Merge https://github.com/YosysHQ/yosys into bram_xilinx

11 files changed, 625 insertions, 35 deletions

diff --git a/tests/arch/gowin/adffs.ys b/tests/arch/gowin/adffs.ys
index fc7ee01f2..87fba83a6 100644
--- a/tests/arch/gowin/adffs.ys
+++ b/tests/arch/gowin/adffs.ys
@@ -34,11 +34,12 @@ proc
 equiv_opt -async2sync -assert -map +/gowin/cells_sim.v synth_gowin # equivalency check
 design -load postopt # load the post-opt design (otherwise equiv_opt loads the pre-opt design)
 cd dffs # Constrain all select calls below inside the top module
-select -assert-count 1 t:DFFS
+select -assert-count 1 t:DFF
+select -assert-count 1 t:LUT2
 select -assert-count 4 t:IBUF
 select -assert-count 1 t:OBUF
 
-select -assert-none t:DFFS t:IBUF t:OBUF %% t:* %D
+select -assert-none t:DFF t:LUT2 t:IBUF t:OBUF %% t:* %D
 
 
 design -load read
diff --git a/tests/arch/gowin/init.v b/tests/arch/gowin/init.v
new file mode 100644
index 000000000..3c30f602d
--- /dev/null
+++ b/tests/arch/gowin/init.v
@@ -0,0 +1,224 @@
+module myDFF (output reg Q, input CLK, D);
+	parameter [0:0] INIT = 1'b0;
+	initial Q = INIT;
+	always @(posedge CLK)
+		Q <= D;
+endmodule
+
+module myDFFE (output reg Q, input D, CLK, CE);
+	parameter [0:0] INIT = 1'b0;
+	initial Q = INIT;
+	always @(posedge CLK) begin
+		if (CE)
+			Q <= D;
+	end
+endmodule // DFFE (positive clock edge; clock enable)
+
+
+module myDFFS (output reg Q, input D, CLK, SET);
+	parameter [0:0] INIT = 1'b1;
+	initial Q = INIT;
+	always @(posedge CLK) begin
+		if (SET)
+			Q <= 1'b1;
+		else
+			Q <= D;
+	end
+endmodule // DFFS (positive clock edge; synchronous set)
+
+
+module myDFFSE (output reg Q, input D, CLK, CE, SET);
+	parameter [0:0] INIT = 1'b1;
+	initial Q = INIT;
+	always @(posedge CLK) begin
+		if (SET)
+			Q <= 1'b1;
+		else if (CE)
+			Q <= D;
+end
+endmodule // DFFSE (positive clock edge; synchronous set takes precedence over clock enable)
+
+
+module myDFFR (output reg Q, input D, CLK, RESET);
+	parameter [0:0] INIT = 1'b0;
+	initial Q = INIT;
+	always @(posedge CLK) begin
+		if (RESET)
+			Q <= 1'b0;
+		else
+			Q <= D;
+	end
+endmodule // DFFR (positive clock edge; synchronous reset)
+
+
+module myDFFRE (output reg Q, input D, CLK, CE, RESET);
+	parameter [0:0] INIT = 1'b0;
+	initial Q = INIT;
+	always @(posedge CLK) begin
+		if (RESET)
+			Q <= 1'b0;
+		else if (CE)
+			Q <= D;
+	end
+endmodule // DFFRE (positive clock edge; synchronous reset takes precedence over clock enable)
+
+
+module myDFFP (output reg Q, input D, CLK, PRESET);
+	parameter [0:0] INIT = 1'b1;
+	initial Q = INIT;
+	always @(posedge CLK or posedge PRESET) begin
+		if(PRESET)
+			Q <= 1'b1;
+		else
+			Q <= D;
+	end
+endmodule // DFFP (positive clock edge; asynchronous preset)
