data processing performed by scalar processor 330.In some example aspects, scalar processor 330 may be coupled to a scalar memory map that may assist scalar processor 330 in accessing substantially all states of vector processor 300. For example, scalar processor 330 may configure the vector units and / or the DMA channels via the scalar memory allocation.In some example aspects, scalar processor 330 may not be permitted to access one or more control registers for blocks that may be used by external processors to execute and debug vector programs.In some example aspects, DMA 340 may be configured to communicate with one or more other components of a chip implementing vector processor 300, for example, via main memory. For example, DMA 340 may be configured to transfer data blocks, e.g., large, contiguous data blocks, to support scalar processor 330 and / or the vector processing block that may manipulate data stored in the local memories. For example, a vector program may read data from the main memory of the chip using DMA 340.In some example aspects, DMA 340 may be configured to communicate with other elements of the chip, for example, via a plurality of DMA channels, e.g., 8 DMA channels, or any other number of DMA channels. For example, a DMA channel, i.e., each DMA channel, may be able to transfer a rectangular patch from the local memories to the main memory of the chip, or vice versa. In other aspects, the DMA channel may transfer any other type of data block between the local memories and the main memory of the chip.In some example aspects, a rectangular patch may be defined by a base pointer, a width, a height, and a pitch.For example, at maximum throughput, 8 bytes per cycle may be transmitted, but overheads may arise for each patch and / or for each row in a patch.In some example aspects, DMA 340 may be configured to transfer data in parallel with computations, e.g., over multiple DMA channels, as long as instructions executed do not access local memory involved in the transfer.As an example, since all channels may access the same memory, I / O cycles may not be saved by using multiple channels to perform a transmission, e.g., as compared to using a single channel. However, the plurality of DMA channels may be used to schedule multiple transfers and perform them in parallel with computations. This may be advantageous, for example, compared to a single channel where a second transmission may not be scheduled prior to completion of the first transmission.In some example aspects, DMA 340 may be associated with a memory map that may assist the DMA channels in accessing vector memory and / or the scalar data. For example, the vector memories can be accessed in parallel with calculations. For example, parallel access to the scalar data is not usually allowed, as the scalar processor 330 may be incorporated into almost any meaningful program and may be accessing its local variables while the transfer is being performed, which may result in a memory conflict with the active DMA channel.In some example aspects, DMA 340 may be configured to provide a technical solution to support parallelization of I / O and computations. For example, a program performing computations need not wait for I / O, e.g., if these computations can be quickly performed by the vector processing block 310.In some example aspects, an external processor, e.g., a CPU, may be configured to initiate execution of a program on the vector processor 300. For example, vector processor 300 may remain idle as long as program execution is not initiated.In some example aspects, the external processor may be configured to debug the program, i.e., each execute a single step, stop when the program reaches breakpoints, and / or verify the content of registers and memories in which the program variables are stored.In some example aspects, external memory allocation may be implemented to assist the external processor in controlling the vector processor 300 and / or debugging the program, for example, by writing to control registers of the vector processor 300.In some example aspects, the external memory allocation may be implemented by a superset of the scalar memory allocation. This implementation may, for example, make all registers and memories defined by the architecture of vector processor 300 accessible to a debug back end running on the external processor.In some example aspects, vector processor 300 may trigger an interrupt signal, such as when vector processor 300 terminates a program.In some example aspects, the interrupt signal may be used, for example, to implement a driver that manages a queue of programs intended for execution by vector processor 300 and / or to launch a new program, for example, by the external processor, for example, upon completion of a previously executed program.Referring to FIG. 1, in some example aspects, compiler 160 may be configured to generate target code 115, for example, configured to use registers of a processor, for example, a vector processor, e.g., vector processor 180, according to a register allocation scheme, e.g., as described below.In some example aspects, the register allocation scheme may be configured to provide a technical solution to use a reduced number of allocated registers for execution of a program by a processor, for example a vector processor, as described below.In one example, the register allocation scheme may be configured to provide a technical solution to use a reduced number of allocated registers that may be allocated from the plurality of vector registers 314 (FIG. 3 ) to execute a program by a vector processor 300 (FIG. 3 ), e.g., as described below.In some example aspects, a compiler, e.g., compiler 160, may be configured to generate target code, e.g., target code 115, which may be configured to use registers of a vector processor, e.g., vector processor 189, according to a register allocation scheme, e.g., as described below.In other aspects, a compiler, e.g., compiler 160, may be configured to generate target code, e.g., target code 115, which may be configured to use registers of any other suitable processor type, e.g., any other suitable processor type, according to the register allocation scheme, e.g., as described below.In some example aspects, the register allocation scheme may be configured to provide a technical solution to, e.g., optimize allocation of registers for execution of the executable program, as described below.In some example aspects, the register allocation scheme may be configured to provide a technical solution to support enhanced allocation, for example, efficient allocation, e.g., optimized allocation, of registers for executing the executable program, e.g., as described below.In some example aspects, the register allocation scheme may be configured to provide a technical solution to use a reduced number, e.g., an optimized number, e.g., a minimum number, of allocated registers to execute the executable program, e.g., as described below.In some example aspects, the register allocation scheme may be configured to provide a technical solution to improve performance of the executable program, for example, by reducing the number of registers allocated to execute the executable program, as described below.In some example aspects, it may be necessary to provide a technical solution to efficiently allocate vector registers of a vector processor for execution of a program, for example, to reduce the number of allocated vector registers, as described below.For example, a number of physical registers implemented by a chip including a processor, e.g., a vector processor or another processor, may be constrained, for example, according to a design and / or layout of the chip. Accordingly, a number of vector registers implemented by the vector processor may be limited by the number of physical registers on the chip implementing the vector processor.In some example aspects, the register allocation scheme may be configured to provide a technical solution to reduce the number of allocated registers, for example, for CPUs, e.g., vector processors, with limited storage capabilities, e.g., a limited register pool, and / or for processors, e.g., vector processors, that only limitedly support or do not support memory overflow / fill operations, e.g., for storing live