[export] Removed __gpu$xla.gpu.triton (Pallas GPU) from the list of custom calls with guaranteed compatibility.

This is because the underlying Triton IR does not guarantee compatibility.

PiperOrigin-RevId: 703127711

Author: gnecula

CHANGELOG.md

@@ -70,6 +70,11 @@ When releasing, please add the new-release-boilerplate to docs/pallas/CHANGELOG.
     return NaN for negative integer inputs, to match the behavior of SciPy from
     https://github.com/scipy/scipy/pull/21827.
   * `jax.clear_backends` was removed after being deprecated in v0.4.26.
+  * We removed the custom call "__gpu$xla.gpu.triton" from the list of custom
+    call that we guarantee export stability. This is because this custom call
+    relies on Triton IR, which is not guaranteed to be stable. If you need
+    to export code that uses this custom call, you can use the `disabled_checks`
+    parameter. See more details in the [documentation](https://jax.readthedocs.io/en/latest/export/export.html#compatibility-guarantees-for-custom-calls).
 
 * New Features
   * {func}`jax.jit` got a new `compiler_options: dict[str, Any]` argument, for

jax/_src/export/_export.py

@@ -1005,7 +1005,8 @@ def _check_lowering(lowering) -> None:
     *_CPU_FFI_KERNELS,
     "Sharding", "SPMDFullToShardShape", "SPMDShardToFullShape",
     "cu_threefry2x32", "cu_threefry2x32_ffi",
-    "__gpu$xla.gpu.triton",  # Pallas call on GPU
+    # Triton IR does not guarantee stability.
+    # "__gpu$xla.gpu.triton",
     # cholesky on CPU
     "lapack_spotrf", "lapack_dpotrf", "lapack_cpotrf", "lapack_zpotrf",
     # eigh on TPU

tests/pallas/export_back_compat_pallas_test.py

@@ -48,9 +48,10 @@ def setUp(self):
       self.skipTest("Only works on GPUs with capability >= sm80")
     super().setUp()
 
-  @unittest.skip("TODO(necula): This test is checking backwards compatibility "
+  @unittest.skip("This test is checking backwards compatibility "
                  "of Triton IR, but Triton doesn't promise backwards "
-                 "compatibility for its IR.")
+                 "compatibility for its IR, and we have since removed "
+                 "the corresponding custom call from the guaranteed stable list.")
   def test_triton_add_one(self):
     def func(x):
       def add_one(x_ref, o_ref):

tests/pallas/export_pallas_test.py

@@ -50,6 +50,10 @@ def add_vectors(x: jax.Array, y: jax.Array) -> jax.Array:
     exp = export.export(
         add_vectors,
         platforms=["tpu", "cuda"],
+        # The Pallas GPU custom call is not enabled for export by default.
+        disabled_checks=[
+            export.DisabledSafetyCheck.custom_call("__gpu$xla.gpu.triton")
+        ]
     )(a, a)
 
     if (jtu.device_under_test() == "tpu" or