+
+
+module myDFFPE (output reg Q, input D, CLK, CE, PRESET);
+	parameter [0:0] INIT = 1'b1;
+	initial Q = INIT;
+	always @(posedge CLK or posedge PRESET) begin
+		if(PRESET)
+			Q <= 1'b1;
+		else if (CE)
+			Q <= D;
+	end
+endmodule // DFFPE (positive clock edge; asynchronous preset; clock enable)
+
+
+module myDFFC (output reg Q, input D, CLK, CLEAR);
+	parameter [0:0] INIT = 1'b0;
+	initial Q = INIT;
+	always @(posedge CLK or posedge CLEAR) begin
+		if(CLEAR)
+			Q <= 1'b0;
+		else
+			Q <= D;
+	end
+endmodule // DFFC (positive clock edge; asynchronous clear)
+
+
+module myDFFCE (output reg Q, input D, CLK, CE, CLEAR);
+	parameter [0:0] INIT = 1'b0;
+	initial Q = INIT;
+	always @(posedge CLK or posedge CLEAR) begin
+		if(CLEAR)
+			Q <= 1'b0;
+		else if (CE)
+			Q <= D;
+	end
+endmodule // DFFCE (positive clock edge; asynchronous clear; clock enable)
+
+
+module myDFFN (output reg Q, input CLK, D);
+	parameter [0:0] INIT = 1'b0;
+	initial Q = INIT;
+	always @(negedge CLK)
+		Q <= D;
+endmodule
+
+module myDFFNE (output reg Q, input D, CLK, CE);
+	parameter [0:0] INIT = 1'b0;
+	initial Q = INIT;
+	always @(negedge CLK) begin
+		if (CE)
+			Q <= D;
+	end
+endmodule // DFFNE (negative clock edge; clock enable)
+
+
+module myDFFNS (output reg Q, input D, CLK, SET);
+	parameter [0:0] INIT = 1'b1;
+	initial Q = INIT;
+	always @(negedge CLK) begin
+		if (SET)
+			Q <= 1'b1;
+		else
+			Q <= D;
+	end
+endmodule // DFFNS (negative clock edge; synchronous set)
+
+
+module myDFFNSE (output reg Q, input D, CLK, CE, SET);
+	parameter [0:0] INIT = 1'b1;
+	initial Q = INIT;
+	always @(negedge CLK) begin
+		if (SET)
+			Q <= 1'b1;
+		else if (CE)
+			Q <= D;
+end
+endmodule // DFFNSE (negative clock edge; synchronous set takes precedence over clock enable)
+
+
+module myDFFNR (output reg Q, input D, CLK, RESET);
+	parameter [0:0] INIT = 1'b0;
+	initial Q = INIT;
+	always @(negedge CLK) begin
+		if (RESET)
+			Q <= 1'b0;
+		else
+			Q <= D;
+	end
+endmodule // DFFNR (negative clock edge; synchronous reset)
+
+
+module myDFFNRE (output reg Q, input D, CLK, CE, RESET);
+	parameter [0:0] INIT = 1'b0;
+	initial Q = INIT;
+	always @(negedge CLK) begin
+		if (RESET)
+			Q <= 1'b0;
+		else if (CE)
+			Q <= D;
+	end
+endmodule // DFFNRE (negative clock edge; synchronous reset takes precedence over clock enable)
+
+
+module myDFFNP (output reg Q, input D, CLK, PRESET);
+	parameter [0:0] INIT = 1'b1;
+	initial Q = INIT;
+	always @(negedge CLK or posedge PRESET) begin
+		if(PRESET)
+			Q <= 1'b1;
+		else
+			Q <= D;
+	end
+endmodule // DFFNP (negative clock edge; asynchronous preset)
+
+
+module myDFFNPE (output reg Q, input D, CLK, CE, PRESET);
