shafik

What is the Strict Aliasing Rule and Why do we care?

(OR Type Punning, Undefined Behavior and Alignment, Oh My!)

What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.

In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.

Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th

Earnestly

C99 List of Undefined Behavior

From N1256: (See http://port70.net/~nsz/c/c99/n1256.html#J.2)

• A "shall" or "shall not" requirement that appears outside of a constraint is violated (clause 4).
• A nonempty source file does not end in a new-line character which is not immediately preceded by a backslash character or ends in a partial preprocessing token or comment (5.1.1.2).
• Token concatenation produces a character sequence matching the syntax of a universal character name (5.1.1.2).
• A program in a hosted environment does not define a function named main using one of the specified forms (5.1.2.2.1).
• A character not in the basic source character set is encountered in a source file, except in an identifier, a character constant, a string literal, a header name, a comment, or a preprocessing token that is never converted to a token (5.2.1).
• An identifier, comment, string literal, character constant, or header name contains an invalid multibyte character or does not

eligrey

/*
 * object.watch polyfill
 *
 * 2012-04-03
 *
 * By Eli Grey, http://eligrey.com
 * Public Domain.
 * NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.
 */

myusuf3

To remove a submodule you need to:

• Delete the relevant section from the .gitmodules file.
• Stage the .gitmodules changes git add .gitmodules
• Delete the relevant section from .git/config.
• Run git rm --cached path_to_submodule (no trailing slash).
• Run rm -rf .git/modules/path_to_submodule (no trailing slash).
• Commit git commit -m "Removed submodule "
• Delete the now untracked submodule files rm -rf path_to_submodule

ocornut

Memory Optimization (Christer Ericson, GDC 2003)
http://realtimecollisiondetection.net/pubs/GDC03_Ericson_Memory_Optimization.ppt

Cache coherency primer (Fabian Giesen)
https://fgiesen.wordpress.com/2014/07/07/cache-coherency/

Code Clinic 2015: How to Write Code the Compiler Can Actually Optimize (Mike Acton)
http://gdcvault.com/play/1021866/Code-Clinic-2015-How-to

drhelius

	LD SP,$fffe		; $0000  Setup Stack

	XOR A			; $0003  Zero the memory from $8000-$9FFF (VRAM)
	LD HL,$9fff		; $0004
Addr_0007:
	LD (HL-),A		; $0007
	BIT 7,H		; $0008
	JR NZ, Addr_0007	; $000a

	LD HL,$ff26		; $000c  Setup Audio

davidnunez

pm list packages -f

PixelSergey

Dumping games with Godmode9

Dumping games is the act of taking a game from your system or gamecart and copying it into a readable format onto your SD card. Dumping is perfectly legal if you keep the dumps to yourself, however sharing these dumps is piracy and is illegal.

This guide will tell you how to dump games from various formats and for various purposes. Dumping 3DS cartriges as .cia files is good if you want to install them to your system. Dumping them as .3ds files is good for emulators. Installed titles cannot be dumped as .3ds files. NDS cartiges can only be dumped as .nds files and cannot be installed (however, you can play them with emulators or flashcarts).

Dumping the RomFS of a game is primarily for romhacking purposess.

paragonie-scott

Hello software developers,

Please check your code to ensure you're not making one of the following mistakes related to cryptography.

I. General Mistakes

• Writing your own home-grown cryptography primitives (For example: Mifare Classic)
  • Exception: For the sake of learning, but don't deploy it in production.
• Using a fast hash function (e.g. MD5, SHA256) for storing passwords. Use bcrypt instead.
• Not using a cryptographically secure random number generator

cuppster

app.use(express.methodOverride());

// ## CORS middleware
// 
// see: http://stackoverflow.com/questions/7067966/how-to-allow-cors-in-express-nodejs
var allowCrossDomain = function(req, res, next) {
    res.header('Access-Control-Allow-Origin', '*');
    res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE');
    res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization');