o i 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$d%Zd&d'Zd(d)Zd*d+Zd,d-Zd>d.d/Zd0d1Zd2d3Zd4d5Z d6d7Z!d8d9Z"d:d;Z#dhd}|j}|j|vr|jdj}|j|vs t|r|SdS)zCReturn the enter op if we can infer `value` to be a loop invariant.>r)Identityr* RefIdentityrN)rr,rArL)valueid_opsrr r r GetLoopConstantEnters    rQcCs"|}|durt|r|j}|S)z8Return the control flow context for the output of an op.N)rr8r;r$r r r rBsrBcCs&|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)rGr;)r stop_ctxtr r r r#s r#cC|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) IsXLAContextr;rr r r rs  rcCrS)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;rUr r r r&s  r&cCs&||ur|dur dS|j}||usdS)z>Returns true if `maybe_containing_ctxt` is or contains `ctxt`.NFT)r;)rmaybe_containing_ctxtr r r IsContainingContexts  rWcCst||Sr)rWrr$r r r OpInContextsrXcCs t|j|Sr)rXr)tensorrr r r TensorInContexts rZc Cs|}t|}d}|sd}nf||urd}n_t|}t|}|dur5|dur(d}t|r.d}t|r4d}n@t||r=d}n8|jrJt|jj|rJd}n+|jrW|jj|jurWd}n|jrc|jj|urcd}n|jru|jjjru|jjjj|urud}|s|rd|j d|j d}nd|j d|j d|j d}|}|d |j |f7}|d |j |f7}|d |j d t |j |j d t |j f7}t |t|d dS)anReturns whether `input_op` can be used from `op`s context. Conceptually, only inputs from op's while context or any ancestor while context (including outside of any context) are valid. In practice, there are many other edge cases as well. Args: op: Operation input_op: Operation Raises: ValueError: if input_op is from an invalid context. FTNz Cannot use 'z' as input to 'z,' because they are in different while loops.z ' because 'z' is in a while loop.z %s while context: %sz %s while context: %sz, Traceback for %s: %s Traceback for %s: %s z See info log for more details.)rrBr#r5r.rW grad_stateforward_context_outer_contextnamejoin traceback format_listlogginginfor) rinput_opop_ctxt input_ctxtvalid while_ctxtinput_while_ctxt error_msglog_msgr r r CheckInputFromValidContextst      rmcCs|}|r |}|S)z.Get the WhileContext to which this op belongs.)rGetWhileContextr$r r r rnjsrnr)%__doc__osratensorflow.pythonrtensorflow.python.platformrrcenabledgetenvr r rrrr"r%r'r.r2r5r8r@rErHrJrLrQrBr#rr&rWrXrZrmrnr r r r sT         d