Merge remote-tracking branch 'origin/master' into clifford/testfast

28 files changed, 626 insertions, 28 deletions

diff --git a/tests/opt/opt_expr.ys b/tests/opt/opt_expr.ys
new file mode 100644
index 000000000..f0306efa1
--- /dev/null
+++ b/tests/opt/opt_expr.ys
@@ -0,0 +1,223 @@
+
+read_verilog <<EOT
+module opt_expr_add_test(input [3:0] i, input [7:0] j, output [8:0] o);
+    assign o = (i << 4) + j;
+endmodule
+EOT
+
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$add r:A_WIDTH=5 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+##########
+
+# alumacc version of above
+design -reset
+read_verilog <<EOT
+module opt_expr_add_test(input [3:0] i, input [7:0] j, output [8:0] o);
+    assign o = (i << 4) + j;
+endmodule
+EOT
+
+alumacc
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$alu r:A_WIDTH=4 r:B_WIDTH=5 r:Y_WIDTH=5 %i %i %i
+
+##########
+
+design -reset
+read_verilog <<EOT
+module opt_expr_add_signed_test(input signed [3:0] i, input signed [7:0] j, output signed [8:0] o);
+    assign o = (i << 4) + j;
+endmodule
+EOT
+
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$add r:A_WIDTH=5 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+##########
+
+# alumacc version of above
+design -reset
+read_verilog <<EOT
+module opt_expr_add_signed_test(input signed [3:0] i, input signed [7:0] j, output signed [8:0] o);
+    assign o = (i << 4) + j;
+endmodule
+EOT
+
+alumacc
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$alu r:A_WIDTH=4 r:B_WIDTH=5 r:Y_WIDTH=5 %i %i %i
+
+##########
+
+design -reset
+read_verilog <<EOT
+module opt_expr_sub_test1(input [3:0] i, input [7:0] j, output [8:0] o);
+    assign o = j - (i << 4);
+endmodule
+EOT
+
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$sub r:A_WIDTH=4 r:B_WIDTH=5 r:Y_WIDTH=5 %i %i %i
+
+##########
+
+# alumacc version of above
+design -reset
+read_verilog <<EOT
+module opt_expr_sub_test1(input [3:0] i, input [7:0] j, output [8:0] o);
+    assign o = j - (i << 4);
+endmodule
+EOT
+
+alumacc
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+dump
+select -assert-count 1 t:$alu r:A_WIDTH=4 r:B_WIDTH=5 r:Y_WIDTH=5 %i %i %i
+
+##########
+
+design -reset
+read_verilog <<EOT
+module opt_expr_sub_signed_test1(input signed [3:0] i, input signed [7:0] j, output signed [8:0] o);
+    assign o = j - (i << 4);
+endmodule
+EOT
+
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$sub r:A_WIDTH=4 r:B_WIDTH=5 r:Y_WIDTH=5 %i %i %i
+
+##########
+
+# alumacc version of above
+design -reset
+read_verilog <<EOT
+module opt_expr_sub_signed_test1(input signed [3:0] i, input signed [7:0] j, output signed [8:0] o);
+    assign o = j - (i << 4);
+endmodule
+EOT
+
+alumacc
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$alu r:A_WIDTH=4 r:B_WIDTH=5 r:Y_WIDTH=5 %i %i %i
+
+##########
+
+design -reset
+read_verilog <<EOT
+module opt_expr_sub_test2(input [3:0] i, input [7:0] j, output [8:0] o);
+    assign o = (i << 4) - j;
+endmodule
+EOT
+