values.For example, processors that do not have fill / overflow functions and / or constrained memory functions may be forced to use computing resources instead.In some example aspects, the register allocation scheme may be configured to provide a technical solution to reduce the number of allocated registers, for example to avoid or even eliminate the use of these additional computing resources.In some example aspects, the register allocation scheme may be configured to provide a technical solution to reduce register pressure for execution of a program by a processor, such as a vector processor or another processor.In some example aspects, the register allocation scheme may be configured to provide a technical solution to reduce register pressure, for example, by reducing the number of allocated registers for execution of the program, e.g., as described below.In some example aspects, the register allocation scheme may be configured to provide a technical solution to support efficient execution of programs, e.g., complex programs that may be sensitive to register pressure. For example, in some programs, a problem with register pressure may be a bottleneck, and register pressure may affect performance.In some example aspects, the register allocation scheme may be configured to provide a technical solution to reduce the number of allocated registers for execution of a program, while providing, for example, an appropriate allocation of registers, e.g., vector registers, for execution of the program, as described below.In some example aspects, compiler 160 may be configured to process a given instruction schedule, e.g., based on source code 112, and generate target code 115, which may be configured to use a reduced number of allocated registers, for example, for successful register allocation, as described below.In some example aspects, compiler 160 may be configured to generate target code 115 configured to use computing devices, e.g., ALUs, of a processor, e.g., a vector processor, to store variables of the executable program, e.g., live values, as described below.In some example aspects, compiler 160 may be configured to generate target code 115 configured to use the computing devices of the vector processor to store one or more variables of the executable program, e.g., live values, rather than storing those variables in one or more registers, as described below.In one example, compiler 160 may be configured to generate target code 115 configured to use one or more of computing devices 316 (FIG. 3 ) to store, e.g., temporarily store, one or more variables of the executable program, e.g., live values, rather than storing one or more of these variables in one or more vector registers 314 (FIG. 3 ), e.g., as described below.In some example aspects, compiler 160 may be configured to generate target code 115 configured to utilize an internal state of ALUs to store the live values in the ALUs, for example, rather than storing those live values in physical registers, as described below.In some example aspects, compiler 160 may be configured to generate target code 115 configured to utilize latency in execution of instructions by the ALUs, for example, to store the live values in the ALUs, as described below.In some example aspects, compiler 160 may be configured to generate target code 115 configured to store live values of variables in the ALUs, e.g., by live interval division, as described below.In some example aspects, the live interval partitioning may include partitioning a live range (interval) of a live value of a variable, for example, into a first live interval in which the live value is stored by an ALU and a second live interval in which the live value is stored in a physical vector register, as described below.In some example aspects, a live range (interval) of a live value of a variable may be divided more than once, e.g., to provide more than two live intervals. For example, the number of live intervals may be increased to provide more cycles in which registers may be available, as described below.In some example aspects, a live range of a variable may include a range of cycles of the executable program, for example, between a first cycle including a first use and / or production of the variable and a second cycle including a second use of the variable, for example, subsequent to the first use, as described below.In some example aspects, compiler 160 may be configured to identify one or more cycles ("unused variable cycles") in the live range of a variable during which the variable is active and not used, as described below.In some example aspects, compiler 160 may be configured to assign, in target code 115, one or more non-operational (no-op) instructions applied to the variable, for example, to store the live value of the variable by an ALU, as described below.In some example aspects, compiler 160 may be configured to assign, in target code, one or more non-operational instructions executed by an ALU, e.g., such that the live value of the variable may be stored by the ALU executing the one or more non-operational instructions, e.g., as described below.In some example aspects, compiler 160 may be configured to generate target code 115 including one or more non-transitory instructions that may be configured to exploit latency of the ALU for execution of instructions, e.g., such that the live value of the variable may be temporarily stored by the ALU, e.g., as described below.In some example aspects, compiler 160 may be configured to generate target code 115 including one or more non-act instructions, which may be configured to provide a technical solution for temporarily storing the live value of the variable by the ALU executing the one or more non-act instructions, for example, instead of storing the live value of the variable in a vector register, as described below.In some example aspects, compiler 160 may be configured to generate target code 115 including one or more instructions without operation to be applied to the variable, for example, even without substantially compromising the throughput of the executable program, as described below.In some example aspects, an un-action instruction may include an instruction that may be configured to cause the ALU to perform a sequence of actions that may be performed by the ALU and may result in the live value of the variable being maintained during one or more cycles, as described below.In some example aspects, the no-operation instruction may include an instruction that may be configured such that the ALU performs a sequence of operations, e.g., including a load operation to load the live value of the variable from a vector register, an operation to be applied to the live value of the variable, e.g., without changing the live value of the variable, and a store operation to store the live value of the variable back to the same register, e.g., as described below.In some example aspects, compiler 160 may be configured to generate target code 115 that includes one or more non-operation instructions that, when executed by the ALU, may cause the ALU to execute the sequence of operations of the non-operation instructions within a number of cycles (latency cycles), which may be based on, for example, latency of the ALU for execution of instructions, as described below.In some example aspects, compiler 160 may be configured to generate target code 115 including one or more non-transitory instructions that, when executed by the ALU, may result in storage of the live value of the variable by the ALU for the duration of the latency cycles.In one example, the one or more instructions may include a zero add instruction without action.In another example, the one or more instructions may include, without action, a zero shift instruction, e.g., a zero left shift instruction or a zero right shift instruction.In another example, the one or more instructions may include a one multiplication instruction without action.In another example, the one or more instructions may include, without operation, any other additional and / or alternative instruction that may be configured to, when executed by an ALU, cause the ALU to store a live value of a variable by the ALU, e.g., for the duration of one or more latency cycles.In some example aspects, compiler 160 may be configured to