62 lines
3.7 KiB
Groff
62 lines
3.7 KiB
Groff
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.TH "AlgorithmOverview" 3 "Mon Apr 27 2020" "Version 1.0" "Kite - Detailed Router" \" -*- nroff -*-
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.ad l
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.nh
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.SH NAME
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AlgorithmOverview \- Description of the algorithm\&.
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.SH SYNOPSIS
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.br
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.PP
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.SH "Detailed Description"
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.PP
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Description of the algorithm\&.
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The algorithm top-level is implemented in the \fC\fBNegociateWindow\fP\fP\&.
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.PP
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\fBFirst step :\fP NegociateWindow::_loadRouting()
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.PD 0
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.IP "1." 4
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Load routing wires (\fCAutoSegment\fP) from \fCKatabaticEngine\fP inside the \fBKite\fP \fCGCell's\fP\&. Then update the \fCGCell's\fP density\&.
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.IP "2." 4
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Sort the \fCGCell's\fP according to decreasing density (denser \fCGCell's\fP are to be routed first)\&.
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.IP "3." 4
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Agglomerate clusters of contiguous GCell's whose density is superior to 0\&.7 to the seed GCell\&. See \fCGCellRoutingSet\fP for the mechanism\&.
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.PP
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GCellRoutingSet receive an increasing order number\&. The higher the order the lower the density\&. This order is transmitted to the \fC\fBTrackSegment\fP\fP of the \fCGCellRoutingSet\fP to be taken into account by the track cost function\&.
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.PP
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.PP
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\fBSecond step :\fP \fCNegociateWindow::_runOnGCellRoutingSet()\fP
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.PP
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For each \fCGCellRoutingSet\fP in decreasing density, negociate the set of associated \fC\fBTrackSegment\fP\fP\&.
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.PD 0
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.IP "1." 4
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Build a \fC\fBRoutingEventQueue\fP\fP from the list of \fC\fBTrackSegment\fP\fP\&. The queue is responsible for allocating the \fC\fBRoutingEvent\fP\fP associated to each \fC\fBTrackSegment\fP\fP\&.
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.IP "2." 4
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The queue is sorted according to the 'event level' then to the priority, which is for now the slack of the \fC\fBTrackSegment\fP\fP\&. That is, constrained \fC\fBTrackSegment\fP\fP are routed first\&.
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.IP "3." 4
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The queue is processed till it's empty (no unprocessed \fC\fBRoutingEvent\fP\fP remains)\&.
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.PP
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Processing a \fC\fBRoutingEvent\fP\fP is trying to insert a \fC\fBTrackSegment\fP\fP in a suitable \fBTrack\fP\&. We proceed as follow :
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.PD 0
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.IP " \(bu" 4
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The maximum ripup count for the to be inserted segment has been reached\&. Issue a severe warning and left unrouted this \fC\fBTrackSegment\fP\fP (for now)\&.
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.IP " \(bu" 4
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Compute the Tracks in which the \fC\fBTrackSegment\fP\fP can be inserted, then compute the insertion cost in each one\&. The candidates are ordered by the insertion cost\&.
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.IP " \(bu" 4
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Now consider the lower cost \fC\fBTrack\fP\fP\&. If there is a free interval for the \fC\fBTrackSegment\fP\fP\&. Issue a \fCSession::addInsertEvent()\fP then finish\&.
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.PP
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If there is a \fI'soft overlap'\fP, that is the overlaping \fC\fBTrackSegment\fP\fP already in the \fC\fBTrack\fP\fP could be shrunk either to the left or the right so the new \fC\fBTrackSegment\fP\fP can be inserted\&. This is managed by \fCRoutingEvent::_setAside()\fP, for each soft overlaping \fC\fBTrackSegment\fP\fP, gets its perpandiculars and issue a displacement request for all of them\&. That is, re-post a \fC\fBRoutingEvent\fP\fP with updated constraints and remove the perpandicular from it's \fBTrack\fP if it has already been routed\&. Note that no request is issued for the overlaping \fC\fBTrackSegment\fP\fP itself has it do not change of \fBTrack\fP\&.
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.PP
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If there is a \fI'hard overlap'\fP, that is the two \fC\fBTrackSegment\fP\fP cannot share the same \fC\fBTrack\fP\fP, remove the previous one from the \fC\fBTrack\fP\fP and re-post a \fC\fBRoutingEvent\fP\fP\&. Note that, the cost object should have selected a \fC\fBTrackSegment\fP\fP which could be ripped-up\&. Otherwise the \fC\fBTrack\fP\fP would'nt even be a candidate\&.
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.PP
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.PP
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When a \fBTrackSegment\fP is riped up, it is re-routed immediately afterward\&. This is done by increasing his event level\&.
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.PP
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.SH "Author"
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.PP
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Generated automatically by Doxygen for Kite - Detailed Router from the source code\&.
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