Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!rice!sun-spots-request
From: km@mathcs.emory.edu
Newsgroups: comp.sys.sun
Subject: Sqrt on Sparc
Keywords: Miscellaneous
Message-ID: <3603@brazos.Rice.edu>
Date: 2 Dec 89 14:37:21 GMT
Sender: root@rice.edu
Organization: Sun-Spots
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Approved: Sun-Spots@rice.edu
X-Sun-Spots-Digest: Volume 8, Issue 214, message 6 of 11

I remember seeing somewhere that the Sun 4/2xx FPU-1 does sqrt in
software, but the FPU-2 did it in hardware.

Now the questions:

What about the 4/60 and 4/3xx. Software or hardware sqrt's?

What is the speedup factor for hardware sqrt?

What is the easiest way to get the C compiler to use the hardware sqrt's
if they exist? Apparently there is more to it than replacing sqrt with
Fsqrt in the source, and putting /usr/lib/libm.il on the command line.

I just did a benchmark that showed a Sun 3/60 with inline 68881 sqrts (in
Fortran), was twice as fast as a Sun 4/280 without inline sqrts (in either
C or Fortran).