Unsupported instruction AtomicExchange at Function

[Jorge Cantón]

I am trying to translate from Spirv to WGSL using Naga

First, I started with the following HLSL:

RWStructuredBuffer<uint1> data: register(u1);

[numthreads(128, 1, 1)]
void csSimpleTest(uint3 ID : SV_GroupThreadID, uint3 GP : SV_GroupID)  
{
                uint1 index = GP.x*100+ID.x;
                uint originalValue;
                InterlockedExchange(data[index].x, 1, originalValue);                        
}

I used the DirectX compiler to translate this HLSL to Spirv (spirv-dis to disassemble it)

; SPIR-V
; Version: 1.0
; Generator: Google spiregg; 0
; Bound: 28
; Schema: 0
               OpCapability Shader
               OpMemoryModel Logical GLSL450
               OpEntryPoint GLCompute %csSimpleTest "csSimpleTest" %gl_LocalInvocationID %gl_WorkGroupID
               OpExecutionMode %csSimpleTest LocalSize 128 1 1
               OpSource HLSL 600
               OpName %type_RWStructuredBuffer_uint "type.RWStructuredBuffer.uint"
               OpName %data "data"
               OpName %csSimpleTest "csSimpleTest"
               OpDecorate %gl_LocalInvocationID BuiltIn LocalInvocationId
               OpDecorate %gl_WorkGroupID BuiltIn WorkgroupId
               OpDecorate %data DescriptorSet 0
               OpDecorate %data Binding 1
               OpDecorate %_runtimearr_uint ArrayStride 4
               OpMemberDecorate %type_RWStructuredBuffer_uint 0 Offset 0
               OpDecorate %type_RWStructuredBuffer_uint BufferBlock
        %int = OpTypeInt 32 1
      %int_0 = OpConstant %int 0
       %uint = OpTypeInt 32 0
   %uint_100 = OpConstant %uint 100
     %uint_0 = OpConstant %uint 0
     %uint_1 = OpConstant %uint 1
%_runtimearr_uint = OpTypeRuntimeArray %uint
%type_RWStructuredBuffer_uint = OpTypeStruct %_runtimearr_uint
%_ptr_Uniform_type_RWStructuredBuffer_uint = OpTypePointer Uniform %type_RWStructuredBuffer_uint
     %v3uint = OpTypeVector %uint 3
%_ptr_Input_v3uint = OpTypePointer Input %v3uint
       %void = OpTypeVoid
         %17 = OpTypeFunction %void
%_ptr_Uniform_uint = OpTypePointer Uniform %uint
       %data = OpVariable %_ptr_Uniform_type_RWStructuredBuffer_uint Uniform
%gl_LocalInvocationID = OpVariable %_ptr_Input_v3uint Input
%gl_WorkGroupID = OpVariable %_ptr_Input_v3uint Input
%csSimpleTest = OpFunction %void None %17
         %19 = OpLabel
         %20 = OpLoad %v3uint %gl_LocalInvocationID
         %21 = OpLoad %v3uint %gl_WorkGroupID
         %22 = OpCompositeExtract %uint %21 0
         %23 = OpIMul %uint %22 %uint_100
         %24 = OpCompositeExtract %uint %20 0
         %25 = OpIAdd %uint %23 %24
         %26 = OpAccessChain %_ptr_Uniform_uint %data %int_0 %25
         %27 = OpAtomicExchange %uint %26 %uint_1 %uint_0 %uint_1
               OpReturn
               OpFunctionEnd

Finally, I used Naga to translate from Spirv to Wgsl and the following error is thrown:
Unsupported instruction AtomicExchange at Function

[Teodor Tanasoaia]

Thanks for the report!

Atomics are not currently supported by the SPIR-V frontend and they are non-trivial to implement.

Closing as duplicate of gfx-rs/wgpu#4489