From 7bb8a4463f4602b50e17786e66f3cf2e8e2e0541 Mon Sep 17 00:00:00 2001
From: Cary R <cygcary@yahoo.com>
Date: Sat, 13 Feb 2021 01:10:38 -0800
Subject: [PATCH] Time literals need to be rounded using the time precision

---
 parse.y  | 16 ++++++++++++----
 pform.cc |  7 +++++++
 pform.h  |  1 +
 3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/parse.y b/parse.y
index a350cc5b9..cab94a7fb 100644
--- a/parse.y
+++ b/parse.y
@@ -3195,7 +3195,7 @@ delay_value_simple
 	: DEC_NUMBER
 		{ verinum*tmp = $1;
 		  if (tmp == 0) {
-			yyerror(@1, "internal error: delay.");
+			yyerror(@1, "internal error: decimal delay.");
 			$$ = 0;
 		  } else {
 			$$ = new PENumber(tmp);
@@ -3206,7 +3206,7 @@ delay_value_simple
 	| REALTIME
 		{ verireal*tmp = $1;
 		  if (tmp == 0) {
-			yyerror(@1, "internal error: delay.");
+			yyerror(@1, "internal error: real time delay.");
 			$$ = 0;
 		  } else {
 			$$ = new PEFNumber(tmp);
@@ -3225,7 +3225,7 @@ delay_value_simple
 		  based_size = 0;
 		  $$         = 0;
 		  if ($1 == 0 || !get_time_unit($1, unit))
-			yyerror(@1, "internal error: delay.");
+			yyerror(@1, "internal error: time literal delay.");
 		  else {
 			double p = pow(10.0,
 			               (double)(unit - pform_get_timeunit()));
@@ -3832,10 +3832,18 @@ expr_primary
           based_size = 0;
           $$         = 0;
           if ($1 == 0 || !get_time_unit($1, unit))
-              yyerror(@1, "internal error: delay.");
+              yyerror(@1, "internal error: time literal.");
           else {
               double p = pow(10.0, (double)(unit - pform_get_timeunit()));
               double time = atof($1) * p;
+              // The time value needs to be rounded at the correct digit
+              // since this is a normal real value and not a delay that
+              // will be rounded later. This style of rounding is not safe
+              // for all real values!
+              int rdigit = pform_get_timeunit() - pform_get_timeprec();
+              assert(rdigit >= 0);
+              double scale = pow(10.0, (double)rdigit);
+              time = round(time*scale)/scale;
 
               verireal *v = new verireal(time);
               $$ = new PEFNumber(v);
diff --git a/pform.cc b/pform.cc
index 30be384d7..b91f61165 100644
--- a/pform.cc
+++ b/pform.cc
@@ -1213,6 +1213,13 @@ int pform_get_timeunit()
       return scopex->time_unit;
 }
 
+int pform_get_timeprec()
+{
+      PScopeExtra*scopex = find_nearest_scopex(lexical_scope);
+      assert(scopex);
+      return scopex->time_precision;
+}
+
 void pform_set_timeprec(const char*txt, bool initial_decl)
 {
       int val;
diff --git a/pform.h b/pform.h
index 98a00684c..f4a8c04ed 100644
--- a/pform.h
+++ b/pform.h
@@ -594,6 +594,7 @@ extern void parm_to_defparam_list(const string&param);
  */
 extern bool get_time_unit(const char*cp, int &unit);
 extern int  pform_get_timeunit();
+extern int  pform_get_timeprec();
 extern void pform_set_timeunit(const char*txt, bool initial_decl);
 extern void pform_set_timeprec(const char*txt, bool initial_decl);
 /*