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1. Intel® FPGA SDK for OpenCL™ Overview 2. Intel® FPGA SDK for OpenCL™ Offline Compiler Kernel Compilation Flows 3. Obtaining General Information on Software, Compiler, and Custom Platform 4. Managing an FPGA Board 5. Structuring Your OpenCL Kernel 6. Designing Your Host Application 7. Compiling Your OpenCL Kernel 8. Emulating and Debugging Your OpenCL Kernel 9. Developing OpenCL Applications Using Third-party IDEs 10. Developing OpenCL™ Applications Using Intel® Code Builder for OpenCL™ 11. Intel® FPGA SDK for OpenCL™ Advanced Features A. Support Statuses of OpenCL Features B. Intel FPGA SDK for OpenCL Pro Edition Programming Guide Archives C. Document Revision History of the Intel® FPGA SDK for OpenCL™ Pro Edition Programming Guide
3.1. Displaying the Software Version (version) 3.2. Displaying the Compiler Version (-version) 3.3. Listing the Intel® FPGA SDK for OpenCL™ Utility Command Options (help) 3.4. Listing the Intel® FPGA SDK for OpenCL™ Offline Compiler Command Options (no argument, -help, or -h) 3.5. Listing the Available FPGA Boards and Custom Platforms (-list-boards and -list-board-packages) 3.6. Displaying the Compilation Environment of an OpenCL Binary (env)
4.1. Installing an FPGA Board (install) 4.2. Uninstalling an FPGA Board (uninstall) 4.3. Querying the Device Name of Your FPGA Board (diagnose) 4.4. Running a Board Diagnostic Test (diagnose <device_name>) 4.5. Programming the FPGA Offline or without a Host (program <device_name>) 4.6. Programming the Flash Memory (flash <device_name>)
5.1. Guidelines for Naming the Kernel 5.2. Programming Strategies for Optimizing Data Processing Efficiency 5.3. Programming Strategies for Optimizing Pointer-to-Local Memory Size 5.4. Implementing the Intel® FPGA SDK for OpenCL™ Channels Extension 5.5. Implementing OpenCL Pipes 5.6. Implementing Arbitrary Precision Integers 5.7. Using Predefined Preprocessor Macros in Conditional Compilation 5.8. Declaring __constant Address Space Qualifiers 5.9. Including Structure Data Types as Arguments in OpenCL Kernels 5.10. Inferring a Register 5.11. Enabling Double Precision Floating-Point Operations 5.12. Single-Cycle Floating-Point Accumulator for Single Work-Item Kernels 5.13. Integer Promotion Rules
5.2.1. Unrolling a Loop (unroll Pragma) 5.2.2. Disabling Pipelining of a Loop (disable_loop_pipelining Pragma) 5.2.3. Coalescing Nested Loops 5.2.4. Fusing Adjacent Loops (loop_fuse Pragma) 5.2.5. Marking Loops to Prevent Automatic Fusion (nofusion Pragma) 5.2.6. Specifying a Loop Initiation interval (II) 5.2.7. Loop Concurrency (max_concurrency Pragma) 5.2.8. Loop Speculation (speculated_iterations Pragma) 5.2.9. Loop Interleaving Control (max_interleaving Pragma) 5.2.10. Floating Point Optimizations (fp contract and fp reassociate Pragma) 5.2.11. Specifying Work-Group Sizes 5.2.12. Specifying Number of Compute Units 5.2.13. Specifying Number of SIMD Work-Items 5.2.14. Specifying the private_copies Memory Attribute 5.2.15. Specifying the use_stall_enable_clusters Cluster-control Attribute
5.4.1. Overview of the Intel® FPGA SDK for OpenCL™ Channels Extension 5.4.2. Channel Data Behavior 5.4.3. Multiple Work-Item Ordering for Channels 5.4.4. Restrictions in the Implementation of Intel® FPGA SDK for OpenCL™ Channels Extension 5.4.5. Enabling the Intel® FPGA SDK for OpenCL™ Channels for OpenCL Kernel
220.127.116.11. Declaring the Channel Handle 18.104.22.168. Implementing Blocking Channel Writes 22.214.171.124. Implementing Blocking Channel Reads 126.96.36.199. Implementing I/O Channels Using the io Channels Attribute 188.8.131.52. Emulating I/O Channels 184.108.40.206. Use Models of Intel® FPGA SDK for OpenCL™ Channels Implementation 220.127.116.11. Implementing Buffered Channels Using the depth Channels Attribute 18.104.22.168. Enforcing the Order of Channel Calls
22.214.171.124. Ensuring Compatibility with Other OpenCL SDKs 126.96.36.199. Declaring the Pipe Handle 188.8.131.52. Implementing Pipe Writes 184.108.40.206. Implementing Pipe Reads 220.127.116.11. Implementing Buffered Pipes Using the depth Attribute 18.104.22.168. Implementing I/O Pipes Using the io Attribute 22.214.171.124. Enforcing the Order of Pipe Calls