compile source code 112 into target code 115, which may be configured for execution by target processor 180, e.g., as described below.In some example aspects, compiler 160 may be configured to compile source code 112 including OpenCL code, e.g., as described below. In other aspects, compiler 160 may be configured to compile any other type of source code 112.In some example aspects, compiler 160 may be configured to compile source code 112 into target code 115, for example, according to an LLVM-based compilation scheme. In other aspects, any other additional or alternative compilation scheme may be used.In some example aspects, compiler 160 may be configured to compile source code 112 into target code 115, which may be configured for execution by, for example, a VLIW SIMD target processor.In some example aspects, compiler 160 may be configured to compile source code 112 into target code 115, which may be configured for execution by, for example, a target vector processor.In other aspects, compiler 160 may be configured to compile source code 112 into target code 115, which may be configured for execution by any other additional or alternative processor type.In some example aspects, target code 115 may be configured for execution by target processor 180 in a plurality of execution cycles, including, for example, a first execution cycle, a second execution cycle after the first execution cycle, and a third execution cycle after the second execution cycle, e.g., as described below.In some example aspects, compiler 160 may be configured to generate target code 115, including, for example, one or more non-act instructions (no-op), which may be configured to maintain a first variable live, for example, such that a value, e.g., a live value, of the first variable is to be available in a register of the target processor, for example, at the first execution cycle and at the third execution cycle, e.g., as described below.In some example aspects, compiler 160 may configure target code 115 to include a first instruction that is applied to, e.g., the value, e.g., the live value, of the first variable in the register at the first execution cycle, e.g., as described below.In some example aspects, compiler 160 may configure target code 115 to include a second instruction that is applied, for example, to a value of a second variable in the register at the second execution cycle, e.g., as described below.In some example aspects, compiler 160 may configure target code 115 to include a third instruction that is applied, for example, to the value, e.g., the live value, of the first variable in the register at the third execution cycle, e.g., as described below.In some example aspects, compiler 160 may be configured to output target code 115 in, for example, a form executable by target processor 180.In some example aspects, compiler 160 may be configured to generate target code 115 configured for execution by, for example, a very long instruction word single instruction / multiple data (VLIW SIMD) target processor, e.g., processor 180.In other aspects, compiler 160 may be configured to generate target code 115 configured for execution by, for example, another suitable type of processor.In some example aspects, compiler 160 may be configured to generate target code 115, for example, based on source code 112 including open computing language (OpenCL) code.In other aspects, compiler 160 may be configured to generate target code 115 based on source code 112, including another suitable type of code, for example.In some example aspects, compiler 160 may be configured to compile source code 112 into target code 115, for example, in accordance with a low-level virtual machine (LLVM)-based (LLVM-based) compilation scheme.In other aspects, compiler 160 may be configured to compile source code 112 into target code 115 according to any other suitable compilation scheme.In some example aspects, compiler 160 may be configured to configure one or more instructions without action, for example, to cause target processor 180 to apply to the value, e.g., the live value, of the first variable one or more actions, which may be configured, for example, such that the value, e.g., the live value, of the first variable remains unchanged between the first execution cycle and the third execution cycle, e.g., as described below.In some example aspects, compiler 160 may be configured to configure one or more instructions without action to cause, for example, a computing device of target processor 180, e.g., computing device 316 (FIG. 3 ) of vector processor 300 (FIG. 3 ) to temporarily maintain the value, e.g., the live value, of the first variable internally in the computing device, for example, between the first execution cycle and the third execution cycle, as described below.In some example aspects, compiler 160 may be configured to configure the one or more non-operation instructions to include, for example, a zero addition instruction, as described below.In some example aspects, compiler 160 may be configured to configure the one or more non-operation instructions to include, for example, a zero displacement instruction, as described below.In some example aspects, compiler 160 may be configured to configure the one or more non-operation instructions to include, for example, a one multiplication instruction, as described below.In other aspects, compiler 160 may be configured to configure the one or more non-act instructions to include any other suitable additional or alternative type of non-act instructions.In some example aspects, compiler 160 may be configured to configure one or more instructions without operation to, for example, cause a computing device of target processor 180, e.g., computing device 316 (FIG. 3 ) of vector processor 300 (FIG. 3 ), to initiate loading of the value, e.g., the live value, of the first variable from the register at the first execution cycle, e.g., as described below.In some example aspects, compiler 160 may be configured to configure one or more non-transitory instructions to, for example, cause the computing device of target processor 180, e.g., computing device 316 (FIG. 3 ) of vector processor 300 (FIG. 3 ), to initiate storage of the value, e.g., the live value, of the first variable in the register in a later execution cycle, e.g., prior to the third execution cycle, as described below.In some example aspects, compiler 160 may be configured to generate the one or more non-act instructions to include a plurality of non-act instructions, e.g., as described below.In some example aspects, compiler 160 may be configured to generate an un-act instruction as the first in a plurality of un-act instructions, which may be configured to cause a computing device of target processor 180, e.g., computing device 316 (FIG. 3 ) of vector processor 300 (FIG. 3 ), to load the value, e.g., the live value, of the first variable from the register, e.g., at the first execution cycle, and to apply, to the value, e.g., the live value, of the first variable, the first act in the order configured, e.g., such that the value, e.g., the live value, of the first variable remains unchanged, e.g., as described below.In some example aspects, compiler 160 may be configured to generate, from the plurality of non-operation instructions, a non-operation instruction that is executed last in order, and that may be configured to cause the computing device of target processor 180, e.g., computing device 316 (FIG. 3 ) of vector processor 300 (FIG. 3 ), to apply, to an output of a previous non-operation instruction, a last non-operation in order, which may be configured such that the value, e.g., the live value, of the first variable remains unchanged, and the value, e.g., the live value, of the first variable is stored in the register, e.g., as described below.In some example aspects, compiler 160 may be configured to generate target code 115, which may be configured to initiate execution of a non-act instruction last in order from one or more non-act instructions by a computing device of target processor 180, e.g., computing device 316 (FIG. 3 ) of vector processor 300 (FIG. 3 ), for example, at a last non-act in order execution cycle, e.g., before the third execution cycle, for example, as described below.In some example aspects, compiler 160 may be