From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id 177EC3858D20; Tue, 31 Oct 2023 13:51:09 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 177EC3858D20
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1698760269;
	bh=PWV2+0SMZrSdUwv1xZD9MFUaijDMaKbur6mbp3wQTgc=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=A2k90zRbfhsBHJ/ExTigLfDmsmd94vDzMAJ99a7fDn/wY1hDmWrPZfbJDp9A75+hG
	 s57i3MH7ITvLhlIoAqpa5FL7THo/ZX9bi45OPaMEwul9hcxTWCkf95nFdqO4B2CTTr
	 Qy4FrtKVWmPyNaYjZZsJBGr8CiGg5JjG4f88ng14=
From: "rth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/112296] __builtin_constant_p doesn't
 propagate through member functions
Date: Tue, 31 Oct 2023 13:51:08 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 13.1.0
X-Bugzilla-Keywords: documentation, missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rth at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: rguenth at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-112296-4-XLc0iVavZ6@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-112296-4@http.gcc.gnu.org/bugzilla/>
References: <bug-112296-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D112296

--- Comment #7 from Richard Henderson <rth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #5)
> int bad1(void) { return __builtin_constant_p(global++); }
...
> Joseph, Richard, do you have anything to add or remember discussions about
> this semantic detail of __builtin_constant_p?

Since it has been 25 years, I don't recall any specific discussions.

The intended use-case at the time was more like

#define macro(x) \
  (__builtin_constant_p(x) \
   ? inline_expression(x)  \
   : out_of_line_function(x))

So I would have expected side effects to have been ignored for
the builtin and expanded via one of the two arms.=