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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/54021] [c++0x] __builtin_constant_p should be constexpr
Date: Thu, 19 Jul 2012 07:12:00 -0000	[thread overview]
Message-ID: <bug-54021-4-Z45z1eATl3@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-54021-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54021

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-07-19 07:12:18 UTC ---
Perhaps the C++ FE could when parsing a constexpr function during
finish_call_expr of __builtin_constant_p just temporarily force optimize = 1
if it is zero to prevent folding it to 0 (or alternatively, if it folds to 0,
build it non-folded), it would be an extension over how this builtin behaves
right now, on the other side as constexpr is "optimized" even at -O0 it would
match the intent of the builtin.  The question is if/when it will be actually
folded to 0 afterwards if not in constexpr context.


  parent reply	other threads:[~2012-07-19  7:12 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-18 19:52 [Bug c++/54021] New: " luto at mit dot edu
2012-07-19  6:53 ` [Bug c++/54021] " jakub at gcc dot gnu.org
2012-07-19  7:12 ` jakub at gcc dot gnu.org [this message]
2012-07-19 20:02 ` jason at gcc dot gnu.org
2012-07-19 20:57 ` jason at gcc dot gnu.org
2012-09-08 21:36 ` david at doublewise dot net
2012-09-08 22:29 ` luto at mit dot edu
2012-09-09  6:00 ` david at doublewise dot net
2012-09-09  6:05 ` luto at mit dot edu
2012-09-09 16:48 ` jason at gcc dot gnu.org

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