+	parameter [0:0] INIT = 1'b1;
+	initial Q = INIT;
+	always @(negedge CLK or posedge PRESET) begin
+		if(PRESET)
+			Q <= 1'b1;
+		else if (CE)
+			Q <= D;
+	end
+endmodule // DFFNPE (negative clock edge; asynchronous preset; clock enable)
+
+
+module myDFFNC (output reg Q, input D, CLK, CLEAR);
+	parameter [0:0] INIT = 1'b0;
+	initial Q = INIT;
+	always @(negedge CLK or posedge CLEAR) begin
+		if(CLEAR)
+			Q <= 1'b0;
+		else
+			Q <= D;
+	end
+endmodule // DFFNC (negative clock edge; asynchronous clear)
+
+
+module myDFFNCE (output reg Q, input D, CLK, CE, CLEAR);
+	parameter [0:0] INIT = 1'b0;
+	initial Q = INIT;
+	always @(negedge CLK or posedge CLEAR) begin
+		if(CLEAR)
+			Q <= 1'b0;
+		else if (CE)
+			Q <= D;
+	end
+endmodule // DFFNCE (negative clock edge; asynchronous clear; clock enable)
diff --git a/tests/arch/gowin/init.ys b/tests/arch/gowin/init.ys
new file mode 100644
index 000000000..ddc0e4757
--- /dev/null
+++ b/tests/arch/gowin/init.ys
@@ -0,0 +1,74 @@
+read_verilog init.v
+read_verilog -lib +/gowin/cells_sim.v
+design -save read
+
+proc
+flatten
+synth_gowin -run coarse:
+
+# check if all init values are handled
+check -assert -noinit
+# check if every flop mapped correctly
+select -assert-count 1 t:DFF
+select -assert-count 1 t:DFFC
+select -assert-count 1 t:DFFCE
+select -assert-count 1 t:DFFE
+select -assert-count 1 t:DFFN
+select -assert-count 1 t:DFFNC
+select -assert-count 1 t:DFFNCE
+select -assert-count 1 t:DFFNE
+select -assert-count 1 t:DFFNP
+select -assert-count 1 t:DFFNPE
+select -assert-count 1 t:DFFNR
+select -assert-count 1 t:DFFNRE
+select -assert-count 1 t:DFFNS
+select -assert-count 1 t:DFFNSE
+select -assert-count 1 t:DFFP
+select -assert-count 1 t:DFFPE
+select -assert-count 1 t:DFFR
+select -assert-count 1 t:DFFRE
+select -assert-count 1 t:DFFS
+select -assert-count 1 t:DFFSE
+
+delete
+design -load read
+
+# these should synth to a flop with reset
+chparam -set INIT 1 myDFF myDFFN myDFFE myDFFNE
+
+# async should give a warning
+# sync should synth to a mux
+chparam -set INIT 0 myDFF*S* myDFF*P*
+chparam -set INIT 1 myDFF*R* myDFF*C*
+
+proc
+flatten
+synth_gowin -run coarse:
+
+# check the flops mapped as expected
+select -assert-count 1 t:DFF
+select -assert-count 1 t:DFFC
+select -assert-count 1 t:DFFCE
+select -assert-count 1 t:DFFE
+select -assert-count 1 t:DFFN
+select -assert-count 1 t:DFFNC
+select -assert-count 1 t:DFFNCE
+select -assert-count 1 t:DFFNE
+select -assert-count 1 t:DFFNP
+select -assert-count 1 t:DFFNPE
+select -assert-count 0 t:DFFNR
+select -assert-count 0 t:DFFNRE
+select -assert-count 2 t:DFFNS
+select -assert-count 2 t:DFFNSE
+select -assert-count 1 t:DFFP
+select -assert-count 1 t:DFFPE
