[menaerus]

It's a platform-agnostic optimization in case of GCC so if your embedded Linux toolchain is based on GCC, and most of them are, it's pretty much the case that it will have this optimization turned on by default.

> This option is enabled by default on most targets. On AVR and MSP430, this option is completely disabled.

[chongli]

Yes and if you’re targeting AVR, an extremely popular 8 bit micro, then it’ll be turned off.