configured to generate target code 115, e.g., which may be configured such that a distance between the last execution cycle without operation and the third execution cycle may be based on, e.g., latency of the computing device of target processor 180, e.g., a computing device 316 (FIG. 3 ) of vector processor 300 (FIG. 3 ), e.g., as described below.In some example aspects, compiler 160 may be configured to configure one or more instructions without action, for example, based on latency of a computing device of target processor 180, e.g., computing device 316 (FIG. 3 ) of vector processor 300 (FIG. 3 ), e.g., as described below.In some example aspects, compiler 160 may be configured to generate target code 115, which may be configured to execute the first instruction, for example, by a first computing device of target processor 180, e.g., a first computing device 316 (FIG. 3 ) of vector processor 300 (FIG. 3 ), e.g., as described below.In some example aspects, compiler 160 may be configured to generate target code 115, e.g., which may be configured to execute one or more instructions without operation, e.g., by a second computing device of target processor 180, e.g., a first computing device 316 (FIG. 3 ) of vector processor 300 (FIG. 3 ), e.g., as described below.In some example aspects, compiler 160 may be configured to generate target code 115, which may be configured to initiate execution of a first non-act instruction in the order of the one or more non-act instructions from the second computing device, for example, at the first execution cycle, as described below.In some example aspects, compiler 160 may be configured to generate target code 115, which may be configured, for example, to execute the second instruction, for example, by the second computing device, as described below.In some example aspects, compiler 160 may be configured to generate target code 115, which may be configured, for example, to execute the third instruction, e.g., by the first computing device, as described below.In some example aspects, the first computing device of the target processor 180 may include a first ALU and / or the second computing device of the target processor 180 may include a second ALU, e.g., as described below. In other aspects, any other additional or alternative type of computing device may be implemented.In some example aspects, compiler 160 may be configured to identify a plurality of live ranges corresponding to a corresponding plurality of variables based on source code 112, e.g., as described below.In some example aspects, compiler 160 may be configured to identify, as a first variable, an identified variable that has, for example, a live range that includes one or more unused execution cycles in which the identified variable is not used, as described below.In some example aspects, compiler 160 may be configured to identify the identified variable as a first variable, for example, based on determining that a number of consecutive unused execution cycles in the live range of the identified variable is greater than a predefined threshold, as described below.In some example aspects, compiler 160 may be configured to configure one or more instructions without action, for example, to maintain the first variable during the one or more unused execution cycles, as described below.In some example aspects, compiler 160 may be configured to assign the register to store the value of the second variable, for example, in an unused execution cycle of the one or more unused execution cycles, as described below.In some example aspects, compiler 160 may be configured to generate target code 115 based on VLIW instructions that may be used to invoke a plurality of different instructions during the same cycle. For example, the plurality of instructions may include a no-action instruction that may be executed in parallel with other instructions so that performance is not affected by the addition of the no-action instruction.In some example aspects, compiler 160 may be configured to receive source code 112 including instruction planning for an executed program, as described below.In some example aspects, compiler 160 may be configured to identify a live range of one or more variables in the executed program, e.g., as described below.In some example aspects, compiler 160 may be configured to identify one or more cycles ("unused cycles") in a live range of a variable.The unused cycles may include, for example, cycles in which the variable is active but not in use, as described below.In some example aspects, compiler 160 may be configured to determine an identified computing device, e.g., an ALU, that has latency when executing instructions without operation and that is available during one or more unused cycles, e.g., as described below.In some example aspects, compiler 160 may be configured to insert one or more non-transitory instructions applied to the variable by the identified computing device, for example, during one or more unused cycles, as described below.In some example aspects, causing the identified computing device to perform the operation without operation on the live variable may result in the identified computing device temporarily storing the variable during the one or more unused cycles, for example, according to the latency of the identified computing device, as described below.In some example aspects, use of the identified computing device to store the variables during one or more unused cycles may provide a technical solution for enabling a register, e.g., a vector register, during one or more unused cycles, e.g., as described below.In some example aspects, the free register, e.g., the free vector register, may be used to store, for example, one or more other live values of other variables, for example, during unused cycles. This can reduce the number of registers, e.g., vector registers, required for execution of the program.In some example aspects, compiler 160 may be configured to generate non-operation instructions that may be configured to use instructions with different latency, for example, to provide a technical solution to enable one or more register cycles as may be required.In some example aspects, compiler 160 may be configured to generate target code 115, for example including one or more non-act instructions, for example, to efficiently assign register vectors, as described below.In some example aspects, compiler 160 may obtain source code 112 of an executed program.In some example aspects, source code 112 may include instruction planning that may be configured to compute an expression based on a first variable, referred to as a, and a second variable, referred to as b, e.g., as follows:In some example aspects, an expression result of Expression 1 may be stored in a result address in memory, referred to as "res_add".In some example aspects, variable a may be stored in a memory address referred to as a_add, and variable b may be stored in a memory address referred to as b_add.In some example aspects, compiler 160 may be configured to compile source code 112 for a processor, such as a vector processor including a first ALU and a second ALU, which may be configured to execute add and multiply instructions, such as with a latency of 2 cycles. For example, the processor, e.g., the vector processor, may have a memory unit with a latency of 1 cycle for a memory access operation, e.g., a memory operation to store a value in the memory unit or a load operation to load a value from the memory unit.In some example aspects, execution of Expression 1 may be implemented according to the following instruction scheduling: TABLE (1) TABLE (1)0a = load(a_add)1a_mul_2=mul(a,2)b = load(b_add)2b_mul_3 = mul(b,3)34sum = add(a_mul_2, b_mul_3)56res = mul(sum, a)78store(res-add,res)As shown in Table 1, one or more first operations may be performed by the first ALU and one or more second operations may be performed by the second ALU.As shown in Table 1, the second ALU must not perform any operations during cycle 1 and cycle 3.As shown in Table 1, the execution of Expression 1 can be performed for 9 cycles.In one example, three registers labeled R0, R1, and R2 may be used to execute the instructions of Table 1, e.g., as follows: TABLE (2) TABLE (2)0Unimportant is the unimportantUnimportant is the unimportantUnimportant