+select -assert-count 0 t:DFFR
+select -assert-count 0 t:DFFRE
+select -assert-count 2 t:DFFS
+select -assert-count 2 t:DFFSE
+select -assert-count 12 t:LUT2
+
+# check the expected leftover init values
+# this would happen if your reset value is not the initial value
+# which would be weird
+select -assert-count 8 a:init
diff --git a/tests/arch/ice40/ice40_opt.ys b/tests/arch/ice40/ice40_opt.ys
index b17c69c91..5186d4800 100644
--- a/tests/arch/ice40/ice40_opt.ys
+++ b/tests/arch/ice40/ice40_opt.ys
@@ -1,4 +1,24 @@
 read_verilog -icells -formal <<EOT
+module \$__ICE40_CARRY_WRAPPER (output CO, O, input A, B, CI, I0, I3);
+  parameter LUT = 0;
+  SB_CARRY carry (
+    .I0(A),
+    .I1(B),
+    .CI(CI),
+    .CO(CO)
+  );
+  \$lut #(
+    .WIDTH(4),
+    .LUT(LUT)
+  ) lut (
+    .A({I0,A,B,I3}),
+    .Y(O)
+  );
+endmodule
+EOT
+design -stash unmap
+
+read_verilog -icells -formal <<EOT
 module top(input CI, I0, output [1:0] CO, output O);
     wire A = 1'b0, B = 1'b0;
 	\$__ICE40_CARRY_WRAPPER #(
@@ -20,7 +40,68 @@ module top(input CI, I0, output [1:0] CO, output O);
 endmodule
 EOT
 
-equiv_opt -assert -map +/ice40/cells_map.v -map +/ice40/cells_sim.v ice40_opt
+equiv_opt -assert -map %unmap -map +/ice40/cells_sim.v ice40_opt
 design -load postopt
 select -assert-count 1 t:*
 select -assert-count 1 t:$lut
+
+# https://github.com/YosysHQ/yosys/issues/1543
+design -reset
+read_verilog <<EOT
+module delay_element (input wire clk, input wire reset, input wire enable,
+                      input wire chainin,  output wire chainout, output reg latch);
+
+
+   reg                           const_zero = 0;
+   reg                           const_one = 1;
+
+    wire                         delay_tap;
+
+
+   //carry logic
+   (* keep *) SB_CARRY carry ( .CO(chainout), .I0(const_zero),
+                    .I1(const_one), .CI(chainin));
+
+
+   //flip flop latch
+   (* keep *) SB_DFFER flipflop( .Q(latch), .C(clk), .E(enable),
+                      .D(delay_tap), .R(reset));
+
+
+   //LUT table
+   // the LUT should just echo the carry in (I3)
+   // carry I0 = LUT I1
+   // carry I1 = LUT I2
+   // carry in = LUT I3
+   // LUT_INIT[0] = 0
+   // LUT_INIT[1] = 0
+   // LUT_INIT[2] = 0
+   // LUT_INIT[3] = 0
+   // LUT_INIT[4] = 0
+   // LUT_INIT[5] = 0
+   // LUT_INIT[6] = 0
+   // LUT_INIT[7] = 0
+   // LUT_INIT[8] = 1
+   // LUT_INIT[9] = 1
+   // LUT_INIT[10] = 1
+   // LUT_INIT[11] = 1
+   // LUT_INIT[12] = 1
+   // LUT_INIT[13] = 1
+   // LUT_INIT[14] = 1
+   // LUT_INIT[15] = 1
+
+   (* keep *) SB_LUT4 lut( .O(delay_tap), .I0(const_zero), .I1(const_zero),
+                .I2(const_one), .I3(chainin));
+
+   //TODO: is this the right way round??
