From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id EAEB03858D1E; Sun, 6 Feb 2022 10:34:32 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org EAEB03858D1E From: "iains at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/104117] [9,10,11,12 Regression] Darwin ppc64 uses invalid non-PIC address to access constants (in PIC code). Date: Sun, 06 Feb 2022 10:34:32 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: 10.3.0 X-Bugzilla-Keywords: link-failure, ra, wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: iains 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: 10.4 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 06 Feb 2022 10:34:33 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D104117 --- Comment #15 from Iain Sandoe --- (In reply to Vladimir Makarov from comment #13) > I think there are two code spots whose pitfalls resulted in the PR. >=20 > The first one is in rs6000.cc::legitimate_lo_sum_address_p which permits > wrong pic low-sum address. Ack,=20 > Another one is in lra-constraints.cc::process_address_1 which permits put > wrong low-sum address in reg and use the reg in memory. >=20 > The following patch solves the problem: >=20 > diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c > index 5404fb18755..306f67f26c4 100644 > --- a/gcc/config/rs6000/rs6000.c > +++ b/gcc/config/rs6000/rs6000.c > @@ -8202,7 +8202,7 @@ legitimate_lo_sum_address_p (machine_mode mode, rtx= x, > int strict) > { > bool large_toc_ok; >=20 > - if (DEFAULT_ABI =3D=3D ABI_V4 && flag_pic) > + if ((DEFAULT_ABI =3D=3D ABI_V4 || DEFAULT_ABI =3D=3D ABI_DARWIN) &= & flag_pic) > return false; > /* LRA doesn't use LEGITIMIZE_RELOAD_ADDRESS as it usually calls > push_reload from reload pass code. LEGITIMIZE_RELOAD_ADDRESS I have a somewhat wider fix which accounts for the case that UNSPEC [ SYMBOL_REF ] MACHOPIC_UNSPEC_OFFSET *is* valid, where SYMBOL_REF is not (but the change you have made could be sufficient - will try to get that into a retest soon). > diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c > index 30d088afbca..998e82be54f 100644 > --- a/gcc/lra-constraints.c > +++ b/gcc/lra-constraints.c > @@ -3517,21 +3517,8 @@ process_address_1 (int nop, bool check_only_p, > *ad.inner =3D gen_rtx_LO_SUM (Pmode, new_reg, addr); > if (!valid_address_p (op, &ad, cn)) > { > - /* Try to put lo_sum into register. */ > - insn =3D emit_insn (gen_rtx_SET > - (new_reg, > - gen_rtx_LO_SUM (Pmode, new_reg, > addr))); > - code =3D recog_memoized (insn); > - if (code >=3D 0) > - { > - *ad.inner =3D new_reg; > - if (!valid_address_p (op, &ad, cn)) > - { > - *ad.inner =3D addr; > - code =3D -1; > - } > - } > - > + *ad.inner =3D addr; > + code =3D -1; > } > } > if (code < 0) >=20 > The patch was successfully tested on x86-64/ppc64 under Linux. The second part of the patch is the same as what I was testing. How to proceed on this (testing an LRA change widely enough)?=