From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 07E673AA8C7C; Fri, 9 Apr 2021 17:42:57 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 07E673AA8C7C From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/99648] [11 regression] gcc.dg/torture/pr71522.c fails starting with r11-165 for 32 bits Date: Fri, 09 Apr 2021 17:42:57 +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: 11.0 X-Bugzilla-Keywords: wrong-code 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: 11.0 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: Fri, 09 Apr 2021 17:42:58 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D99648 --- Comment #7 from Jakub Jelinek --- --- gcc/simplify-rtx.c.jj 2021-04-09 16:18:24.275668496 +0200 +++ gcc/simplify-rtx.c 2021-04-09 19:26:24.963134240 +0200 @@ -7059,12 +7059,19 @@ simplify_immed_subreg (fixed_size_mode o while (buffer.length () < buffer_bytes) buffer.quick_push (filler); } - else + else if (!native_encode_rtx (innermode, x, buffer, first_byte, inner_byt= es)) + return NULL_RTX; + rtx ret =3D native_decode_rtx (outermode, buffer, 0); + if (ret && MODE_COMPOSITE_P (outermode)) { - if (!native_encode_rtx (innermode, x, buffer, first_byte, inner_byte= s)) + auto_vec buffer2 (buffer_bytes); + if (!native_encode_rtx (outermode, ret, buffer2, 0, buffer_bytes)) return NULL_RTX; - } - return native_decode_rtx (outermode, buffer, 0); + for (unsigned int i =3D 0; i < buffer_bytes; ++i) + if (buffer[i] !=3D buffer2[i]) + return NULL_RTX; + } + return ret; } /* Simplify SUBREG:OUTERMODE(OP:INNERMODE, BYTE) Makes simplify_subreg fail when trying to subreg a constant into a composite floating mode that doesn't decode back. Unfortunately, this causes ICE: pr71522.c: In function =E2=80=98main=E2=80=99: pr71522.c:27:1: error: unrecognizable insn: 27 | } | ^ (insn 5 2 6 2 (set (reg/v:TF 118 [ d ]) (subreg:TF (const_vector:V16QI [ (const_int 65 [0x41]) repeated x15 (const_int 0 [0]) ]) 0)) "pr71522.c":20:3 -1 (nil)) during RTL pass: vregs store_bit_field_1 calls simplify_gen_subreg and that when simplify_immed_su= breg fails will happily create the above subreg. So I'm quite afraid the above change could break quite a lot and so might be better to defer it for GCC12.=