4 files changed, 207 insertions, 0 deletions
diff --git a/tests/opt/opt_expr_alu.ys b/tests/opt/opt_expr_alu.ys
new file mode 100644
index 000000000..a3361ca43
--- /dev/null
+++ b/tests/opt/opt_expr_alu.ys
@@ -0,0 +1,63 @@
+read_verilog <<EOT
+module test(input a, output [1:0] y);
+assign y = {a,1'b0} + 1'b1;
+endmodule
+EOT
+
+alumacc
+equiv_opt opt_expr -fine
+design -load postopt
+select -assert-count 1 t:$pos
+select -assert-count none t:$pos t:* %D
+
+
+design -reset
+read_verilog <<EOT
+module test(input a, output [1:0] y);
+assign y = {a,1'b1} + 1'b1;
+endmodule
+EOT
+
+alumacc
+select -assert-count 1 t:$alu
+select -assert-count none t:$alu t:* %D
+
+
+design -reset
+read_verilog <<EOT
+module test(input a, output [1:0] y);
+assign y = {a,1'b1} - 1'b1;
+endmodule
+EOT
+
+equiv_opt opt_expr -fine
+design -load postopt
+select -assert-count 1 t:$pos
+select -assert-count none t:$pos t:* %D
+
+
+design -reset
+read_verilog <<EOT
+module test(input a, output [3:0] y);
+assign y = {a,3'b101} - 1'b1;
+endmodule
+EOT
+
+equiv_opt opt_expr -fine
+design -load postopt
+select -assert-count 1 t:$pos
+select -assert-count none t:$pos t:* %D
+
+
+design -reset
+read_verilog <<EOT
+module test(input a, output [3:0] y);
+assign y = {a,3'b101} - 1'b1;
+endmodule
+EOT
+
+alumacc
+equiv_opt opt_expr -fine
+design -load postopt
+select -assert-count 1 t:$pos
+select -assert-count none t:$pos t:* %D
diff --git a/tests/opt/opt_expr_xor.ys b/tests/opt/opt_expr_xor.ys
new file mode 100644
index 000000000..21439fd53
--- /dev/null
+++ b/tests/opt/opt_expr_xor.ys
@@ -0,0 +1,52 @@
+read_verilog <<EOT
+module top(input a, output [3:0] y);
+assign y[0] = a^1'b0;
+assign y[1] = 1'b1^a;
+assign y[2] = a~^1'b0;
+assign y[3] = 1'b1^~a;
+endmodule
+EOT
+design -save read
+select -assert-count 2 t:$xor
+select -assert-count 2 t:$xnor
+
+equiv_opt opt_expr
+design -load postopt
+select -assert-none t:$xor
+select -assert-none t:$xnor
+select -assert-count 2 t:$not
+
+
+design -load read
+simplemap
+equiv_opt opt_expr
+design -load postopt
+select -assert-none t:$_XOR_
+select -assert-none t:$_XNOR_ # NB: simplemap does $xnor -> $_XOR_+$_NOT_
+select -assert-count 3 t:$_NOT_
+
+
+design -reset
+read_verilog -icells <<EOT
+module top(input a, output [1:0] y);
+$_XNOR_ u0(.A(a), .B(1'b0), .Y(y[0]));
+$_XNOR_ u1(.A(1'b1), .B(a), .Y(y[1]));
+endmodule
+EOT
+select -assert-count 2 t:$_XNOR_
+equiv_opt opt_expr
+design -load postopt
+select -assert-none t:$_XNOR_ # NB: simplemap does $xnor -> $_XOR_+$_NOT_
+select -assert-count 1 t:$_NOT_
+
+
+design -reset
+read_verilog <<EOT
+module top(input a, output [1:0] w, x, y, z);
+assign w = a^1'b0;
+assign x = a^1'b1;
+assign y = a~^1'b0;
+assign z = a~^1'b1;
+endmodule
+EOT
+equiv_opt opt_expr
diff --git a/tests/opt/opt_merge_init.ys b/tests/opt/opt_merge_init.ys
index a29c29df6..0176f09c7 100644
--- a/tests/opt/opt_merge_init.ys
+++ b/tests/opt/opt_merge_init.ys
@@ -20,6 +20,7 @@ endmodule
 EOT
 
 opt_merge
+select -assert-count 1 t:$dff
 select -assert-count 1 a:init=1'0
 
 
@@ -46,4 +47,31 @@ endmodule
 EOT
 
 opt_merge
+select -assert-count 1 t:$dff
 select -assert-count 1 a:init=2'bx1
+
+
+design -reset
+read_verilog -icells <<EOT
+module top(input clk, i, (* init = 1'b0 *) output o, /* NB: no init here! */ output p);
+  \$dff  #(
+    .CLK_POLARITY(1'h1),
+    .WIDTH(32'd1)
+  ) ffo  (
+    .CLK(clk),
+    .D(i),
+    .Q(o)
+  );
+  \$dff  #(
+    .CLK_POLARITY(1'h1),
+    .WIDTH(32'd1)
+  ) ffp  (
+    .CLK(clk),
+    .D(i),
+    .Q(p)
+  );
+endmodule
+EOT
+
+opt_merge
+select -assert-count 2 t:$dff
diff --git a/tests/opt/opt_merge_keep.ys b/tests/opt/opt_merge_keep.ys
new file mode 100644
index 000000000..2a9202901
--- /dev/null
+++ b/tests/opt/opt_merge_keep.ys
@@ -0,0 +1,64 @@
+read_verilog -icells <<EOT
+module top(input clk, i, output o, p);
+  (* keep *)
+  \$_DFF_P_ ffo  (
+    .C(clk),
+    .D(i),
+    .Q(o)
+  );
+  \$_DFF_P_ ffp  (
+    .C(clk),
+    .D(i),
+    .Q(p)
+  );
+endmodule
+EOT
+
+opt_merge
+select -assert-count 1 t:$_DFF_P_
+select -assert-count 1 a:keep
+
+
+design -reset
+read_verilog -icells <<EOT
+module top(input clk, i, output o, p);
+  \$_DFF_P_ ffo  (
+    .C(clk),
+    .D(i),
+    .Q(o)
+  );
+  (* keep *)
+  \$_DFF_P_ ffp  (
+    .C(clk),
+    .D(i),
+    .Q(p)
+  );
+endmodule
+EOT
+
+opt_merge
+select -assert-count 1 t:$_DFF_P_
+select -assert-count 1 a:keep
+
+
+design -reset
+read_verilog -icells <<EOT
+module top(input clk, i, output o, p);
+  (* keep *)
+  \$_DFF_P_ ffo  (
+    .C(clk),
+    .D(i),
+    .Q(o)
+  );
+  (* keep *)
+  \$_DFF_P_ ffp  (
+    .C(clk),
+    .D(i),
+    .Q(p)
+  );
+endmodule
+EOT
+
+opt_merge
+select -assert-count 2 t:$_DFF_P_
+select -assert-count 2 a:keep