HELP! Floating Point Problems

[Dave Mack]

HELP !!!

I have a problem with C compiler floating point operations under
Microport Unix 386 Version 2.2.  Any code that contains floating point
operations blows away both cc and lint.  In some cases this also locks
up the computer such that I have to reboot.  In other cases the "comp"
process spawned by cc just runs forever.  I dont think that this is
an 80387 problem because the crash happens during the compile or
lint phase rather than during execution.  There is no "core" file created
when I reboot or when I "kill -9" the comp process.

My version of Microport System V.3 is 2.2.  DOS Merge/386 and Streams are also
installed.  My system is an ALR 386/220 with the 80387 floating
point coprocessor, 2 MB of RAM, and a Seagate 80 Mb hard disk with
a Western Digital controller.

I took delivery of this system with the Microport operating system
on May 28, 1988 from Advanced System Concepts of Arlington, Va.
I reported this floating point problem to Microport (with examples 
on floppy disk) on 6/21/88.  Microport technical support acknowledged 
receipt on 6/24 and have responded that they were unable to duplicate 
my results.   On 7/14 I contacted the Microport sales with some related
questions on their next release.  I was told that Version 2.2 does not
include either 80387 support or 80387 emulation (i.e. no floating point
support); however, the next release scheduled about August 1 will 
include these features in addition to the Green Hills C compiler.

I am still communicating with Microport on this problem and the 
possible information discrepency between their sales and tech support.

This is not an attempt to complain about Microport.  I feel that they 
provided me with a reasonable System V.3 port; however, I am posting 
this in hopes that someone else has encountered simular problems,
isolated the cause and discovered a workaround.

Please mail your responses to "uunet!bts!bill".  I will summarize and
post the results.  

A typical code segment that causes "comp" to run forever on "cc -c test.c"
follows:

/* test.c */

main()
{
	float x,y,z;
	z = 2.0;
	x = 3.0;
	y = x * z;
}
/* end test.c */

Thanks in advance for any useful suggestions;

bill

Bill Hatch
Computational Engineering
(formerly Business and Technological Systems)
14504 Greenview Drive  Suite 500
Laurel, Maryland 20708
(301)470-3839
uunet!bts!bill