Help catching floating point exceptions

[jsalter at ibmpa.awdpa.ibm.com]

In article <1991Jun5.030043.3520 at ux1.cso.uiuc.edu> beddini at uxh.cso.uiuc.edu (Robert A Beddini) writes:
> requested info on this from IBM a year ago, and voiced my opinions about
>the lack of FPP traps at that time to our local IBM tech rep. He, in turn,
>requested further info internally.  The response at that time was along the
>lines of "here's the way the FPP can be checked,... why do you need to trap?"

He didn't talk to the right person.  We knew before release that IEEE-754
exception handling and trapping was necessary to truly make it in the
marketplace.

>We eventually purchased a 530 and are pleased with its speed on *PRODUCTION*
>calculations. However it is still not being used for major code development,
>and its use in this capacity will be limited until IBM recognizes the need
>for user conveniences (necessities) such as FPP traps as a compiler
>options/defaults.

We've recognized this need.  We recognized this before release, as noted
above, but because of time-to-market pressures, we were not able to make
this functionality available.  If you'll notice, the <fptrap.h> and <FP.h>
and <fpxcp.h> header files in AIXv3 all point to the fact that we knew
exception handling and trapping was important.

>It is regretable that the subject of the need for FPP traps continues to
>be discussed at length without IBM recognizing that this capability should
>be a priority.

This is false.  We've recognized it, and are working hard to implement it.
The <fptrap.h> file proves we recognized the need a long time ago.  The
implementation, of course, is not trivial.  But, it should be available in
the next major AIX release.

jim/jsalter  IBM PSP, Palo Alto  T465/(415)855-4427  VNET: JSALTER at AUSVMQ
Internet: jsalter at slo.awdpa.ibm.com         UUCP: ..!uunet!ibmsupt!jsalter 
"IBM part #23521, aka Lt. Commander Data"    The stuff above is on my own.