1 files changed, 49 insertions, 0 deletions
diff --git a/dom/webgpu/tests/cts/checkout/src/webgpu/shader/execution/expression/call/builtin/atomicCompareExchangeWeak.spec.ts b/dom/webgpu/tests/cts/checkout/src/webgpu/shader/execution/expression/call/builtin/atomicCompareExchangeWeak.spec.ts
new file mode 100644
index 0000000000..9172e3a638
--- /dev/null
+++ b/dom/webgpu/tests/cts/checkout/src/webgpu/shader/execution/expression/call/builtin/atomicCompareExchangeWeak.spec.ts
@@ -0,0 +1,49 @@
+export const description = `
+Performs the following steps atomically:
+ * Load the original value pointed to by atomic_ptr.
+ * Compare the original value to the value v using an equality operation.
+ * Store the value v only if the result of the equality comparison was true.
+
+Returns a two member structure, where the first member, old_value, is the original
+value of the atomic object and the second member, exchanged, is whether or not
+the comparison succeeded.
+
+Note: the equality comparison may spuriously fail on some implementations.
+That is, the second component of the result vector may be false even if the first
+component of the result vector equals cmp.
+`;
+
+import { makeTestGroup } from '../../../../../../common/framework/test_group.js';
+import { GPUTest } from '../../../../../gpu_test.js';
+
+export const g = makeTestGroup(GPUTest);
+
+g.test('stage')
+  .specURL('https://www.w3.org/TR/WGSL/#atomic-rmw')
+  .desc(
+    `
+Atomic built-in functions must not be used in a vertex shader stage.
+`
+  )
+  .params(u => u.combine('stage', ['fragment', 'vertex', 'compute'] as const))
+  .unimplemented();
+
+g.test('exchange')
+  .specURL('https://www.w3.org/TR/WGSL/#atomic-rmw')
+  .desc(
+    `
+SC is storage or workgroup
+T is i32 or u32
+
+fn atomicCompareExchangeWeak(atomic_ptr: ptr<SC, atomic<T>, read_write>, cmp: T, v: T) -> __atomic_compare_exchange_result<T>
+
+struct __atomic_compare_exchange_result<T> {
+  old_value : T,    // old value stored in the atomic
+  exchanged : bool, // true if the exchange was done
+}
+`
+  )
+  .params(u =>
+    u.combine('SC', ['storage', 'uniform'] as const).combine('T', ['i32', 'u32'] as const)
+  )
+  .unimplemented();