Path: utzoo!attcan!uunet!mcvax!nikhefh!i91
From: i91@nikhefh.hep.nl (Fons Rademakers)
Newsgroups: comp.sys.apollo
Subject: Problem with FPX on 580-T
Message-ID: <471@nikhefh.hep.nl>
Date: 8 Jun 88 16:50:38 GMT
Reply-To: i91@nikhefh.hep.nl (Fons Rademakers)
Organization: Nikhef-H, Amsterdam (the Netherlands).
Lines: 117

I have the following problem, see below the dashed line.

What I would like to know is 
  1) does this happen on all DN5(8|9)0-T with a FPX
  2) how come that it also goes wrong in the case when compiled without
     -cpu fpx, is the FPX always used?
  3) is there maybe a microcode fix

Thanks in advance for answering.
   -- Fons Rademakers


-------------------------------------------------
      PROGRAM AAP

      REAL PA(3)

      PA(1) = 100.00001
      PA(2) = 100.00001
      PA(3) = 100.00001

      SAVXYZ = PA(1)*PA(2)*PA(3)

      IF (PA(1)*PA(2)*PA(3) .NE. SAVXYZ) THEN
         PRINT *, '1 NOT OK'
         PRINT 10000, PA(1)*PA(2)*PA(3) - SAVXYZ
      ELSE
         PRINT *, '1 OK'
      ENDIF

      SAVXY2 = PA(1)*PA(2)*PA(3)

      IF (SAVXY2 .NE. SAVXYZ) THEN
         PRINT *, '2 NOT OK'
         PRINT 10000, SAVXY2 - SAVXYZ
      ELSE
         PRINT *, '2 OK'
      ENDIF

10000 FORMAT(E40.15)

      END

*------------------------------ RESULTS -------------------------------
* [86] ftn aap -save -indexl -zero -dba
* no errors, no warnings in AAP, Fortran version 9.66 1988/06/08 16:29:38 MET (Wed)
* [87] aap.bin
*  1 NOT OK
*                   -0.211181500000000E-01
*  2 OK
* [88] ftn aap -save -indexl -zero -dba -cpu fpx
* no errors, no warnings in AAP, Fortran version 9.66 1988/06/08 16:29:47 MET (Wed)
* [89] aap.bin
*  1 NOT OK
*                   -0.211181500000000E-01
*  2 OK
* [90] ftn aap -save -indexl -zero -cpu fpx
* no errors, no warnings in AAP, Fortran version 9.66 1988/06/08 16:29:59 MET (Wed)
* [91] aap.bin
*  1 OK
*  2 NOT OK
*                   -0.211181500000000E-01
* [92] ftn aap -save -indexl -zero
* no errors, no warnings in AAP, Fortran version 9.66 1988/06/08 16:30:11 MET (Wed)
* [93] aap.bin
*  1 OK
*  2 OK
* [94] ftn aap -save -indexl -zero -dbs
* no errors, no warnings in AAP, Fortran version 9.66 1988/06/08 17:47:09 MET (Wed)
* [95] aap.bin
*  1 OK
*  2 OK

*--------------------------------- CONFIGURATION ---------------------
* [140] /com/netstat -config
* 
* 
*      The node ID of this node is 4950.
* 
* **** Node 4950 ****  //mars
* Time 1988/06/08.17:50:35  Up since 1988/05/30.17:04:10  
* 
* Net I/O:         total= 2447728   rcvs = 1323752   xmits = 1123976
* Winchester I/O:  total= 265714   reads= 110012   writes= 155702
* No ring hardware failure report.
* System configured with 8.0 mb of memory.
* 
*   NODE CONFIGURATION
*     Node Type:  DN580-T
*     Hardware  Version:  1.50
*     Display type:  1280 x 1024 color display
*     Graphics Accelerator Board present.
*     Floating Point Accelerator Unit present.
*     Microcode Version:  2.5
*     Peripheral configuration:
*         Disks:  winchester
*         Networks: Ring
*         Tapes:  1/4" cartridge tape
*     Disk types:  MSD-190M  

*--------------------------------- REMARKS -------------------------
* Error does only occur on the machine with the FPX installed.
* 
* On one of our other DN580-T without FPX as well as on all our other
* DN330/3000/4000 the program produces no errors in any of the above cases.
* 
* Note that moving the SAVXY2 = ... statement to just below SAVXYZ = ...
* make the result of [91] look like [89]. I.e. '2 NOT OK' does not 
* occur anymore.
*
* I know it is dangerous to compare REALs, but an error in the second IF
* is still quite worrysome.
-- 
Org:    NIKHEF-H, National Institute for Nuclear and High-Energy Physics.
Mail:   Kruislaan 409, P.O. Box 41882, 1009 DB Amsterdam, the Netherlands
Phone:  (20)5925018 or 5925003                      Telex: 10262 (hef nl)
UUCP:   i91@nikhefh.hep.nl               BITNET: nikhefh!i91@mcvax.bitnet