+   defparam lut.LUT_INIT=16'hFF00;
+
+
+endmodule // delay_element
+EOT
+
+synth_ice40
+select -assert-count 1 t:SB_LUT4
+select -assert-count 1 t:SB_CARRY
+select -assert-count 1 t:SB_CARRY a:keep %i
+select -assert-count 1 t:SB_CARRY c:carry %i
diff --git a/tests/arch/ice40/ice40_wrapcarry.ys b/tests/arch/ice40/ice40_wrapcarry.ys
new file mode 100644
index 000000000..fb9fccc3a
--- /dev/null
+++ b/tests/arch/ice40/ice40_wrapcarry.ys
@@ -0,0 +1,54 @@
+read_verilog <<EOT
+module top(input A, B, CI, output O, CO);
+	SB_CARRY carry (
+		.I0(A),
+		.I1(B),
+		.CI(CI),
+		.CO(CO)
+	);
+	SB_LUT4 #(
+		.LUT_INIT(16'b 0110_1001_1001_0110)
+	) adder (
+		.I0(1'b0),
+		.I1(A),
+		.I2(B),
+		.I3(1'b0),
+		.O(O)
+	);
+endmodule
+EOT
+
+ice40_wrapcarry
+select -assert-count 1 t:$__ICE40_CARRY_WRAPPER
+
+design -reset
+read_verilog <<EOT
+module top(input A, B, CI, output O, CO);
+    (* foo = "bar", answer = 42, keep=0 *)
+	SB_CARRY carry (
+		.I0(A),
+		.I1(B),
+		.CI(CI),
+		.CO(CO)
+	);
+    (* keep, blah="blah", answer = 43 *)
+	SB_LUT4 #(
+		.LUT_INIT(16'b 0110_1001_1001_0110)
+	) adder (
+		.I0(1'b0),
+		.I1(A),
+		.I2(B),
+		.I3(1'b0),
+		.O(O)
+	);
+endmodule
+EOT
+
+ice40_wrapcarry
+select -assert-count 1 t:$__ICE40_CARRY_WRAPPER
+select -assert-count 0 t:* t:$__ICE40_CARRY_WRAPPER %d
+select -assert-count 1 a:keep=1 a:SB_CARRY.\foo=bar %i a:SB_CARRY.\answer=42 %i a:SB_LUT4.\blah=blah %i a:SB_LUT4.\answer=43 %i
+
+ice40_wrapcarry -unwrap
+select -assert-count 1 c:carry a:src=<<EOT:3 %i a:keep=0 %i a:foo=bar %i a:answer=42 %i
+select -assert-count 1 c:adder a:src=<<EOT:10 %i a:keep=1 %i a:blah=blah %i a:answer=43 %i
diff --git a/tests/arch/ice40/wrapcarry.ys b/tests/arch/ice40/wrapcarry.ys
deleted file mode 100644
index 10c029e68..000000000
--- a/tests/arch/ice40/wrapcarry.ys
+++ /dev/null
@@ -1,22 +0,0 @@
-read_verilog <<EOT
-module top(input A, B, CI, output O, CO);
-	SB_CARRY carry (
-		.I0(A),
-		.I1(B),
-		.CI(CI),
-		.CO(CO)
-	);
-	SB_LUT4 #(
-		.LUT_INIT(16'b 0110_1001_1001_0110)
-	) adder (
-		.I0(1'b0),
-		.I1(A),
-		.I2(B),
-		.I3(1'b0),
-		.O(O)
-	);
-endmodule
-EOT
-
-ice40_wrapcarry
-select -assert-count 1 t:$__ICE40_CARRY_WRAPPER
diff --git a/tests/arch/xilinx/dsp_fastfir.ys b/tests/arch/xilinx/dsp_fastfir.ys
new file mode 100644
index 000000000..0067a822b
--- /dev/null
+++ b/tests/arch/xilinx/dsp_fastfir.ys
@@ -0,0 +1,69 @@
