aboutsummaryrefslogtreecommitdiffstats
path: root/ecp5/pack.cc
diff options
context:
space:
mode:
Diffstat (limited to 'ecp5/pack.cc')
-rw-r--r--ecp5/pack.cc24
1 files changed, 24 insertions, 0 deletions
diff --git a/ecp5/pack.cc b/ecp5/pack.cc
index aa7fdd22..ac16536d 100644
--- a/ecp5/pack.cc
+++ b/ecp5/pack.cc
@@ -1573,6 +1573,30 @@ class Ecp5Packer
autocreate_empty_port(ci, ctx->id(port + std::to_string(i)));
for (int i = 0; i < 11; i++)
autocreate_empty_port(ci, ctx->id("OP" + std::to_string(i)));
+
+ // Find the MULT18X18Ds feeding this ALU54B's inputs and
+ // constrain them to the ALU.
+ for (auto port : {id_MA0, id_MB0}) {
+ CellInfo *mult = net_driven_by(
+ ctx, ci->ports.at(port).net,
+ [](const Context *ctx, const CellInfo *cell) {
+ return cell->type == id_MULT18X18D;
+ }, id_P0
+ );
+ if(mult != nullptr) {
+ if(port == id_MA0) {
+ mult->constr_x = mult->constr_z = -3;
+ } else if(port == id_MB0) {
+ mult->constr_x = mult->constr_z = -2;
+ }
+ mult->constr_y = 0;
+ mult->constr_parent = ci;
+ ci->constr_children.push_back(mult);
+ log_info("DSP: Constraining MULT18X18D '%s' to ALU54B '%s' port %s\n",
+ mult->name.c_str(ctx), cell.first.c_str(ctx),
+ ctx->nameOf(port));
+ }
+ }
}
}
}