is the unimportant1a aUnimportant is the unimportantUnimportant is the unimportant2a aUnimportant is the unimportantb b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b3a aa_mul_2Unimportant is the unimportant4a aa_mul_2b_mul_35a aUnimportant is the unimportantUnimportant is the unimportant6a aSum sumUnimportant is the unimportant7Unimportant is the unimportantUnimportant is the unimportantUnimportant is the unimportant8res res resUnimportant is the unimportantUnimportant is the unimportantAs shown in Table 2, register R0 may be required to store variable a during cycles 1 through 6 and to store the expression result during cycle 8.As shown in Table 2, register R2 may be required to store the multiplication result, referred to as b_mul_3, of the product of variables b and 3 during cycle 4.As shown in Table 2, register R2 may be required during cycles 2 and 4, while register R1 may be required to store the value a_mul_2 during cycles 3.4 and store the value sum in cycle 6.In some example aspects, compiler 160 may be configured to identify live ranges of variables in instruction planning according to Table 1, e.g., as follows: TABLE (3) TABLE (3)a a[1, 6]: R0b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b[2.2]: R2a_mul_2[3, 4] R1b_mul_3[4, 4] R2sum[6, 6]: R1res res res[8, 8]: R0As shown in Table 3, variable a may have a live range between cycle 1 and cycle 6, while variable a may not be used during some of these cycles, e.g., cycles 2-5 as shown in Table 1.In some example aspects, compiler 160 may recognize that variable a is not used during one or more unused cycles, e.g., cycles 2 through 5, within the live range between cycle 1 and cycle 6.In some example aspects, compiler 160 may recognize that second ALU (ALU2) is free during cycle 1 and cycle 3.In some example aspects, compiler 160 may insert a first non-operation instruction, referred to as a_ 1, with a latency of 2 cycles, executed by the second ALU (ALU2) in cycle 1, for example, to enable register R 0 during cycle 2, as described below.In some example aspects, compiler 160 may insert a second non-operation instruction, referred to as a_ 2, with a latency of 2 cycles, executed by the second ALU (ALU2) in cycle 3 to, for example, enable register R 0 during cycle 4, as described below.In some example aspects, compiler 160 may assign register R 0 to store multiplication result b_mul_ 3, for example during cycle 4. For example, register R 0, which may be free in cycle 4, may be used to store multiplication result b_mul_ 3, e.g., instead of register R 2. Accordingly, register R2 may become superfluous because, as shown in Table 2, no other operation requires the use of register R2.In some example aspects, compiler 160 may determine target code 115 based on an updated instruction schedule that includes the first and second instructions without operation, e.g., as follows: TABLE (4) TABLE (4)0a = load(a_add)1a_mul_2=mul(a,2)a_1=add(a, 0)b = load(b_add)2b_mul_3 = mul(b,3)3a_2=add(a_1, 0)4sum = add(a_mul_2, b_mul_3)56res = mul(sum, a_2)78store(res_add, res)In some example aspects, the updated command planning variables may have updated live ranges that may be different from the live ranges in Table 3, e.g., as follows. TABLE (5) TABLE (5)a a[1], [3], [5, 6]: R0R0 is available in cycles 2 and 4b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b[2,2]: R0a_mul_2[3, 4] R1b_mul_3[4, 4]: R0sum[6, 6]: R1res res res[8, 8]: R0As shown in Table 5, the variable a may be assigned to the register R0 in cycle 1, cycle 3, cycle 5, and cycle 6.As shown in Table 5, the variable a must not be assigned to the register R0 in cycle 2 and cycle 4, e.g., since the variable a may be temporarily stored by the second ALU, e.g., when executing the instructions without operation.As shown in Table 5, the multiplication result b_mul_ 3 in cycle 4 may be assigned to the register R 0. This can make the register R2 unnecessary.In some example aspects, the updated instruction scheduling may be configured to assign two vector registers, e.g., registers R 0 and R 1, while third register R 2 is not required, e.g., as follows. TABLE (6) TABLE (6)0Unimportant is the unimportantUnimportant is the unimportant1a aUnimportant is the unimportant2b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b bUnimportant is the unimportant3a aa_mul_24b_mul_3a_mul_25a aUnimportant is the unimportant6a asum7Unimportant is the unimportantUnimportant is the unimportant8res res resUnimportant is the unimportantAs shown in Table 6, compiler 160 may assign register R 0 to store variable a in cycle 1, cycle 3, cycle 5, and cycle 6; to store multiplication result b_mul_ 3 in cycle 4; and to store the result in cycle 8.As shown in Table 6, the register R2 may become redundant.In some example aspects, some cycles of the executed program according to the instruction set of Table 1 may correspond to a number of cycles of the executed program according to the instruction set of Table 4, e.g., 9 cycles. However, the number of registers allocated may be reduced by the updated instruction scheduling, e.g., from three registers to two registers. Accordingly, the instruction set of Table 4 may be implemented to provide a technical solution with improved, e.g. optimized, performance, e.g. as follows: TABLE (7) TABLE (7)Total Running Time (Cycles)99Number of registers used32In some example aspects, as shown in Table 7, the register allocation scheme may be implemented to provide a technical solution by which a vector register may be stored for use without compromising performance.For example, in some use cases and / or scenarios, a schedule for a program may result in an unsuccessful register assignment, e.g., due to a limited number of registers.One example: Attempting to schedule execution of Expression 1 according to the instruction scheduling in Table 1 may result in an unsuccessful register allocation, e.g., when only two registers are available. One way to address this issue is to loosen the instruction scheduling, e.g., to reduce the number of live variables that use the same execution cycles. However, this option may result in degradation.In some example aspects, execution of Expression 1 according to the register allocation scheme described above, e.g., using the instruction scheduling of Table 4, may provide a technical solution to support successful register allocation, e.g., even when only two registers are available while avoiding the performance degradation resulting from the instruction scheduling of Table 1.Referring to FIG. 4, which schematically illustrates a method for compiling code for a processor. For example, one or more operations of the method of FIG. 4 may be performed by a system, e.g., system 100 (FIG. 1 ), a device, e.g., device 102 (FIG. 1 ), a server, e.g., server 170 (FIG. 1 ), and / or a compiler, e.g., compiler 160 (FIG. 1 ) and / or compiler 200 (FIG. 2 ).In some example aspects, as indicated in block 402, the method may include observing live ranges, for example live ranges above a predefined threshold, e.g., relatively large live ranges, in which a variable "x" may not be used for a period of time, e.g., a relatively long time. For example, compiler 160 (FIG. 1 ) may identify one or more unused cycles in the live range, as described above.In some example aspects, as indicated in block 404, the method may include checking if there is a free ALU in the unused cycles that can perform an operation without operation. For example, compiler 160 (FIG. 1 ) may identify a computing device of the processor that is available during one or more unused cycles, e.g., as described above.In some example aspects, as indicated in block 406, the method may include employing one or more non-acting instructions acting on the variable "x", whereby the variable "x" may be returned to the same register after one or more latency cycles during unused cycles. For example, compiler 160 (FIG. 1 ) may generate target code 115 based on one or more non-transitory instructions executed during the live range of the variables, as described above.In some example aspects, one or more operations of the method of FIG. 4 may be repeated, e.g., for each variable in source code, to generate target code 115, for example, according to a register allocation scheme that may be configured to reduce the number of registers