BigInt Div library

Overview

A fast and space-efficient big int division library written in NASM assembly.

Exposed Function

int64_t mdiv(int64_t *x, size_t n, int64_t y);

Parameters:

• x: Pointer to an array of n 64-bit integers representing the dividend in little-endian order.
• n: Number of elements in the array x.
• y: 64-bit signed integer divisor.

Returns:

• The remainder of the division (x % y).
• The quotient (x / y) is stored back in the array x.

Error Handling: In cases of overflow or division by zero, the function triggers an overflow condition (SIGFPE signal on Linux).

Limitations

• The divisor (y) must be a signed 64-bit integer (int64_t).

Building and Running

Prerequisites:

• For the library (mdiv.o):
  • NASM assembler
• For the example program (example.c):
  • CMake version 3.30 or higher.
  • A C compiler supporting the C17 standard (e.g., GCC or Clang)
  • NASM assembler

Steps

1. Clone the Repository:

   git clone https://github.com/Iteron-dev/bigint-div.git
   cd bigint-div

2. Building the Library Only:

   To compile just the library (mdiv.o) for use in your own projects:

   nasm -f elf64 -w+all -w+error -o mdiv.o mdiv.asm

3. Building the Example Program:

   To build the example program demonstrating the library usage:

   a) Using CMake:

   cmake -B build/
   make -C build/

   This will create the example executable in the build/ directory.

   b) Manual Compilation:

   If you prefer to compile manually without CMake:

   nasm -f elf64 -w+all -w+error -o mdiv.o mdiv.asm
   
   gcc -c -Wall -Wextra -std=c17 -O2 -o example.o example.c
   gcc -z noexecstack -o example example.o mdiv.o

Example Usage

For demonstration purposes, you can refer to and modify the example.c file. It showcases a sample usage of this library.

License

This project is licensed under the GNU General Public License v3.0.
See LICENSE for the full terms.