Fix TruncatedNormal's sample/log_prob dtype when jax_enable_x64=True.

PiperOrigin-RevId: 378583501

Author: SiegeLordEx

tensorflow_probability/python/distributions/truncated_normal.py

@@ -341,13 +341,15 @@ def grad(dy):
     return std_samples * scale[tf.newaxis] + loc[tf.newaxis]
 
   def _log_prob(self, x):
+    np_dtype = dtype_util.as_numpy_dtype(x.dtype)
     loc, scale, low, high = self._loc_scale_low_high()
-    log_prob = -(0.5 * tf.square(
-        (x - loc) / scale) + 0.5 * np.log(2. * np.pi) + tf.math.log(scale) +
+    log_prob = -(np_dtype(0.5) * tf.square(
+        (x - loc) / scale) + (0.5 * np.log(2. * np.pi)).astype(np_dtype) +
+                 tf.math.log(scale) +
                  self._log_normalizer(loc=loc, scale=scale, low=low, high=high))
     # p(x) is 0 outside the bounds.
     bounded_log_prob = tf.where((x > high) | (x < low),
-                                dtype_util.as_numpy_dtype(x.dtype)(-np.inf),
+                                np_dtype(-np.inf),
                                 log_prob)
     return bounded_log_prob
 

tensorflow_probability/python/internal/backend/numpy/random_generators.py

@@ -246,9 +246,10 @@ def _truncated_normal_jax(
   import jax.random as jaxrand  # pylint: disable=g-import-not-at-top
   if seed is None:
     raise ValueError('Must provide PRNGKey to sample in JAX.')
+  dtype = utils.common_dtype([means, stddevs, minvals, maxvals])
   std_low = (minvals - means) / stddevs
   std_high = (maxvals - means) / stddevs
-  std_samps = jaxrand.truncated_normal(seed, std_low, std_high, shape)
+  std_samps = jaxrand.truncated_normal(seed, std_low, std_high, shape, dtype)
   return std_samps * stddevs + means