Using Texture2D<bool*>.Load results in validation errors with both DXIL and SPIR-V backends (not with FXC)

[Dredhog]

Title

Using Texture2D<bool*>.Load results in validation errors with both DXIL and SPIR-V backends (not with FXC)

Functional impact

Cannot use bool typed textures. Breaks compatibility with FXC.

Minimal repro steps

1. Compile the following shader with dxc.exe -T ps_6_0 -E PSMain issue_shader.txt:

Texture2D<bool> myTex;
float4 PSMain() : SV_Target0 {
    bool temp = myTex.Load(int3(0,0,0)).r;
    
    if(temp)
        return float4(1, 1, 1, 1);
    else
    	return float4(0, 0, 0, 0);
}

2. Observe compiler output for the DXIL backend:

error: validation errors
Invalid resource return type''

Validation failed.

3. Compile the same shader for the SPIR-V by adding the -spirv flag dxc.exe -T ps_6_0 -E PSMain -spirv issue_shader.txt and observe the compiler output:

fatal error: generated SPIR-V is invalid: Expected Sampled Type to be a 32-bit int or float scalar type for Vulkan environment
  %type_2d_image = OpTypeImage %bool 2D 2 0 0 1 Unknown

note: please file a bug report on https://github.com/Microsoft/DirectXShaderCompiler/issues with source code if possible

Expected result

Validation/compilation succeeds.

Actual result

Validation/compilation fails when targeting either DXIL or SPIR-V

Further technical details

Note: the same happens when using bool2, bool3 or bool4 as the Texture2D template argument. For convenience, here's the link to the original example on shader-playground.

[ehsannas]

To track progress of DXIL and SPIR-V separately, I have filed #3236 for the SPIR-V side.

This issue can track the fix for DXIL.