Naga generates HLSL that makes DXC crash

[jimblandy]

The HLSL that Naga generates for data97.wgsl (extracted from the Bevy WebGPU demos) in the attached .zip file causes DXC to crash.

$ naga data97.wgsl bad.hlsl
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.14s
     Running `/home/jimb/rust/wgpu/target/debug/naga data97.wgsl bad.hlsl`
$ ~/DirectXShaderCompiler/build/bin/dxc -Wno-parentheses-equality -Zi -Qembed_debug -Od -HV 2018 -T cs_6_7 -E main bad.hlsl 
Error: assert()
File:
(0)
Func:	
Illegal instruction (core dumped)
$ 

naga-crashes-dxc.zip

[jimblandy]

I'm using DXC built from https://github.com/FirefoxGraphics/DirectXShaderCompiler/tree/moz-1.8.2502

[jimblandy]

The following HLSL makes that DXC crash:

void main()
{
    int i = asuint(int(1));
}

[jimblandy]

Upstream: microsoft/DirectXShaderCompiler#7395

[jimblandy]

This issue has been fixed in the branch of DXC that Firefox ships, so this is no longer a P1 for Mozilla. However, until
microsoft/DirectXShaderCompiler#7396 is merged it makes sense to leave this issue open for the wider wgpu community.