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Merge pull request #746 from YosysHQ/gatecat/ic-can-invert-const

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interchange: Handle canInvert PIPs when processing preferred constants
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gatecat 2021-07-01 15:28:24 +01:00 committed by GitHub
commit 55c663f7ac
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1 changed files with 9 additions and 5 deletions
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14
fpga_interchange/site_router.cc
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@ -858,9 +858,7 @@ static void apply_constant_routing(Context *ctx, const SiteArch &site_arch, NetI
NPNR_ASSERT(net == vcc_net || net == gnd_net);
for (auto &user : site_net->users) {
// FIXME: Handle case where pip is "can_invert", and that
// inversion helps with accomidating "best constant".
bool is_path_inverting = false;
bool is_path_inverting = false, path_can_invert = false;
SiteWire wire = user;
PipId inverting_pip;
@ -879,10 +877,16 @@ static void apply_constant_routing(Context *ctx, const SiteArch &site_arch, NetI
inverting_pip = pip.pip;
}
if (site_arch.canInvert(pip)) {
path_can_invert = true;
NPNR_ASSERT(pip.type == SitePip::SITE_PIP);
inverting_pip = pip.pip;
}
wire = site_arch.getPipSrcWire(pip);
}
if (!is_path_inverting) {
if (!is_path_inverting && !path_can_invert) {
// This routing is boring, use base logic.
apply_simple_routing(ctx, site_arch, net, site_net, user);
continue;
@ -956,7 +960,7 @@ static void apply_constant_routing(Context *ctx, const SiteArch &site_arch, NetI
SitePip site_pip = site_net->wires.at(wire).pip;
NPNR_ASSERT(site_arch.getPipDstWire(site_pip) == wire);
if (site_arch.isInverting(site_pip)) {
if (site_arch.isInverting(site_pip) || site_arch.canInvert(site_pip)) {
NPNR_ASSERT(after_inverter);
after_inverter = false;