Re: Fine. (was: Re: C Non-Programming Non-Challenge)

On 17 Jun 2024 22:14:24 GMT, vallor wrote:

 
What I would like to do is someday figure out how to build
with -march=native .  Haven't bothered yet, because my machine is already
plenty fast.
 

I don't think that it is possible to pass custom CFLAGS to the kernel
build.

A quick search brings this:

march is controlled by the choice in arch/x86/Kconfig.cpu
optimization level is controlled by CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE/CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3/CONFIG_CC_OPTIMIZE_FOR_SIZE
frame pointer use is controlled by CONFIG_FRAME_POINTER
stack protector is controlled by CONFIG_STACK_PROTECTOR CONFIG_STACKPROTECTOR_STRONG
fcf-protection is disabled in the kernel as the kernel does not support its use either in kernel space or user space

https://bbs.archlinux.org/viewtopic.php?id=270652

The best is to set all performance options during configuration, especially
the "Processor Type and Features" section.

Incidentally, to see all the options that are set with "-march=native"
just do:

gcc -march=native -E -v - </dev/null 2>&1 | grep cc1


One must wean oneself from the distro because the distro caters only
to the lowest common denominator.