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$sub r:A_WIDTH=9 r:B_WIDTH=8 r:Y_WIDTH=9 %i %i %i
+
+##########
+
+# alumacc version of above
+design -reset
+read_verilog <<EOT
+module opt_expr_sub_test2(input [3:0] i, input [7:0] j, output [8:0] o);
+    assign o = (i << 4) - j;
+endmodule
+EOT
+
+alumacc
+opt_expr -fine
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$alu r:A_WIDTH=9 r:B_WIDTH=8 r:Y_WIDTH=9 %i %i %i
+
+##########
+
+design -reset
+read_verilog <<EOT
+module opt_expr_sub_test4(input [3:0] i, output [8:0] o);
+    assign o = 5'b00010 - i;
+endmodule
+EOT
+
+wreduce
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$sub r:A_WIDTH=2 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+##########
+
+# alumacc version of above
+design -reset
+read_verilog <<EOT
+module opt_expr_sub_test4(input [3:0] i, output [8:0] o);
+    assign o = 5'b00010 - i;
+endmodule
+EOT
+
+wreduce
+alumacc
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$alu r:A_WIDTH=2 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+###########
+
+design -reset
+read_verilog -icells <<EOT
+module opt_expr_alu_test_ci0_bi0(input [7:0] a, input [3:0] b, output [8:0] x, y, co);
+    \$alu #(.A_SIGNED(0), .B_SIGNED(0), .A_WIDTH(8), .B_WIDTH(8), .Y_WIDTH(9)) alu (.A(a), .B({b, 4'b0000}), .CI(1'b0), .BI(1'b0), .X(x), .Y(y), .CO(co));
+endmodule
+EOT
+check
+
+equiv_opt -assert opt_expr -fine
+design -load postopt
+select -assert-count 1 t:$alu r:A_WIDTH=4 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+###########
+
+design -reset
+read_verilog -icells <<EOT
+module opt_expr_alu_test_ci1_bi1(input [7:0] a, input [3:0] b, output [8:0] x, y, co);
+    \$alu #(.A_SIGNED(0), .B_SIGNED(0), .A_WIDTH(8), .B_WIDTH(8), .Y_WIDTH(9)) alu (.A(a), .B({b, 4'b0000}), .CI(1'b1), .BI(1'b1), .X(x), .Y(y), .CO(co));
+endmodule
+EOT
+check
+
+equiv_opt opt_expr -fine
+design -load postopt
+select -assert-count 1 t:$alu r:A_WIDTH=4 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+###########
+
+design -reset
+read_verilog -icells <<EOT
+module opt_expr_alu_test_ci0_bi1(input [7:0] a, input [3:0] b, output [8:0] x, y, co);
+    \$alu #(.A_SIGNED(0), .B_SIGNED(0), .A_WIDTH(8), .B_WIDTH(8), .Y_WIDTH(9)) alu (.A(a), .B({b, 4'b0000}), .CI(1'b0), .BI(1'b1), .X(x), .Y(y), .CO(co));
+endmodule
+EOT
+check
+
+equiv_opt opt_expr -fine
+design -load postopt
+select -assert-count 1 t:$alu r:A_WIDTH=8 r:B_WIDTH=8 r:Y_WIDTH=9 %i %i %i
diff --git a/tests/opt/opt_ff.v b/tests/opt/opt_ff.v
deleted file mode 100644
index a01b64b61..000000000
--- a/tests/opt/opt_ff.v
+++ /dev/null
@@ -1,21 +0,0 @@
-module top(
-    input clk,
-    input rst,
-    input [2:0] a,
-    output [1:0] b
-);
-    reg [2:0] b_reg;
-    initial begin
-        b_reg <= 3'b0;
-    end
-
-    assign b = b_reg[1:0];
-    always @(posedge clk or posedge rst) begin
-        if(rst) begin
-            b_reg <= 3'b0;
-        end else begin
-            b_reg <= a;
-        end
-    end
-endmodule
-
