Merge pull request #1432 from YosysHQ/eddie/fix1427

Refactor peepopt_dffmux and be sensitive to \init when trimming

tests/sat/initval.ys

@@ -2,3 +2,23 @@ read_verilog -sv initval.v
 proc;;
 
 sat -seq 10 -prove-asserts
+
+read_verilog <<EOT
+module gold(input clk, input i, output reg [1:0] o);
+initial o = 2'b10;
+always @(posedge clk)
+   o[0] <= {i,i};
+endmodule
+
+module gate(input clk, input i, output reg [1:0] o);
+initial o = 2'b10;
+always @(posedge clk)
+   o[0] <= i;
+always @*
+   o[1] <= o[0];
+endmodule
+EOT
+
+proc
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -seq 1 -falsify -prove-asserts -show-ports miter

tests/various/peepopt.ys

@@ -131,8 +131,8 @@ EOT
 proc
 equiv_opt -assert peepopt
 design -load postopt
-select -assert-count 1 t:$dff r:WIDTH=5 %i
-select -assert-count 1 t:$mux r:WIDTH=5 %i
+select -assert-count 1 t:$dff r:WIDTH=4 %i
+select -assert-count 1 t:$mux r:WIDTH=4 %i
 select -assert-count 0 t:$dff t:$mux %% t:* %D
 
 ####################
@@ -173,3 +173,41 @@ select -assert-count 1 t:$dff r:WIDTH=2 %i
 select -assert-count 2 t:$mux
 select -assert-count 2 t:$mux r:WIDTH=2 %i
 select -assert-count 0 t:$logic_not t:$dff t:$mux %% t:* %D
+
+####################
+
+design -reset
+read_verilog <<EOT
+module peepopt_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 peepopt
+
+design -save gold
+peepopt
+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:$dff r:WIDTH=4 %i
+select -assert-count 2 t:$mux
+select -assert-count 2 t:$mux r:WIDTH=4 %i
+select -assert-count 0 t:$logic_not t:$dff t:$mux %% t:* %D