6.1. Host Programming Requirements 6.2. Allocating OpenCL Buffers for Manual Partitioning of Global Memory 6.3. Triggering Collection Profiling Data During Kernel Execution 6.4. Accessing Custom Platform-Specific Functions 6.5. Modifying Host Program for Structure Parameter Conversion 6.6. Managing Host Application 6.7. Allocating Shared Memory for OpenCL Kernels Targeting SoCs 6.8. Sharing Multiple Devices Across Multiple Host Programs
126.96.36.199. Linking Your Host Application to the Khronos ICD Loader Library 188.8.131.52. Displaying Flags for Compiling Host Application (compile-config) 184.108.40.206. Displaying Paths to OpenCL Host Runtime and MMD Libraries (ldflags) 220.127.116.11. Listing OpenCL Host Runtime and MMD Libraries (ldlibs) 18.104.22.168. Displaying Information on OpenCL Host Runtime and MMD Libraries (link-config or linkflags)
7.1. Compiling Your Kernel to Create Hardware Configuration File 7.2. Compiling Your Kernel without Building Hardware (-c) 7.3. Compiling and Linking Your Kernels or Object Files without Building Hardware (-rtl) 7.4. Specifying the Location of Header Files (-I=<directory>) 7.5. Specifying the Name of an Intel® FPGA SDK for OpenCL™ Offline Compiler Output File (-o <filename>) 7.6. Compiling a Kernel for a Specific FPGA Board and Custom Platform (-board=<board_name>) and (-board-package=<board_package_path>) 7.7. Resolving Hardware Generation Fitting Errors during Kernel Compilation (-high-effort) 7.8. Specifying Schedule Fmax Target for Kernels (-clock=<clock_target>) 7.9. Defining Preprocessor Macros to Specify Kernel Parameters (-D<macro_name>) 7.10. Generating Compilation Progress Report (-v) 7.11. Displaying the Estimated Resource Usage Summary On-Screen (-report) 7.12. Suppressing Warning Messages from the Intel® FPGA SDK for OpenCL™ Offline Compiler (-W) 7.13. Converting Warning Messages from the Intel® FPGA SDK for OpenCL™ Offline Compiler into Error Messages (-Werror) 7.14. Removing Debug Data from Compiler Reports and Source Code from the .aocx File (-g0) 7.15. Disabling Burst-Interleaving of Global Memory (-no-interleaving=<global_memory_type>) 7.16. Forcing Ring Interconnect for Global Memory (-global-ring) 7.17. Forcing a Single Store Ring to Reduce Area at the Expense of Write Throughput to Global Memory (-force-single-store-ring) 7.18. Forcing Fewer Read Data Reorder Units to Reduce Area at the Expense of Read Throughput to Global Memory (-num-reorder) 7.19. Configuring Constant Memory Cache Size (-const-cache-bytes=<N>) 7.20. Relaxing the Order of Floating-Point Operations (-ffp-reassociate) 7.21. Reducing Floating-Point Rounding Operations (-ffp-contract=fast) 7.22. Speeding Up Your OpenCL Compilation (-fast-compile) 7.23. Compiling Your Kernel Incrementally (-incremental) 7.24. Compiling Your Kernel with Memory Error Correction Coding (-ecc) 7.25. Disabling Hardware Kernel Invocation Queue (-no-hardware-kernel-invocation-queue) 7.26. Modifying the Handshaking Protocol (-hyper-optimized-handshaking) 7.27. Pipelining Loops in Non-task Kernels (-auto-pipeline)
8.1. Setting up the Emulator 8.2. Modifying Channels Kernel Code for Emulation 8.3. Compiling a Kernel for Emulation (-march=emulator) 8.4. Emulating Your OpenCL Kernel 8.5. Debugging Your OpenCL Kernel on Linux 8.6. Limitations of the Intel® FPGA SDK for OpenCL™ Emulator 8.7. Discrepancies in Hardware and Emulator Results 8.8. Emulator Environment Variables 8.9. Extensions Supported by the Emulator 8.10. Emulator Known Issues
11.1.1. Creating Library Objects From OpenCL Code 11.1.2. Understanding RTL Modules and the OpenCL Pipeline 11.1.3. Packaging an OpenCL Helper Function File for an OpenCL Library 11.1.4. Packaging an RTL Component for an OpenCL Library 11.1.5. Verifying the RTL Modules 11.1.6. Specifying an OpenCL Library when Compiling an OpenCL Kernel 11.1.7. Debugging Your OpenCL Library Through Simulation (Preview) 11.1.8. Using an OpenCL Library that Works with Simple Functions (Example 1) 11.1.9. Using an OpenCL Library that Works with External Memory (Example 2) 11.1.10. OpenCL Library Command-Line Options
22.214.171.124. Overview: Intel FPGA SDK for OpenCL Pipeline Approach 126.96.36.199. Integration of an RTL Module into the Intel FPGA SDK for OpenCL Pipeline 188.8.131.52. Stall-Free RTL 184.108.40.206. RTL Module Interfaces 220.127.116.11. Avalon Streaming Interface 18.104.22.168. RTL Reset and Clock Signals 22.214.171.124. Object Manifest File Syntax of an RTL Module 126.96.36.199. Interaction between RTL Module and External Memory 188.8.131.52. Order of Threads Entering an RTL Module 184.108.40.206. OpenCL C Model of an RTL Module 220.127.116.11. Potential Incompatibility between RTL Modules and Partial Reconfiguration