diff --git a/tests/opt/opt_ff.ys b/tests/opt/opt_ff.ys
deleted file mode 100644
index 704c7acf3..000000000
--- a/tests/opt/opt_ff.ys
+++ /dev/null
@@ -1,3 +0,0 @@
-read_verilog opt_ff.v
-synth_ice40
-ice40_unlut
diff --git a/tests/opt/opt_lut.ys b/tests/opt/opt_lut.ys
index 59b12c351..a9fccbb62 100644
--- a/tests/opt/opt_lut.ys
+++ b/tests/opt/opt_lut.ys
@@ -1,4 +1,2 @@
 read_verilog opt_lut.v
-synth_ice40
-ice40_unlut
-equiv_opt -map +/ice40/cells_sim.v -assert opt_lut -dlogic SB_CARRY:I0=1:I1=2:CI=3
+equiv_opt -map +/ice40/cells_sim.v -assert synth_ice40
diff --git a/tests/opt/opt_rmdff.v b/tests/opt/opt_rmdff.v
new file mode 100644
index 000000000..b1c06703c
--- /dev/null
+++ b/tests/opt/opt_rmdff.v
@@ -0,0 +1,50 @@
+module opt_rmdff_test (input C, input D, input E, output [29:0] Q);
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) remove0 (.CLK(C), .D(D), .EN(1'b0), .Q(Q[0])); // EN is never active
+(* init = "1'b1" *) wire Q1; assign Q[1] = Q1;
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) remove1 (.CLK(C), .D(D), .EN(1'b0), .Q(Q1)); // EN is never active
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) remove2 (.CLK(C), .D(D), .EN(1'bx), .Q(Q[2])); // EN is don't care
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) keep3 (.CLK(C), .D(D), .EN(1'b1), .Q(Q[3])); // EN is always active
+(* init = "1'b0" *) wire Q4; assign Q[4] = Q4;
+\$dffe #(.WIDTH(1), .CLK_POLARITY(0), .EN_POLARITY(1)) keep4 (.CLK(C), .D(D), .EN(1'b1), .Q(Q4)); // EN is always active
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(0)) remove5 (.CLK(C), .D(D), .EN(1'b1), .Q(Q[5])); // EN is never active
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(0)) remove6 (.CLK(C), .D(D), .EN(1'bx), .Q(Q[6])); // EN is don't care
+(* init = "1'b0" *) wire Q7; assign Q[7] = Q7;
+\$dffe #(.WIDTH(1), .CLK_POLARITY(0), .EN_POLARITY(0)) keep7 (.CLK(C), .D(D), .EN(E), .Q(Q7)); // EN is non constant
+
+\$_DFFE_PP_ remove8 (.C(C), .D(D), .E(1'b0), .Q(Q[8])); // EN is never active
+(* init = "1'b1" *) wire Q9; assign Q[9] = Q9;
+\$_DFFE_PP_ remove9 (.C(C), .D(D), .E(1'b0), .Q(Q9)); // EN is never active
+\$_DFFE_PP_ remove10 (.C(C), .D(D), .E(1'bx), .Q(Q[10])); // EN is don't care
+\$_DFFE_PP_ keep11 (.C(C), .D(D), .E(1'b1), .Q(Q[11])); // EN is always active
+(* init = "1'b0" *) wire Q12; assign Q[12] = Q12;
+\$_DFFE_PP_ keep12 (.C(C), .D(D), .E(1'b1), .Q(Q12)); // EN is always active
+
+\$_DFFE_NN_ remove13 (.C(C), .D(D), .E(1'b1), .Q(Q[13])); // EN is never active
+(* init = "1'b1" *) wire Q14; assign Q[14] = Q14;
+\$_DFFE_NN_ remove14 (.C(C), .D(D), .E(1'b1), .Q(Q14)); // EN is never active
+\$_DFFE_NN_ remove15 (.C(C), .D(D), .E(1'bx), .Q(Q[15])); // EN is don't care
+\$_DFFE_NN_ keep16 (.C(C), .D(D), .E(1'b0), .Q(Q[16])); // EN is always active
+(* init = "1'b0" *) wire Q17; assign Q[17] = Q17;
+\$_DFFE_NN_ keep17 (.C(C), .D(D), .E(1'b0), .Q(Q17)); // EN is always active
+
