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Re: Serious code generation/optimisation bug (I think)

From: Ian Lance Taylor <iant at google dot com>
To: Laurent GUERBY <laurent at guerby dot net>
Cc: James Dennett <james dot dennett at gmail dot com>, zoltan at bendor dot com dot au, gcc at gcc dot gnu dot org
Date: Tue, 27 Jan 2009 13:10:54 -0800
Subject: Re: Serious code generation/optimisation bug (I think)
References: <Pine.LNX.4.31.0901271825250.29022-100000@susu.bendor.com.au> <18738acb0901270011m2a3dbf12p9db3d36beb7b517f@mail.gmail.com> <1233064416.17541.564.camel@localhost>

Laurent GUERBY <laurent@guerby.net> writes:

> Just curious: is there a "portable" way to read from memory
> address zero in C code? "portable" here means likely to work
> on most compilers without exotic compile flags in 2009.

char *my_null_pointer;
char fn() { return *my_null_pointer; }

It will be quite a while before whole program optimization is good
enough to prove that my_null_pointer is not referenced by anything
else.

Ian

Follow-Ups:
- Re: Serious code generation/optimisation bug (I think)
  - From: Chris Lattner

References:
- Serious code generation/optimisation bug (I think)
  - From: zoltan
- Re: Serious code generation/optimisation bug (I think)
  - From: James Dennett
- Re: Serious code generation/optimisation bug (I think)
  - From: Laurent GUERBY

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