Csaba Osztrogonác f5e3faeaff Make ecma_number_make_nan more optimal and C99 conform (#3163)
This change makes ecma_number_make_nan and ecma_number_make_infinity
always return constant value without any function call. Previously we
relied on compiler optimizations.

The ecma_number_t_accessor union is introduced to be able to access
float values as float and uint32_t (and doubles as double and uint64_t)
properly, without violating strict aliasing rules. There were many
copies of it, all of them were replaced to this new union.

Additionally ecma_number_make_nan should return QNaN instead of SNaN,
same value as C99 nan(""). Unfortunately calling nan("") here isn't
always optimal, because compilers sometimes generate constant returns,
sometimes function calls.

Before this change ecma_number_make_nan returned SNaN:
- double: 0x7FF0 0000 0000 0001 (sign:0, exponent: all 1 bits, fraction: 0...01)
- float: 0x7F8 00001 (sign:0, exponent: all 1 bits, fraction: 0...01)

After this change ecma_number_make_nan returns QNaN:
- double: 0x7FF8 0000 0000 0000 (sign:0, exponent: all 1 bits, fraction: 10..0)
- float: 0x7FC0 0000 (sign:0, exponent: all 1 bits, fraction: 10...0)

JerryScript-DCO-1.0-Signed-off-by: Csaba Osztrogonác oszi@inf.u-szeged.hu
2019-10-02 12:17:27 +02:00
2019-07-04 10:35:05 +02:00
2019-04-24 14:46:14 +02:00
2019-09-23 14:56:11 +02:00
2016-02-05 13:37:16 +01:00
2016-02-05 13:37:16 +01:00

JerryScript: JavaScript engine for the Internet of Things

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JerryScript is a lightweight JavaScript engine for resource-constrained devices such as microcontrollers. It can run on devices with less than 64 KB of RAM and less than 200 KB of flash memory.

Key characteristics of JerryScript:

  • Full ECMAScript 5.1 standard compliance
  • 160K binary size when compiled for ARM Thumb-2
  • Heavily optimized for low memory consumption
  • Written in C99 for maximum portability
  • Snapshot support for precompiling JavaScript source code to byte code
  • Mature C API, easy to embed in applications

Additional information can be found on our project page and Wiki.

Memory usage and Binary footprint are measured at here with real target daily.

The following table shows the latest results on the devices:

STM32F4-Discovery Remote Testrunner
Raspberry Pi 2 Remote Testrunner

IRC channel: #jerryscript on freenode Mailing list: jerryscript-dev@groups.io, you can subscribe here and access the mailing list archive here.

Quick Start

Getting the sources

git clone https://github.com/jerryscript-project/jerryscript.git
cd jerryscript

Building JerryScript

python tools/build.py

For additional information see Getting Started.

Documentation

Contributing

The project can only accept contributions which are licensed under the Apache License 2.0 and are signed according to the JerryScript Developer's Certificate of Origin. For further information please see our Contribution Guidelines.

License

JerryScript is open source software under the Apache License 2.0. Complete license and copyright information can be found in the source code.

FOSSA Status

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.

Description
Ultra-lightweight JavaScript engine for the Internet of Things.
Readme Apache-2.0 77 MiB
Languages
C 70.5%
JavaScript 25.1%
Python 2.7%
CMake 1%
Shell 0.5%