this post was submitted on 30 Oct 2024
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Linux

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Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

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[–] [email protected] 17 points 1 week ago (2 children)
[–] [email protected] 19 points 1 week ago (1 children)

Bah, they'll never have my precious -march=native!

[–] [email protected] 1 points 1 week ago

I doubt they want my fun and safe math optimizations either tbh

[–] [email protected] 3 points 1 week ago (1 children)

Jokes on you, my system is (mostly) -O3

[–] [email protected] 1 points 1 week ago (1 children)
[–] [email protected] -1 points 1 week ago (2 children)

How do they avoid the subsequent bugs O3 tends to produce?

[–] [email protected] 10 points 1 week ago

They don't.

[–] [email protected] 5 points 1 week ago (1 children)

First time I'm hearing of this. Do you have some more details?

[–] [email protected] -3 points 1 week ago (1 children)

Not like Ubuntu works very well on old hardware but hopefully O2 support will still be there. Many people need it.

[–] [email protected] 9 points 1 week ago (2 children)

-O2 vs -O3 adds -fgcse-after-reload -fipa-cp-clone -floop-interchange -floop-unroll-and-jam -fpeel-loops -fpredictive-commoning -fsplit-loops -fsplit-paths -ftree-loop-distribution -ftree-partial-pre -funswitch-loops -fvect-cost-model=dynamic -fversion-loops-for-strides

I don't think any of these optimizations require more modern hardware?

[–] [email protected] 1 points 4 days ago

Yeah, adding a separate microarchitecture like amd64v3 would be a separate item. They might be able to do that with amd64v3 overlay repos that only contain packages that most benefit from the newer microarchitecture.

[–] [email protected] 5 points 1 week ago (1 children)

Right. GCC -f optimizations are basically like "how hard are we going to try to be clever" and are, I believe, orthogonal to the actual instructions used. Machine dependent args start with -m, like -march or -mavx etc.

[–] [email protected] 1 points 1 week ago

I was reasonably certain, but left it open in case OP knew of some edge case where flags that are intended to be machine independent caused bugs on different architectures

[–] [email protected] -3 points 1 week ago

op-ti-mize [verb (trans.)]* … (gcc) to modify executable code so that it fails more quickly.