5 files changed, 195 insertions, 0 deletions
diff --git a/tests/opt/bug2318.ys b/tests/opt/bug2318.ys
new file mode 100644
index 000000000..9de6f88ec
--- /dev/null
+++ b/tests/opt/bug2318.ys
@@ -0,0 +1,12 @@
+read_verilog <<EOT
+module t(input [3:0] A, input [3:0] B, output signed [3:0] Y);
+
+wire [7:0] P = A * B;
+wire signed [7:0] SP = P;
+wire signed [3:0] SB = B;
+assign Y = SP / SB;
+
+endmodule
+EOT
+
+equiv_opt -assert peepopt
diff --git a/tests/opt/opt_dff_dffmux.ys b/tests/opt/opt_dff_dffmux.ys
new file mode 100644
index 000000000..43190cc31
--- /dev/null
+++ b/tests/opt/opt_dff_dffmux.ys
@@ -0,0 +1,129 @@
+design -reset
+read_verilog <<EOT
+module opt_dffmuxext_unsigned(input clk, ce, input [1:0] i, output reg [3:0] o);
+    always @(posedge clk) if (ce) o <= i;
+endmodule
+EOT
+
+proc
+equiv_opt -assert opt
+design -load postopt
+select -assert-count 1 t:$dffe r:WIDTH=2 %i
+select -assert-count 0 t:$dffe %% t:* %D
+
+####################
+
+design -reset
+read_verilog <<EOT
+module opt_dffmuxext_signed(input clk, ce, input signed [1:0] i, output reg signed [3:0] o);
+    always @(posedge clk) if (ce) o <= i;
+endmodule
+EOT
+
+proc
+equiv_opt -assert opt
+design -load postopt
+wreduce
+select -assert-count 1 t:$dffe r:WIDTH=2 %i
+select -assert-count 0 t:$dffe %% t:* %D
+
+###################
+
+design -reset
+read_verilog <<EOT
+module opt_dffmuxext_const(input clk, ce, input [1:0] i, output reg [5:0] o);
+    always @(posedge clk) if (ce) o <= {1'b0, i[1], 2'b1x, i[0], 1'bz};
+endmodule
+EOT
+
+proc
+equiv_opt -assert opt
+design -load postopt
+select -assert-count 1 t:$dffe r:WIDTH=2 %i
+select -assert-count 0 t:$dffe %% t:* %D
+
+###################
+
+design -reset
+read_verilog <<EOT
+module opt_dffmuxext_const_init(input clk, ce, input [1:0] i, (* init=6'b0x00x1 *) output reg [5:0] o);
+    always @(posedge clk) if (ce) o <= {1'b0, i[1], 2'b1x, i[0], 1'bz};
+endmodule
+EOT
+
+proc
+equiv_opt -assert opt
+design -load postopt
+select -assert-count 1 t:$dffe r:WIDTH=4 %i
+select -assert-count 0 t:$dffe %% t:* %D
+
+####################
+
+design -reset
+read_verilog <<EOT
+module opt_dffmuxext_unsigned_rst(input clk, ce, rst, input [1:0] i, output reg [3:0] o);
+    always @(posedge clk) if (rst) o <= 0; else if (ce) o <= i;
+endmodule
+EOT
+
+proc
+equiv_opt -assert opt
+design -load postopt
+wreduce
+select -assert-count 1 t:$sdffe r:WIDTH=2 %i
+select -assert-count 0 t:$sdffe %% t:* %D
+
+####################
+
+design -reset
+read_verilog <<EOT
+module opt_dffmuxext_signed_rst(input clk, ce, rstn, input signed [1:0] i, output reg signed [3:0] o);
+    always @(posedge clk) begin
+        if (ce) o <= i;
+        if (!rstn) o <= 4'b1111;
+    end
+endmodule
+EOT
+
+proc
+equiv_opt -assert opt
+design -load postopt
+wreduce
+select -assert-count 1 t:$sdffe r:WIDTH=2 %i
+select -assert-count 0 t:$sdffe %% t:* %D
+
+####################
+
+design -reset
+read_verilog <<EOT
+module opt_dffmuxext_signed_rst_init(input clk, ce, rstn, input signed [1:0] i, output reg signed [3:0] o);
+    initial o <= 4'b0010;
+    always @(posedge clk) begin
+        if (ce) o <= i;
+        if (!rstn) o <= 4'b1111;
+    end
+endmodule
+EOT
+
+proc
+# NB: equiv_opt uses equiv_induct which covers
+#     only the induction half of temporal induction
+#     --- missing the base-case half
+#     This makes it akin to `sat -tempinduct-inductonly`
+#     instead of `sat -tempinduct-baseonly` or
+#     `sat -tempinduct` which is necessary for this
+#     testcase
+#equiv_opt -assert opt
+
+design -save gold
+opt
+wreduce
+design -stash gate
+design -import gold -as gold
+design -import gate -as gate
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -tempinduct -verify -prove-asserts -show-ports miter
+
+design -load gate
+select -assert-count 1 t:$sdffe r:WIDTH=3 %i
+select -assert-count 0 t:$sdffe %% t:* %D
diff --git a/tests/opt/opt_share_bug2334.ys b/tests/opt/opt_share_bug2334.ys
new file mode 100644
index 000000000..004d98349
--- /dev/null
+++ b/tests/opt/opt_share_bug2334.ys
@@ -0,0 +1,13 @@
+read_verilog <<EOT
+
+module t(input [3:0] A, input [3:0] B, input [3:0] C, input S, output [3:0] Y);
+
+wire [3:0] t = A + C;
+
+assign Y = S ? A + B : {4{t[0]}};
+
+endmodule
+
+EOT
+
+equiv_opt -assert opt_share
diff --git a/tests/opt/opt_share_bug2335.ys b/tests/opt/opt_share_bug2335.ys
new file mode 100644
index 000000000..0846a9ec3
--- /dev/null
+++ b/tests/opt/opt_share_bug2335.ys
@@ -0,0 +1,27 @@
+read_verilog <<EOT
+
+module top(...);
+
+input [3:0] A, B, C;
+input S;
+input [1:0] T;
+output [3:0] X;
+output reg [3:0] Y;
+
+wire [3:0] D = A + B;
+
+assign X = S ? D : A + C;
+always @* begin
+        case(T)
+        2'b01: Y <= A;
+        2'b10: Y <= B;
+        default: Y <= D;
+        endcase
+end
+
+endmodule
+
+EOT
+
+proc
+equiv_opt -assert opt_share
diff --git a/tests/opt/opt_share_bug2336.ys b/tests/opt/opt_share_bug2336.ys
new file mode 100644
index 000000000..cd472ef46
--- /dev/null
+++ b/tests/opt/opt_share_bug2336.ys
@@ -0,0 +1,14 @@
+read_verilog <<EOT
+
+module top(input [3:0] A, B, C, input S, output [2:0] O);
+
+wire [3:0] tb = A + B;
+wire [3:0] tc = A + C;
+
+assign O = S ? tb[3:1] : tc[3:1];
+
+endmodule
+
+EOT
+
+equiv_opt -assert opt_share