scottm@tekgen.UUCP (Scott Maxson) (07/08/86)
I recently posted a request here for reviews of various
Macintosh C compilers. I am particularly interested in
programming scientific applications, so things like floating
point execution speed and good math lib's are important to me.
belsley@bcvax3.bitnet mailed this in response:
-----
Subject: C compilers
To: scottm@tekgen
Scott:
I have done bench marking among Megamax, Aztec and Consulair C and there
is no question that Consulair's Mac C (version 4.5) is the best floating
point compiler among them. It produces significantly faster executing
floating-point code than the others when doing QR decompositions, or SVD
decompositions (matrix inversions and the like). This is in part due to the
way Consulair passes arguments to functions through the registers rather
than the stack.
Furthermore, Consulair C is the only C compiler for the Mac that I know of
that has added SANE's "extended" and "comp" types as new data types in C.
Thus, you can declare an identifier as extended or comp. This actually speeds
operations up even more, since all the SANE functions are done in extended,
and hence doubles and floats must be cast to extended before they are passed
to the SANE routines anyway. This just adds time. The cost, of course, is
that the extended numbers eat up more core (80 bits instead of 64) and this
can be problemful for very large arrays.
If you have access to Info-mac, I have just posted some comparative timings
for various floating-point problems. But they all give a substantial edge
to the Consulair product.
I do not have posting access to Usenet, so you might want to repost this
report there for me. I have no vested interest with Consulair; I just like
their product because, I too, and trying to find the best scientific
environment for the Mac. Mac C is, so far, just that. This little known
fact seems wholly lost in many recent postings I have seen for Lightspeed C.
I have not yet used Lightspeed C, but I would be interested in any
figures comparing its floating-point speed with that of Consulair C's.
david a. belsley
boston college belsley@bcvax3.bitnet
-----
If anyone has done a comparison between Lightspeed C
and Mac C, I'd like to see the results also.
Scott Maxson
Tektronix
{ucbvax,decvax,ihnp4,allegra}!tektronix!tekgen!scottm