Compute pipeline compile fails with "Compiler encountered an internal error."

[squidbus]

The below compute shader and pipeline are producing the following error from vkCreateComputePipelines:

[mvk-error] VK_ERROR_INITIALIZATION_FAILED: Compute pipeline compile failed (Error code 3):
Compiler encountered an internal error.

The crash report for MTLCompilerService says the following:

unable to legalize instruction: %62:_(s32), %63:_(s1) = 145 %59:_, %55:_
Context:
%62:_(s32), %63:_(s1) = 145 %59:_, %55:_
%59:_(s32) = 181 %58:_(s32)
%55:_(s32) = 90 %57:_(p64) :: (dereferenceable load (s32) from `i32 addrspace(64)* bitcast (i8 addrspace(64)* getelementptr inbounds ([28 x i8], [28 x i8] addrspace(64)* @memorycache0, i32 0, i32 8) to i32 addrspace(64)*)`, !tbaa !50, !alias.scope !54, !noalias !61, addrspace 64)
%58:_(s32) = 19 $r10
%57:_(p64) = 193 %7:_, %17:_(s64)
%7:_(p64) = 71 @memorycache0
%17:_(s64) = 120 i64 8
(in function: agc.main)

Compute shader (SPIR-V and generated MSL included): https://gist.github.com/squidbus/50273067f4bd89752473c04683524a93

Pipeline:

• Push Descriptor Layout:
  • Uniform Buffer at Binding 0
  • Uniform Texel Buffer at Binding 1
  • Storage Image at Binding 2
• Push Constants: Offset = 0, Size = 104

System: M3 Max w/ macOS 15.1 Beta 5 (and macOS 15)

This seems to be coming from the last line with the image write, as if I replace the coordinates argument with a fixed zero vector it compiles.

Note that there is no error if I use the command line shader compiler, only when compiling a pipeline at runtime.

I have a feeling this may be triggering a Metal compiler bug, but I felt it would be worth reporting here for a look, in case it could be worked around in the SPIR-V to Metal translation for better compatibility.

[cdavis5e]

This is a Metal compiler bug--more specifically, a bug in the AGX backend. I can't see anything wrong with the generated code.

This needs to be reported upstream to Apple. In the meantime, if you want a workaround in SPIRV-Cross, this issue should probably be filed there.

[squidbus]

Okay, I've reported this to SPIRV-Cross as well here: KhronosGroup/SPIRV-Cross#2385

I will try to report to Apple but I'm not sure how much traction feedback reports get.