Slang generates not spec compliant sequence of NonSemantic.DebugInfo instructions

[kleints]

For very long shaders, when the source strings are split up in DebugSource and DebugSourceContinued, Slang produces a sequence of instructions that is not following the spec for DebugSourceContinued. That says: "The previous instruction must be a DebugSource or DebugSourceContinued instruction.". However, for the first DebugSource/DebugSourceContinued the DebugCompilationUnit instruction is interleaved.

For example:
%4 = OpExtInst %void %2 DebugSource %5 %1
%10 = OpExtInst %void %2 DebugCompilationUnit %uint_100 %uint_5 %4 %uint_11
%51 = OpExtInst %void %2 DebugSourceContinued %50
%53 = OpExtInst %void %2 DebugSourceContinued %52
%67 = OpExtInst %void %2 DebugSourceContinued %66

[csyonghe]

I tried this with a simple shader and unable to reproduce the interleaving. The interleaving could have been introduced by spirv-opt instead of slang. Have you tried -O0 to disable spirv-opt?

[csyonghe]

We will need a reproducer to proceed with this issue.

[cheneym2]

I filed a Khronos issue with a minimal repro: KhronosGroup/SPIRV-Tools#5950

[csyonghe]

We should try a top of tree build of spirv-opt and see if that addresses the issue.

[cheneym2]

The release I used is only days old. 1.4.304.0 from 1/13/2025

[cheneym2]

Oh, my mistake. While the SDK is from 1/13/2025, the Spirv-tools binaries are from 12/5/2024, so there is a bigger gap, and in fact the change that fixed this issue was identified as one that was submitted on 12/13/2024.

[cheneym2]

Confirmed it is fixed at TOT

[cheneym2]

Update slang to use newer spirv-tools: #6145