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authorgatecat <gatecat@ds0.me>2021-12-19 16:41:34 +0000
committergatecat <gatecat@ds0.me>2021-12-19 17:15:15 +0000
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archapi: Use arbitrary rather than actual placement in predictDelay
This makes predictDelay be based on an arbitrary belpin pair rather than a arc of a net based on cell placement. This way 'what-if' decisions can be evaluated without actually changing placement; potentially useful for parallel placement. A new helper predictArcDelay behaves like the old predictDelay to minimise the impact on existing passes; only arches need be updated. Signed-off-by: gatecat <gatecat@ds0.me>
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diff --git a/docs/archapi.md b/docs/archapi.md
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@@ -517,7 +517,7 @@ result, and for that estimate it is considered more acceptable to return a
slightly too high result and it is considered less acceptable to return a
too low result (thus "low upper bound").
-### delay\_t predictDelay(const NetInfo \*net\_info, const PortRef &sink) const
+### delay\_t predictDelay(BelId src_bel, IdString src_pin, BelId dst_bel, IdString dst_pin) const
Return a reasonably good estimate for the total `maxDelay()` delay for the
given arc. This should return a low upper bound for the fastest route for that arc.