corrected the treatment of the <<= and >>= operators

lang/cem/cemcom/ch7.c

@@ -324,6 +324,7 @@ ch7asgn(expp, oper, expr)
 		EVAL should however take care of evaluating (typeof (f op e))f
 	*/
 	int fund = (*expp)->ex_type->tp_fund;
+	struct type *tp;
 
 	/* We expect an lvalue */
 	if (!(*expp)->ex_lvalue)	{
@@ -333,6 +334,7 @@ ch7asgn(expp, oper, expr)
 	}
 	if (oper == '=') {
 		ch7cast(&expr, oper, (*expp)->ex_type);
+		tp = expr->ex_type;
 	}
 	else {	/* turn e into e' where typeof(e') = typeof (f op e) */
 		struct expr *extmp = intexpr((arith)0, INT);
@@ -341,13 +343,14 @@ ch7asgn(expp, oper, expr)
 		extmp->ex_lvalue = 1;
 		extmp->ex_type = (*expp)->ex_type;
 		ch7bin(&extmp, oper, expr);
-		/* note that ch7bin creates a tree of the expression
+		/* Note that ch7bin creates a tree of the expression
 			((typeof (f op e))f op (typeof (f op e))e),
-		   where f ~ extmp and e ~ expr;
+		   where f ~ extmp and e ~ expr.
-		   we have to use (typeof (f op e))e
+		   We want to use (typeof (f op e))e.
 		   Ch7bin does not create a tree if both operands
 		   were illegal or constants!
 		*/
+		tp = extmp->ex_type;	/* perform the arithmetic in type tp */
 		if (extmp->ex_class == Oper) {
 			expr = extmp->OP_RIGHT;
 			extmp->OP_RIGHT = NILEXPR;
@@ -356,13 +359,17 @@ ch7asgn(expp, oper, expr)
 		else
 			expr = extmp;
 	}
+
 #ifndef NOBITFIELD
 	if (fund == FIELD)
 		*expp = new_oper((*expp)->ex_type->tp_up, *expp, oper, expr);
 	else
-#endif NOBITFIELD
 		*expp = new_oper((*expp)->ex_type, *expp, oper, expr);
-	(*expp)->OP_TYPE = expr->ex_type;	/* for EVAL() */
+#else NOBITFIELD
+	*expp = new_oper((*expp)->ex_type, *expp, oper, expr);
+#endif NOBITFIELD
+
+	(*expp)->OP_TYPE = tp;	/* for EVAL() */
 }
 
 /*	Some interesting (?) questions answered.

lang/cem/cemcom/ch7bin.c

@@ -156,7 +156,8 @@ ch7bin(expp, oper, expr)
 	case RIGHTAB:
 		opnd2integral(expp, oper);
 		opnd2integral(&expr, oper);
-		ch7cast(&expr, oper, int_type); /* leftop should be int	*/
+		fund = arithbalance(expp, oper, &expr); /* ch. 7.5 */
+		ch7cast(&expr, oper, int_type); /* cvt. rightop to int */
 		non_commutative_binop(expp, oper, expr);
 		break;
 	case '<':

lang/cem/cemcom/eval.c

@@ -35,7 +35,7 @@
 #include	"atw.h"
 
 #define	CRASH()		crash("EVAL: CRASH at line %u", __LINE__)
-#define	roundup(n)	((n) < word_size ? word_size : (n))
+#define	toword(n)	((n) < word_size ? word_size : (n))
 
 char *symbol2str();
 char *long2str();
@@ -374,6 +374,10 @@ EVAL(expr, val, code, true_label, false_label)
 		case ANDAB:
 		case XORAB:
 		case ORAB:
+		{
+			arith old_offset;
+			arith tmpvar = tmp_pointer_var(&old_offset);
+
 #ifndef NOBITFIELD
 			if (leftop->ex_type->tp_fund == FIELD)	{
 				eval_field(expr, code);
@@ -381,34 +385,29 @@ EVAL(expr, val, code, true_label, false_label)
 			}
 #endif NOBITFIELD
 			if (leftop->ex_class != Value) {
-				arith old_offset;
-				arith tmpvar = tmp_pointer_var(&old_offset);
-
 				EVAL(leftop, LVAL, TRUE, NO_LABEL, NO_LABEL);
 				C_lal(tmpvar);
 				C_sti(pointer_size);
 				C_lal(tmpvar);
 				C_loi(pointer_size);
 				C_loi(leftop->ex_type->tp_size);
-				conversion(leftop->ex_type, tp);
+			}
-				EVAL(rightop, RVAL, TRUE, NO_LABEL, NO_LABEL);
+			else	{
-				assop(tp, oper);
+				load_val(leftop, RVAL);
-				conversion(tp, leftop->ex_type);
+			}
-				if (gencode)
+			conversion(leftop->ex_type, tp);
-					C_dup(roundup(leftop->ex_type->tp_size));
+			EVAL(rightop, RVAL, TRUE, NO_LABEL, NO_LABEL);
+			assop(tp, oper);
+			conversion(tp, leftop->ex_type);
+			if (gencode)
+				C_dup(toword(leftop->ex_type->tp_size));
+			if (leftop->ex_class != Value) {
 				C_lal(tmpvar);
 				C_loi(pointer_size);
 				C_sti(leftop->ex_type->tp_size);
 				free_tmp_var(old_offset);
 			}
-			else	{
+			else {
-				load_val(leftop, RVAL);
-				conversion(leftop->ex_type, tp);
-				EVAL(rightop, RVAL, TRUE, NO_LABEL, NO_LABEL);
-				assop(tp, oper);
-				conversion(tp, leftop->ex_type);
-				if (gencode)
-					C_dup(roundup(leftop->ex_type->tp_size));
 				store_val(
 					&(leftop->ex_object.ex_value),
 					leftop->ex_type
@@ -417,6 +416,7 @@ EVAL(expr, val, code, true_label, false_label)
 			if (gencode)
 				conversion(leftop->ex_type, expr->ex_type);
 			break;
+		}
 		case '(':
 		{
 			register struct expr *expr;