I have experienced the same results. Assumed I was using the round function
incorrectly. Looking for a work around as well.
"J Chapman Flack" <[EMAIL PROTECTED]> wrote in message
news:46710@palm-dev-forum...
>
> Hello,
>
> I have run these tests on PalmOS 3.1H3 on a Visor:
>
> Directly after a reset, _f_itof( 33554434) returns 0x4c000000,
> _f_itof(33554435) returns 0x4c000001, _f_itof(-33554434) returns
0xcc000000,
> _f_itof(-33554435) returns 0xcc000001. (The chosen inputs are 26 bit
values, so
> the low two bits will not fit in a 24-bit float and must be rounded. The
> numbers that end in 10 were rounded toward zero, those ending 11 were
rounded
> away from zero. Consistent with round-to-nearest mode. So far so good.
>
> After _fp_round(flpTowardZero):
>
> The returns from _f_itof (same values) are 0x4c000000, 0x4c000000,
0xcc000000,
> 0xcc000000. All rounded toward zero. Still so far so good.
>
> After _fp_round(flpUpward):
>
> The returns are 0x4c000001, 0x4c000001, 0xcc000000, 0xcc000000. The
positive
> ones rounded away from zero (up) and the negative ones toward zero (up).
Still
> good.
>
> After _fp_round(flpDownward):
>
> The returns are 0x4c000001, 0x4c000001, 0xcc000000, 0xcc000000--the same
> as flpUpward. OOPS!
>
> That's not all: now after _fp_round(flpToNearest) or
_fp_round(flpTowardZero)--
> both of which worked before--the results will still be as for flpUpward.
It is
> as if flpUpward mode is sticky. A reset will restore flpToNearest mode.
Also,
> _fp_round(flpDownward) gives upward mode even if it is the first _fp_round
call
> after a reset. There is no way to get downward mode.
>
> Finally, the return value from _fp_round is not as documented in the
FloatMgr.h
> file comments (3.5 SDK). The comments say it returns the masked, two-bit
value
> passed in. What it really returns is that value leftshifted 4 places.
Somebody
> knew about that because the constants flpModeMask and flpModeShift are
defined
> accordingly, but the behavior is contrary to the comments and also to the
> M*CORE sfpe docs for _fp_round.
>
> What gives? Is there a fix or workaround? How can a person select
Downward
> mode, and how can a person get back to Nearest or TowardZero without a
reset?
>
> Thanks,
> Chapman Flack
> [EMAIL PROTECTED]
>
>
>
>
>
>
>
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