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From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.unix.wizards
Subject: Re: Should optimizing compilers automatically assign registers?
Message-ID: <12804@smoke.BRL.MIL>
Date: 7 May 90 20:00:53 GMT
References: <512@hhb.UUCP>
Followup-To: comp.lang.c
Organization: U.S. Army Ballistic Research Laboratory
Lines: 9

In article <512@hhb.UUCP> istvan@hhb.UUCP (Istvan Mohos) writes:
>Is the automatic allocation of a few variables into registers
>too much to ask from an optimizing compiler?

Use of the cc -O flag does not magically transform the compiler
into an "optimizing compiler".  In fact, for older (PCC-based)
compilers, it merely invokes a peephole optimizer on the
resulting assembly code.  Naturally, it is too late to reassign
registers at that point.