CURRENT state of acpi and -O'ptimisations in buildworld

Jon Noack noackjr at alumni.rice.edu
Fri Dec 12 13:13:15 PST 2003


On 12/12/2003 9:23 AM, toxa wrote:
> On Friday 12 December 2003 18:00, Ryan Sommers wrote:
> 
> 
>>>The second is about buildworld. Usually I use this opimisaton flags to
>>>build world and userland (putting them to /etc/make.conf):
>>>
>>>CFLAGS= -O3 -pipe -ffast-math -funroll-loops -mno-sse2 -march=pentium4
>>>COPTFLAGS= -O2 -pipe -march=pentium4 -ffast-math -funroll-loops
>>>CPUTYPE= p4
>>
>>Building with any optimization higher then -O is not supported.
> 
> 
> Does it mean that -O3 really translated into -O then making buildworld OR that 
> with any optimisation higher than -O you may have _success_ with buildworld 
> BUT binaries may be _broken_? I have used -O2 and -O3 with 5-CURRENT for many 
> months (cvsuping to -current since 5.1-release) without any problem until 
> tonight.
> 
> Thanks for your reply.

They are not translated to -O -- they simply may not work (as you have 
seen).

The following are excerpts from /etc/defaults/make.conf.

On CFLAGS:
"Note that optimization settings above -O (-O2, ...) are not recommended 
or supported for compiling the world or the kernel - please revert any 
nonstandard optimization settings to "-O" before submitting bug reports 
to the developers."

On COPTFLAGS:
"There is very little to gain by using higher optimization levels, and 
doing so can cause problems."

Jon Noack



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