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From: dewar@cs.nyu.edu (Robert Dewar)
Subject: Re: C is 'better' than Ada because...
Date: 1996/07/30
Message-ID: <dewar.838699292@schonberg>#1/1
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references: <31e02c32.342948604@netline-fddi.jpl.nasa.gov>
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organization: Courant Institute of Mathematical Sciences
newsgroups: comp.lang.ada,comp.lang.c
Date: 1996-07-30T00:00:00+00:00
List-Id: <comp.lang.ada>


Sandy said

"   The one big advantage C has traditionally had over other
   languages is efficient compilation.  The reason is that 'C' is one
   of the few languages that provides concepts such as register
   variables to give hints to the compiler."


This is incorrect. In practice the register declarations are useless to
a modern optimizing compiler, and merely represent an unuseful attempt
to intefere with choices that the compiler can make better anyway. Most
modern C compilers, including gcc, pretty much ignore register declarations
(they cannot be completely ignored, since they introduce some (rather ugly)
semantic restrictions).

An exception to this is the extension in GNU C that allows global variabels
to be placed in registers. Here the programmer can do better than the
compiler, since the compiler does not see the whole program.