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Re: [tree-ssa] Minor improvement to folding
- From: law at redhat dot com
- To: Richard Henderson <rth at redhat dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Thu, 26 Feb 2004 16:46:20 -0700
- Subject: Re: [tree-ssa] Minor improvement to folding
- Reply-to: law at redhat dot com
In message <20040226233413.GB28578@redhat.com>, Richard Henderson writes:
>On Thu, Feb 26, 2004 at 12:03:59PM -0700, law@redhat.com wrote:
>> This change basically allows us to determine that the address of
>> two distinct, non-weak variables can not be the same.
>
> int foo = 0;
> extern int bar __attribute__((alias("foo")));
> bool test() { return &foo == &bar; }
>
>If both variables are extern, we don't even have access to
>whether or not there's an attribute involved.
Sigh. I guess we'll need to avoid this for externs. I'll also need to
check for alias attributes (I'd forgotten about those).
Updates tonight or tomorrow :-)
jef