Re: optimization/8300: [3.2/3.3/3.4 regression] [sparc] ICE in gen_reg_rtx, at emit-rtl.c:662

[Robert Schiele <rschiele@uni-mannheim.de>]

The following reply was made to PR optimization/8300; it has been noted by GNATS.

From: Robert Schiele <rschiele@uni-mannheim.de>
To: Andreas Schwab <schwab@suse.de>
Cc: Richard Henderson <rth@redhat.com>, gcc-bugs@gcc.gnu.org,
   tneumann@pi3.informatik.uni-mannheim.de, gcc-gnats@gcc.gnu.org
Subject: Re: optimization/8300: [3.2/3.3/3.4 regression] [sparc] ICE in gen_reg_rtx, at emit-rtl.c:662
Date: Mon, 17 Mar 2003 17:21:09 +0100

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 On Mon, Mar 17, 2003 at 04:34:38PM +0100, Andreas Schwab wrote:
 > Ignoring the missing initialisation of b this is undefined under the
 > aliasing rules.
 
 Ok, behaviour is undefined.  As this is only a sample to produce an
 ICE, this is no problem for me.
 
 But do you think this code is illegal in the sense that the compiler
 cannot generate valid code out of it?  In that case I would be happy
 about a pointer to the specs that tell me that this is not allowed.
 
 Does any spec _force_ me to initialize b?  When I do so, the error is
 vanished.  Again, I don't care about undefined behaviour here.  This
 is also the reason, why I omitted the initialization.
 
 My point, as far as I understand this situation, is that the compiler
 should generate a binary out of it.  The resulting code is completely
 braindead --- I know that --- and may even SIGBUS or whatever he likes
 to do at _runtime_, but I don't see, why this should be seen as
 illegal at _compile_ time.
 
 Robert
 
 --=20
 Robert Schiele			Tel.: +49-621-181-2517
 Dipl.-Wirtsch.informatiker	mailto:rschiele@uni-mannheim.de
 
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