https://github.com/sporeventexplosion/one-byte-inc

Increment a variable on x86-64 with just 1 byte!
https://github.com/sporeventexplosion/one-byte-inc

assembly x86 x86-64

Last synced: about 2 months ago
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Increment a variable on x86-64 with just 1 byte!

• Host: GitHub
• URL: https://github.com/sporeventexplosion/one-byte-inc
• Owner: sporeventexplosion
• License: gpl-3.0
• Created: 2024-11-02T22:18:02.000Z (3 months ago)
• Default Branch: master
• Last Pushed: 2024-11-02T22:22:35.000Z (3 months ago)
• Last Synced: 2024-11-10T05:25:13.769Z (3 months ago)
• Topics: assembly, x86, x86-64
• Language: C
• Homepage:
• Size: 44.9 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# 1-Byte INC in 64-bit code!

![Logo](/logo.png)

Are you still mad at AMD for destroying the one-byte encoding of INC when they stomped over the whole row from 40h to 4Fh with their newfangled "REX" prefixes?

Think of the code density!

Be mad no more with `one_byte_inc`!!!

As we all know, x86-64 CPUs all support *compatibility mode*, so the instruction decoder still needs to support the 1-byte INC.

If only we can access it in 64-bit code...

Well, now you can!!!

## Usage

Simply include `one_byte_inc.h` in your source and link with `-lone_byte_inc`.

In your code, initialize the library using `init_one_byte_inc()`, which returns 0 on success.

-1 is returned on error and errno is set.

After that, just use `one_byte_inc()` for all your 1-byte incrementing needs!

## Example

```c

#include 

#include "one_byte_inc.h"

int main() {

    init_one_byte_inc();

    printf("%d\n", one_byte_inc(89017)); // prints: 89018

}

```

See also the example in `example.c`.

## Building

Run `./build.sh` to generate static and dynamic libraries, as well as the example binary.

## How does it work?

umm... uhh...