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 637A53856261; Wed, 10 May 2023 16:33:00 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 637A53856261
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1683736380;
	bh=cB/WD94HnQYNgKSTVQ9UHZxcoNRM3TOmJEOMMugciNk=;
	h=From:To:Subject:Date:From;
	b=J2eXxa50/6l0GqsWoRRpUGugHPXICi1MD41SoEe8b4lRZqjkL19ib9W9lEDi9V7+E
	 FSteRRPxtuJxnScrGKVCQjLSWN8ULfKAASBPusCeoz5icUaeM79HQWNLDU8hbadLSl
	 AHfAHMSdLgUxuKIklP6SfLMtNKukLCUnRywu35Ak=
From: "acoplan at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/109800] New: [11/12/13/14 Regression] arm: ICE
 (segfault) loading double with -mpure-code -mbig-endian
Date: Wed, 10 May 2023 16:32:59 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 13.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: acoplan at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
Message-ID: <bug-109800-4@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=3D109800

            Bug ID: 109800
           Summary: [11/12/13/14 Regression] arm: ICE (segfault) loading
                    double with -mpure-code -mbig-endian
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: acoplan at gcc dot gnu.org
  Target Milestone: ---

The following fails:

$ cat t.c
double f() { return 5.0; }
$ gcc/xgcc -B gcc -c -S -o /dev/null -O2 -march=3Darmv7-m -mfloat-abi=3Dhard
-mfpu=3Dfpv4-sp-d16 -mbig-endian -mpure-code t.c
xgcc: internal compiler error: Segmentation fault signal terminated program=
 cc1
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
See <https://gcc.gnu.org/bugs/> for instructions.

It started with r11-966-g9a182ef9ee011935d827ab5c6c9a7cd8e22257d8 .

Looking at the dumpfile 291r.split1, it looks like we end up splitting
indefinitely:

;; Function f (f, funcdef_no=3D0, decl_uid=3D5948, cgraph_uid=3D1, symbol_o=
rder=3D0)

Splitting with gen_split_111 (vfp.md:2138)
scanning new insn with uid =3D 12.
scanning new insn with uid =3D 13.
deleting insn with uid =3D 9.
Splitting with gen_split_111 (vfp.md:2138)
scanning new insn with uid =3D 14.
scanning new insn with uid =3D 15.
deleting insn with uid =3D 12.
Splitting with gen_split_111 (vfp.md:2138)
scanning new insn with uid =3D 16.
scanning new insn with uid =3D 17.
deleting insn with uid =3D 14.

I think we can adjust the splitter to avoid the new simplification introduc=
ed
above from undoing our subreg punning.=