Performance enhancements

ReturnInfinity / BareMetal-OS-legacy

BareMetal is a 64-bit OS for x86-64 based computers. The OS is written entirely in Assembly while applications can be written in Assembly, C/C++, and Rust.

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Performance enhancements #58

Closed benjaminsavoy closed 10 years ago

benjaminsavoy commented 10 years ago

Optimized the following parts of the OS:

BMFS had a performance anti-pattern, which has been replaced, it looked like that:

sub rax, 1 cmp rax, 0 jne some_label
Memory allocation has been rewritten, while using exactly the same algorithm. Typical gain should be 3 cycles per call + 3 cycles per allotted block.

benjaminsavoy commented 10 years ago

Not very groundbreaking work, but I wanted to get a test environment running, and learn some more about how the OS works. Hope the enhancements help!

Also, I noticed that memory allocation returned something in RCX, which is probably not necessary as RAX is already set to 0 on error, so I marked it as deprecated until it (maybe) gets removed?

tomberek commented 10 years ago

Thanks. btw: any update on parallax?

IanSeyler commented 10 years ago

Thanks! Yes, I'll remove the RCX return value as it is not needed anymore.

As for Parallax, not yet but soon!