> We are using RedHat 6.0 kernel on an AMD SC400 66Mhz board with
> two serial ports and an ethernet port. <...>
AMD SC410, which lack Floating Point Unit? (We designed a board with that
processor but since it's got so poor address decoding options (very few
programmable chipselects) we ditched it and went with the SC520 instead (FPU
included).)
<...>I am seeing following
> weirdness for compute intensive pieces of code:
>
> double x = 3.4;
> doubly y = 5.67;
> for (long i=1; i<10000; i++) {
> double z = x+y;
> }
>
>
> The above piece of code takes 2 seconds to 3 seconds.
> But if I surround the above piece of code with: asm("cli") and asm("sti")
> i.e. turn of interrupts, it takes only 9 milliseconds.
Is this dependent on the loop-operation is done on doubles or integers? Are
you using -fsoft-float?
Either way, thats 2.3/0.009 >= 250 times difference, which is a Huge
difference!
Singh, Pawan reported poor math emulation performance a week or two ago.
I'm not sure what was discovered there but could these two be different side
of the same coin?
//Bj�rnen.
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