Commentary for third public review of X3J11 C

[David Hough]

The third public review of X3J11's Draft ANSI Standard C
is nearing its close on 1 September 1988.  This third review
is based upon a draft dated 13 May 1988 which is not greatly
changed from earlier drafts except that the controversial
"noalias" keyword was removed.

Consequently the Draft still leaves a good deal to be
desired from the numerical point of view.

I have two documents available for electronic 
distribution.  
I will be glad to send you
tbl/troff -ms source for these;
I'll send both unless you specify that you only want the newer one
described below.  Unfortunately the
Draft ANSI Standard itself is not publicly available in
electronic form.

The first available document is my 29 March 1988 commentary prepared 
for the second public review period (30 pages), with X3J11's
formal responses of 22 April interspersed.  The following were 
co-conspirators:

Greg Astfalk     Larry Breed     D. Burton  
W. J. Cody       Iain Johnstone  W. Kahan       
Zhishun Alex Liu David Mendel    Jim Meyering    
K-C Ng           Gene Spafford   Philippe Toint  
Stein Wallace   

The second available document is a draft,
subject to revision until submitted about 25 August, of my commentary
for the third public review.  It's only about 10 pages
since I generally avoided directly repeating what was in
the earlier document.  I'm looking for additional reviewers
and conspirators on this one.   The abstract follows:

          The proposed  C  standard  suffers  numerical
     shortcomings  - many inherited from its precursors
     - in areas of interest to  providers  of  portable
     mathematical  software.   I comment in detail upon
     the following aspects of the proposed standard:

Comment #1, Section 3.9:        encourage sound practices
Comment #2, Section 3.9:        disparage hazardous practices
Comment #3, Section 1.1:        emphasize surprises in rationale
Comment #4, Section 1.1:        anticipate supplemental standards
Comment #5, Section 2.2.4.2:    use "significand"
Comment #6, Section 2.2.4.2:    <float.h> has too many names, not enough information
Comment #7, Section 3.2.1.4:    round conversions between floating types
Comment #8, Section 3.5.4.2:    fix arrays
Comment #9, Section 4.5:        exceptions in mathematical functions
Comment #10, Section 4.5:       tell more in the rationale
Comment #11, Section 4.5:       standardize hypot
Comment #12, Section 4.5.4.6:   delete modf
Comment #13, Section 4.7:       specify which signals can arise

David Hough

dhough at sun.com   
na.hough at na-net.stanford.edu
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