Add calculated delay, real valued, non-blocking assignments.

This patch add the ability to do a non-blocking assignment
for real values using a non-constant (calculated) delay.

tgt-vvp/vvp_process.c

@@ -531,7 +531,7 @@ static int show_stmt_assign_nb_real(ivl_statement_t net)
       unsigned long use_word = 0;
 	/* thread address for a word value. */
       int word;
-      unsigned long delay;
+      unsigned long delay = 0;
 
 	/* Must be exactly 1 l-value. */
       assert(ivl_stmt_lvals(net) == 1);
@@ -547,20 +547,25 @@ static int show_stmt_assign_nb_real(ivl_statement_t net)
 	    use_word = get_number_immediate(word_ix);
       }
 
-      delay = 0;
       if (del && (ivl_expr_type(del) == IVL_EX_ULONG)) {
 	    delay = ivl_expr_uvalue(del);
 	    del = 0;
       }
 
-	/* XXXX For now, presume delays are constant. */
-      assert(del == 0);
-
 	/* Evaluate the r-value */
       word = draw_eval_real(rval);
 
+	/* We need to calculate the delay expression. */
+      if (del) {
+	    int delay_index = allocate_word();
+	    draw_eval_expr_into_integer(del, delay_index);
+	    fprintf(vvp_out, "   %%assign/wr/d v%p_%lu, %d, %u;\n",
+	            sig, use_word, delay_index, word);
+	    clr_word(delay_index);
+      } else {
 	    fprintf(vvp_out, "   %%assign/wr v%p_%lu, %lu, %u;\n",
 	            sig, use_word, delay, word);
+      }
 
       clr_word(word);
 

vvp/codes.h

@@ -48,6 +48,7 @@ extern bool of_ASSIGN_V0D(vthread_t thr, vvp_code_t code);
 extern bool of_ASSIGN_V0X1(vthread_t thr, vvp_code_t code);
 extern bool of_ASSIGN_V0X1D(vthread_t thr, vvp_code_t code);
 extern bool of_ASSIGN_WR(vthread_t thr, vvp_code_t code);
+extern bool of_ASSIGN_WRD(vthread_t thr, vvp_code_t code);
 extern bool of_ASSIGN_X0(vthread_t thr, vvp_code_t code);
 extern bool of_BLEND(vthread_t thr, vvp_code_t code);
 extern bool of_BLEND_WR(vthread_t thr, vvp_code_t code);

vvp/compile.cc

@@ -93,6 +93,7 @@ const static struct opcode_table_s opcode_table[] = {
       { "%assign/v0/x1",of_ASSIGN_V0X1,3,{OA_FUNC_PTR,OA_BIT1,OA_BIT2} },
       { "%assign/v0/x1/d",of_ASSIGN_V0X1D,3,{OA_FUNC_PTR,OA_BIT1,OA_BIT2} },
       { "%assign/wr",of_ASSIGN_WR,3,{OA_VPI_PTR,OA_BIT1,     OA_BIT2} },
+      { "%assign/wr/d",of_ASSIGN_WRD,3,{OA_VPI_PTR,OA_BIT1,     OA_BIT2} },
       { "%assign/x0",of_ASSIGN_X0,3,{OA_FUNC_PTR,OA_BIT1,    OA_BIT2} },
       { "%blend",    of_BLEND,   3,  {OA_BIT1,     OA_BIT2,     OA_NUMBER} },
       { "%blend/wr", of_BLEND_WR,2,  {OA_BIT1,     OA_BIT2,     OA_NONE} },

vvp/opcodes.txt

@@ -89,7 +89,7 @@ where the assignment should be schedule, and the <bit> is the base of
 the vector to be assigned to the destination. The vector width is in
 index register 0.
 
-The %assign/v0/d variation puts the delay instead into an integer
+The %assign/v0/d variation gets the delay instead from an integer
 register that is given by the <delayx> value. This should not be 0, of
 course, because integer 0 is taken with the vector width.
 
@@ -104,9 +104,14 @@ index register with the canonical index of the destination where the
 vector is to be written. This allows for part writes into the vector.
 
 * %assign/wr <vpi-label>, <delay>, <index>
+* %assign/wr/d <vpi-label>, <delayx>, <index>
 
-This instruction causes a non-blocking assign of the indexed value to
+This instruction provides a non-blocking assign of the real value
-the real object addressed by the <vpi-label> label.
+given in <index> to the real object addressed by the <vpi-label>
+label after the given <delay>.
+
+The %assign/wr/d variation gets the delay from integer register
+<delayx>.
 
 * %assign/x0 <var-label>, <delay>, <bit> (OBSOLETE -- See %assign/v0x)
 

vvp/vthread.cc

@@ -820,6 +820,25 @@ bool of_ASSIGN_WR(vthread_t thr, vvp_code_t cp)
       return true;
 }
 
+bool of_ASSIGN_WRD(vthread_t thr, vvp_code_t cp)
+{
+      unsigned delay = thr->words[cp->bit_idx[0]].w_int;
+      unsigned index = cp->bit_idx[1];
+      s_vpi_time del;
+
+      del.type = vpiSimTime;
+      vpip_time_to_timestruct(&del, delay);
+
+      struct __vpiHandle*tmp = cp->handle;
+
+      t_vpi_value val;
+      val.format = vpiRealVal;
+      val.value.real = thr->words[index].w_real;
+      vpi_put_value(tmp, &val, &del, vpiInertialDelay);
+
+      return true;
+}
+
 bool of_ASSIGN_X0(vthread_t thr, vvp_code_t cp)
 {
 #if 0