A.1.1. OpenCL 1.0 C Programming Language Implementation A.1.2. OpenCL C Programming Language Restrictions A.1.3. Argument Types for Built-in Geometric Functions A.1.4. Numerical Compliance Implementation A.1.5. Image Addressing and Filtering Implementation A.1.6. Atomic Functions A.1.7. Embedded Profile Implementation
- 3.4. Listing the Intel® FPGA SDK for OpenCL™ Offline Compiler Command Options (no argument, -help, or -h)
- 7.5. Specifying the Name of an Intel® FPGA SDK for OpenCL™ Offline Compiler Output File (-o <filename>)
- 7.6. Compiling a Kernel for a Specific FPGA Board and Custom Platform (-board=<board_name>) and (-board-package=<board_package_path>)
- 7.13. Converting Warning Messages from the Intel® FPGA SDK for OpenCL™ Offline Compiler into Error Messages (-Werror)
- 7.17. Forcing a Single Store Ring to Reduce Area at the Expense of Write Throughput to Global Memory (-force-single-store-ring)
- 7.18. Forcing Fewer Read Data Reorder Units to Reduce Area at the Expense of Read Throughput to Global Memory (-num-reorder)
8. Emulating and Debugging Your OpenCL Kernel
The Intel® FPGA SDK for OpenCL™ Emulator assesses the functionality of your kernel.
The Intel® FPGA SDK for OpenCL™ Emulator generates a .aocx file that executes on x86-64 Windows or Linux host. This feature allows you to emulate the functionality of your kernel and iterate on your design without executing it on the actual FPGA each time. For Linux platform, you can also use the Emulator to perform functional debug.
Important: Emulation does not support cross-compilation to ARM® processor. To run emulation on a design that targets an ARM SoC device, emulate on a non-SoC board (for example, <board_package_path>/s10_ref or <board_package_path>/a10_ref). When you are satisfied with the emulation results, you may target your design on an SoC board for subsequent optimization steps.
The emulator supports 64-bit Windows and Linux operating systems. On Linux systems, the GNU C Library (glibc) version 2.15 or later is required. .
Note: You cannot use the execution time of an emulated design to estimate its execution time on an FPGA. Furthermore, running an emulated design is not a substitute for natively running a functionally equivalent C/C++ implementation on an x86-64 host.
- Setting up the Emulator
If you installed the Intel® FPGA SDK for OpenCL™ Pro edition with administrator privileges, no additional setup is needed. If you did not install the Intel® FPGA SDK for OpenCL™ with administrator privileges, you must perform some additional steps to enable the emulator.
- Modifying Channels Kernel Code for Emulation
To emulate applications with a channel that reads or writes to an I/O channel, modify your kernel to add a read or write channel that replaces the I/O channel, and make the source code that uses it is conditional.
- Compiling a Kernel for Emulation (-march=emulator)
To compile an OpenCL™ kernel for emulation, include the -march=emulator option in your aoc command.
- Emulating Your OpenCL Kernel
To emulate your OpenCL™ kernel, run the emulation .aocx file on the platform on which you built your kernel. The OpenCL Emulator uses a different OpenCL platform than when targeting FPGA hardware.
- Debugging Your OpenCL Kernel on Linux
For Linux systems, you can direct the Intel® FPGA SDK for OpenCL™ Emulator to run your OpenCL kernel in the debugger and debug it functionally as part of the host application.
- Limitations of the Intel FPGA SDK for OpenCL Emulator
The Intel® FPGA SDK for OpenCL™ Emulator feature has some limitations.
- Discrepancies in Hardware and Emulator Results
When you emulate a kernel, your OpenCL system might produce results different from that of the kernel compiled for hardware. You can further debug your kernel before you compile for hardware by running your kernel through simulation.
- Emulator Environment Variables
Several environment variables are available to modify the behavior of the emulator.
- Extensions Supported by the Emulator
The emulator offers varying levels of support for different OpenCL extensions.
- Emulator Known Issues
A few known issues might affect your use of the emulator. Review these issues to avoid possible problems when using the emulator.
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