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) remove18 (.CLK(1'b0), .D(D), .EN(E), .Q(Q[18])); // CLK is constant
+(* init = "1'b1" *) wire Q19; assign Q[19] = Q19;
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) remove19 (.CLK(1'b1), .D(D), .EN(E), .Q(Q19)); // CLK is constant
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) remove20 (.CLK(C), .D(1'bx), .EN(E), .Q(Q[20])); // D is undriven, Q has no initial value
+(* init = "1'b0" *) wire Q21; assign Q[21] = Q21;
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) keep21 (.CLK(C), .D(1'bx), .EN(E), .Q(Q21)); // D is undriven, Q has initial value
+//\$dffe #(.WIDTH(1), .CLK_POLARITY(0), .EN_POLARITY(1)) remove22 (.CLK(C), .D(1'b0), .EN(1'b1), .Q(Q[22])); // D is constant, no initial Q value, EN is always active
+//                                                                                                           // (TODO, Q starts with 1'bx and becomes 1'b0)
+(* init = "1'b0" *) wire Q23; assign Q[23] = Q23;
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) noenable23 (.CLK(C), .D(1'b0), .EN(1'b1), .Q(Q23)); // D is constant, initial Q value same as D, EN is always active
+(* init = "1'b1" *) wire Q24; assign Q[24] = Q24;
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(0)) keep24 (.CLK(C), .D(1'b0), .EN(1'b0), .Q(Q24)); // D is constant, initial Q value NOT same as D, EN is always active
+(* init = "1'b1" *) wire Q25; assign Q[25] = Q25;
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(0)) remove25 (.CLK(C), .D(1'b0), .EN(1'b1), .Q(Q25)); // D is constant, EN is never active
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) remove26 (.CLK(C), .D(Q[26]), .EN(1'b1), .Q(Q[26])); // D is Q, EN is always active
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(0)) remove27 (.CLK(C), .D(Q[27]), .EN(1'b1), .Q(Q[27])); // D is Q, EN is never active, but no initial value
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(0)) remove28 (.CLK(C), .D(Q[28]), .EN(E), .Q(Q[28])); // EN is nonconst, but no initial value
+(* init = "1'b1" *) wire Q29; assign Q[29] = Q29;
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) keep29 (.CLK(C), .D(Q[29]), .EN(1'b1), .Q(Q29)); // EN is always active, but with initial value
+
+endmodule
diff --git a/tests/opt/opt_rmdff.ys b/tests/opt/opt_rmdff.ys
new file mode 100644
index 000000000..83a162f44
--- /dev/null
+++ b/tests/opt/opt_rmdff.ys
@@ -0,0 +1,26 @@
+read_verilog -icells opt_rmdff.v
+prep
+design -stash gold
+read_verilog -icells opt_rmdff.v
+proc
+opt_rmdff
+
+select -assert-count 0 c:remove*
+select -assert-min 7 c:keep*
+select -assert-count 0  t:$dffe 7:$_DFFE_* %u c:noenable* %i
+
+design -stash gate
+
+design -import gold -as gold
+design -import gate -as gate
+
+equiv_make gold gate equiv
+hierarchy -top equiv
+equiv_simple -undef
+equiv_status -assert
+
+#design -load gold
+#stat
+#
+#design -load gate
+#stat
diff --git a/tests/opt/opt_ff_sat.v b/tests/opt/opt_rmdff_sat.v
index 5a0a6fe37..5a0a6fe37 100644
