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-rw-r--r--passes/opt/opt_merge.cc17
-rw-r--r--tests/opt/opt_merge_init.ys49
2 files changed, 65 insertions, 1 deletions
diff --git a/passes/opt/opt_merge.cc b/passes/opt/opt_merge.cc
index aaea6159e..8823a9061 100644
--- a/passes/opt/opt_merge.cc
+++ b/passes/opt/opt_merge.cc
@@ -222,7 +222,9 @@ struct OptMergeWorker
return true;
}
- if (cell1->type.begins_with("$") && conn1.count(ID(Q)) != 0) {
+ if (conn1.count(ID(Q)) != 0 && (cell1->type.begins_with("$dff") || cell1->type.begins_with("$dlatch") ||
+ cell1->type.begins_with("$_DFF") || cell1->type.begins_with("$_DLATCH") || cell1->type.begins_with("$_SR_") ||
+ cell1->type.in("$adff", "$sr", "$ff", "$_FF_"))) {
std::vector<RTLIL::SigBit> q1 = dff_init_map(cell1->getPort(ID(Q))).to_sigbit_vector();
std::vector<RTLIL::SigBit> q2 = dff_init_map(cell2->getPort(ID(Q))).to_sigbit_vector();
for (size_t i = 0; i < q1.size(); i++)
@@ -323,6 +325,19 @@ struct OptMergeWorker
log_signal(it.second), log_signal(other_sig));
module->connect(RTLIL::SigSig(it.second, other_sig));
assign_map.add(it.second, other_sig);
+
+ if (it.first == ID(Q) && (cell->type.begins_with("$dff") || cell->type.begins_with("$dlatch") ||
+ cell->type.begins_with("$_DFF") || cell->type.begins_with("$_DLATCH") || cell->type.begins_with("$_SR_") ||
+ cell->type.in("$adff", "$sr", "$ff", "$_FF_"))) {
+ for (auto c : it.second.chunks()) {
+ auto jt = c.wire->attributes.find(ID(init));
+ if (jt == c.wire->attributes.end())
+ continue;
+ for (int i = c.offset; i < c.offset + c.width; i++)
+ jt->second[i] = State::Sx;
+ }
+ dff_init_map.add(it.second, Const(State::Sx, GetSize(it.second)));
+ }
}
}
log_debug(" Removing %s cell `%s' from module `%s'.\n", cell->type.c_str(), cell->name.c_str(), module->name.c_str());
diff --git a/tests/opt/opt_merge_init.ys b/tests/opt/opt_merge_init.ys
new file mode 100644
index 000000000..a29c29df6
--- /dev/null
+++ b/tests/opt/opt_merge_init.ys
@@ -0,0 +1,49 @@
+read_verilog -icells <<EOT
+module top(input clk, i, (* init = 1'b0 *) output o, p);
+ \$dff #(
+ .CLK_POLARITY(1'h1),
+ .WIDTH(32'd1)
+ ) ffo (
+ .CLK(clk),
+ .D(i),
+ .Q(o)
+ );
+ \$dff #(
+ .CLK_POLARITY(1'h1),
+ .WIDTH(32'd1)
+ ) ffp (
+ .CLK(clk),
+ .D(i),
+ .Q(p)
+ );
+endmodule
+EOT
+
+opt_merge
+select -assert-count 1 a:init=1'0
+
+
+design -reset
+read_verilog -icells <<EOT
+module top(input clk, i, (* init = 2'b11 *) output [1:0] o);
+ \$dff #(
+ .CLK_POLARITY(1'h1),
+ .WIDTH(32'd1)
+ ) ff1 (
+ .CLK(clk),
+ .D(i),
+ .Q(o[1])
+ );
+ \$dff #(
+ .CLK_POLARITY(1'h1),
+ .WIDTH(32'd1)
+ ) ff0 (
+ .CLK(clk),
+ .D(i),
+ .Q(o[0])
+ );
+endmodule
+EOT
+
+opt_merge
+select -assert-count 1 a:init=2'bx1