writer/spirv: Generate load of atomic value arguments

Fixed: tint:926
Change-Id: Ia27abe605ebfb46a7524b50500ecebd6e4656d1d
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/55883
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: David Neto <dneto@google.com>
Auto-Submit: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>

test/bug/tint/926.wgsl

@@ -0,0 +1,14 @@
+[[block]] struct DrawIndirectArgs {
+  vertexCount : atomic<u32>;
+};
+[[group(0), binding(5)]] var<storage, read_write> drawOut : DrawIndirectArgs;
+
+var<private> cubeVerts : u32 = 0u;
+
+[[stage(compute)]]
+fn computeMain([[builtin(global_invocation_id)]] global_id : vec3<u32>) {
+  // Increment cubeVerts based on some criteria...
+
+  // This fails SPIR-V validation
+  let firstVertex : u32 = atomicAdd(&drawOut.vertexCount, cubeVerts);
+}

test/bug/tint/926.wgsl.expected.hlsl

@@ -0,0 +1,15 @@
+RWByteAddressBuffer drawOut : register(u5, space0);
+static uint cubeVerts = 0u;
+
+struct tint_symbol_1 {
+  uint3 global_id : SV_DispatchThreadID;
+};
+
+[numthreads(1, 1, 1)]
+void computeMain(tint_symbol_1 tint_symbol) {
+  const uint3 global_id = tint_symbol.global_id;
+  uint atomic_result = 0u;
+  drawOut.InterlockedAdd(0u, 0u, atomic_result);
+  const uint firstVertex = atomic_result;
+  return;
+}

test/bug/tint/926.wgsl.expected.msl

@@ -0,0 +1,17 @@
+SKIP: FAILED
+
+
+[[block]]
+struct DrawIndirectArgs {
+  vertexCount : atomic<u32>;
+};
+
+[[group(0), binding(5)]] var<storage, read_write> drawOut : DrawIndirectArgs;
+
+[[stage(compute)]]
+fn computeMain([[builtin(global_invocation_id)]] global_id : vec3<u32>) {
+  [[internal(disable_validation__function_var_storage_class)]] var<private> tint_symbol_1 : u32 = 0u;
+  let firstVertex : u32 = atomicAdd(&(drawOut.vertexCount), tint_symbol_1);
+}
+
+Failed to generate: error: unknown type in EmitType: __atomic__u32

test/bug/tint/926.wgsl.expected.spvasm

@@ -0,0 +1,41 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 21
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %computeMain "computeMain"
+               OpExecutionMode %computeMain LocalSize 1 1 1
+               OpName %DrawIndirectArgs "DrawIndirectArgs"
+               OpMemberName %DrawIndirectArgs 0 "vertexCount"
+               OpName %drawOut "drawOut"
+               OpName %cubeVerts "cubeVerts"
+               OpName %tint_symbol "tint_symbol"
+               OpName %computeMain "computeMain"
+               OpDecorate %DrawIndirectArgs Block
+               OpMemberDecorate %DrawIndirectArgs 0 Offset 0
+               OpDecorate %drawOut DescriptorSet 0
+               OpDecorate %drawOut Binding 5
+               OpDecorate %tint_symbol BuiltIn GlobalInvocationId
+       %uint = OpTypeInt 32 0
+%DrawIndirectArgs = OpTypeStruct %uint
+%_ptr_StorageBuffer_DrawIndirectArgs = OpTypePointer StorageBuffer %DrawIndirectArgs
+    %drawOut = OpVariable %_ptr_StorageBuffer_DrawIndirectArgs StorageBuffer
+     %uint_0 = OpConstant %uint 0
+%_ptr_Private_uint = OpTypePointer Private %uint
+  %cubeVerts = OpVariable %_ptr_Private_uint Private %uint_0
+     %v3uint = OpTypeVector %uint 3
+%_ptr_Input_v3uint = OpTypePointer Input %v3uint
+%tint_symbol = OpVariable %_ptr_Input_v3uint Input
+       %void = OpTypeVoid
+         %11 = OpTypeFunction %void
+     %uint_1 = OpConstant %uint 1
+%_ptr_StorageBuffer_uint = OpTypePointer StorageBuffer %uint
+%computeMain = OpFunction %void None %11
+         %14 = OpLabel
+         %19 = OpAccessChain %_ptr_StorageBuffer_uint %drawOut %uint_0
+         %20 = OpLoad %uint %cubeVerts
+         %15 = OpAtomicIAdd %uint %19 %uint_1 %uint_0 %20
+               OpReturn
+               OpFunctionEnd

test/bug/tint/926.wgsl.expected.wgsl

@@ -0,0 +1,13 @@
+[[block]]
+struct DrawIndirectArgs {
+  vertexCount : atomic<u32>;
+};
+
+[[group(0), binding(5)]] var<storage, read_write> drawOut : DrawIndirectArgs;
+
+var<private> cubeVerts : u32 = 0u;
+
+[[stage(compute)]]
+fn computeMain([[builtin(global_invocation_id)]] global_id : vec3<u32>) {
+  let firstVertex : u32 = atomicAdd(&(drawOut.vertexCount), cubeVerts);
+}