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Re: Linux kernel patch


On Wed, Nov 26, 1997 at 12:18:54PM -0500, Michael Meissner wrote:
> + Compiler supports -mcpu=pentiumpro and -march=pentiumpro
> + CONFIG_GCC_PENTIUMPRO
> +   This enables support to use the -mcpu=pentiumpro and -march=pentiumpro
> +   switches that are available on newer GCC compilers.  If you use this
> +   switch, then your kernel will not run on a Pentium, 486, or 386
> +   processor.

Better to simply have the makefile detect if these options are 
available.  It is already the case that if you configure for 586
that you cannot run the kernel on a 386.

Something like 

ifdef CONFIG_M686
CFLAGS := $(CFLAGS) -malign-loops=2 -malign-jumps=2 -malign-functions=2 -DCPU=686 \
	  $(shell if $(CC) -mcpu=pentiumpro -march=pentiumpro -xc /dev/null -c -o /dev/null > /dev/null 2>&1 ; then echo -mcpu=pentiumpro -march=pentiumpro ; else echo -m486 ; fi)
endif


r~


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