wcs@alice.UUCP (Bill Stewart, usually) (12/19/88)
Are there any machines that implement quad-precision (128-bit) floating point numbers in hardware? Are there any commercial Fortran compilers that support it? (e.g. IBM 370 Fortran-H) We've had a couple applications that have come by recently that want it, and I had never known anyone supported it. (Will I have to write an extended-precision package? We probably don't have the information to do numerical analysis on this code to see if they really needed it.) Thanks; Bill -- # Thanks; # Bill Stewart, att!ho95c!wcs, AT&T Bell Labs Holmdel NJ 1-201-949-0705
mac3n@babbage.acc.virginia.edu (Alex Colvin) (12/19/88)
In article <8561@alice.UUCP>, wcs@alice.UUCP (Bill Stewart, usually) writes: > Are there any machines that implement quad-precision (128-bit) floating > point numbers in hardware? Are there any commercial Fortran compilers Honeywell(-Bull?) DPS series do 100-decimal-digit floating point in hard(firm?)ware. Probably not available directly in fortran. try calling PL/I. for that matter, try PL/I on your local mainframe.
ags@s.cc.purdue.edu (Dave Seaman) (12/19/88)
In article <8561@alice.UUCP> wcs@alice.UUCP (Bill Stewart, usually) writes: >Are there any machines that implement quad-precision (128-bit) floating >point numbers in hardware? Are there any commercial Fortran compilers >that support it? (e.g. IBM 370 Fortran-H) We've had a couple >applications that have come by recently that want it, and I had never >known anyone supported it. Basically all of the CDC, ETA, and Cray machines support 128-bit floating point numbers, but it is called double precision, not quad precision. Single precision on those machines is 64 bits. Double precision is, of course, supported by the Fortran compilers. Hardware support comes in all sorts of flavors. All the machines I mentioned obviously have hardware instructions that make 128-bit floats possible, but I don't think any of them make it quite as convenient as 64-bit floats when you look at the instructions that are generated. -- Dave Seaman ags@j.cc.purdue.edu
JONESD@kcgl1.eng.ohio-state.edu (David Jones) (12/19/88)
Some VAXes supports 128 bit floating point in hardware (they call the data type H_floating). The VAX-11 FORTRAN compiler supports H-floating data as REAL*16. David L. Jones | Phone: (614) 292-6929 Ohio State Unviversity | Internet: 1971 Neil Ave. Rm. 406 | jonesd@kcgl1.eng.ohio-state.edu Columbus, OH 43210 | jones-d@eng.ohio-state.edu Disclaimer: A repudiation of a claim.
schwartz@shire.cs.psu.edu (Scott Schwartz) (12/20/88)
In article <8561@alice.UUCP>, wcs@alice (Bill Stewart, usually) writes: >Are there any machines that implement quad-precision (128-bit) floating >point numbers in hardware? Are there any commercial Fortran compilers >that support it? The Prime x50 series had this, and their f77 compiler supported it, in at least one instruction mode. -- Scott Schwartz <schwartz@shire.cs.psu.edu>
PLS@cup.portal.com (Paul L Schauble) (12/21/88)
The Honeywell-Bull DPS90 and DPS9000, both current production models, implement floating point using a 36 bit word. They have hardware support for single, double, and quad (144 bit) floating point. The Fortran compiler has full support for this, including math library. Mail me if you want more info. ++PLS
seanf@sco.COM (Sean Fagan) (12/24/88)
In article <8561@alice.UUCP> wcs@alice.UUCP (Bill Stewart, usually) writes: >Are there any machines that implement quad-precision (128-bit) floating >point numbers in hardware? Yes. Cyber's, which have 60-bit single precision, have 120-bit double precision. Their decendents, the Cray's, have 64-bit single precision, and 128-bit double precision. They are, however, probably a bit much for you. An ETA-10 is also a 64-bit s.p. machine, and I believe it is also a 128-bit d.p. machine. And, yes, the FORTRAN compilers on all of these machines support the 128-bit stuff. -- Sean Eric Fagan | "Merry Christmas, drive carefully and have some great sex." seanf@sco.UUCP | -- Art Hoppe (408) 458-1422 | Any opinions expressed are my own, not my employers'.
bga@raspail.UUCP (Bruce Albrecht) (12/29/88)
In article <1973@scolex>, seanf@sco.COM (Sean Fagan) writes: > In article <8561@alice.UUCP> wcs@alice.UUCP (Bill Stewart, usually) writes: > >Are there any machines that implement quad-precision (128-bit) floating > >point numbers in hardware? > > Yes. Cyber's, which have 60-bit single precision, have 120-bit double > precision. Their decendents, the Cray's, have 64-bit single precision, and > 128-bit double precision. They are, however, probably a bit much for you. The Cyber 180's have 64 bit words, with 128 bit quad. I believe the 930, roughly comparable to a high-end Vax, is priced under $100k.
gould@pilot.njin.net (Brian Jay Gould) (01/04/89)
I've seen some references to Cray and Cyber 205s relating to quad precision. The Cray manuals (X-MP and Y-MP) state that double precision (128 bit) is done by software emulation. The ETA/CDC manuals state that hardware can perform both full (64 bit) and half precision. The HNS (formerly Honeywell-NEC Systems) SX-2 *does* 128 bit floating-point in HARDWARE. But, only in the scalar processor. The vector units are limited to 32 and 64 bit precision. --> Any disclaimers, made by me or by anyone on my behalf, may or may not accurately represent my representation of myself or others. -- ------------------------------------------------------------------------- - Brian Jay Gould :: INTERNET gould@jvnca.csc.org BITNET gould@jvncc - - UUCP rutgers!njin!gould Telephone (201) 329-9616 - ------------------------------------------------------------------------s
turk@Apple.COM (Ken "Turk" Turkowski) (01/12/89)
Any machine with double precision can have quad precision floating point. Look at: Linnainmaa, Seppo _Software for Doubled-Precision Floating-Point Computations_ ACM Transactions on Mathematical Software Vol. 7, No. 3, Sept. 1981, pp. 272-283 -- Ken Turkowski @ Apple Computer, Inc., Cupertino, CA Internet: turk@apple.com Applelink: Turkowski1