Intel® FPGA SDK for OpenCL™ Pro Edition: Programming Guide

ID 683846
Date 12/19/2022
Public
Document Table of Contents
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8.6. Limitations of the Intel® FPGA SDK for OpenCL™ Emulator

The Intel® FPGA SDK for OpenCL™ Emulator feature has some limitations.
  • Execution model

    The Emulator supports the same compilation modes as the FPGA variant. As a result, you must call the clCreateProgramBinary function to create cl_program objects for emulation.

  • Concurrent execution

    Modeling of concurrent kernel executions has limitations. During execution, the Emulator does not actually run interacting work-items in parallel. Therefore, some concurrent execution behaviors, such as different kernels accessing global memory without a barrier for synchronization, might generate inconsistent emulation results between executions.

  • Same address space execution

    The Emulator executes the host runtime and the kernels in the same address space. Certain pointer or array usages in your host application might cause the kernel program to fail, and vice versa. Example usages include indexing external allocated memory and writing to random pointers. You may use memory leak detection tools such as Valgrind to analyze your program. However, the host might encounter a fatal error caused by out-of-bounds write operations in your kernel, and vice versa.

  • Conditional channel operations

    Emulation of channel behavior has limitations, especially for conditional channel operations where the kernel does not call the channel operation in every loop iteration. In these cases, the Emulator might execute channel operations in a different order than on the hardware.

  • GCC version

    Emulator host programs on Linux* must be run with a version of libstdc++.so from GCC 7.2.0 or later. This can be achieved either by installing GCC 7.2.0 or later on your system, or setting the LD_LIBRARY_PATH environment variable such that a compatible libstdc++.so is identified.