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 CF259385DC03; Thu,  9 Apr 2020 09:33:27 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org CF259385DC03
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
 s=default; t=1586424807;
 bh=haIAf1G7gzxfHNztbnoYYi4h/bBs8ocZ4acWt+DKrgo=;
 h=From:To:Subject:Date:In-Reply-To:References:From;
 b=NXioRDL9eK28iq+bQCrdUKqm1VdMc0HxRKf2lu9K2U7HnNs1eIM1lNZq7eqIGqRak
 nSgbC2u4wK/cslCaWbywE5HHkAnSiKaOp5Y382mMyJSKu4FF0hODMYvr9p88cEQsOG
 TkCUsSHI4xwxhG1d8R8G06URxgC9SOEx1cH8X1Ug=
From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug debug/94495] [10 Regression] Debug info size growth since
 r10-7515-g2c0fa3ecf70d199a
Date: Thu, 09 Apr 2020 09:33:27 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: debug
X-Bugzilla-Version: 10.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: jakub at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 10.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: attachments.created
Message-ID: <bug-94495-4-vhSJh6oNzq@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-94495-4@http.gcc.gnu.org/bugzilla/>
References: <bug-94495-4@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
X-BeenThere: gcc-bugs@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-bugs mailing list <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <http://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <http://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Thu, 09 Apr 2020 09:33:27 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94495

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 48246
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=3D48246&action=3Dedit
gcc10-pr94495.patch

Untested fix.  This does two things during var-tracking.  One is try to reu=
se
even more the SP_DERIVED_VALUE_P and VALUEs equated to that + CONST_INT in
!frame_pointer_needed functions (ideally have just a single SP_DERIVED_VALU=
E_P)
and through that make sure they can be all expressed using cfa_base_rtx or
cfa_base_rtx + CONST_INT (and thus in DWARF using DW_OP_fbreg).
And the second change is that for VALUEs that can be expressed that way it
throws away all MO_VAL_SETs, we have the best expression for it (DW_OP_fbre=
g)
that is constant through the function, so it is not beneficial to express i=
t in
one part of the function using that, in another part of the function using =
the
stack pointer, in yet another part using some other register.=