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From: gwyn@brl-smoke.ARPA (Doug Gwyn )
Newsgroups: comp.lang.c
Subject: Re: C and Floating Point
Message-ID: <5732@brl-smoke.ARPA>
Date: Wed, 8-Apr-87 21:20:28 EST
Article-I.D.: brl-smok.5732
Posted: Wed Apr  8 21:20:28 1987
Date-Received: Mon, 13-Apr-87 03:45:41 EST
References: <15958@sun.uucp> <5716@brl-smoke.ARPA> <14680@cca.CCA.COM> <790@xanth.UUCP>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 42
Keywords: C Fortran Floating Point

In article <790@xanth.UUCP> kent@xanth.UUCP (Kent Paul Dolan) writes:
>I'm sorry to be talking to a crowd of compiler writers, ...  Within
>reason, the speed of compiled code is a _very_minor_ cost factor in the
>code's life cycle cost, compared to the people costs of creating the code.

Reminder:  My opinions are not official X3J11 positions.

I agree with many of Mr. Dolan's points.  Undoubtedly X3J11 meetings are
predominately attended by compiler implementors (several of them
specializing in the IBM PC market, alas), which occasionally biases if
not the decisions then certainly the discussions.  It should be noted that
virtually all C compiler implementors are also C users, and there are a
few X3J11 members, such as myself, who represent the C user (as opposed
to implementor) viewpoint.

>... it is not
>a _minor_ matter when someting like the proposed unary plus override on
>parenthesis evaluation order is added to a language.  It is a utility
>destroying set of blunders by the language designers.

I think there is a misperception that should be cleared up.  Certainly
it is true that even a nominally "small" change to a language can have
major practical repercussions.  However, the dpANS for C has not changed
the significance of parentheses; C compilers have always been allowed to
reorder theoretically-commutative and -associative operations.  The new
unary plus operator provides the additional functionality of providing
the control over order of evaluation that many numeric programmers were
requesting.  Since unary plus is a new invention for C, it does not harm
existing code and has no effect unless used (when it has the desired
order-of-evaluation-forcing effect).

I don't take responsibility for these X3J11 committee decisions, but I
really do think X3J11 got them right.

I'm sorry that Mr. Dolan finds C so much harder to use effectively than
other languages.  Now that I am used to C, I find it excruciating when
I have to deal with applications written in Fortran (for example).  It
would seem that programming languages, like text editors, establish a
mind-set in their users that acts as a "definition" for what such
facilities should be like.  I'm pretty happy with C for application
development; the few significant deficiencies that I see tend not to be
the points that people in this newsgroup argue about.