required to execute the source code. For example, reducing the number of registers required may provide a technical solution to support efficient use of CPUs with a limited number of registers and / or without support for memory overflow / fill.Referring to FIG. 5, which schematically illustrates a method for compiling code for a processor. For example, one or more operations of the method of FIG. 5 may be performed by a system, e.g., system 100 (FIG. 1 ), a device, e.g., device 102 (FIG. 1 ), a server, e.g., server 170 (FIG. 1 ), and / or a compiler, e.g., compiler 160 (FIG. 1 ) and / or compiler 200 (FIG. 2 ).In some example aspects, as indicated in block 502, the method may include compiling source code into target code. For example, the target code may be configured for execution by a target processor in a plurality of execution cycles, including, for example, a first execution cycle, a second execution cycle after the first execution cycle, and a third execution cycle after the second execution cycle. For example, the target code may include one or more non-operational (no-op) instructions, e.g., which may be configured to maintain a first variable live such that a value, e.g., a live value, of the first variable is available in a register of the target processor at the first execution cycle and the third execution cycle. For example, the target code may include a first instruction applied to the value, e.g., the live value, of the first variable in the register at the first execution cycle, a second instruction applied to a value of a second variable in the register at the second execution cycle, and / or a third instruction applied to the value, e.g., the live value, of the first variable in the register at the third execution cycle. For example, compiler 160 (FIG. 1 ) may be configured to generate target code 115 including one or more non-operation instructions, as described above.In some example aspects, as indicated in block 504, the method may include outputting the target code. - For example, compiler 160 (FIG. 1 ) may be configured to output the target code 115 (FIG. 1 ), e.g., as described above.Reference is made to FIG. 6, which schematically illustrates a product of manufacture 600 in accordance with some example aspects. Product 600 may include one or more tangible computer readable ("machine readable") non-transitory storage media 602 that may contain computer executable instructions, e.g., implemented by logic 604, which, when executed by at least one computer processor, enables the at least one computer processor to implement one or more operations on device 102 (FIG. 1 ), server 170 (FIG. 1 ), and / or compiler 160 (FIG. 1 ), to cause device 102 (FIG. 1 ), server 170 (FIG. 1 ), and / or compiler 160 (FIG. 1 ) to perform, trigger, and / or implement one or more operations and / or functionalities, and / or to perform one or more operations and / or functionalities, These are described with reference to FIGS. 1-5, and / or to perform, trigger, and / or implement one or more operations described herein. The terms "non-transitory machine readable medium" and "computer readable non-transitory storage medium" may be construed to include all computer readable media, with the only exception of a transitory transmitted signal.In some example aspects, the product 600 and / or the machine readable storage medium 602 may include one or more types of computer readable storage media capable of storing data including volatile memory, non-volatile memory, removable or non-removable memory, erasable or non-erasable memory, writable or rewritable memory, and the like. For example, machine readable storage media 602 may include RAM, DRAM, double data rate DRAM (DDR DRAM), SDRAM, static RAM (SRAM), ROM, programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory (e.g., NOR or NAND flash memory), content addressable memory (CAM), polymer memory, phase change memory, ferroelectric memory, silicon oxide nitride oxide silicon memory (SONOS), a disk, a hard disk, and the like. The computer readable storage medium may include any suitable medium that is involved in the download or transfer of a computer program from a remote computer to a requesting computer transmitted by data signals embodied in a carrier wave or other propagation medium over a communication link, e.g., a modem, a radio or network link.In some example aspects, logic 604 may include instructions, data, and / or code that, when executed by a machine, may cause the machine to perform a method, process, and / or operations as described herein. The machine may include, for example, any suitable processing platform, computing platform, computing unit, processing unit, computer system, processing system, computer, processor, or the like, and may be implemented using any suitable combination of hardware, software, firmware, and the like.In some example aspects, logic 604 may include, or be implemented as, software, a software module, an application, a program, a subroutine, instructions, an instruction set, a computational code, words, values, symbols, and the like. The instructions may include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like. The instructions may be implemented according to a predefined computer language, type, or syntax to instruct a processor to perform a particular function. The instructions may be implemented using any suitable high-level, low-level, object-oriented, visual, compiled and / or interpreted programming language, machine code, and the like.EXAMPLESThe following examples are directed to further aspects.Example 1 includes a product comprising one or more tangible computer-readable non-transitory storage media comprising computer-executable instructions that, when executed by at least one computer processor, enable the at least one computer processor to cause a compiler to compile source code into target code, the target code configured for execution by a target processor in a plurality of execution cycles comprising a first execution cycle, a second execution cycle after the first execution cycle, and a third execution cycle after the second execution cycle, the target code comprising one or more non-operational (no-op) instructions configured to maintain a first variable live such that a value of the first variable is to be available in a register of the target processor in the first execution cycle and in the third execution cycle, wherein the target code comprises a first instruction to be applied to the value of the first variable in the register in the first execution cycle, a second instruction to be applied to a value of a second variable in the register in the second execution cycle, and a third instruction to be applied to the value of the first variable in the register in the third execution cycle; and outputting the target code.Example 2 includes the subject matter of Example 1, and optionally, wherein the one or more non-transitory instructions are configured to cause the target processor to apply to the value of the first variable one or more transitory operations configured to maintain the value of the first variable unchanged between the first execution cycle and the third execution cycle.Example 3 includes the subject matter of Example 1 or 2, and optionally, wherein the one or more instructions are configured without action to cause a computing device of the target processor to temporarily maintain the value of the first variable internally in the computing device between the first execution cycle and the third execution cycle.Example 4 includes the subject matter of any of Examples 1-3, and optionally, wherein the one or more instructions are configured without operation to cause a computing device of the target processor to initiate loading of the value of the first variable from the register at the first execution cycle and initiate storing of the value of the first variable in the register at a later execution cycle prior to the third execution cycle.Example 5 includes the subject matter of any one of Examples 1 to 4, and optionally, wherein the one or more non-operation instructions comprises a plurality of non-operation instructions comprising a first non-operation in-order instruction and a last non-operation in-order instruction, wherein the first non-operation instruction is