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Merge pull request #767 from YosysHQ/gatecat/ic-pref-const

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interchange: Fix preferred constant handling when canInvert
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gatecat 2021-07-20 12:04:12 +01:00 committed by GitHub
commit f3be638ea9
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1 changed files with 10 additions and 1 deletions
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11
fpga_interchange/site_router.cc
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@ -862,6 +862,8 @@ static void apply_constant_routing(Context *ctx, const SiteArch &site_arch, NetI
SiteWire wire = user;
PipId inverting_pip;
PhysicalNetlist::PhysNetlist::NetType pref_const = PhysicalNetlist::PhysNetlist::NetType::SIGNAL;
while (wire != site_net->driver) {
SitePip pip = site_net->wires.at(wire).pip;
NPNR_ASSERT(site_arch.getPipDstWire(pip) == wire);
@ -884,9 +886,16 @@ static void apply_constant_routing(Context *ctx, const SiteArch &site_arch, NetI
}
wire = site_arch.getPipSrcWire(pip);
pref_const = site_arch.prefered_constant_net_type(pip);
}
if (!is_path_inverting && !path_can_invert) {
bool is_pref_const = true;
if (pref_const == PhysicalNetlist::PhysNetlist::NetType::VCC && net == gnd_net)
is_pref_const = false;
else if (pref_const == PhysicalNetlist::PhysNetlist::NetType::GND && net == vcc_net)
is_pref_const = false;
if (!is_path_inverting && (!path_can_invert || is_pref_const)) {
// This routing is boring, use base logic.
apply_simple_routing(ctx, site_arch, net, site_net, user);
continue;