Path: utzoo!attcan!uunet!cs.utexas.edu!sun-barr!ames!apple!well!gors
From: gors@well.UUCP (Gordon Stewart)
Newsgroups: comp.unix.i386,comp.sys.ibm.pc
Subject: Re: What would you use for Fast Floating-Point?
Keywords: Floating-point,Coprocessors
Message-ID: <12368@well.UUCP>
Date: 24 Jun 89 16:58:13 GMT
References: <2105@randvax.UUCP> <8437@killer.DALLAS.TX.US>
Reply-To: gors@well.UUCP (Gordon Stewart)
Organization: Whole Earth 'Lectronic Link, Sausalito, CA
Lines: 33

>With Microsoft C (5.1), I get about 160,000 Flops on a 20MHz Everex Step/386
>with a 387.  And on a 10 MHz AST Premium/286 with a 287, I get about 28,000
>(AST runs the 287 at 8 MHz).
>
>Charles Marslett
>chasm@killer.dallas.tx.us


I have a Mylex MI-386/20 w/a 387 chip running the Microway NDP C compiler
which requires the Phar Lap Assembler and DOS Xtender to run under MS DOS
(btw they have a UNIX version for V/386)

My results are (based on Linpack and Whetstone and Dhrystone):
	
	~4 MIPS
	560,000 FLOPS

An optimizing compiler will give better results than a faster FPU, since
even with an infinitely fast FPU, a CPU-bound program may only run twice
as fast.  The true 32 bit code helps a whole lot, a smart global optimizer
helps a whole lot, and writing optimizable code helps a lot.

NDP have a Fortran compiler, and if that's yer thang, read the new book
called (paraphrase) "a guide to Fortran on Supercomputers.." on Academic
Press by a coupla guys from Pacific Sierra Research.

They discuss issues of coding style and how it affects an optimizers
ability to generate good code.

-- 
    Michael Sierchio (in his guise as Gordon Stewart)

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