Merge pull request #586 from larsclausen/struct-signed

Add  support for signed packed structs/unions

elab_type.cc

@@ -180,6 +180,7 @@ netstruct_t* struct_type_t::elaborate_type_raw(Design*des, NetScope*scope) const
       netstruct_t*res = new netstruct_t;
 
       res->packed(packed_flag);
+      res->set_signed(signed_flag);
 
       if (union_flag)
 	    res->union_flag(true);

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

netstruct.h

@@ -51,6 +51,10 @@ class netstruct_t : public LineInfo, public ivl_type_s {
       void packed(bool flag);
       bool packed(void) const;
 
+        // When the struct is accessed as a primary it can be signed or unsigned
+      void set_signed(bool flag) { signed_ = flag; }
+      bool get_signed(void) const { return signed_; }
+
 	// Append a new member to the struct/union. This must be done
 	// after the union_flag and packed settings are set. This
 	// function does error checking, and the "des" argument is
@@ -74,6 +78,7 @@ class netstruct_t : public LineInfo, public ivl_type_s {
     private:
       bool union_;
       bool packed_;
+      bool signed_;
       std::vector<member_t>members_;
 };
 

parse.y

@@ -457,6 +457,11 @@ static void current_function_set_statement(const YYLTYPE&loc, std::vector<Statem
 	    PExpr*expr;
       } genvar_iter;
 
+      struct {
+	    bool packed_flag;
+	    bool signed_flag;
+      } packed_signing;
+
       verinum* number;
 
       verireal* realtime;
@@ -571,7 +576,7 @@ static void current_function_set_statement(const YYLTYPE&loc, std::vector<Statem
 %type <number>  number pos_neg_number
 %type <flag>    signing unsigned_signed_opt signed_unsigned_opt
 %type <flag>    import_export
-%type <flag>    K_genvar_opt K_packed_opt K_reg_opt K_static_opt K_virtual_opt
+%type <flag>    K_genvar_opt K_reg_opt K_static_opt K_virtual_opt
 %type <flag>    udp_reg_opt edge_operator
 %type <drive>   drive_strength drive_strength_opt dr_strength0 dr_strength1
 %type <letter>  udp_input_sym udp_output_sym
@@ -642,6 +647,7 @@ static void current_function_set_statement(const YYLTYPE&loc, std::vector<Statem
 %type <struct_member>  struct_union_member
 %type <struct_members> struct_union_member_list
 %type <struct_type>    struct_data_type
+%type <packed_signing> packed_signing
 
 %type <class_declaration_extends> class_declaration_extends_opt
 
@@ -2988,38 +2994,54 @@ enum_name
       }
   ;
 
-struct_data_type
+/* `signed` and `unsigned` are only valid if preceded by `packed` */
-  : K_struct K_packed_opt '{' struct_union_member_list '}'
+packed_signing /* IEEE 1800-2012 A.2.2.1 */
+  : K_packed unsigned_signed_opt
+      { $$.packed_flag = true;
+        $$.signed_flag = $2;
+      }
+  |
+      { $$.packed_flag = false;
+        $$.signed_flag = false;
+      }
+  ;
+
+struct_data_type /* IEEE 1800-2012 A.2.2.1 */
+  : K_struct packed_signing '{' struct_union_member_list '}'
       { struct_type_t*tmp = new struct_type_t;
 	FILE_NAME(tmp, @1);
-	tmp->packed_flag = $2;
+	tmp->packed_flag = $2.packed_flag;
+	tmp->signed_flag = $2.signed_flag;
 	tmp->union_flag = false;
 	tmp->members .reset($4);
 	$$ = tmp;
       }
-  | K_union K_packed_opt '{' struct_union_member_list '}'
+  | K_union packed_signing '{' struct_union_member_list '}'
       { struct_type_t*tmp = new struct_type_t;
 	FILE_NAME(tmp, @1);
-	tmp->packed_flag = $2;
+	tmp->packed_flag = $2.packed_flag;
+	tmp->signed_flag = $2.signed_flag;
 	tmp->union_flag = true;
 	tmp->members .reset($4);
 	$$ = tmp;
       }
-  | K_struct K_packed_opt '{' error '}'
+  | K_struct packed_signing '{' error '}'
       { yyerror(@3, "error: Errors in struct member list.");
 	yyerrok;
 	struct_type_t*tmp = new struct_type_t;
 	FILE_NAME(tmp, @1);
-	tmp->packed_flag = $2;
+	tmp->packed_flag = $2.packed_flag;
+	tmp->signed_flag = $2.signed_flag;
 	tmp->union_flag = false;
 	$$ = tmp;
       }
-  | K_union K_packed_opt '{' error '}'
+  | K_union packed_signing '{' error '}'
       { yyerror(@3, "error: Errors in union member list.");
 	yyerrok;
 	struct_type_t*tmp = new struct_type_t;
 	FILE_NAME(tmp, @1);
-	tmp->packed_flag = $2;
+	tmp->packed_flag = $2.packed_flag;
+	tmp->signed_flag = $2.signed_flag;
 	tmp->union_flag = true;
 	$$ = tmp;
       }
@@ -7453,7 +7475,6 @@ unique_priority
      collect those rules here. */
 
 K_genvar_opt   : K_genvar    { $$ = true; } | { $$ = false; } ;
-K_packed_opt   : K_packed    { $$ = true; } | { $$ = false; } ;
 K_reg_opt      : K_reg       { $$ = true; } | { $$ = false; } ;
 K_static_opt   : K_static    { $$ = true; } | { $$ = false; } ;
 K_virtual_opt  : K_virtual   { $$ = true; } | { $$ = false; } ;

pform_types.h

@@ -207,6 +207,7 @@ struct struct_type_t : public data_type_t {
 
       bool packed_flag;
       bool union_flag;
+      bool signed_flag;
       std::unique_ptr< std::list<struct_member_t*> > members;
 };