もひかん

LLVM is a complex piece of software. There are several paths one may take on the quest of understanding how it works, none of which is simple. I recently had to dig in some areas of LLVM I was not previously familiar with, and this article is one of the outcomes of this quest. What I aim to do here is follow the various incarnations an "instruction" takes when it goes through LLVM’s multiple compilation stages, starting from a syntactic construct in the source language and until being encoded as binary machine code in an output object file. This article in itself will not teach one how LLVM works. It assumes some existing familiarity with LLVM’s design and code base, and leaves a lot of "obvious" details out. Note that unless otherwise stated, the information here is relevant to LLVM 3.2. LLVM and Clang are fast-moving projects, and future changes may render parts of this article incorrect. If you notice any discrepancies, please let me know and I’ll do my best

Before: mozilla-central$ which grep /usr/bin/grep mozilla-central$ time git ls-files -z | xargs -0 grep foobar > /dev/null real 0m19.583s user 0m18.853s sys 0m0.722s After: mozilla-central$ which grep /opt/local/bin/grep mozilla-central$ time git ls-files -z | xargs -0 grep foobar > /dev/null real 0m1.386s user 0m0.754s sys 0m0.613s via jlebar.com http://scalper.posterous.com/gnu-grep-is-10x-faster-than-mac-grep

via artemyankov.com http://scalper.posterous.com/webtcp-making-tcp-connections-from-browser-ar

MK802 Raspberry Model B Processor 1.5ghz 1.0ghz RAM 1 gig 512 meg Internal Storage 4 gig None USB Ports One Two Networking Wireless Wired Video Out HDMI Mini HDMI, RCA Audio Out HDMI HDMI, 3.5m Storage Micro SD SDHC Size 8.8 x 3.5 x 1.2 cm 8.560 cm × 5.4 cm Cost+Shipping to US 38.50 43.33 via jeffhoogland.blogspot.jp http://scalper.posterous.com/thoughts-on-technology-raspberry-pi-vs-mk802

MicrosoftのInternet Explorer PMである Jatinder Mann氏 は、BUILD 2012で HTML5アプリとサイトを高速化する50のパフォーマンストリック というセッションで、Webアプリケーションを高速化する多くのチップスを提供した。 Mann氏が提供したアドバイスは、以下の6つの原則を中心に構成されていた。 via infoq.com http://scalper.posterous.com/web50

jQuery.zyngaScroller.js is a jQuery plugin that wraps the excellent Zynga Scroller as a simple jQuery plugin with a couple new additions: (1) Real-time collaboration is now possible by leveraging the SignalR hook baked into the jQuery.signalRamp.js plugin, and (2) the version of EasyScroller.js that this project uses is different than the original Zynga Scroller with collaboration hooks and support for IE8 and above. via timheckel.github.com http://scalper.posterous.com/zyngascroller-by-timheckel

pyMCU via pymcu.com http://scalper.posterous.com/pymcu-the-python-controlled-microcontroller

Photo: James Dyson Award/O2 Pursuit オーストラリアで工学を学ぶ大学院生ディーン・ベンステッドのプロジェクトである「 O2 Pursuit 」は、車載タンクに蓄えられている圧縮空気で走るバイクだ。 このプロジェクトは、まず 圧縮空気ロータリー・エンジン から始まり、それを中心にモトクロス用のダート・バイクを組み立てたものだ。フレームには「Yamaha WR250R」を使用し、後輪には動力を供給するスキューバダイビングのタンクと25ポンドのエンジンが追加されている。 スロットル・レバーを握ると空気が放出されてバイクが加速する。その性能は素晴らしい。O2 Pursuitはタンク満タンでの 走行距離がおよそ100km で、 最高時速は約140km に達するという。 via wired.jp http://scalper.posterous.com/140km-wiredjp

