vhdlpp: Evaluate power (**) and division remainder (REM) operators.

vhdlpp/expression_emit.cc

@@ -375,6 +375,22 @@ int ExpArithmetic::emit(ostream&out, Entity*ent, ScopeBase*scope)
 {
       int errors = 0;
 
+      if(fun_ == REM) {
+          // Special case: division remainder, defined in the VHDL standard 1076-2008/9.2.7
+          // there is no direct counterpart, therefore output the formula to
+          // compute a remainder: A rem B = A - (A/B) * B;
+          out << "((";
+          errors += emit_operand1(out, ent, scope);
+          out << ")-((";
+          errors += emit_operand1(out, ent, scope);
+          out << ")/(";
+          errors += emit_operand2(out, ent, scope);
+          out << "))*(";
+          errors += emit_operand2(out, ent, scope);
+          out << "))";
+          return errors;
+      }
+
       errors += emit_operand1(out, ent, scope);
 
       switch (fun_) {
@@ -396,9 +412,8 @@ int ExpArithmetic::emit(ostream&out, Entity*ent, ScopeBase*scope)
 	  case POW:
 	    out << " ** ";
 	    break;
-	  case REM:
+	  case REM: // should not happen as it is handled above, suppress warnings
-	    out << " /* ?remainder? */ ";
+            ivl_assert(*this, 0);
-	    break;
 	  case xCONCAT:
 	    ivl_assert(*this, 0);
 	    out << " /* ?concat? */ ";

vhdlpp/expression_evaluate.cc

@@ -23,6 +23,7 @@
 # include  "architec.h"
 # include  <ivl_assert.h>
 # include  <limits>
+# include  <cmath>
 
 bool Expression::evaluate(ScopeBase*, int64_t&) const
 {
@@ -68,9 +69,13 @@ bool ExpArithmetic::evaluate(ScopeBase*scope, int64_t&val) const
 	    val = val1 % val2;
 	    break;
 	  case REM:
+	    if (val2 == 0)
+		  return false;
+	    val = val1 - (val1 / val2) * val2;
 	    return false;
 	  case POW:
-	    return false;
+	    val = (int64_t) pow(val1, val2);
+	    break;
 	  case xCONCAT: // not possible
 	    return false;
       }