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>
"nextpnr.h" is no longer the god header. Important improvements:
- Functions in log.h can be used without including
BaseCtx/Arch/Context. This means that log_X functions can be called
without included "nextpnr.h"
- NPNR_ASSERT can be used without including "nextpnr.h" by including
"nextpnr_assertions.h". This allows NPNR_ASSERT to be used safely in
any header file.
- Types defined in "archdefs.h" are now available without including
BaseCtx/Arch/Context. This means that utility classes that will be
used inside of BaseCtx/Arch/Context can be defined safely in a
self-contained header.
Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
