[Android Software/Hacking General [Developers Only]] MWisBest:
I do agree that the most cherry-picked commit you linked is terrible, and while this is some nice work you've done, it's misleading and not entirely true.

Android is NOT 90% thumb. I'd give it a maximum of 50%, and that's being extremely generous. On Linaro's website I recall reading about potential future experiments for them, and one of them was to see what else could be improved by using thumb. If Android is already 90% thumb, that'd be a useless task and you might as well compile everything as thumb, and looking at my build logs there's plenty more things compiled as ARM than there are thumb.

I agree that the people saying usage of -Os is good are way out of date and stuck in the past. With older ARM chips it was a good idea, but anything Cortex-A9 (if not Cortex-A8) and newer is plenty good enough for at least -O2.

The kernel's compiler flags are all defined in the kernel itself. None of the flags in the build section of Android end up in the kernel.

There are a number of "changes" you've made which actually didn't do anything:

1. -DNDEBUG was already defined in TARGET_RELEASE_CFLAGS, which if I remember correctly is just all appended or prepended (doesn't matter which it is in this case) to your usual TARGET_arm_CFLAGS and TARGET_thumb_CFLAGS, so debugging code was already disabled.

2. The -fgcse-after-reload and -funswitch-loops flags are already enabled by using -O3, so it is not necessary nor helpful to add it by hand.

3. The -frename-registers flag was already enabled in TARGET_RELEASE_CFLAGS, as was -fomit-frame-pointer, so again these additions have no effect or change.

4. The -frerun-cse-after-loop is already enabled by using -O3 and it's even enabled at as low as -Os, so this is unnecessary as well and even in the unmodified build flags would already be there.

There is a flag which you've stated is broken, but actually works just fine and can be extremely beneficial: -flto (Link-Time Optimization).

I've been using LTO for at least 5 months now.

You're also missing out on using C++11, this allows for some extra optimizations as well.

There is a change you've made which is EXTREMELY DANGEROUS and could result in crashes or maybe even worse:

You've used the "-Wno-error=strict-aliasing" flag. strict-aliasing is a fatal error by default for a reason!! You should definitely give this a read: http://cellperformance.beyond3d.com/articles/2006/06/understanding-strict-aliasing.html

Fixing those violations is extremely time-consuming, and resulted in me having to fork over 30 git repos to do so, but if I didn't do that I could end up being responsible for the loss of data on a thousand or more devices. I don't want something like that on my conscious.

Now, I've never been one to try and advertise my work or say my work is better than other people's, but I've been hearing about stuff like this for a long time now and I'm getting sick and tired of it.

My GitHub: https://github.com/MWisBest/

My ROM's thread: http://xdaforums.com/galaxy-nexus/verizon-develop/rom-fml-fork-life-01-09-2014-t2427087/

If you take a look at my thread you'll see I'm extremely humble. Heck, if somebody posts that they've moved on to/liked a different ROM better, I'm actually happy that they've found something they like! All I hope for is that people find a ROM they like. If it's mine, great! If it's not, that's just dandy too! I don't boast about the amount of users my ROM has, I don't brag about (let alone bring up) being the first person to get a KitKat ROM on the VZW Galaxy Nexus, etc. I'm not in this for fame and internet points. My expectation when I released my ROM was for it to just fall back page by page and have just a few users.

I don't know how long you've been working on this stuff, but I've been working on it for 9 months and I'm constantly refining and improving it. I don't claim to be an expert at it, but compared to the people that get attention for similar work I'd say what I've done is better. To put what I've just said into perspective: That is the only time I've ever said anything I've done is better than somebody else here.

I've been sitting here debating whether or not to press the "Submit Reply" button, in the end I decided that the risks of people using the work posted here outweigh any potential negative outcome from me submitting this post.