memory_dff: Fix checking of feedback mux input when more than one mux

Signed-off-by: David Shah <dave@ds0.me>

diff --git a/passes/memory/memory_dff.cc b/passes/memory/memory_dff.cc
index 5215cce440ade3a4c18d3dd01411e5947d071b87..32b97f27a5a75c6c49a4e0dde3d2d5a5cb6e0127 100644 (file)
--- a/passes/memory/memory_dff.cc
+++ b/passes/memory/memory_dff.cc
@@ -17,6 +17,7 @@
  *
  */
 
+#include <algorithm>
 #include "kernel/yosys.h"
 #include "kernel/sigtools.h"
 
@@ -183,12 +184,12 @@ struct MemoryDffWorker
                if (mux_cells_a.count(sig_data) || mux_cells_b.count(sig_data))
                {
                        RTLIL::SigSpec en;
-                       RTLIL::SigSpec check_q;
+                       std::vector<RTLIL::SigSpec> check_q;
 
                        do {
                                bool enable_invert = mux_cells_a.count(sig_data) != 0;
                                Cell *mux = enable_invert ? mux_cells_a.at(sig_data) : mux_cells_b.at(sig_data);
-                               check_q = sigmap(mux->getPort(enable_invert ? "\\B" : "\\A"));
+                               check_q.push_back(sigmap(mux->getPort(enable_invert ? "\\B" : "\\A")));
                                sig_data = sigmap(mux->getPort("\\Y"));
                                en.append(enable_invert ? module->LogicNot(NEW_ID, mux->getPort("\\S")) : mux->getPort("\\S"));
                        } while (mux_cells_a.count(sig_data) || mux_cells_b.count(sig_data));
@@ -197,7 +198,8 @@ struct MemoryDffWorker
                                if (sigbit_users_count[bit] > 1)
                                        goto skip_ff_after_read_merging;
 
-                       if (find_sig_before_dff(sig_data, clk_data, clk_polarity, true) && clk_data != RTLIL::SigSpec(RTLIL::State::Sx) && sig_data == check_q)
+                       if (find_sig_before_dff(sig_data, clk_data, clk_polarity, true) && clk_data != RTLIL::SigSpec(RTLIL::State::Sx) &&
+                                       std::all_of(check_q.begin(), check_q.end(), [&](const SigSpec &cq) {return cq == sig_data; }))
                        {
                                disconnect_dff(sig_data);
                                cell->setPort("\\CLK", clk_data);

diff --git a/tests/memories/read_two_mux.v b/tests/memories/read_two_mux.v
new file mode 100644 (file)
index 0000000..4f2e7e1
--- /dev/null
+++ b/tests/memories/read_two_mux.v
@@ -0,0 +1,16 @@
+// expect-wr-ports 1
+// expect-rd-ports 1
+// expect-no-rd-clk
+
+module top(input clk, input we, re, reset, input [7:0] addr, wdata, output reg [7:0] rdata);
+
+reg [7:0] bram[0:255];
+(* keep *) reg dummy;
+
+always @(posedge clk) begin
+       rdata <= re ? (reset ? 8'b0 : bram[addr]) : rdata;
+       if (we)
+               bram[addr] <= wdata;
+end
+
+endmodule

diff --git a/tests/memories/run-test.sh b/tests/memories/run-test.sh
index 76acaa9cdfa5c96e1f12b2b66645f6229e61380f..8d1a8b41396d3c6c33e5831b622fcdb15aa25f0b 100755 (executable)
--- a/tests/memories/run-test.sh
+++ b/tests/memories/run-test.sh
@@ -31,6 +31,10 @@ for f in `egrep -l 'expect-(wr-ports|rd-ports|rd-clk)' *.v`; do
                grep -q "connect \\\\RD_CLK \\$(gawk '/expect-rd-clk/ { print $3; }' $f)\$" ${f%.v}.dmp ||
                                { echo " ERROR: Unexpected read clock."; false; }
        fi
+       if grep -q expect-no-rd-clk $f; then
+               grep -q "connect \\\\RD_CLK 1'x\$" ${f%.v}.dmp ||
+                               { echo " ERROR: Expected no read clock."; false; }
+       fi
        echo " ok."
 done