Blue Spark Digital condenser microphone provides users with zero-latency headphone output, and is fitted with volume and gain controls, as well as instant mute, similar to its other microphones. via geeky-gadgets.com http://scalper.posterous.com/blue-launches-spark-digital-the-worlds-first

20+ Apps! With over 20 apps now available for Sphero, you'll never run out of ways to play. Check out our collection of the top Sphero apps . Made For Requires iOS 4.0+ or greater or Android devices with operating system 2.2 or greater. Please see our Compatibility Page for a complete list. Sphero Details Sphero is an Orbotix Smart Robot on the inside and an opaque, high-impact polycarbonate shell on the outside. It's even waterproof. Induction Charger Over an hour of full throttle play with cable-free induction charging. Simply set Sphero in his cradle to recharge. For The Geeks With speeds of up to 3ft per second and a 50ft plus range, Sphero's Bl

Apple users working with their untouchable Mac computers will be pumped up to see that Mimo Monitors have brought forth a brand new USB powered-and-connected 10.1-inch monitor that works with OS X like a charm! This Mimo Magic Touch monitor is the first of many models that’ll be offered by Mimo Monitors ready to rock with OS X with just a download of a special driver. This model also works with Windows 7 and can be used as a display-only unit for Windows XP, Vista, and 2000. The Mimo Magic Touch is the first model released by Mimo Monitors to be assured readiness to work with the official Mac OS X Touchscreen Driver distributed by Mimo Monitors as well. This driver works with Intel Macs only and is compatible with systems up to and including OS X Mountain Lion. The driver, incidentally, is an alpha release – but once the final version is ready for action, you’ll get that upgrade for free. via slashgear.com http://scalper.posterous.com/mimo-magic-touch-brings-touchscreen

盲点だったわ。 まさか クルトンをコーン にしてしまうなんて...。 via gizmodo.jp http://scalper.posterous.com/167895093

"Off Canvas" patterns are different ways to approach layout where content on the web isn't just laid out in a vertical column. For instance, navigation could be positioned hidden off the left edge of the "canvas" (visible browser window) and slid in on demand. Anthony Colangelo created jPanelMenu to do just that. Hakim El Hattab's Meny is fancier but similar in what it accomplishes. They both use JavaScript. I thought it would be fun to try and recreate Anthony's jPanelMenu using only CSS. It's do-able - with several advantages and disadvantages. View Demo via css-tricks.com http://scalper.posterous.com/off-canvas-menu-with-css-target-css-tricks

Arduinoが汎用電子プロトタイピングツールであることはみんな知ってるけど、高い電流を扱えないという欠点がある。それに対応すべく、デザイナーとプログラマーのチームが、 Heatit を開発した。これはオープンソースのボードで、デザインの最終ステージではArduinoをベースにしているが、12ボルト500ミリアンペアの出力を8系統備えている。この出力ピンは、結合させることでさらに大きな電流を得ることができる。 via jp.makezine.com http://scalper.posterous.com/make-japan-heatit

モバイルGPUのPowerVRで知られるイマジネーション(Imagination Technology)が、CPUのMIPSを買収することで合意に達したと発表しました。総額は6000万ドル。イマジネーションはMIPSの事業と従業員に加えて、MIPSが保有する特許580件のうちCPUコアにかかわる主要特許82件を獲得するとしています。 それ以外の498特許については業界コンソーシアムBridge Crossing LLCが3億5000万ドルで購入し、イマジネーションは無料で無期限の使用ライセンスを得ます。流れとしては、まずMIPSが498の特許をBridge Crossingに売却し、そのあとで別の取引としてイマジネーションがMIPSコア主要特許82件とMIPS社を購入するかたち。 via japanese.engadget.com http://scalper.posterous.com/powervrmipsarm-engadget-japanese

