Using glslc to compile a shader containing atomicAdd causes a bug

[JonathanWoollett-Light]

I discovered a bug which lead any shader using atomicAdd to be unable to compile from SPIR-V when using wgpu-rs (gfx-rs/wgpu-rs#564).

Eventually after using SPIRV-Tools-master-windows-x64-Release\bin\spirv-val.exe (from https://github.com/KhronosGroup/SPIRV-Tools) to check the .spv file and it producing:

C:\Users\jonat>C:\Users\jonat\Desktop\SPIRV-Tools-master-windows-x64-Release\bin\spirv-val.exe C:\Users\jonat\Projects\test-project\spir-v\atomicArraySum.spv
error: line 8: Invalid capability operand: 6033
error: line 8: Invalid capability operand: 6033

It was suggested (gfx-rs/wgpu-rs#564 (comment)) the bug likely originates from an error in the tool used to compile the GLSL to SPIR-V (C:/VulkanSDK/1.2.148.1/Bin/glslc).

Since I beleive this is the repo for glslc I thought it best to open this issue here.

Comment from the issue which contains link to test project (importantly the GLSL .comp file and resultant SPIR-V .spv file): gfx-rs/wgpu-rs#564 (comment)

Compilation of the GLSL to SPIR-V has been done by running:

C:/VulkanSDK/1.2.148.1/Bin/glslc C:/Users/jonat/Projects/test-project/glsl/atomicArraySum.comp -o C:/Users/jonat/Projects/test-project/spir-v/atomicArraySum.spv --target-env=vulkan1.0

(--target-env=vulkan1.1 has also been tried)

There is a bunch of info in the original issue (gfx-rs/wgpu-rs#564), but I would recommend reading from the bottom up since it is quite long and the stuff near the bottom is most relevant.

I also considered opening an issue in the https://github.com/KhronosGroup/glslang repo but decided against it for now.

[zoddicus]

Running on ToT checkouts of shaderc and spirv-tools I am unable to reproduce this on Linux.

The specific error you are seeing appears to be for a relatively new extension, so I suspect there is a version issue somewhere along the way, i.e. some tools have support for this extension and others do not.

I am not sure if there is much for shaderc to do, but I am going to send this over to dneto@ since he is more familiar with package/release process for the ecosystem, so might have some thoughts.

[dneto0]

I agree with @zoddicus

Your copy of spirv-val is old. It was built without support for SPV_EXT_shader_atomic_float_add, and so it doesn't know about OpCapability AtomicFloat32AddEXT

spirv-val comes from the SPIRV-Tools project. If you built SPIRV-Tools locally, be sure to rebuild it with an updated copy of SPIRV-Headers, as that is where it gets most of its information about the set of valid tokens (and extensions).