o ?e1@sXdZddlZddlZddlmZddlmZer!e ddkp@e dddkp@e dddkp@e dddkp@e d ddka d d Z d d Z ddZ ddZddZddZddZddZddZddZddZd d!Zd"d#Zd$d%Zd&d'Zd(d)Zd*d+Zd,d-Zd>d.d/Zd0d1Zd2d3Zd4d5Z d6d7Z!d8d9Z"d:d;Z#dhd}|j}|j|vr|jdj}|j|vs t|r|SdS)zCReturn the enter op if we can infer `value` to be a loop invariant.>ZIdentityZ RefIdentityr r!rN)rr#r/r9)valueZid_opsrrrrGetLoopConstantEnters    r;cCs"|}|durt|r|j}|S)z8Return the control flow context for the output of an op.N)rr)r*rrrrr0sr0cCs&|r|s ||kr |S|j}|sdS)aReturns the first ancestor WhileContext of `ctxt`. Returns `ctxt` if `ctxt` is a WhileContext, or None if `ctxt` is not in a while loop. Args: ctxt: ControlFlowContext stop_ctxt: ControlFlowContext, optional. If provided, the search will end if it sees stop_ctxt. Returns: `ctxt` if `ctxt` is a WhileContext, the most nested WhileContext containing `ctxt`, or None if `ctxt` is not in a while loop. If `stop_ctxt` is not `None`, this returns `ctxt` if it matches `stop_ctxt` in its traversal. N)r4r*)rZ stop_ctxtrrrrs rcC|r |r|S|j}|sdS)a@Returns the first ancestor XLAContext of `ctxt`. Returns `ctxt` if `ctxt` is a XLAContext, or None if `ctxt` is not in a while loop. Args: ctxt: ControlFlowContext Returns: `ctxt` if `ctxt` is a XLAContext, the most nested XLAContext containing `ctxt`, or None if `ctxt` is not in a while loop. N)Z IsXLAContextr*rrrrrs  rcCr<)a6Returns the first ancestor CondContext of `ctxt`. Returns `ctxt` if `ctxt` is a CondContext, or None if `ctxt` is not in a cond. Args: ctxt: ControlFlowContext Returns: `ctxt` if `ctxt` is a CondContext, the most nested CondContext containing `ctxt`, or None if `ctxt` is not in a cond. N)r+r*r=rrrrs  rcCs&||ur|dur dS|j}||usdS)z>Returns true if `maybe_containing_ctxt` is or contains `ctxt`.NFT)r*)rZmaybe_containing_ctxtrrrIsContainingContexts  r>cCst||Sr)r>rrrrr OpInContextsr?cCs t|j|Sr)r?r)ZtensorrrrrTensorInContexts r@c Cs|}t|}d}|sd}nf||urd}n_t|}t|}|dur5|dur(d}t|r.d}t|r4d}n@t||r=d}n8|jrJt|jj|rJd}n+|jrW|jj|jurWd}n|jrc|jj|urcd}n|jru|jjjru|jjjj|urud}|s|rd|j d|j d}nd|j d|j d|j d}|}|d |j |f7}|d |j |f7}|d |j d t |j |j d t |j f7}t |t|d dS)anReturns whether `input_op` can be used from `op`s context. Conceptually, only inputs from op's while context or any ancestor while context (including outside of any context) are valid. In practice, there are many other edge cases as well. Args: op: Operation input_op: Operation Raises: ValueError: if input_op is from an invalid context. FTNz Cannot use 'z' as input to 'z,' because they are in different while loops.z ' because 'z' is in a while loop.z %s while context: %sz %s while context: %sz, Traceback for %s: %s Traceback for %s: %s z See info log for more details.)rr0rr(r%r>Z grad_stateZforward_contextZ_outer_contextnamejoin traceback format_listlogginginfor) rZinput_opZop_ctxtZ input_ctxtZvalidZ while_ctxtZinput_while_ctxt error_msgZlog_msgrrrCheckInputFromValidContextsz      rIcCs|}|r |}|S)z.Get the WhileContext to which this op belongs.)rGetWhileContextrrrrrJjsrJr)%__doc__osrDZtensorflow.pythonrZtensorflow.python.platformrrFenabledgetenvrrr rrrrrr%r'r(r)r.r2r5r7r9r;r0rrrr>r?r@rIrJrrrrsT         d