configured to cause a computing device of the target processor to load the value of the first variable from the register at the first execution cycle and apply to the value of the first variable a first non-operation in-order operation configured to maintain the value of the first variable unchanged, wherein the non-operation last in-order instruction is configured to cause the computing device of the target processor to apply to an output of a previous non-operation in-order instruction configured to:, maintaining the value of the first variable unchanged, and storing the value of the first variable in the register.Example 6 includes the subject matter of any of Examples 1-5, and optionally wherein the target code is configured such that execution of a last non-operational instruction is initiated by a computing device of the processor in a last non-operational execution cycle prior to the third execution cycle, wherein a distance between the last non-operational execution cycle and the third execution cycle is based on a latency of the computing device.Example 7 includes the subject matter of any of Examples 1-6, and optionally, wherein the instructions, when executed, cause the compiler to configure the one or more instructions without action based on a latency of a computing device of the target processor.Example 8 includes the subject matter of any of Examples 1-7, and optionally, wherein the target code is configured such that the first instruction is to be executed by a first computing device of the target processor and the one or more instructions are to be executed without operation by a second computing device of the target processor.Example 9 includes the subject matter of Example 8, and optionally, wherein the target code is configured to initiate execution of a first non-operational instruction of the one or more non-operational instructions by the second computing device at the first execution cycle.Example 10 includes the subject matter of Example 8 or 9, and optionally, wherein the destination code is configured such that the second instruction is to be executed by the second computing device.Example 11 includes the subject matter of any of Examples 8-10, and optionally, wherein the destination code is configured to execute the third instruction by the first computing device.Example 12 includes the subject matter of any of Examples 8-11, and optionally, wherein the first computing device comprises a first arithmetic logic unit (ALU) and the second computing device comprises a second ALU.Example 13 includes the subject matter of any of Examples 1-12, and optionally, wherein the instructions, when executed, cause the compiler to identify a plurality of live ranges corresponding to a corresponding plurality of variables based on the source code, and identify, as the first variable, an identified variable that includes a live range having one or more unused execution cycles in which the identified variable is not used.Example 14 includes the subject matter of Example 13, and optionally, wherein the instructions, when executed, cause the compiler to identify the identified variable as the first variable based on a determination that a number of consecutive unused execution cycles in the live range of the identified variable is greater than a predefined threshold.Example 15 includes the subject matter of Example 13 or 14, and optionally, wherein the instructions, when executed, cause the compiler to configure the one or more instructions without operation such that the first variable is maintained live during the one or more unused execution cycles.Example 16 includes the subject matter of any of Examples 13 to 15, and optionally, wherein the instructions, when executed, cause the compiler to assign the register to store the value of the second variable in an unused execution cycle of the one or more unused execution cycles.Example 17 includes the subject matter of any of Examples 1-16, and optionally, wherein the one or more instructions comprise, without action, at least one of the following instructions: a zero add instruction, a zero shift instruction, or a one multiply instruction.Example 18 includes the subject matter of any of Examples 1-17, and optionally, wherein the source code comprises open computing language (OpenCL) code.Example 19 includes the subject matter of any of Examples 1-18, and optionally, wherein the instructions, when executed, cause the compiler to compile the source code into the target code according to a low level virtual machine (LLVM)-based (LLVM-based) compilation scheme.Example 20 includes the subject matter of any of Examples 1-19, and optionally, wherein the target code is configured for execution by a very long instruction word (VLIW SIMD) target processor.Example 21 includes the subject matter of any one of Examples 1 to 20, and optionally, wherein the destination code is configured for execution by a destination vector processor.Example 22 includes a compiler configured to perform any of the described operations of any of Examples 1 to 21.Example 23 includes a computing unit configured to perform any of the described operations of any of Examples 1 to 21.Example 24 includes a computer system comprising at least one memory to store instructions and at least one processor to fetch instructions from the memory and execute the instructions to cause the computer system to perform any of the described operations of any of Examples 1 to 21.Example 25 includes a computer system comprising a compiler for generating target code according to any of the described acts of any of Examples 1 to 21, and a processor for executing the target code.Example 26 includes an apparatus comprising means for performing any of the described operations of any of Examples 1 to 21.Example 27 includes an apparatus comprising: a memory interface; and processing circuitry configured to perform any of the described operations of any of Examples 1 to 21.Example 28 includes a method including any of the described acts of any of Examples 1 to 21.Functions, acts, components, and / or features described herein with reference to one or more aspects may be combined with or used in combination with one or more other functions, acts, components, and / or features described herein with reference to one or more other aspects, or vice versa.While certain features have been illustrated and described herein, many modifications, substitutions, alterations, and equivalents may occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all modifications and changes which come within the true spirit of the disclosure.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedUS 63 / 415,303

[0001]

Claims

A product comprising one or more tangible computer-readable non-transitory storage media comprising computer-executable instructions that, when executed by at least one processor, enable the at least one processor to cause a compiler to: compile source code into target code, wherein the target code is configured for execution by a target processor in a plurality of execution cycles comprising a first execution cycle, a second execution cycle after the first execution cycle, and a third execution cycle after the second execution cycle, wherein the target code comprises one or more non-operational (no-op) instructions configured to keep a first variable live such that a value of the first variable is to be available in a register of the target processor in the first execution cycle and in the third execution cycle, wherein the target code comprises a first instruction to be applied to the value of the first variable in the register in the first execution cycle, a second instruction to be applied to a value of a second variable in the register in the second execution cycle, and a third instruction to be applied to the value of the first variable in the register in the third execution cycle; and outputting the target code.The product of claim 1, wherein the one or more non-operational instructions are configured to cause the target processor to apply to the value of the first variable one or more operations configured to maintain the value of the first variable unchanged between the first execution cycle and the third execution cycle.The product of claim 1, wherein the one or more instructions are configured without