Fix rounding issue (#2890)

Fixes #2802

JerryScript-DCO-1.0-Signed-off-by: Daniella Barsony bella@inf.u-szeged.hu

tests/jerry/arithmetics-bignums.js

@@ -23,8 +23,35 @@ assert(big == 2147483648); // overflow on 32bit numbers
 big++;
 assert(big == 2147483649); // overflow on 32bit numbers
 
-assert ((1152921504606846976).toString() === "1152921504606847000")
+assert ((1152921504606846976).toString() === "1152921504606847000");
 
 assert (1.797693134862315808e+308 === Infinity);
 
 assert (9999999999999999 == 10000000000000000);
+
+assert((9007199254740993).toString() === "9007199254740992");
+
+assert((9007199254740992).toString() === "9007199254740992");
+
+assert((9007199254740994).toString() === "9007199254740994");
+
+assert((1.00517e+21).toString() === "1.0051699999999999e+21");
+
+assert((1.00001e+21).toString() === "1.0000099999999999e+21");
+
+assert((9007199254740995).toString() === "9007199254740996");
+
+assert((18014398509481989).toString() === "18014398509481988");
+
+assert((18014398509481990).toString() === "18014398509481992");
+
+assert((18014398509481991).toString() === "18014398509481992");
+
+assert((18014398509481993).toString() === "18014398509481992");
+
+assert((18014398509481994).toString() === "18014398509481992");
+
+assert((18014398509481997).toString() === "18014398509481996");
+
+assert((18014398509481998).toString() === "18014398509482000");
+

tests/jerry/regression-test-issue-2802.js

@@ -0,0 +1,15 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+assert(2e23 == 1.9999999999999998e+23);