n-body in x86-64 assembly

This is the n-body problem from The Computer Language Benchmarks Game site, written in x86-64 assembly.

It's not ready, I only wrote it as a learning experience.

It's ~1.9x slower than the optimized C version, optimizations still missing include:

• Using SIMD instructions. (movapd, addpd, subpd, rsqrtps, etc)
• Calculating dx, dy, and dz, magnitude, velocity, and final position each in their own loop to improve cache coherence and to calculate multiple bodies at the same time.
• Use rsqrtps with two Newton's method steps.

Build steps

nasm -felf64 nbody.asm && gcc -no-pie nbody.o -o nbody

Running it

./nbody <number here>

(If you don't pass it a number it will segfault :))