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Re: const weak variables are inlined.

From: Mark Mitchell <mark at codesourcery dot com>
To: Richard Guenther <richard dot guenther at gmail dot com>
Cc: "Joseph S. Myers" <joseph at codesourcery dot com>, Christian BRUEL <christian dot bruel at st dot com>, gcc-patches at gcc dot gnu dot org, Nathan Sidwell <nathan at codesourcery dot com>, Jason Merrill <jason at redhat dot com>
Date: Wed, 07 May 2008 12:53:23 -0700
Subject: Re: const weak variables are inlined.
References: <48185537.5070500@st.com> <4821F32D.8090605@codesourcery.com> <Pine.LNX.4.64.0805071832580.27791@digraph.polyomino.org.uk> <84fc9c000805071215y69c36605k73f2bc69c7c89ff1@mail.gmail.com>

Richard Guenther wrote:

CCP and SCCVN do this optimization as well.  I don't see why volatile const
should disable the optimization.

"const volatile" means the program cannot change the value, but that the value may be changing by itself, as from a read-only hardware register. We definitely should not propagate the value in that case, and there is no conflict with C++; that's not a valid integral constant expression.

--
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713

References:
- Re: const weak variables are inlined.
  - From: Mark Mitchell
- Re: const weak variables are inlined.
  - From: Joseph S. Myers
- Re: const weak variables are inlined.
  - From: Richard Guenther

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