From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-x232.google.com (mail-lj1-x232.google.com [IPv6:2a00:1450:4864:20::232]) by sourceware.org (Postfix) with ESMTPS id 3629A3858D28 for ; Wed, 3 May 2023 06:14:44 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 3629A3858D28 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-lj1-x232.google.com with SMTP id 38308e7fff4ca-2ac762d3bb4so722841fa.3 for ; Tue, 02 May 2023 23:14:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1683094482; x=1685686482; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=cgQERRzc5WamDNlc4+ezqUrdo5o7xF8Mqi/6/bhkdWE=; b=ICJJQcbPPqr+GmNNHr3mBt5jw9zoEhPlKGtsJX1+UIQWeJUUpLJGFZlXYx4aAfhs/C pdtBMPmNLN7Dtpzmjlc7koHPfc7emvZyRh/nmRhokikSvqABPzRlaXfZ8gm2I9d0Dkrq JG+seRoK3Tsz/tm7bYmEfgvEjPl9Ap2HyT2pY2iuLwYvsmGNhn/FXmoEQATJ7aMsEh6C etvtuFNDaSxhMTAWUyDvogDn0t+ZpWCWLMzbw4us/uet1SxO5ywH7DMJ7vD+vosuuYwj 5HuPZUYY0DCScr2/UfWjJpyXpJUvp+RQ8T+1Mr2V74hlvyIAHgeRImrXi8w55pG4fbzW iHfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683094482; x=1685686482; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=cgQERRzc5WamDNlc4+ezqUrdo5o7xF8Mqi/6/bhkdWE=; b=a0PNce5LO3Q5DqINLQT0JKF4M8uMr4C+7oIQwgZs56wNUs0prvuMbEWOHQhb7hIEdm qb86DNkd0k8M8CSDaVKNGWU2C0qG/BjukiyHhVTECuOtFmvlQIq7qBtosVP7RK+m3EX0 sxi9TS4Pcyv861XVnvI1RbTxyz3vR63cJWr+JRDZC4ejxR7Omf9C/FVt8IIgMdb2IIle W7/cQT7R3uCbc3agTfCoc7M6PYLh5EUD1e7nV1ujeRIC0U7Rrzdqs0w0TtZZp/qFQR8+ njTsLGNKKi37bWuQw7jYwRpHoDRqbLo0nPOBqZXKArmo01BMKmoDmI9/diQP+N3PnmEN e66Q== X-Gm-Message-State: AC+VfDwlLD4xH40j7Nv11x/IymFoC0NMMJL8iV/xzo4a5kyjdjQSkm9M K3cVHfys81p49O8sgNcto5Eq0Dbo+zdCk7HIyqY= X-Google-Smtp-Source: ACHHUZ7Xe0dfBASLTJGKY4bKqc4zoVj91y3wPRV+1hDb2G1SZZZNgn+Ghzu6C4pH34mutd/TbnhxyYRp6niwQNModFk= X-Received: by 2002:a2e:3803:0:b0:2a0:3f9f:fec6 with SMTP id f3-20020a2e3803000000b002a03f9ffec6mr4885276lja.37.1683094482248; Tue, 02 May 2023 23:14:42 -0700 (PDT) MIME-Version: 1.0 References: <20230430211356.762030-1-apinski@marvell.com> In-Reply-To: From: Richard Biener Date: Wed, 3 May 2023 08:14:30 +0200 Message-ID: Subject: Re: [PATCH] PHIOPT: Improve replace_phi_edge_with_variable for diamond shapped bb To: Andrew Pinski Cc: Andrew Pinski , gcc-patches@gcc.gnu.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,GIT_PATCH_0,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Wed, May 3, 2023 at 12:04=E2=80=AFAM Andrew Pinski w= rote: > > On Tue, May 2, 2023 at 5:26=E2=80=AFAM Richard Biener via Gcc-patches > wrote: > > > > On Sun, Apr 30, 2023 at 11:14=E2=80=AFPM Andrew Pinski via Gcc-patches > > wrote: > > > > > > While looking at differences between what minmax_replacement > > > and match_simplify_replacement does. I noticed that they sometimes > > > chose different edges to remove. I decided we should be able to do > > > better and be able to remove both empty basic blocks in the > > > case of match_simplify_replacement as that moves the statements. > > > > > > This also updates the testcases as now match_simplify_replacement > > > will remove the unused MIN/MAX_EXPR and they were checking