+read_verilog <<EOT
+// Citation https://github.com/ZipCPU/dspfilters/blob/master/rtl/fastfir.v
+module fastfir_dynamictaps(i_clk, i_reset, i_tap_wr, i_tap, i_ce, i_sample, o_result);
+  wire [30:0] _00_;
+  wire [23:0] _01_;
+  wire [11:0] _02_;
+  wire [30:0] _03_;
+  wire [23:0] _04_;
+  wire [30:0] _05_;
+  wire [23:0] _06_;
+  wire [30:0] _07_;
+  wire [23:0] _08_;
+  wire [11:0] _09_;
+  wire [30:0] _10_;
+  wire [23:0] _11_;
+  wire [30:0] _12_;
+  wire [23:0] _13_;
+  wire [11:0] \fir.FILTER[0].tapk.delayed_sample ;
+  reg [30:0] \fir.FILTER[0].tapk.o_acc  = 31'h00000000;
+  wire [11:0] \fir.FILTER[0].tapk.o_sample ;
+  reg [23:0] \fir.FILTER[0].tapk.product ;
+  reg [11:0] \fir.FILTER[0].tapk.tap  = 12'h000;
+  wire [11:0] \fir.FILTER[1].tapk.delayed_sample ;
+  wire [30:0] \fir.FILTER[1].tapk.o_acc ;
+  wire [11:0] \fir.FILTER[1].tapk.o_sample ;
+  reg [23:0] \fir.FILTER[1].tapk.product ;
+  reg [11:0] \fir.FILTER[1].tapk.tap  = 12'h000;
+  input i_ce;
+  input i_clk;
+  input i_reset;
+  input [11:0] i_sample;
+  input [11:0] i_tap;
+  input i_tap_wr;
+  output [30:0] o_result;
+  reg [30:0] o_result;
+  assign _03_ = 31'h00000000 + { \fir.FILTER[0].tapk.product [23], \fir.FILTER[0].tapk.product [23], \fir.FILTER[0].tapk.product [23], \fir.FILTER[0].tapk.product [23], \fir.FILTER[0].tapk.product [23], \fir.FILTER[0].tapk.product [23], \fir.FILTER[0].tapk.product [23], \fir.FILTER[0].tapk.product  };
+  assign _04_ = $signed(\fir.FILTER[0].tapk.tap ) * $signed(i_sample);
+  always @(posedge i_clk)
+      \fir.FILTER[0].tapk.tap  <= _02_;
+  always @(posedge i_clk)
+      \fir.FILTER[0].tapk.o_acc  <= _00_;
+  always @(posedge i_clk)
+      \fir.FILTER[0].tapk.product  <= _01_;
+  assign _02_ = i_tap_wr ? i_tap : \fir.FILTER[0].tapk.tap ;
+  assign _05_ = i_ce ? _03_ : \fir.FILTER[0].tapk.o_acc ;
+  assign _00_ = i_reset ? 31'h00000000 : _05_;
+  assign _06_ = i_ce ? _04_ : \fir.FILTER[0].tapk.product ;
+  assign _01_ = i_reset ? 24'h000000 : _06_;
+  assign _10_ = \fir.FILTER[0].tapk.o_acc  + { \fir.FILTER[1].tapk.product [23], \fir.FILTER[1].tapk.product [23], \fir.FILTER[1].tapk.product [23], \fir.FILTER[1].tapk.product [23], \fir.FILTER[1].tapk.product [23], \fir.FILTER[1].tapk.product [23], \fir.FILTER[1].tapk.product [23], \fir.FILTER[1].tapk.product  };
+  assign _11_ = $signed(\fir.FILTER[1].tapk.tap ) * $signed(i_sample);
