[comp.sys.transputer] T800 floating pt. results

ARCR1@biology.cambridge.ac.uk (Andy Raine) (04/25/91)

Hello all

I just tried the test program on a T800 in our Meiko in-sun computing surface, 
as well as a SUN 4/110 and a microVAX 3100. the results I got were:

MEIKO C (CStools/SUN) compiled for T800:

The Expected Results:> free_l[1]=-0.000002 and free_l[2]=0.000007
The Calculated Values:> free_l[1]=0.000031 and free_l[2]=-0.000118
Done...

MEIKO C (CStools/SUN) compiled for T414:

The Expected Results:> free_l[1]=-0.000002 and free_l[2]=0.000007
The Calculated Values:> free_l[1]=0.000031 and free_l[2]=-0.000118
Done...

SUN C (SunOS 4.0.3):

The Expected Results:> free_l[1]=-0.000002 and free_l[2]=0.000007
The Calculated Values:> free_l[1]=-0.000002 and free_l[2]=0.000007
Done...

VAX C (VMS 5.4-1):

The Expected Results:> free_l[1]=0.000000 and free_l[2]=0.000000
The Calculated Values:> free_l[1]=0.000000 and free_l[2]=0.000000
Done...

Interesting huh?

Andy

kirchner@informatik.uni-kl.de (Reinhard Kirchner) (04/26/91)

From article <7983.9104251204@prg.oxford.ac.uk>, by ARCR1@biology.cambridge.ac.uk (Andy Raine):
> Hello all
> 
> 
> The Expected Results:> free_l[1]=-0.000002 and free_l[2]=0.000007
> The Calculated Values:> free_l[1]=0.000031 and free_l[2]=-0.000118
> 
> The Expected Results:> free_l[1]=-0.000002 and free_l[2]=0.000007
> The Calculated Values:> free_l[1]=0.000031 and free_l[2]=-0.000118
> 
> The Expected Results:> free_l[1]=-0.000002 and free_l[2]=0.000007
> The Calculated Values:> free_l[1]=-0.000002 and free_l[2]=0.000007
> 
> The Expected Results:> free_l[1]=0.000000 and free_l[2]=0.000000
> The Calculated Values:> free_l[1]=0.000000 and free_l[2]=0.000000

This is why mathmaticians at Karlsruhe University think about optimal
arithmetic since about 20 years and why they have developed products
which help to produce results you can trust.

For details send mail to

Michael Neaga         ae18@dkauni2.bitnet

Reinhard Kirchner
Univ. Kaiserslautern, Germany

( formerly working on these things and still having connections )

arc1@ukc.ac.uk (Tony) (04/26/91)

In article <7983.9104251204@prg.oxford.ac.uk> ARCR1@biology.cambridge.ac.uk (Andy Raine) writes:

Andy> I just tried the test program on a T800 in our Meiko
Andy> in-sun computing surface, as well as a SUN 4/110 and a
Andy> microVAX 3100. the results I got were:

Andy> blah, blah, blah, his results.

I just ran the same program here on various things (sparc,
meiko sparc-hosted, mips).  Here are the results of the Kent
jury...

(t800) mcc txxx.c ; mrun m.out

The Expected Results:> free_l[1]=-0.000002 and free_l[2]=0.000007
The Calculated Values:> free_l[1]=0.000031 and free_l[2]=-0.000118
Done...

---------------------------------------------------------------------------------
(sparc) cc txxx.c ; a.out

the Expected Results:> free_l[1]=-0.000002 and free_l[2]=0.000007
The Calculated Values:> free_l[1]=-0.000002 and free_l[2]=0.000007
Done...

---------------------------------------------------------------------------------
(t414) mcc -t4 txxx.c ; mrun m.out

[node`m] register dump at iptr 0x8000ad88 (0x4be0) wptr 0x8001b625 (0xec5) (program error)

---------------------------------------------------------------------------------
(sparc) gcc txxx.c ; a.out

The Expected Results:> free_l[1]=-0.000002 and free_l[2]=0.000007
The Calculated Values:> free_l[1]=0.000000 and free_l[2]=-0.000000
Done...

---------------------------------------------------------------------------------
(mips) cc txxx.c ; a.out

The Expected Results:> free_l[1]=-0.000002 and free_l[2]=0.000007
The Calculated Values:> free_l[1]=-0.000002 and free_l[2]=0.000007
Done...

---------------------------------------------------------------------------------
(mips) gcc txxx.c ; a.out

The Expected Results:> free_l[1]=-0.000002 and free_l[2]=0.000007
The Calculated Values:> free_l[1]=0.000000 and free_l[2]=0.000000
Done...

---------------------------------------------------------------------------------