Add regression test for signed struct

Add a test that checks that signing annotations on structs are supported
and that signed structs are properly evaluated as a signed value.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

ivtest/ivltests/struct_signed.v

@@ -0,0 +1,58 @@
+// Tests that packed structs can have signed/unsigned modifier and that signed
+// packed structs when used as a primary behave correctly.
+
+module test;
+
+  // Unsigned by default
+  struct packed {
+    logic [15:0] x;
+  } s1;
+
+  // Explicitly unsigned
+  struct packed unsigned {
+    logic [15:0] x;
+  } s2;
+
+  // Explicitly signed
+  struct packed signed {
+    logic [15:0] x;
+  } s3;
+
+
+  bit failed = 1'b0;
+
+  `define check(x) \
+    if (!(x)) begin \
+      $display("FAILED: ", `"x`"); \
+      failed = 1'b1; \
+    end
+
+  initial begin
+    s1 = -1;
+    s2 = -1;
+    s3 = -1;
+
+    `check(!$is_signed(s1));
+    `check(!$is_signed(s2));
+    `check($is_signed(s3));
+
+    // These evaluate as signed
+    `check($signed(s1) < 0);
+    `check($signed(s2) < 0);
+    `check(s3 < 0);
+
+    // These all evaluate as unsigned
+    `check(s1 > 0);
+    `check(s2 > 0);
+    `check(s3.x > 0)
+    `check(s3[15:0] > 0)
+    `check({s3} > 0)
+    `check($unsigned(s3) > 0)
+    `check(s3 > 16'h0)
+
+    if (!failed) begin
+      $display("PASSED");
+    end
+  end
+
+endmodule

ivtest/regress-sv.list

@@ -383,6 +383,7 @@ struct_packed_array2	normal,-g2009		ivltests
 struct_packed_sysfunct	normal,-g2009		ivltests
 struct_packed_write_read2	normal,-g2009	ivltests
 struct_invalid_member	CE,-g2009		ivltests gold=struct_invalid_member.gold
+struct_signed		normal,-g2009		ivltests
 sv-constants		normal,-g2005-sv	ivltests
 sv_array_assign_pattern2	normal,-g2009	ivltests
 sv_cast_integer		normal,-g2005-sv	ivltests

ivtest/regress-vlog95.list

@@ -838,6 +838,7 @@ size_cast3		normal,-g2009,-pallowsigned=1	ivltests
 size_cast5		normal,-g2009,-pallowsigned=1	ivltests
 struct_packed_array	normal,-g2009,-pallowsigned=1	ivltests
 struct_packed_array2	normal,-g2009,-pallowsigned=1	ivltests
+struct_signed		normal,-g2009,-pallowsigned=1	ivltests
 sv_for_variable  normal,-g2009,-pallowsigned=1	ivltests
 sv_foreach1		normal,-g2009,-pallowsigned=1	ivltests
 sv_foreach5		normal,-g2009,-pallowsigned=1	ivltests

ivtest/regression_report-devel.txt

@@ -2158,6 +2158,7 @@ test_mos_strength_reduction: Passed.
      struct_packed_sysfunct: Passed.
   struct_packed_write_read2: Passed.
       struct_invalid_member: Passed - CE.
+              struct_signed: Passed.
                sv-constants: Passed.
    sv_array_assign_pattern2: Passed.
             sv_cast_integer: Passed.
@@ -2565,4 +2566,4 @@ test_mos_strength_reduction: Passed.
                 ufuncsynth1: Passed.
 ============================================================================
 Test results:
-  Total=2563, Passed=2557, Failed=3, Not Implemented=0, Expected Fail=3
+  Total=2564, Passed=2558, Failed=3, Not Implemented=0, Expected Fail=3

ivtest/regression_report-fsv.txt

@@ -2165,6 +2165,7 @@ test_mos_strength_reduction: Passed.
      struct_packed_sysfunct: Passed.
   struct_packed_write_read2: Passed.
       struct_invalid_member: Passed - CE.
+              struct_signed: Passed.
                sv-constants: Passed.
    sv_array_assign_pattern2: Passed.
             sv_cast_integer: Passed.
@@ -2565,4 +2566,4 @@ test_mos_strength_reduction: Passed.
                 ufuncsynth1: Passed.
 ============================================================================
 Test results:
-  Total=2563, Passed=2543, Failed=17, Not Implemented=3, Expected Fail=0
+  Total=2564, Passed=2544, Failed=17, Not Implemented=3, Expected Fail=0

ivtest/regression_report-strict.txt

@@ -2154,6 +2154,7 @@ test_mos_strength_reduction: Passed.
      struct_packed_sysfunct: Passed.
   struct_packed_write_read2: Passed.
       struct_invalid_member: Passed - CE.
+              struct_signed: Passed.
                sv-constants: Passed.
    sv_array_assign_pattern2: Passed.
             sv_cast_integer: Passed.
@@ -2562,4 +2563,4 @@ test_mos_strength_reduction: Passed.
                 ufuncsynth1: Passed.
 ============================================================================
 Test results:
-  Total=2560, Passed=2554, Failed=3, Not Implemented=0, Expected Fail=3
+  Total=2561, Passed=2555, Failed=3, Not Implemented=0, Expected Fail=3

ivtest/regression_report-vlog95.txt

@@ -664,6 +664,7 @@ Running vlog95 compiler/VVP tests for Icarus Verilog version: 12.
                  size_cast5: Passed.
         struct_packed_array: Passed.
        struct_packed_array2: Passed.
+              struct_signed: Passed.
             sv_for_variable: Passed.
                 sv_foreach1: Passed.
                 sv_foreach5: Passed.
@@ -2565,4 +2566,4 @@ test_mos_strength_reduction: Passed.
            synth_if_no_else: Passed.
 ============================================================================
 Test results:
-  Total=2563, Passed=2524, Failed=2, Not Implemented=3, Expected Fail=34
+  Total=2564, Passed=2525, Failed=2, Not Implemented=3, Expected Fail=34