Add test for br_gh1248

ivtest/gold/br_gh1248-vvp-stdout.gold

@@ -0,0 +1,10 @@
+0.000: x xxx x
+1.000: x xx0 0
+1.070: x x00 0
+1.130: 0 000 0
+2.000: 0 001 1
+2.050: 0 011 1
+2.120: 1 111 1
+3.000: 1 110 0
+3.070: 1 100 0
+3.130: 0 000 0

ivtest/ivltests/br_gh1248.sdf

@@ -0,0 +1,40 @@
+(DELAYFILE
+ (SDFVERSION "3.0")
+ (DESIGN "br_gh1248")
+ (DATE "Thu Feb 19 22:00:00 2026")
+ (VENDOR "Custom")
+ (PROGRAM "Custom")
+ (VERSION "1.0.0")
+ (DIVIDER /)
+ (VOLTAGE 1.200)
+ (PROCESS "1.000")
+ (TEMPERATURE 25.000)
+ (TIMESCALE 1ns)
+ (CELL
+  (CELLTYPE "top")
+  (INSTANCE dut)
+  (DELAY
+   (ABSOLUTE
+    (INTERCONNECT i1/Y i2/A (0.010))
+   )
+  )
+ )
+ (CELL
+  (CELLTYPE "buff")
+  (INSTANCE dut/i1)
+  (DELAY
+   (ABSOLUTE
+    (IOPATH A Y (0.050) (0.070))
+   )
+  )
+ )
+ (CELL
+  (CELLTYPE "buff")
+  (INSTANCE dut/i2)
+  (DELAY
+   (ABSOLUTE
+    (IOPATH A Y (0.060) (0.050))
+   )
+  )
+ )
+)

ivtest/ivltests/br_gh1248.v

@@ -0,0 +1,40 @@
+`timescale 1ns/1ps
+
+module tb;
+  reg in;
+  wire out;
+
+  top dut(out, in);
+
+  initial begin
+    $monitor("%.3f: %b %b %b",$realtime,out,dut.int,in);
+    $sdf_annotate("ivltests/br_gh1248.sdf");
+    #1;
+    in = 1'b0;
+    #1;
+    in = 1'b1;
+    #1;
+    in = 1'b0;
+    #1;
+  end
+endmodule
+
+module top(output wire out, input wire in);
+  wire [2:0] int;
+
+  assign int[0] = in;
+  buff i1 (.Y(int[1]), .A(int[0]));
+  buff i2 (.Y(int[2]), .A(int[1]));
+  assign out = int[2];
+endmodule
+
+`celldefine
+module buff(output wire Y, input wire A);
+  buf (Y, A);
+
+  specify
+    (A => Y) = 0;
+  endspecify
+ 
+endmodule
+`endcelldefine

ivtest/regress-vvp.list

@@ -63,6 +63,7 @@ br_gh1180b			vvp_tests/br_gh1180b.json
 br_gh1181			vvp_tests/br_gh1181.json
 br_gh1184			vvp_tests/br_gh1184.json
 br_gh1242			vvp_tests/br_gh1242.json
+br_gh1248			vvp_tests/br_gh1248.json
 br_gh1256a			vvp_tests/br_gh1256a.json
 br_gh1256b			vvp_tests/br_gh1256b.json
 br_gh1258a			vvp_tests/br_gh1258a.json

ivtest/vvp_tests/br_gh1248.json

@@ -0,0 +1,10 @@
+{
+    "type"          : "normal",
+    "source"        : "br_gh1248.v",
+    "iverilog-args" : [ "-Ttyp", "-ginterconnect", "-gspecify" ],
+    "gold"   : "br_gh1248",
+    "vlog95" : {
+        "__comment" : "The buffer module output is not connected.",
+	"type"      : "TE"
+    }
+}