+  always @(posedge i_clk)
+      \fir.FILTER[1].tapk.tap  <= _09_;
+  always @(posedge i_clk)
+      o_result <= _07_;
+  always @(posedge i_clk)
+      \fir.FILTER[1].tapk.product  <= _08_;
+  assign _09_ = i_tap_wr ? \fir.FILTER[0].tapk.tap  : \fir.FILTER[1].tapk.tap ;
+  assign _12_ = i_ce ? _10_ : o_result;
+  assign _07_ = i_reset ? 31'h00000000 : _12_;
+  assign _13_ = i_ce ? _11_ : \fir.FILTER[1].tapk.product ;
+  assign _08_ = i_reset ? 24'h000000 : _13_;
+  assign \fir.FILTER[1].tapk.o_acc  = o_result;
+endmodule
+EOT
+
+synth_xilinx
+cd fastfir_dynamictaps
+select -assert-count 2 t:DSP48E1
+select -assert-none t:* t:DSP48E1 %d t:BUFG %d
diff --git a/tests/arch/xilinx/macc.sh b/tests/arch/xilinx/macc.sh
index 2272679ee..154a29848 100644
--- a/tests/arch/xilinx/macc.sh
+++ b/tests/arch/xilinx/macc.sh
@@ -1,3 +1,3 @@
-../../../yosys -qp "synth_xilinx -top macc2; rename -top macc2_uut" macc.v -o macc_uut.v
+../../../yosys -qp "synth_xilinx -top macc2; rename -top macc2_uut" -o macc_uut.v macc.v
 iverilog -o test_macc macc_tb.v macc_uut.v macc.v ../../../techlibs/xilinx/cells_sim.v
 vvp -N ./test_macc
diff --git a/tests/opt/bug1525.ys b/tests/opt/bug1525.ys
new file mode 100644
index 000000000..972bc0ac7
--- /dev/null
+++ b/tests/opt/bug1525.ys
@@ -0,0 +1,13 @@
+read_verilog << EOF
+module top(...);
+input A1, A2, B, S;
+output O;
+
+assign O = S ? (A1 & B) : (A2 & B);
+
+endmodule
+EOF
+
+simplemap
+opt_share
+dump
diff --git a/tests/simple_abc9/abc9.v b/tests/simple_abc9/abc9.v
index 64b625efe..de60619d1 100644
--- a/tests/simple_abc9/abc9.v
+++ b/tests/simple_abc9/abc9.v
@@ -218,12 +218,6 @@ module MUXF8(input I0, I1, S, output O);
 endmodule
 
 // Citation: https://github.com/alexforencich/verilog-ethernet
-// TODO: yosys -p "synth_xilinx -abc9 -top abc9_test022" abc9.v -q
-// returns before b4321a31
-//   Warning: Wire abc9_test022.\m_eth_payload_axis_tkeep [7] is used but has no
-//   driver.
-//   Warning: Wire abc9_test022.\m_eth_payload_axis_tkeep [3] is used but has no
-//   driver.
 module abc9_test022
 (
     input  wire        clk,
@@ -237,9 +231,6 @@ module abc9_test022
 endmodule
 
 // Citation: https://github.com/riscv/riscv-bitmanip
-// TODO: yosys -p "synth_xilinx -abc9 -top abc9_test023" abc9.v -q
-// returns before 14233843
-//   Warning: Wire abc9_test023.\dout [1] is used but has no driver.