--- a/tests/opt/opt_ff_sat.v
+++ b/tests/opt/opt_rmdff_sat.v
diff --git a/tests/opt/opt_ff_sat.ys b/tests/opt/opt_rmdff_sat.ys
index 4e7cc6ca4..1c3dd9c05 100644
--- a/tests/opt/opt_ff_sat.ys
+++ b/tests/opt/opt_rmdff_sat.ys
@@ -1,4 +1,4 @@
-read_verilog opt_ff_sat.v
+read_verilog opt_rmdff_sat.v
 prep -flatten
 opt_rmdff -sat
 synth
diff --git a/tests/opt/opt_share_add_sub.v b/tests/opt/opt_share_add_sub.v
new file mode 100644
index 000000000..d918f27cc
--- /dev/null
+++ b/tests/opt/opt_share_add_sub.v
@@ -0,0 +1,10 @@
+module opt_share_test(
+  input [15:0]  a,
+  input [15:0]  b,
+  input         sel,
+  output [15:0] res,
+  );
+
+  assign res = {sel ? a + b : a - b};
+
+endmodule
diff --git a/tests/opt/opt_share_add_sub.ys b/tests/opt/opt_share_add_sub.ys
new file mode 100644
index 000000000..4a5406791
--- /dev/null
+++ b/tests/opt/opt_share_add_sub.ys
@@ -0,0 +1,13 @@
+read_verilog opt_share_add_sub.v
+proc;;
+copy opt_share_test merged
+
+alumacc merged
+opt merged
+opt_share merged
+opt_clean merged
+
+miter -equiv -flatten -ignore_gold_x -make_outputs -make_outcmp opt_share_test merged miter
+sat -set-def-inputs -verify -prove trigger 0 -show-inputs -show-outputs miter
+
+select -assert-count 1 -module merged t:$alu
diff --git a/tests/opt/opt_share_cat.v b/tests/opt/opt_share_cat.v
new file mode 100644
index 000000000..7fb97fef5
--- /dev/null
+++ b/tests/opt/opt_share_cat.v
@@ -0,0 +1,15 @@
+module opt_share_test(
+  input [15:0]  a,
+  input [15:0]  b,
+  input [15:0]  c,
+  input [15:0]  d,
+  input         sel,
+  output [63:0] res,
+  );
+
+  reg [31: 0]   cat1 = {a+b, c+d};
+  reg [31: 0]   cat2 = {a-b, c-d};
+
+  assign res = {b, sel ? cat1 : cat2, a};
+
+endmodule
diff --git a/tests/opt/opt_share_cat.ys b/tests/opt/opt_share_cat.ys
new file mode 100644
index 000000000..7de69bfde
--- /dev/null
+++ b/tests/opt/opt_share_cat.ys
@@ -0,0 +1,13 @@
+read_verilog opt_share_cat.v
+proc;;
+copy opt_share_test merged
+
+alumacc merged
+opt merged
+opt_share merged
+opt_clean merged
+
+miter -equiv -flatten -ignore_gold_x -make_outputs -make_outcmp opt_share_test merged miter
+sat -set-def-inputs -verify -prove trigger 0 -show-inputs -show-outputs miter
+
+select -assert-count 2 -module merged t:$alu
diff --git a/tests/opt/opt_share_cat_multiuser.v b/tests/opt/opt_share_cat_multiuser.v
new file mode 100644
index 000000000..b250689d9
--- /dev/null
+++ b/tests/opt/opt_share_cat_multiuser.v
@@ -0,0 +1,22 @@
+module opt_share_test(
+  input [15:0]      a,
+  input [15:0]      b,
+  input [15:0]      c,
+  input [15:0]      d,
+  input             sel,
+  output reg [47:0] res,
+  );
+
+  wire [15:0]       add_res = a+b;
+  wire [15:0]       sub_res = a-b;
+  wire [31: 0]      cat1 = {add_res, c+d};
+  wire [31: 0]      cat2 = {sub_res, c-d};
+
+  always @* begin
+    case(sel)
+      0: res = {cat1, add_res};
+      1: res = {cat2, add_res};
+    endcase
+  end
+
+endmodule
diff --git a/tests/opt/opt_share_cat_multiuser.ys b/tests/opt/opt_share_cat_multiuser.ys
