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Re: kernel compile: -mno-fpu

On Sun, Jun 15, 2003 at 12:01:00AM -0400, Brian C Miles wrote:
> While building 2.4.21 on my SS20 SMP box, I noticed "-mno-fpu" being used
> as a CFLAG.  Does anyone know why?  This isn't an indication that fp
> emulation is being compiled into the kernel (i.e. though it may very well
> be), but a directive to tell GCC to try and use software implementations
> of fp math.  Does anyone know why this is enabled by default?  Does this
> have any negative performance impact on machines that have hardware FPU? 
> Is it safe to compile the kernel without this flag?
> There are several dead-end threads about this topic on various newsgroup
> archives.  If any one could shed some light on this, it would be much
> appreciated.

There is no floating point used in the kernel. So it has no real affect.
I don't know for sure, but -mno-fpu may also allow the compiler to make
some assumptions about the code it is compiling, for better scheduling
and performance.

Debian     - http://www.debian.org/
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Deqo       - http://www.deqo.com/

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