 module abc9_test023 #(
 	parameter integer N = 2,
 	parameter integer M = 2
@@ -267,3 +258,9 @@ module abc9_test026(output [3:0] o, p);
 assign o = { 1'b1, 1'bx };
 assign p = { 1'b1, 1'bx, 1'b0 };
 endmodule
+
+module abc9_test030(input [3:0] d, input en, output reg [3:0] q);
+always @*
+  if (en)
+    q <= d;
+endmodule
diff --git a/tests/techmap/iopadmap.ys b/tests/techmap/iopadmap.ys
new file mode 100644
index 000000000..f4345e906
--- /dev/null
+++ b/tests/techmap/iopadmap.ys
@@ -0,0 +1,99 @@
+read_verilog << EOT
+module ibuf ((* iopad_external_pin *) input i, output o); endmodule
+module obuf (input i, (* iopad_external_pin *) output o); endmodule
+module obuft (input i, input oe, (* iopad_external_pin *) output o); endmodule
+module iobuf (input i, input oe, output o, (* iopad_external_pin *) inout io); endmodule
+
+module a(input i, output o);
+assign o = i;
+endmodule
+
+module b(input i, output o);
+assign o = i;
+ibuf b (.i(i), .o(o));
+endmodule
+
+module c(input i, output o);
+obuf b (.i(i), .o(o));
+endmodule
+
+module d(input i, oe, output o, o2, o3);
+assign o = oe ? i : 1'bz;
+assign o2 = o;
+assign o3 = ~o;
+endmodule
+
+module e(input i, oe, inout io, output o2, o3);
+assign io = oe ? i : 1'bz;
+assign o2 = io;
+assign o3 = ~io;
+endmodule
+EOT
+
+opt_clean
+tribuf
+simplemap
+iopadmap -bits -inpad ibuf o:i -outpad obuf i:o -toutpad obuft oe:i:o -tinoutpad iobuf oe:o:i:io
+opt_clean
+
+select -assert-count 1 a/t:ibuf
+select -assert-count 1 a/t:obuf
+select -set ib w:i %a %co a/t:ibuf %i
+select -set ob w:o %a %ci a/t:obuf %i
+select -assert-count 1 @ib
+select -assert-count 1 @ob
+select -assert-count 1 @ib %co %co @ob %i
+
+select -assert-count 1 b/t:ibuf
+select -assert-count 1 b/t:obuf
+select -set ib w:i %a %co b/t:ibuf %i
+select -set ob w:o %a %ci b/t:obuf %i
+select -assert-count 1 @ib
+select -assert-count 1 @ob
+select -assert-count 1 @ib %co %co @ob %i
+
+select -assert-count 1 c/t:ibuf
+select -assert-count 1 c/t:obuf
+select -set ib w:i %a %co c/t:ibuf %i
+select -set ob w:o %a %ci c/t:obuf %i
+select -assert-count 1 @ib
+select -assert-count 1 @ob
+select -assert-count 1 @ib %co %co @ob %i
+
+select -assert-count 2 d/t:ibuf
+select -assert-count 2 d/t:obuf
+select -assert-count 1 d/t:obuft
+select -set ib w:i %a %co d/t:ibuf %i
+select -set oeb w:oe %a %co d/t:ibuf %i
+select -set ob w:o %a %ci d/t:obuft %i
+select -set o2b w:o2 %a %ci d/t:obuf %i
+select -set o3b w:o3 %a %ci d/t:obuf %i
+select -assert-count 1 @ib
+select -assert-count 1 @oeb
+select -assert-count 1 @ob
+select -assert-count 1 @o2b
+select -assert-count 1 @o3b
+select -assert-count 1 @ib %co %co @ob %i
+select -assert-count 1 @oeb %co %co @ob %i
+select -assert-count 1 @ib %co %co @o2b %i
+select -assert-count 1 @ib %co %co t:$_NOT_ %i
+select -assert-count 1 @o3b %ci %ci t:$_NOT_ %i
+
+select -assert-count 2 e/t:ibuf
+select -assert-count 2 e/t:obuf
+select -assert-count 1 e/t:iobuf
+select -set ib w:i %a %co e/t:ibuf %i
+select -set oeb w:oe %a %co e/t:ibuf %i
+select -set iob w:io %a %ci e/t:iobuf %i
+select -set o2b w:o2 %a %ci e/t:obuf %i
+select -set o3b w:o3 %a %ci e/t:obuf %i
+select -assert-count 1 @ib
+select -assert-count 1 @oeb
+select -assert-count 1 @iob
+select -assert-count 1 @o2b
+select -assert-count 1 @o3b
+select -assert-count 1 @ib %co %co @iob %i
+select -assert-count 1 @oeb %co %co @iob %i
+select -assert-count 1 @iob %co %co @o2b %i
+select -assert-count 1 @iob %co %co t:$_NOT_ %i
+select -assert-count 1 @o3b %ci %ci t:$_NOT_ %i