From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 28109 invoked by alias); 5 Aug 2011 10:51:43 -0000 Received: (qmail 28096 invoked by uid 22791); 5 Aug 2011 10:51:40 -0000 X-SWARE-Spam-Status: No, hits=-2.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,TW_TM X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 05 Aug 2011 10:50:29 +0000 From: "irar at il dot ibm.com" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/49955] Fails to do partial basic-block SLP X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: enhancement X-Bugzilla-Who: irar at il dot ibm.com X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Date: Fri, 05 Aug 2011 10:51:00 -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 X-SW-Source: 2011-08/txt/msg00616.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49955 --- Comment #3 from Ira Rosen 2011-08-05 10:50:27 UTC --- (In reply to comment #1) > The loop that remains after fixing PR49957 in 410.bwaves is the following, > which loop SLP does not handle (well, I'm not exactly sure) because > > t.f:18: note: ==> examining statement: t1_62 = *q_61(D)[D.1645_60]; > > t.f:18: note: num. args = 4 (not unary/binary/ternary op). > t.f:18: note: vect_is_simple_use: operand *q_61(D)[D.1645_60] > t.f:18: note: not ssa-name. > t.f:18: note: use not simple. > t.f:18: note: no array mode for V2DF[5] > t.f:18: note: the size of the group of strided accesses is not a power of 2 > t.f:18: note: not vectorized: relevant stmt not supported: t1_62 = > *q_61(D)[D.1645_60]; > > t.f:18: note: bad operation or unsupported loop bound. > t.f:1: note: vectorized 0 loops in function. > > probably the issue that we can't handle this kind of "invariants" in the > SLP group? Thus, the SLP group should be q(2,..), q(3,...) ... q(5, ...) > which is size 4, q(1,..) should be treated as invariant. > This loop is not SLPed because there is no SLP opportunity here besides the loads. The only isomorphism after that is t2=q(2,i,j,k)/t1 t3=q(3,i,j,k)/t1 t4=q(4,i,j,k)/t1 and somewhat here t7=((dabs(t2)+t6)/dx+mu/dx**2)**2 + 1 ((dabs(t3)+t6)/dy+mu/dy**2)**2 + 2 ((dabs(t4)+t6)/dz+mu/dz**2)**2 but these are groups of 3. Moreover, the current implementation starts building SLP tree from a group of strided stores, or a group of reductions, or a reduction chain. None of these exist here. But, again, even if we could start from a group of loads, it wouldn't help us much here anyway. Ira