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James Price edited this page May 20, 2014 · 3 revisions

Program Structure

Oclgrind consists of three distinct components. The core is the SPIR interpreter/OpenCL device simulator, which can be used either via an OpenCL runtime API implementation or using a standalone kernel interface.

TODO: More implementation details

Oclgrind Core

This component lives in src/core, and produces the library oclgrind. Classes within this component are encapsulated in the oclgrind namespace. The header files defining the core classes will be installed to INSTALL_PATH/include/oclgrind/.

OpenCL Runtime API

The runtime lives in src/runtime, and produces the libraries oclgrind-rt and oclgrind-rt-icd. These libraries are almost identical; the only difference is that the -icd version adds underscores to the API functions to avoid clashing with the ICD loader. On Unix systems, an oclgrind script is also generated that uses LD_PRELOAD/DYLD_INSERT_LIBRARIES to force an application to run with Oclgrind (rather than the ICD or an alternative implementation).

Kernel Interface

This component lives in src/kernel, and produces the binary oclgrind-kernel.

Build Systems

There are two build systems used in Oclgrind: autotools and CMake.

Clang/SPIR Generator

At present, Oclgrind has only been tested with patched version of Clang 3.2 that compiles OpenCL C to SPIR, released by the Khronos Group. In the future, the intention is to modify Oclgrind to build with newer versions of LLVM that support SPIR generation out-of-the-box.

Precompiled Headers

During installation, Clang is used to generate a precompiled header for clc.h. This greatly improves compilation times when providing OpenCL C source code to Oclgrind.

Tests

TODO: Details about adding new tests

There are three categories of tests:

  • tests/kernels - tests for kernel language functionality (using oclgrind-kernel)
  • tests/runtime - tests for the OpenCL runtime API
  • tests/apps - full applications that test general functionality

The tests can be with the commands make check (autotools) or make test (CMake). With Visual Studio a RUN_TESTS project will be generated that will run the tests.

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