Issue generating SPIR-V from "BC from generated OpenCL C++ kernel".. about spirv-llvm-translator HOT 2 CLOSED

Hi @oscarbg,

./llvm-spirv clpp.bc clppspir.spv

You need to use:

./llvm-spirv clcpp.bc -o clppspir.spv
# or
./llvm-spirv clcpp.bc # to get clcpp.spv file

Offline compilation into SPIR-V or device binary

• Generates SPIR-V 1.0 for most features
• Uses SPIR-V 1.2 where necessary

From personal experience, I would say it generates not only SPIR-V 1.0 in some cases. For example, if you have functions which accept arguments by reference in your OpenCL C++ code, SPIRV-LLVM-Translator will generate some additional decorations and will generate SPIR-V 1.1 binary.

can share when SPIR-V 1.2 instead of SPIR-V 1.0 is needed?

I'm not sure that there is some well-documented list of OpenCL C++ features that requires SPIR-V 1.2 instead of SPIR-V 1.0, but at least you can take a look at spec changelog to find some information.

also some additional argument to llmv-spirv or clang compilation steps is needed in such cases?

If I understand correctly, SPIRV-LLVM-Translator automatically selects resulting version based on features used in input file.

Unfortunately, there are no options to force min/max or required version of the resulting SPIR-V file. And that leads to a "hacks" like this one - this options allows you to generate SPIR-V 1.0 even if source code contains functions which accept arguments by reference.

from spirv-llvm-translator.

Hi @AlexeySachkov ,
many thanks for very informative answer!
now that I can generate SPIR-V binaries I will play a little with it..

from spirv-llvm-translator.