Add support for real % in a continuous assignment.

This patch adds conditional support (2001X) for the real modulus
operator in a continuous assignment.

elab_net.cc

@@ -828,20 +828,28 @@ NetNet* PEBinary::elaborate_net_mod_(Design*des, NetScope*scope,
 	    des->errors += 1;
       }
 
-      if (lsig->data_type() == IVL_VT_REAL) {
-	    cerr << get_fileline() << ": error: The modulus operator "
-		    "is not supported for real values." << endl;
+        /* The % operator does not support real arguments in baseline
+           Verilog. But we allow it in our extended form of Verilog. */
+      if (generation_flag < GN_VER2001X && lsig->data_type() == IVL_VT_REAL) {
+	    cerr << get_fileline() << ": error: Modulus operator may not "
+	    "have REAL operands." << endl;
 	    des->errors += 1;
       }
 
 	/* rwidth is result width. */
       unsigned rwidth = lwidth;
       if (rwidth == 0) {
-	    rwidth = lsig->vector_width();
-	    if (rsig->vector_width() > rwidth)
-		  rwidth = rsig->vector_width();
+	      /* Reals are always 1 wide and lsig/rsig types match here. */
+	    if (lsig->data_type() == IVL_VT_REAL) {
+		  lwidth = 1;
+		  rwidth = 1;
+	    } else {
+		  rwidth = lsig->vector_width();
+		  if (rsig->vector_width() > rwidth)
+		        rwidth = rsig->vector_width();
 
-	    lwidth = rwidth;
+		  lwidth = rwidth;
+	    }
       }
 
       NetModulo*mod = new NetModulo(scope, scope->local_symbol(), rwidth,

tgt-vvp/vvp_scope.c

@@ -1701,7 +1701,7 @@ static void draw_lpm_add(ivl_lpm_t net)
 	    break;
 	  case IVL_LPM_MOD:
 	    if (dto == IVL_VT_REAL)
-		  assert(0);  /* Not supported for reals, */
+		  type = "mod.r";
 	    else
 		  type = "mod";
 	    break;

vvp/arith.cc

@@ -805,6 +805,23 @@ void vvp_arith_div_real::recv_real(vvp_net_ptr_t ptr, double bit)
       vvp_send_real(ptr.ptr()->out, val);
 }
 
+/* Real modulus. */
+vvp_arith_mod_real::vvp_arith_mod_real()
+{
+}
+
+vvp_arith_mod_real::~vvp_arith_mod_real()
+{
+}
+
+void vvp_arith_mod_real::recv_real(vvp_net_ptr_t ptr, double bit)
+{
+      dispatch_operand_(ptr, bit);
+
+      double val = fmod(op_a_, op_b_);
+      vvp_send_real(ptr.ptr()->out, val);
+}
+
 /* Real summation. */
 vvp_arith_sum_real::vvp_arith_sum_real()
 {

vvp/arith.h

@@ -231,6 +231,14 @@ class vvp_arith_div_real : public vvp_arith_real_ {
       void recv_real(vvp_net_ptr_t ptr, double bit);
 };
 
+class vvp_arith_mod_real : public vvp_arith_real_ {
+
+    public:
+      explicit vvp_arith_mod_real();
+      ~vvp_arith_mod_real();
+      void recv_real(vvp_net_ptr_t ptr, double bit);
+};
+
 class vvp_arith_mult_real : public vvp_arith_real_ {
 
     public:

vvp/compile.cc

@@ -956,6 +956,18 @@ void compile_arith_mod(char*label, long wid,
       make_arith(arith, label, argc, argv);
 }
 
+void compile_arith_mod_r(char*label, unsigned argc, struct symb_s*argv)
+{
+      if (argc != 2) {
+	    fprintf(stderr, "%s .arith/mod.r has wrong number of symbols\n", label);
+	    compile_errors += 1;
+	    return;
+      }
+
+      vvp_arith_real_ *arith = new vvp_arith_mod_real;
+      make_arith(arith, label, argc, argv);
+}
+
 void compile_arith_mult(char*label, long wid,
 			unsigned argc, struct symb_s*argv)
 {

vvp/compile.h

@@ -173,6 +173,7 @@ extern void compile_arith_mult_r(char*label, unsigned argc,
                                  struct symb_s*argv);
 extern void compile_arith_pow_r(char*label, unsigned argc, struct symb_s*argv);
 extern void compile_arith_div_r(char*label, unsigned argc, struct symb_s*argv);
+extern void compile_arith_mod_r(char*label, unsigned argc, struct symb_s*argv);
 extern void compile_arith_sum_r(char*label, unsigned argc, struct symb_s*argv);
 extern void compile_arith_sub_r(char*label, unsigned argc, struct symb_s*argv);
 extern void compile_cmp_eq_r(char*label, unsigned argc, struct symb_s*argv);

vvp/lexor.lex

@@ -91,6 +91,7 @@
 ".arith/div.r"  { return K_ARITH_DIV_R; }
 ".arith/div.s"  { return K_ARITH_DIV_S; }
 ".arith/mod"  { return K_ARITH_MOD; }
+".arith/mod.r"  { return K_ARITH_MOD_R; }
 ".arith/mult" { return K_ARITH_MULT; }
 ".arith/mult.r" { return K_ARITH_MULT_R; }
 ".arith/pow.r" { return K_ARITH_POW_R; }

vvp/parse.y

@@ -66,9 +66,10 @@ static struct __vpiModPath*modpath_dst = 0;
 };
 
 %token K_ALIAS K_ALIAS_S K_ALIAS_R
-%token K_ARITH_DIV K_ARITH_DIV_R K_ARITH_DIV_S K_ARITH_MOD K_ARITH_MULT
-%token K_ARITH_MULT_R K_ARITH_SUB K_ARITH_SUB_R K_ARITH_SUM K_ARITH_SUM_R
-%token K_ARITH_POW_R K_ARRAY K_ARRAY_I K_ARRAY_R K_ARRAY_S K_ARRAY_PORT
+%token K_ARITH_DIV K_ARITH_DIV_R K_ARITH_DIV_S K_ARITH_MOD K_ARITH_MOD_R
+%token K_ARITH_MULT K_ARITH_MULT_R K_ARITH_SUB K_ARITH_SUB_R
+%token K_ARITH_SUM K_ARITH_SUM_R K_ARITH_POW_R
+%token K_ARRAY K_ARRAY_I K_ARRAY_R K_ARRAY_S K_ARRAY_PORT
 %token K_CMP_EEQ K_CMP_EQ K_CMP_EQ_R K_CMP_NEE K_CMP_NE K_CMP_NE_R
 %token K_CMP_GE K_CMP_GE_R K_CMP_GE_S K_CMP_GT K_CMP_GT_R K_CMP_GT_S
 %token K_CONCAT K_DEBUG K_DELAY K_DFF
@@ -270,6 +271,11 @@ statement
 		  compile_arith_mod($1, $3, obj.cnt, obj.vect);
 		}
 
+	| T_LABEL K_ARITH_MOD_R T_NUMBER ',' symbols ';'
+		{ struct symbv_s obj = $5;
+		  compile_arith_mod_r($1, obj.cnt, obj.vect);
+		}
+
 	| T_LABEL K_ARITH_MULT T_NUMBER ',' symbols ';'
 		{ struct symbv_s obj = $5;
 		  compile_arith_mult($1, $3, obj.cnt, obj.vect);