Re: APIC, AMD-K6/2 -mcpu=586...

[Bill Pringlemeir <bpringle@sympatico.ca>]

>>>>> "WJP" == Bill Pringlemeir <bpringle@sympatico.ca> writes:
[snip]
 WJP> I have the 2.4.4 distribution from kernel.org.

 WJP>  "http://www.kernel.org/pub/linux/kernel/v2.4/"

 WJP> I have a Mandrake system and selected the AMD processors and
 WJP> APIC option.  The egcs-2.91.66 compiler with -mcpu=586.  It
 WJP> appears that the structure alignment of the floating point

Sorry,

I compiled from a user account and `/usr/bin' was before
`/usr/local/bin' on my path.  I had actually installed the tools as
per Documentation/Changes, honest! I was compiling with the
pgcc-2.91.66 and not egcs-2.91.66.  The root account was set up to use
egcs-2.91.66.

Why don't the build scripts run a dummy file to determine where the 
floating point registers should be placed?

...
const int value = offsetof(struct task_struct, thread.i387.fxsave) & 15;
...

VAL = objdump --all-headers foo.o | grep value | cut -c 48-57
PAD_SIZE = objdump --start-address=$VAL --disassemble-all foo.o | cut...

Or perhaps some better method for determining the offset on the host,

Compiling and execute won't work in cross development mode...

int main(){return offsetof(struct task_struct, thread.i387.fxsave) & 15;}

Perhaps this is a bit much to demand, instead of having a specific
compiler.

fwiw,
Bill Pringlemeir.