new file mode 100644
index 000000000..6a82fbd79
--- /dev/null
+++ b/tests/opt/opt_share_cat_multiuser.ys
@@ -0,0 +1,13 @@
+read_verilog opt_share_cat_multiuser.v
+proc;;
+copy opt_share_test merged
+
+alumacc merged
+opt merged
+opt_share merged
+opt_clean merged
+
+miter -equiv -flatten -ignore_gold_x -make_outputs -make_outcmp opt_share_test merged miter
+sat -set-def-inputs -verify -prove trigger 0 -show-inputs -show-outputs miter
+
+select -assert-count 3 -module merged t:$alu
diff --git a/tests/opt/opt_share_diff_port_widths.v b/tests/opt/opt_share_diff_port_widths.v
new file mode 100644
index 000000000..1a37c80a6
--- /dev/null
+++ b/tests/opt/opt_share_diff_port_widths.v
@@ -0,0 +1,21 @@
+module opt_share_test(
+  input [15:0]       a,
+  input [15:0]       b,
+  input [15:0]       c,
+  input [1:0]      sel,
+  output reg [15:0] res
+  );
+
+  wire [15:0]       add0_res = a+b;
+  wire [15:0]       add1_res = a+c;
+
+  always @* begin
+    case(sel)
+      0: res = add0_res[10:0];
+      1: res = add1_res[10:0];
+      2: res = a - b;
+      default: res = 32'bx;
+    endcase
+  end
+
+endmodule
diff --git a/tests/opt/opt_share_diff_port_widths.ys b/tests/opt/opt_share_diff_port_widths.ys
new file mode 100644
index 000000000..ec5e9f7b0
--- /dev/null
+++ b/tests/opt/opt_share_diff_port_widths.ys
@@ -0,0 +1,13 @@
+read_verilog opt_share_diff_port_widths.v
+proc;;
+copy opt_share_test merged
+
+alumacc merged
+opt merged
+opt_share merged
+opt_clean merged
+
+miter -equiv -flatten -ignore_gold_x -make_outputs -make_outcmp opt_share_test merged miter
+sat -set-def-inputs -verify -prove trigger 0 -show-inputs -show-outputs miter
+
+select -assert-count 2 -module merged t:$alu
diff --git a/tests/opt/opt_share_extend.v b/tests/opt/opt_share_extend.v
new file mode 100644
index 000000000..d39f19069
--- /dev/null
+++ b/tests/opt/opt_share_extend.v
@@ -0,0 +1,18 @@
+module opt_share_test(
+  input signed [7:0]       a,
+  input signed [10:0]      b,
+  input signed [15:0]      c,
+  input [1:0]              sel,
+  output reg signed [15:0] res
+  );
+
+  always @* begin
+    case(sel)
+      0: res = a + b;
+      1: res = a - b;
+      2: res = a + c;
+      default: res = 16'bx;
+    endcase
+  end
+
+endmodule
diff --git a/tests/opt/opt_share_extend.ys b/tests/opt/opt_share_extend.ys
new file mode 100644
index 000000000..c553ee0fb
--- /dev/null
+++ b/tests/opt/opt_share_extend.ys
@@ -0,0 +1,13 @@
+read_verilog opt_share_extend.v
+proc;;
+copy opt_share_test merged
+
+alumacc merged
+opt merged
+opt_share merged
+opt_clean merged
+
+miter -equiv -flatten -ignore_gold_x -make_outputs -make_outcmp opt_share_test merged miter
+sat -set-def-inputs -verify -prove trigger 0 -show-inputs -show-outputs miter
+
+select -assert-count 1 -module merged t:$alu
diff --git a/tests/opt/opt_share_large_pmux_cat.v b/tests/opt/opt_share_large_pmux_cat.v
new file mode 100644
index 000000000..416ba3766
--- /dev/null