for > > > those. > > > > > > OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions. > > > > > > gcc/ChangeLog: > > > > > > * tree-ssa-phiopt.cc (copy_phi_args): New function. > > > (replace_phi_edge_with_variable): Handle diamond form bb > > > with forwarder only empty blocks better. > > > > > > gcc/testsuite/ChangeLog: > > > > > > * gcc.dg/tree-ssa/minmax-15.c: Update test. > > > * gcc.dg/tree-ssa/minmax-16.c: Update test. > > > * gcc.dg/tree-ssa/minmax-3.c: Update test. > > > * gcc.dg/tree-ssa/minmax-4.c: Update test. > > > * gcc.dg/tree-ssa/minmax-5.c: Update test. > > > * gcc.dg/tree-ssa/minmax-8.c: Update test. > > > --- > > > gcc/testsuite/gcc.dg/tree-ssa/minmax-15.c | 3 +- > > > gcc/testsuite/gcc.dg/tree-ssa/minmax-16.c | 9 ++-- > > > gcc/testsuite/gcc.dg/tree-ssa/minmax-3.c | 2 +- > > > gcc/testsuite/gcc.dg/tree-ssa/minmax-4.c | 2 +- > > > gcc/testsuite/gcc.dg/tree-ssa/minmax-5.c | 2 +- > > > gcc/testsuite/gcc.dg/tree-ssa/minmax-8.c | 2 +- > > > gcc/tree-ssa-phiopt.cc | 51 +++++++++++++++++++++= +- > > > 7 files changed, 59 insertions(+), 12 deletions(-) > > > > > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-15.c b/gcc/testsuit= e/gcc.dg/tree-ssa/minmax-15.c > > > index 8a39871c938..6731f91e6c3 100644 > > > --- a/gcc/testsuite/gcc.dg/tree-ssa/minmax-15.c > > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-15.c > > > @@ -30,5 +30,6 @@ main (void) > > > return 0; > > > } > > > > > > -/* { dg-final { scan-tree-dump-times "MIN_EXPR" 3 "phiopt1" } } */ > > > +/* There should only be two MIN_EXPR left, the 3rd one was removed. = */ > > > +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 2 "phiopt1" } } */ > > > /* { dg-final { scan-tree-dump-times "MAX_EXPR" 0 "phiopt1" } } */ > > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-16.c b/gcc/testsuit= e/gcc.dg/tree-ssa/minmax-16.c > > > index 623b12b3f74..094364e6424 100644 > > > --- a/gcc/testsuite/gcc.dg/tree-ssa/minmax-16.c > > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-16.c > > > @@ -25,11 +25,8 @@ main (void) > > > return 0; > > > } > > > > > > -/* After phiopt1, there really should be only 3 MIN_EXPR in the IR (= including debug statements). > > > - But the way phiopt does not cleanup the CFG all the time, the PHI= might still reference the > > > - alternative bb's moved statement. > > > - Note in the end, we do dce the statement and other debug statemen= ts to end up with only 2 MIN_EXPR. > > > - So check that too. */ > > > -/* { dg-final { scan-tree-dump-times "MIN_EXPR" 4 "phiopt1" } } */ > > > +/* After phiopt1, will be only 2 MIN_EXPR in the IR (including debug= statements). */ > > > +/* xk will only have the final result so the extra debug info does n= ot change anything. */ > > > +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 2 "phiopt1" } } */ > > > /* { dg-final { scan-tree-dump-times "MIN_EXPR" 2 "optimized" } } */ > > > /* { dg-final { scan-tree-dump-times "MAX_EXPR" 0 "phiopt1" } } */ > > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-3.c b/gcc/testsuite= /gcc.dg/tree-ssa/minmax-3.c > > > index 2af10776346..521afe3e4d9 100644 > > > --- a/gcc/testsuite/gcc.dg/tree-ssa/minmax-3.c > > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-3.c > > > @@ -25,5 +25,5 @@ main (void) > > > return 0; > > > } > > > > > > -/* { dg-final { scan-tree-dump-times "MIN_EXPR" 3 "phiopt1" } } */ > > > +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 2 "phiopt1" } } */ > > > /* { dg-final { scan-tree-dump-times "MAX_EXPR" 0 "phiopt1" } } */ > > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-4.c b/gcc/testsuite= /gcc.dg/tree-ssa/minmax-4.c > > > index 973f39bfed3..49e27185b5e 100644 > > > --- a/gcc/testsuite/gcc.dg/tree-ssa/minmax-4.c > > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-4.c > > > @@ -26,4 +26,4 @@ main (void) > > > } > > > > > > /* { dg-final { scan-tree-dump-times "MIN_EXPR" 0 "phiopt1" } } */ > > > -/* { dg-final { scan-tree-dump-times "MAX_EXPR" 3 "phiopt1" } } */ > > > +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 2 "phiopt1" } } */ > > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-5.c b/gcc/testsuite= /gcc.dg/tree-ssa/minmax-5.c > > > index 34e4e720511..194c881cc98 100644 > > > --- a/gcc/testsuite/gcc.dg/tree-ssa/minmax-5.c > > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-5.c > > > @@ -25,5 +25,5 @@ main (void) > > > return 0; > > > } > > > > > > -/* { dg-final { scan-tree-dump-times "MIN_EXPR" 2 "phiopt1" } } */ > > > +/* { dg-final { scan-tree-dump-times "MIN_EXPR" 1 "phiopt1" } } */ > > > /* { dg-final { scan-tree-dump-times "MAX_EXPR" 1 "phiopt1" } } */ > > > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-8.c b/gcc/testsuite= /gcc.dg/tree-ssa/minmax-8.c > > > index 0160e573fef..d5cb53145ea 100644 > > > --- a/gcc/testsuite/gcc.dg/tree-ssa/minmax-8.c > > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-8.c > > > @@ -26,4 +26,4 @@ main (void) > > > } > > > > > > /* { dg-final { scan-tree-dump-times "MIN_EXPR" 1 "phiopt1" } } */ > > > -/* { dg-final { scan-tree-dump-times "MAX_EXPR" 2 "phiopt1" } } */ > > > +/* { dg-final { scan-tree-dump-times "MAX_EXPR" 1 "phiopt1" } } */ > > > diff --git a/gcc/tree-ssa-phiopt.cc b/gcc/tree-ssa-phiopt.cc > > > index 65b3deea34a..311423efeb5 100644 > > > --- a/gcc/tree-ssa-phiopt.cc > > > +++ b/gcc/tree-ssa-phiopt.cc > > > @@ -82,6 +82,25 @@ single_non_singleton_phi_for_edges (gimple_seq seq= , edge e0, edge e1) > > > return phi; > > > } > > > > > > +/* For each PHI in BB, copy the argument associated with SRC_E to TG= T_E. */ > > > + > > > +static void > > > +copy_phi_args (basic_block bb, edge src_e, edge tgt_e) > > > +{ > > > + gphi_iterator gsi; > > > + int src_indx =3D src_e->dest_idx; > > > + > > > + for (gsi =3D gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi= )) > > > + { > > > + gphi *phi =3D gsi.phi (); > > > + tree def =3D gimple_phi_arg_def (phi, src_indx); > > > + location_t locus =3D gimple_phi_arg_location (phi, src_indx); > > > + > > > + add_phi_arg (phi, def, tgt_e, locus); > > > + } > > > +} > > > > Doesn't flush_pending_stmts (tgt_e) do this? > > No, In fact the