A new Android mini PC has been launched on to the market this week in the form of the Minix NEOG G4 which is now available to purchase for just $76, and is powered by a Rockchip RK3066 dual core processor. The Rockchip RK3066 dual core processor within the Minix NEOG G4 Android mini PC is supported by 1GB of RAM and comes with 8GB of internal storage. The Minix NEOG G4 comes supplied running Google’s Android 4.0 Ice Cream Sandwich (ICS) operating system, but an update to support Google’s latest Android 4.1 Jelly Bean operating system is currently under development and is expected to be released very soon. Other features of the Minix NEOG G4 include HDMI and USB ports, for direct conniption to your HDTV, with wireless 802.11b/g/n connectivity and a microSD card slot also available for extra 32GB of storage when required. But unfortunately due to the use of a Rockchip RK3066 dual core processor Linux is not supported on the devices as yet. via geeky-gadgets.com http://scalper.post

AMD's Opteron 6300 chips operate at a base frequency of up to 3.5GHz (Opteron 6308) and a Turbo frequency of up to 3.8GHz (Opteron 6328). Half of the 10 available Opteron 6300 Series processors are 16-core parts, two are 12-core chips, another two feature 8 cores, and one of them is a quad-core part. AMD says its new server CPUs are the only x86 processors to support ultralow voltage (ULV) 1.25v memory. Pricing for the Opteron 6300 Series runs from $293 to $1,392. via maximumpc.com http://scalper.posterous.com/amd-puts-servers-datacenters-in-a-piledriver

We live in the as-a era. IaaS, SaaS, PaaS. Even Database-as-a-Service where companies offer SQL and NoSQL database management systems hosted online. We played with the concept a bit, and, in an era which is also the one of cloud storage with Dropbox, Box, Google Drive, Skydrive and the like, we wondered why applications and services shouldn't just use our cloud storage account to store our data. Why everything should be centralized? Why all applications and services behave like Mega and not like BitTorrent? That's why we introduced in Opa 1.0.7 a new database back-end working on top of Dropbox. If you're new to Opa , you can read this introduction , but as the syntax should look familiar, you should still understand the code without any prior knowledge of Opa. via blog.opalang.org http://scalper.posterous.com/dropbox-as-a-database-the-opa-blog

マグナス効果とは「流体中を回転しながら移動する球や円柱の進行方向が変化する現象．（中略）最初は弾道学上の問題で，1852年にドイツのH，G. Magnusが法則化した」（法則の辞典・朝倉書店より）。検索すると、野球や卓球やバレーボールのサイトで、変化球の理論のひとつとして説明されてます。これを小型飛行ロボットの揚力発生に利用したのが、電通大の「UEC2012 Magnus」。翼が筒になっていて、それをウイーンと回転させて浮上します（推力源は前面のプロペラ）。10月13日に開催された 全日本学生室内飛行ロボットコンテスト に登場した模様。ほかにも、面白そうな飛行体がいっぱいです。 via jp.makezine.com http://scalper.posterous.com/make-japan-30558

The Open 7400 Logic Competition is a crowd-sourced contest with a simple but broad criteria for entry: build something interesting out of discrete logic chips. It's now in its second year, and this time around I was inspired to enter it. Discrete logic, for anyone who isn't familiar, are any of a number of families of ICs who each perform a single, usually fairly straightforward, function. Typical discrete logic ICs include basic logic gates like AND, OR and NAND, Flip-Flops, shift registers, and multiplexers. For smaller components like gates and flipflops, a single IC will usually contain several independent ones. As you can imagine, building anything complex out of discrete logic involves using a lot of parts; these days they're typically used as 'glue' logic rather than as first-class components, having been largely supplanted by a combination of specialised devices, microcontrollers, and FPGAs. Building a microcontroller or CPU out of discrete logic

Designing Javascript APIs We at Filepicker.io spend a lot of time thinking about APIs. With the release of our Version 1.0 javascript API, we thought about best practices for javascript API design, and wanted to share them so that when we use your API, it’ll be just as awesome as when you use ours. Rules of your Javascript API via blog.filepicker.io http://scalper.posterous.com/designing-javascript-apis-filepickerio