+++ b/tests/opt/opt_share_large_pmux_cat.v
@@ -0,0 +1,21 @@
+module opt_share_test(
+  input [15:0]      a,
+  input [15:0]      b,
+  input [15:0]      c,
+  input [2:0]       sel,
+  output reg [31:0] res
+  );
+
+  always @* begin
+    case(sel)
+      0: res = {a + b, a};
+      1: res = {a - b, b};
+      2: res = {a + c, c};
+      3: res = {a - c, a};
+      4: res = {b, b};
+      5: res = {c, c};
+      default: res = 32'bx;
+    endcase
+  end
+
+endmodule
diff --git a/tests/opt/opt_share_large_pmux_cat.ys b/tests/opt/opt_share_large_pmux_cat.ys
new file mode 100644
index 000000000..4186ca52e
--- /dev/null
+++ b/tests/opt/opt_share_large_pmux_cat.ys
@@ -0,0 +1,13 @@
+read_verilog opt_share_large_pmux_cat.v
+proc;;
+copy opt_share_test merged
+
+alumacc merged
+opt merged
+opt_share merged
+opt_clean merged
+
+miter -equiv -flatten -ignore_gold_x -make_outputs -make_outcmp opt_share_test merged miter
+sat -set-def-inputs -verify -prove trigger 0 -show-inputs -show-outputs miter
+
+select -assert-count 1 -module merged t:$alu
diff --git a/tests/opt/opt_share_large_pmux_cat_multipart.v b/tests/opt/opt_share_large_pmux_cat_multipart.v
new file mode 100644
index 000000000..34d2bd9a8
--- /dev/null
+++ b/tests/opt/opt_share_large_pmux_cat_multipart.v
@@ -0,0 +1,25 @@
+module opt_share_test(
+  input [15:0]      a,
+  input [15:0]      b,
+  input [15:0]      c,
+  input [15:0]      d,
+  input [2:0]       sel,
+  output reg [31:0] res
+  );
+
+  wire [15:0]       add0_res = a+d;
+
+  always @* begin
+    case(sel)
+      0: res = {add0_res, a};
+      1: res = {a - b, add0_res[7], 15'b0};
+      2: res = {b-a, b};
+      3: res = {d, b - c};
+      4: res = {d, b - a};
+      5: res = {c, d};
+      6: res = {a - c, b-d};
+      default: res = 32'bx;
+    endcase
+  end
+
+endmodule
diff --git a/tests/opt/opt_share_large_pmux_cat_multipart.ys b/tests/opt/opt_share_large_pmux_cat_multipart.ys
new file mode 100644
index 000000000..610bb8c6c
--- /dev/null
+++ b/tests/opt/opt_share_large_pmux_cat_multipart.ys
@@ -0,0 +1,14 @@
+read_verilog opt_share_large_pmux_cat_multipart.v
+proc;;
+copy opt_share_test merged
+
+alumacc merged
+opt merged
+
+opt_share merged
+opt_clean merged
+
+miter -equiv -flatten -ignore_gold_x -make_outputs -make_outcmp opt_share_test merged miter
+sat -set-def-inputs -verify -prove trigger 0 -show-inputs -show-outputs miter
+
+select -assert-count 4 -module merged t:$alu
diff --git a/tests/opt/opt_share_large_pmux_multipart.v b/tests/opt/opt_share_large_pmux_multipart.v
new file mode 100644
index 000000000..535adf96f
--- /dev/null
+++ b/tests/opt/opt_share_large_pmux_multipart.v
@@ -0,0 +1,23 @@
+module opt_share_test(
+  input [15:0]      a,
+  input [15:0]      b,
+  input [15:0]      c,
+  input [15:0]      d,
+  input [2:0]       sel,
+  output reg [15:0] res
+  );
+
+  always @* begin
+    case(sel)
+      0: res = a + d;
+      1: res = a - b;
+      2: res = b;
+      3: res = b - c;
