prototype 'remat' in hlo metadata

jax/_src/ad_checkpoint.py

@@ -629,8 +629,9 @@ def transposed(*args_flat):
                 pe.PartialVal.known(next(ins_iter))
                 for aval, lin in zip(jaxpr.in_avals, in_lin)]
     assert next(ins_iter, None) is None
-    lin_jaxpr, _, consts = pe.trace_to_jaxpr_nounits(
-        lu.wrap_init(core.jaxpr_as_fun(jaxpr)), in_pvals, False)
+    with source_info_util.extend_name_stack('rematted_computation'):
+      lin_jaxpr, _, consts = pe.trace_to_jaxpr_nounits(
+          lu.wrap_init(core.jaxpr_as_fun(jaxpr)), in_pvals, False)
 
     # Transpose the linear jaxpr (which only has linear inputs).
     out_cts_iter = iter(out_cts_flat)
@@ -696,7 +697,7 @@ def remat_lowering(*args, jaxpr: core.Jaxpr, prevent_cse: bool,
   else:
     translation_rule = lambda *args, jaxpr: core.eval_jaxpr(jaxpr, (), *args)
 
-  return api.named_call(translation_rule, name="remat")(*args, jaxpr=jaxpr)
+  return api.named_call(translation_rule, name="checkpoint")(*args, jaxpr=jaxpr)
 
 def _remat_translation_using_opt_barrier(*args, jaxpr: core.Jaxpr):
   args = _optimization_barrier(args)

tests/name_stack_test.py

@@ -23,6 +23,7 @@
 from jax import config
 from jax._src import test_util as jtu
 from jax._src.lib import xla_client
+from jax._src import ad_checkpoint
 
 config.parse_flags_with_absl()
 
@@ -267,6 +268,18 @@ def g(y):
     self.assertIn('jvp(pjit(f))/pjit(g)/cos', hlo_text)
     self.assertIn('transpose(jvp(pjit(f)))/pjit(g)/mul', hlo_text)
 
+  def test_remat_appears_in_hlo(self):
+    @ad_checkpoint.remat
+    def f(x):
+      return jnp.sin(x)
+
+    hlo_text = _get_hlo(f)(2.)
+    hlo_text_grad = _get_hlo(jax.grad(f))(2.)
+    self.assertNotIn('rematted_computation', hlo_text)
+    self.assertNotIn('remat', hlo_text)
+    self.assertIn('checkpoint', hlo_text)
+    self.assertIn('rematted_computation', hlo_text_grad)
+
 
 class NameStackControlFlowTest(jtu.JaxTestCase):