Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!husc6!panda!teddy!jpn
From: jpn@teddy.UUCP
Newsgroups: comp.lang.c
Subject: Re: C and Floating Point
Message-ID: <3937@teddy.UUCP>
Date: Fri, 10-Apr-87 13:19:54 EST
Article-I.D.: teddy.3937
Posted: Fri Apr 10 13:19:54 1987
Date-Received: Sat, 11-Apr-87 17:49:33 EST
References: <15958@sun.uucp| <5716@brl-smoke.ARPA| <14680@cca.CCA.COM| <788@kodak.UUCP| <4968@ut-ngp.UUCP| <802@viper.UUCP|
Reply-To: jpn@teddy.UUCP (John P. Nelson)
Organization: GenRad, Inc., Concord, Mass.
Lines: 14
Keywords: C Fortran Floating Point Parenthases

|||      To satisfy the time critical applications, I would recommend either
||| a compile time command line option such as -Oe (optimize expressions) or
||| a reserved word #define, such as #define OPT_EXPR (which could also be
||| specified on the compiler line).
||
|| Making a #define directive affect the compiler is not a good idea ...
|
|The -Oe declaration will effect the entire module being compiled with that
|flag.  Using a define allows you to "define" it at some point in the program
|and then undefine it later.

Isn't this what #pragma is for?  Use #pragma optimize_expressions and
#pragma dont_reorder_expressions.  Microsoft C 4.0 has something like this
for stack probes.  Is this a mis-use of the #pragma directive?