operation to cause a computing device of the target processor to temporarily maintain the value of the first variable internally in the computing device between the first execution cycle and the third execution cycle.The product of claim 1, wherein the one or more non-operational instructions are configured to cause a computing device of the target processor to initiate loading of the value of the first variable from the register at the first execution cycle and initiate storage of the value of the first variable in the register at a later execution cycle prior to the third execution cycle.The product of claim 1, wherein the one or more non-acting instructions comprise a plurality of non-acting instructions comprising a first non-acting in order instruction and a last non-acting in order instruction, wherein the first non-acting in order instruction is configured to cause a computing device of the target processor to load the value of the first variable from the register on the first execution cycle and apply to the value of the first variable a first non-acting in order configured to maintain the value of the first variable unchanged, wherein the last non-acting in order instruction is configured to cause the computing device of the target processor to apply to an output of a previous non-acting instruction a last non-acting in order configured to:, maintaining the value of the first variable unchanged, and storing the value of the first variable in the register.The product of claim 1, wherein the target code is configured such that execution of a last non-act instruction in the order of the one or more non-act instructions is initiated by a computing device of the processor in a last non-act execution cycle in the order before the third execution cycle, wherein a distance between the last non-act execution cycle and the third execution cycle is based on a latency of the computing device.The product of claim 1, wherein the instructions, when executed, cause the compiler to configure the one or more instructions without action based on a latency of a computing device of the target processor.The product of claim 1, wherein the target code is configured such that the first instruction is to be executed by a first computing device of the target processor and the one or more instructions are to be executed by a second computing device of the target processor without operation.The product of claim 8, wherein the target code is configured such that execution of a first non-operational instruction is to be initiated by the second computing device at the first execution cycle in the order of the one or more non-operational instructions.The product of claim 8, wherein the target code is configured such that the second instruction is to be executed by the second computing device.The product of claim 8, wherein the target code is configured such that the third instruction is to be executed by the first computing device.The product of claim 8, wherein the first data processing unit comprises a first arithmetic logic unit (ALU) and the second data processing unit comprises a second ALU.The product of any of claims 1 to 12, wherein the instructions, when executed, cause the compiler to identify a plurality of live ranges corresponding to a respective plurality of variables based on the source code and identify, as the first variable, an identified variable having a live range that includes one or more unused execution cycles in which the identified variable is not used.The product of claim 13, wherein the instructions, when executed, cause the compiler to identify the identified variable as a first variable based on determining that a count of consecutive unused execution cycles in the live range of the identified variable is greater than a predefined threshold.The product of claim 13, wherein the instructions, when executed, cause the compiler to configure the one or more instructions without action such that the first variable is maintained live during the one or more unused execution cycles.The product of claim 13, wherein the instructions, when executed, cause the compiler to assign the register to store the value of the second variable in an unused execution cycle of the one or more unused execution cycles.The product of any of claims 1 to 12, wherein the one or more non-acting instructions comprise at least one of the following instructions: a zero add instruction, a zero shift instruction, or a one multiply instruction.The product of any of claims 1 to 12, wherein the source code comprises open computing language (OpenCL) code.The product of any of claims 1 to 12, wherein the instructions, when executed, cause the compiler to compile the source code into the target code according to a low level virtual machine (LLVM)-based (LLVM-based) compilation scheme.The product of any of claims 1 to 12, wherein the target code is configured for execution by a very long instruction word single instruction / multiple data (VLIW SIMD) target processor.The product of any of claims 1 to 12, wherein the destination code is configured for execution by a destination vector processor.A computer system comprising: at least one memory for storing instructions; and at least one processor for retrieving the instructions from the memory and executing the instructions to cause the computer system to: compile source code into target code, the target code configured for execution by a target processor in a plurality of execution cycles comprising a first execution cycle, a second execution cycle after the first execution cycle, and a third execution cycle after the second execution cycle, the target code comprising one or more non-operational (no-op) instructions configured to keep a first variable live such that a value of the first variable is to be available in a register of the target processor in the first execution cycle and the third execution cycle, the target code comprising a first instruction, which is to be applied to the value of the first variable in the register in the first execution cycle, comprises a second instruction to be applied to a value of a second variable in the register in the second execution cycle, and a third instruction to be applied to the value of the first variable in the register in the third execution cycle; and outputting the target code.The computer system of claim 22, wherein the one or more non-operational instructions are configured to cause the target processor to apply to the value of the first variable one or more operations configured to maintain the value of the first variable unchanged between the first execution cycle and the third execution cycle.The computer system of claim 22, wherein the one or more non-transitory instructions are configured to cause a computing device of the target processor to initiate the loading of the value of the first variable from the register at the first execution cycle and initiate the storing of the value of the first variable in the register at a later execution cycle prior to the third execution cycle.The computer system of claim 22, comprising the destination processor.A method comprising: compiling source code into target code, the target code configured for execution by a target processor in a plurality of execution cycles comprising a first execution cycle, a second execution cycle after the first execution cycle, and a third execution cycle after the second execution cycle, the target code comprising one or more non-operational (no-op) instructions configured to live a first variable such that a value of the first variable is to be available in a register of the target processor at the first execution cycle and at the third execution cycle, wherein the target code comprises a first instruction to be applied to the value of the first variable in the register at the first execution cycle, a second instruction to be applied to a value of a second variable in the register at the second execution cycle, and a third instruction to be applied to the value of the first variable in the register in the third execution cycle; and outputting the target code.The method of claim 26, wherein the one or more non-acting instructions comprise at least one of the following instructions: a zero add instruction, a zero shift instruction, or a one multiply instruction.

Images