> > =

> >  Just wondering if my idea can be applied to RiscBSD - I don't know a=
bout how =

> > the ARM FPE works, but this should considerably reduce the amount of =
time spent =

> > in the kernel by FP intensive apps.
> > =

> > For those who don't frequent c.s.a.programmer, my idea is essentially=
 to =

> > have the handler for the FP instruction exception trap decode the arg=
uments, =

> > put them in a table indexed by address then overwrite the FP instruct=
ion with a =

> > BL to some handler routine which would then pick the results from the=
 table and =

> > emulate the instruction.  This should produce a considerable increase=
 in speed =

> > and reduction of time spent in SVC mode.
> > =


You can't precalculate all results. This only works for trigonimetric =

functions with a tolerable amount of arraysize.
The most overhead currently is trap and interupt handling I guess. This c=
an be =

avoided if you write the softfloat library for the gcc which is still mis=
sing. =

But this must provide *all* floatingpoint operations (mainly +,-,*,/).

A other way is to use builtin functions and map the original calls to you=
r =

functions like

	#define sin(a)	_mysinfunc(a)

where _mysinfunc() is your array using functions. This way you can substi=
tite =

them step-by-step and the result is the same, but it will only work with =

selfcompiled programs.



Ciao, Peter

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|                                                                        =
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|                            >>> FutureGroove <<<                        =
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|                                                                        =
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| Peter Berg                                       Music production &    =
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| w3: http://www.ww.tu-freiberg.de/~pberg                                =
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| email: Peter.Berg@ww.tu-freiberg.de                                    =
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