 
   July 1, 1994                                                        SIS(1)
 
   speed_up [-m model] [-d #] [-w #] [-t #.#] [-i] [-c] [-T] [-a #] [-vD]
     node-list
 
     Speed-up the nodes in the node-list. If no nodes are specified, it
     selects the nodes to be speeded-up in order to speed-up the entire net-
     work. The best decomposition seen so far is accepted (except with the -c
     flag).  The network after running speed_up is composed of 2-input AND
     gates and inverters.
 
     The -m model option selects the delay model according to which the delay
     data is computed. The values allowed for model are unit, unit-fanout and
     mapped.  The unit delay model counts the level of the circuit as its
     delay.  The unit-fanout model is intended to capture a technology-
     independent model and it assigns a delay of 1 unit to each gate and 0.2
     units to each fanout stem. The mapped delay model uses the delay data in
     the library to compute delay.
 
     The -d # option selects the distance up to which the critical fanins are
     collapsed in order to do the speed-up.  A fast value is 3, a good one is
     6.
 
     The -t #.# option determines which nodes are considered critical. The
     critical nodes are those with a slack within #.# of the most negative
     slack.
 
     The -w # option selects between the area mode and the pure timing mode.
     A value of 0 selects pure-timing mode while a value of 1 will conserve
     as much area as possible.
 
     The -i option specifies that only the initial 2-input NAND decomposition
     be carried out.
 
     The -c option specifies that one pass be carried out.  The new decompo-
     sition is always accepted, even if it results in a slower circuit.
 
     The -T option displays the delay as the iterations progress.
 
     The -a # option tries to do the specified number of attempts when res-
     tructuring a node. By default the algorithm tries only one attempt at
     the restructuring. This option is for experimental use at this stage.
 
     The -v and -D options display debugging information.
 
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