robert@csustan.UUCP (Robert Zeff) (06/12/88)
I'm having trouble with ceil () & floor ().
This program returns the correct values on the first loop only.
On successive passes, floor() returns the same result as ceil().
I'm using a Tektronix 4301 (68020, UTEK & BSD4.3,
GreenHills C compiler.)
#include <math.h>
main () {
double value, ceil (), floor ();
for (;;) {
printf ("\nInput value: ");
scanf ("%lf", &value);
printf ("\nCeiling: %lf, Floor: %lf\n", ceil (value), floor (value));
}
}
Anyone else having this problem on other hardware?
thanks,
--
Robert Zeff (209) 577-4268 voice, FAX: (209) 577-8548
2549 Yosemite Blvd Ste. E {lll-lcc,lll-crg}!csustan!zhome!robert
Modesto, Ca. 95354 {lll-lcc,lll-crg}!csustan!robertandrew@frip.gwd.tek.com (Andrew Klossner) (06/12/88)
> I'm having trouble with ceil () & floor (). > This program returns the correct values on the first loop only. > On successive passes, floor() returns the same result as ceil(). > I'm using a Tektronix 4301 (68020, UTEK & BSD4.3, > GreenHills C compiler.) > > #include <math.h> > main () { > double value, ceil (), floor (); > > for (;;) { > printf ("\nInput value: "); > scanf ("%lf", &value); > printf ("\nCeiling: %lf, Floor: %lf\n", ceil (value), floor (value)); > } > } > > Anyone else having this problem on other hardware? Blush. This isn't a hardware problem; it's a bug in the Tektronix implementation of libm. The rest of you 68881 users can breathe easy. Thanks for pointing out this bug. It will be corrected in an upcoming software release. In the meantime, you can work around by putting the following into a shell script and executing it as root: --------------- Cut here chdir /tmp cat >floor.s <<"EOF" .globl _floor _floor: fmove.l fpcr,d0 move.l d0,d1 and.l #0xFFFFFFF0,d0 or.l #0x00000020,d0 fmove.l d0,fpcr fint.d 4(a7),fp0 fmove.l d1,fpcr rts EOF cat >ceil.s <<"EOF" .globl _ceil _ceil: fmove.l fpcr,d0 move.l d0,d1 and.l #0xFFFFFFF0,d0 or.l #0x00000030,d0 fmove.l d0,fpcr fint.d 4(a7),fp0 fmove.l d1,fpcr rts EOF cat >rint.s <<"EOF" .globl _rint _rint: fmove.l fpcr,d0 move.l d0,d1 and.l #0xFFFFFFF0,d0 fmove.l d0,fpcr fint.d 4(a7),fp0 fmove.l d1,fpcr rts EOF as -68020 -M floor.s as -68020 -M ceil.s as -68020 -M rint.s mv /usr/lib/libm.a /usr/lib/libm.a.OLD cp /usr/lib/libm.a.OLD /usr/lib/libm.a ar r /usr/lib/libm.a floor.o ceil.o rint.o rm floor.s floor.o ceil.s ceil.o rint.s rint.o --------------- Cut here If you use profiled libraries, make similar changes to /usr/lib/libm_p.a. -=- Andrew Klossner (decvax!tektronix!tekecs!andrew) [UUCP] (andrew%tekecs.tek.com@relay.cs.net) [ARPA]
haugj@pigs.UUCP (The Beach Bum) (06/14/88)
In article <1146@csustan.UUCP>, robert@csustan.UUCP (Robert Zeff) writes: > > I'm having trouble with ceil () & floor (). > I'm using a Tektronix 4301 (68020, UTEK & BSD4.3, > GreenHills C compiler.) I'm running a Plexus P/95 (68020, System V, no 68881) and have the Greenhills C compiler. We currently have 1.8.0 of the compiler. I haven't had any trouble with the compiler. I compiled the example which was given and all seems well. - John. -- The Beach Bum Big "D" Home for Wayward Hackers UUCP: ...!killer!rpp386!jfh jfh@rpp386.uucp :SMAILERS "You are in a twisty little maze of UUCP connections, all alike" -- fortune