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5443602d89
Release 13.4 of the CUDA Samples supported by CUDA Toolkit 13.4. See Changelog for more information.
65 lines
2.3 KiB
Markdown
65 lines
2.3 KiB
Markdown
Introduction
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============
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This sample demonstrates linking a libnvvm-generated module with an existing
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CUDA C library. The LLVM C++ API is used to generate an LLVM IR module that
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conforms to the NVVM IR specification and contains a call to an externally-
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defined function, and this module is compiled to PTX with libnvvm. The JIT
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linker (part of the CUDA Driver API) is then used to assemble the PTX and link
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it with the math library, creating a linked CUBIN image. This image is then
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executed on the first CUDA device on the system.
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Files
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-----
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- cuda-c-linking.cpp - Main source file demonstrating the generated of a
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PTX file using libnvvm and linking it with a CUDA C
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device library
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- math-funcs - CUDA C device library source file
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- CMakeLists.txt - CMake build script
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Building
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--------
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This sample is optionally built as part of the libnvvm samples from the CUDA
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samples tree. Please see the README file at the root of the libnvvm samples
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for build instructions.
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It requires the LLVM development headers and libraries, version 7 or newer.
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LLVM 15 and newer emit opaque pointers, which libNVVM accepts only for
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Blackwell and later architectures, so such a build cannot run on an older GPU:
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$ ./cuda-c-linking
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Using CUDA Device [0]: NVIDIA L4
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Device Compute Capability: 8.9
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This sample was built against LLVM 18, which emits opaque pointers, but
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libNVVM accepts only LLVM 7 IR for compute_89. Build against LLVM 14 or
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older to run on this device, or run on a Blackwell or later device.
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The sample exits with code 2 in that case, reporting an unmet requirement
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rather than a failure. Building against LLVM 7 to 14 produces a binary that
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runs on any device this sample supports.
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Usage
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-----
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Once built, the sample can be executed by running the "cuda-c-linking" binary.
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Linux:
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$ cd $SAMPLES_INSTALL_DIR
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$ ./cuda-c-linking
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Windows:
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$ cd %SAMPLES_INSTALL_DIR%
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$ cuda-c-linking.exe
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For inspection purposes, the following command-line options are available:
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- -save-ptx - Write generated PTX kernel to cuda-c-linking.kernel.ptx
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- -save-ir - Write generated LLVM IR to cuda-c-linking.kernel.ll
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- -save-cubin - Write linked CUBIN image to cuda-c-linking.linked.cubin
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