+      4: res = b - a;
+      5: res = c;
+      6: res = a - c;
+      default: res = 16'bx;
+    endcase
+  end
+
+endmodule
diff --git a/tests/opt/opt_share_large_pmux_multipart.ys b/tests/opt/opt_share_large_pmux_multipart.ys
new file mode 100644
index 000000000..11182df1a
--- /dev/null
+++ b/tests/opt/opt_share_large_pmux_multipart.ys
@@ -0,0 +1,13 @@
+read_verilog opt_share_large_pmux_multipart.v
+proc;;
+copy opt_share_test merged
+
+alumacc merged
+opt merged
+opt_share merged
+opt_clean merged
+
+miter -equiv -flatten -ignore_gold_x -make_outputs -make_outcmp opt_share_test merged miter
+sat -set-def-inputs -verify -prove trigger 0 -show-inputs -show-outputs miter
+
+select -assert-count 2 -module merged t:$alu
diff --git a/tests/opt/opt_share_large_pmux_part.v b/tests/opt/opt_share_large_pmux_part.v
new file mode 100644
index 000000000..a9008fb5a
--- /dev/null
+++ b/tests/opt/opt_share_large_pmux_part.v
@@ -0,0 +1,21 @@
+module opt_share_test(
+  input [15:0]      a,
+  input [15:0]      b,
+  input [15:0]      c,
+  input [2:0]       sel,
+  output reg [15:0] res
+  );
+
+  always @* begin
+    case(sel)
+      0: res = a + b;
+      1: res = a - b;
+      2: res = a + c;
+      3: res = a - c;
+      4: res = b;
+      5: res = c;
+      default: res = 16'bx;
+    endcase
+  end
+
+endmodule
diff --git a/tests/opt/opt_share_large_pmux_part.ys b/tests/opt/opt_share_large_pmux_part.ys
new file mode 100644
index 000000000..6b594a3d6
--- /dev/null
+++ b/tests/opt/opt_share_large_pmux_part.ys
@@ -0,0 +1,13 @@
+read_verilog opt_share_large_pmux_part.v
+proc;;
+copy opt_share_test merged
+
+alumacc merged
+opt merged
+opt_share merged
+opt_clean merged
+
+miter -equiv -flatten -ignore_gold_x -make_outputs -make_outcmp opt_share_test merged miter
+sat -set-def-inputs -verify -prove trigger 0 -show-inputs -show-outputs miter
+
+select -assert-count 1 -module merged t:$alu
diff --git a/tests/opt/opt_share_mux_tree.v b/tests/opt/opt_share_mux_tree.v
new file mode 100644
index 000000000..cc5ae4eb9
--- /dev/null
+++ b/tests/opt/opt_share_mux_tree.v
@@ -0,0 +1,18 @@
+module opt_share_test(
+  input [15:0]      a,
+  input [15:0]      b,
+  input [15:0]      c,
+  input [1:0]       sel,
+  output reg [15:0] res
+  );
+
+  always @* begin
+    case(sel)
+      0: res = a + b;
+      1: res = a - b;
+      2: res = a + c;
+      default: res = 16'bx;
+    endcase
+  end
+
+endmodule
diff --git a/tests/opt/opt_share_mux_tree.ys b/tests/opt/opt_share_mux_tree.ys
new file mode 100644
index 000000000..58473039f
--- /dev/null
+++ b/tests/opt/opt_share_mux_tree.ys
@@ -0,0 +1,13 @@
+read_verilog opt_share_mux_tree.v
+proc;;
+copy opt_share_test merged
+
+alumacc merged
+opt merged
+opt_share merged
+opt_clean merged
+
+miter -equiv -flatten -ignore_gold_x -make_outputs -make_outcmp opt_share_test merged miter
+sat -set-def-inputs -verify -prove trigger 0 -show-inputs -show-outputs miter
+
+select -assert-count 1 -module merged t:$alu