Added forked versions of stateless If and While ops. They should only be used,

when the if then/else body of If or the While body funcs do not have stateful
ops.

The are lowered to the same XLA ops.

One use case is in the S4TF compiler: https://github.com/apple/swift/pull/18509

PiperOrigin-RevId: 207977126

4 files changed, 81 insertions, 0 deletions

diff --git a/tensorflow/core/api_def/base_api/api_def_StatelessIf.pbtxt b/tensorflow/core/api_def/base_api/api_def_StatelessIf.pbtxt
new file mode 100644
index 0000000000..c0a6ba15e6
--- /dev/null
+++ b/tensorflow/core/api_def/base_api/api_def_StatelessIf.pbtxt
@@ -0,0 +1,43 @@
+op {
+  graph_op_name: "StatelessIf"
+  in_arg { name: "cond"  description: "The predicate." }
+  in_arg {
+    name: "cond"
+    description: <<END
+      A Tensor. If the tensor is a scalar of non-boolean type, the
+      scalar is converted to a boolean according to the
+      following rule: if the scalar is a numerical value, non-zero means
+      `True` and zero means False; if the scalar is a string, non-empty
+      means `True` and empty means `False`. If the tensor is not a scalar,
+      being empty means False and being non-empty means True.
+
+      This should only be used when the if then/else body functions do not
+      have stateful ops.
+END
+  }
+  in_arg {
+    name: "input"
+    description: "A list of input tensors."
+  }
+  out_arg {
+    name: "output"
+    description: "A list of return values."
+  }
+  attr { name: "Tin"  description: "A list of input types." }
+  attr { name: "Tout"  description: "A list of output types." }
+  attr {
+    name: "then_branch"
+    description: <<END
+      A function that takes 'inputs' and returns a list of tensors, whose
+      types are the same as what else_branch returns.
+END
+  }
+  attr {
+    name: "else_branch"
+    description: <<END
+    A function that takes 'inputs' and returns a list of tensors, whose
+    types are the same as what then_branch returns.
+END
+  }
+  summary: "output = cond ? then_branch(input) : else_branch(input)"
+}
diff --git a/tensorflow/core/api_def/base_api/api_def_StatelessWhile.pbtxt b/tensorflow/core/api_def/base_api/api_def_StatelessWhile.pbtxt
new file mode 100644
index 0000000000..87c0e09673
--- /dev/null
+++ b/tensorflow/core/api_def/base_api/api_def_StatelessWhile.pbtxt
@@ -0,0 +1,36 @@
+op {
+  graph_op_name: "StatelessWhile"
+  in_arg {
+    name: "input"
+    description: "A list of input tensors whose types are T."
+  }
+  out_arg {
+    name: "output"
+    description: "A list of output tensors whose types are T."
+  }
+  attr { name: "T"  description: "dtype in use." }
+  attr {
+    name: "cond"
+    description: <<END
+      A function takes 'input' and returns a tensor.  If the tensor is
+      a scalar of non-boolean, the scalar is converted to a boolean
+      according to the following rule: if the scalar is a numerical
+      value, non-zero means True and zero means False; if the scalar is
+      a string, non-empty means True and empty means False. If the
+      tensor is not a scalar, non-emptiness means True and False
+      otherwise.
+
+      This should only be used when the while condition and body functions
+      do not have stateful ops.
+END
+  }
+  attr {
+    name: "body"
+    description: <<END
+      A function that takes a list of tensors and returns another
+      list of tensors. Both lists have the same types as specified
+      by T.
+END
+  }
+  summary: "output = input; While (Cond(output)) { output = Body(output) }"
+}
diff --git a/tensorflow/core/api_def/python_api/api_def_StatelessIf.pbtxt b/tensorflow/core/api_def/python_api/api_def_StatelessIf.pbtxt
new file mode 100644
index 0000000000..0298c4852c
--- /dev/null
+++ b/tensorflow/core/api_def/python_api/api_def_StatelessIf.pbtxt
@@ -0,0 +1 @@
+op { graph_op_name: "StatelessIf" visibility: HIDDEN }
diff --git a/tensorflow/core/api_def/python_api/api_def_StatelessWhile.pbtxt b/tensorflow/core/api_def/python_api/api_def_StatelessWhile.pbtxt
new file mode 100644
index 0000000000..c138a71087
--- /dev/null
+++ b/tensorflow/core/api_def/python_api/api_def_StatelessWhile.pbtxt
@@ -0,0 +1 @@
+op { graph_op_name: "StatelessWhile" visibility: HIDDEN }