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From: eric@cosmos.ph.utexas.edu
Newsgroups: comp.lang.c,comp.unix.cray
Subject: Vectorizing C compilers
Message-ID: <15388@ut-emx.UUCP>
Date: 18 Jul 89 15:09:42 GMT
Sender: news@ut-emx.UUCP
Reply-To: eric@chaos.utexas.edu ()
Organization: University of Texas at Austin, Center for Nonlinear Dynamics
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What is the state of the art regarding vectorizing C compilers 
for Crays and other "minisuper" machines like Alliant, Convex, etc.?  
I have seen one or two C compilers (on a Unicos Cray) that vectorize
loops like

	for(j = 0; j < n; j++)
		y[j] = x[j] + z[j];

but never a C compiler that can vectorize something like

	for(j = 0; j < n; j++)
		y[j] = sqrt(x[j]);

even where a suitable Fortran mathematical library is available.

I am trying to develop some software for studying dynamical systems
that will use the X11 window system for interactive graphics.  However,
the code will be numerically intensive, and I need to use vector
hardware efficiently.  I prefer to write the program in C rather than
a mixture of C and Fortran.

Any advice out there in netland?

--Eric Kostelich