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From: ags@s.cc.purdue.edu (Dave Seaman)
Newsgroups: comp.arch,comp.lang.fortran,comp.misc,comp.lang.c++
Subject: Re: Quadruple-Precision Floating Point ?
Keywords: REAL*16 hardware? obscure
Message-ID: <3688@s.cc.purdue.edu>
Date: 19 Dec 88 14:13:58 GMT
References: <8561@alice.UUCP>
Reply-To: ags@s.cc.purdue.edu (Dave Seaman)
Organization: Purdue University
Lines: 20

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