above code is very similar to the code from > remove_forwarder_block in tree-cfgcleanup.cc (I copied it and changed > it from copy_phi_args in tree-ssa-threadupdate.cc though as I don't > need a mapping). > Let me factor out the code from remove_forwarder_block and put it in > some common spot and then use that; it will be the same logic even. Hmm, but it's odd - if you redirect an edge on GIMPLE then there should be helpers available to do all this. I think you're doing something wrong (without actually looking too close) Richard. > Thanks, > Andrew > > > > > > + > > > + > > > /* Replace PHI node element whose edge is E in block BB with variabl= e NEW. > > > Remove the edge from COND_BLOCK which does not lead to BB (COND_B= LOCK > > > is known to have two edges, one of which must reach BB). */ > > > @@ -94,6 +113,7 @@ replace_phi_edge_with_variable (basic_block cond_b= lock, > > > basic_block bb =3D gimple_bb (phi); > > > gimple_stmt_iterator gsi; > > > tree phi_result =3D PHI_RESULT (phi); > > > + bool deleteboth =3D false; > > > > > > /* Duplicate range info if they are the only things setting the ta= rget PHI. > > > This is needed as later on, the new_tree will be replacing > > > @@ -137,7 +157,14 @@ replace_phi_edge_with_variable (basic_block cond= _block, > > > keep_edge =3D EDGE_SUCC (cond_block, 1); > > > } > > > else if ((keep_edge =3D find_edge (cond_block, e->src))) > > > - ; > > > + { > > > + basic_block bb1 =3D EDGE_SUCC (cond_block, 0)->dest; > > > + basic_block bb2 =3D EDGE_SUCC (cond_block, 1)->dest; > > > + if (single_pred_p (bb1) && single_pred_p (bb2) > > > + && single_succ_p (bb1) && single_succ_p (bb2) > > > + && empty_block_p (bb1) && empty_block_p (bb2)) > > > + deleteboth =3D true; > > > + } > > > else > > > gcc_unreachable (); > > > > > > @@ -148,6 +175,28 @@ replace_phi_edge_with_variable (basic_block cond= _block, > > > e->probability =3D profile_probability::always (); > > > delete_basic_block (edge_to_remove->dest); > > > > > > + /* Eliminate the COND_EXPR at the end of COND_BLOCK. */ > > > + gsi =3D gsi_last_bb (cond_block); > > > + gsi_remove (&gsi, true); > > > + } > > > + else if (deleteboth) > > > + { > > > + basic_block bb1 =3D EDGE_SUCC (cond_block, 0)->dest; > > > + basic_block bb2 =3D EDGE_SUCC (cond_block, 1)->dest; > > > + > > > + edge newedge =3D redirect_edge_and_branch (keep_edge, bb); > > > + /* no new edge should be the same. */ > > > + gcc_assert (newedge =3D=3D keep_edge); > > > + keep_edge->flags |=3D EDGE_FALLTHRU; > > > + keep_edge->flags &=3D ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE); > > > + keep_edge->probability =3D profile_probability::always (); > > > + /* Copy the edge's phi entry from the old one */ > > > + copy_phi_args(bb, e, keep_edge); > > > + > > > + /* Delete the old 2 empty basic blocks */ > > > + delete_basic_block (bb1); > > > + delete_basic_block (bb2); > > > + > > > /* Eliminate the COND_EXPR at the end of COND_BLOCK. */ > > > gsi =3D gsi_last_bb (cond_block); > > > gsi_remove (&gsi, true); > > > -- > > > 2.31.1 > > >