Use Elemwise NumPy information to convert CAReduce nodes to JAX

tests/sandbox/test_jax.py

@@ -518,9 +518,15 @@ def test_tensor_basics():
     # optimizations are turned on; however, when using JAX mode, it should
     # leave the expression alone.
     out = y.dot(alpha * A).dot(x) + beta * y
-
     fgraph = theano.gof.FunctionGraph([y, x, A, alpha, beta], [out])
+    _ = compare_jax_and_py(fgraph, [get_test_value(i) for i in fgraph.inputs])
+
+    out = tt.maximum(y, x)
+    fgraph = theano.gof.FunctionGraph([y, x], [out])
+    _ = compare_jax_and_py(fgraph, [get_test_value(i) for i in fgraph.inputs])
 
+    out = tt.max(y)
+    fgraph = theano.gof.FunctionGraph([y], [out])
     _ = compare_jax_and_py(fgraph, [get_test_value(i) for i in fgraph.inputs])
 
 

theano/sandbox/jaxify.py

@@ -528,28 +528,40 @@ def jax_funcify_FunctionGraph(fgraph):
 
 @jax_funcify.register(CAReduce)
 def jax_funcify_CAReduce(op):
-    def careduce(x):
     axis = op.axis
+    op_nfunc_spec = getattr(op, "nfunc_spec", None)
+    scalar_nfunc_spec = getattr(op.scalar_op, "nfunc_spec", None)
+    scalar_op_name = getattr(op.scalar_op, "name", None)
+    scalar_op_identity = getattr(op.scalar_op, "identity", None)
+    acc_dtype = getattr(op, "acc_dtype", None)
+
+    def careduce(x):
+        nonlocal axis, op_nfunc_spec, scalar_nfunc_spec, scalar_op_name, scalar_op_identity, acc_dtype
 
         if axis is None:
             axis = list(range(x.ndim))
 
-        to_reduce = reversed(sorted(axis))
-
-        if hasattr(op, "acc_dtype") and op.acc_dtype is not None:
-            acc_dtype = op.acc_dtype
-        else:
+        if acc_dtype is None:
             acc_dtype = x.dtype.type
 
+        if op_nfunc_spec:
+            jax_op = getattr(jnp, op_nfunc_spec[0])
+            return jax_op(x, axis=axis).astype(acc_dtype)
+
+        # The Theano `Op` didn't tell us which NumPy equivalent to use (or
+        # there isn't one), so we use this fallback approach
+        if scalar_nfunc_spec:
+            scalar_fn_name = scalar_nfunc_spec[0]
+        elif scalar_op_name:
+            scalar_fn_name = scalar_op_name
+
+        to_reduce = reversed(sorted(axis))
+
         if to_reduce:
-            if getattr(op.scalar_op, "name", None):
-                jax_op = getattr(jax.lax, op.scalar_op.name)
-            elif getattr(op.scalar_op, "nfunc_spec", None):
             # In this case, we need to use the `jax.lax` function (if there
             # is one), and not the `jnp` version.
-                jax_op = getattr(jax.lax, op.scalar_op.nfunc_spec[0])
-
-            init_value = jnp.array(op.scalar_op.identity, dtype=acc_dtype)
+            jax_op = getattr(jax.lax, scalar_fn_name)
+            init_value = jnp.array(scalar_op_identity, dtype=acc_dtype)
             return jax.lax.reduce(x, init_value, jax_op, to_reduce).astype(acc_dtype)
         else:
             return x