From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32635 invoked by alias); 10 Mar 2015 09:41:18 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 29819 invoked by uid 48); 10 Mar 2015 09:41:14 -0000 From: "jakub at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/65368] [4.8/4.9/5 Regression]_bzhi_u32 intrinsic generates incorrect code when -O1 or above is specified and index is an immediate Date: Tue, 10 Mar 2015 09:41:00 -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: 4.9.2 X-Bugzilla-Keywords: wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: jakub at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: jakub at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.8.5 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-SW-Source: 2015-03/txt/msg01081.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D65368 --- Comment #6 from Jakub Jelinek --- (In reply to Uro=C5=A1 Bizjak from comment #5) > (In reply to Jakub Jelinek from comment #3) > > For zero_extract RTL we require that the POS and LEN arguments are in t= he > > right ranges, while bextr allows any values, and either uses 0 for bits > > outside of the original operand and for LEN uses umin (len, ). >=20 > Ah, thanks, this explains my question from Comment #4. >=20 > Speculating a bit further, is BZHI just a special case of BEXTR, where st= art > =3D 0 (I'm referring to [1]). It would be nice to make these insn as gene= ral > as possible, so combine will have a chance here. >=20 > [1] http://en.wikipedia.org/wiki/Bit_Manipulation_Instruction_Sets To some extent BZHI is a special case of BEXTR, but I'm afraid any generalization is much harder due to the weirdo encoding of the operands, unless both the START and LEN are CONST_INTs (and if they are constants, it= is questionable if BEXTR or BZHI are the best instructions to use, because both take just register for the LEN or START/LEN pair, so one would need to set = some register to a constant and then perform BEXTR/BZHI, so two instructions, wh= ile there is always the option to perform AND and right shift (or right shift a= nd AND). >>From gcc-bugs-return-479940-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Tue Mar 10 09:51:52 2015 Return-Path: Delivered-To: listarch-gcc-bugs@gcc.gnu.org Received: (qmail 6028 invoked by alias); 10 Mar 2015 09:51:51 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Delivered-To: mailing list gcc-bugs@gcc.gnu.org Received: (qmail 3710 invoked by uid 48); 10 Mar 2015 09:51:48 -0000 From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/44563] GCC uses a lot of RAM when compiling a large numbers of functions Date: Tue, 10 Mar 2015 09:51:00 -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: 4.3.4 X-Bugzilla-Keywords: compile-time-hog, memory-hog X-Bugzilla-Severity: normal X-Bugzilla-Who: rguenth at gcc dot gnu.org X-Bugzilla-Status: NEW 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: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2015-03/txt/msg01084.txt.bz2 Content-length: 423 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=44563 --- Comment #22 from Richard Biener --- I wonder why we have split_bb_on_noreturn_calls in cfg-cleanup rather than in fixup_cfg. It's quite expensive, walking all stmts and calling gimple_call_noreturn_p which is very expensive. We fixup noreturn calls in fixup cfg so I wonder why we have this leftover in cfgcleanup... testing removal.