From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by sourceware.org (Postfix) with ESMTPS id 75F213858D20 for ; Thu, 16 Nov 2023 06:52:05 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 75F213858D20 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=suse.de ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 75F213858D20 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=195.135.220.28 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1700117527; cv=none; b=gVjQ4hhUurADA6Q6tLljNDK2XXml2rndqRQltcvmnEY9QQE5+Gba1NnbREb44imAID9+GE0BGUh1HyDk+V1pHO3Vgpsn5LZw1t1pLn8zp+lJNdXoP71n3rv4Fg/TAG+3MEPVVJUhHPi1ED30sIrPSdq0A/7eOsAfwnxOeWdPQhs= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1700117527; c=relaxed/simple; bh=TpxBDvHsDOXExnoMsTeKF+NYkQnrPzxRNVSNlwNO3Dc=; h=Date:From:To:Subject:Message-ID:MIME-Version; b=Ab3aJZmtPu5GJQbrdkxICokD2g2zqgoJ9UIhN9LkkeXVsz2Pey65ax3Or7EFpCMgNKi1ZB5Dhi/Y6z9/oKrnpg7nyut219h6lzZ7zKPfqTGoMGz5vnb9EjhWp+eI0LTsrOnY0Kzt+ijgJSgFkUFAFDPF5x5r4P5xuWhNPxRmCbY= ARC-Authentication-Results: i=1; server2.sourceware.org Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id ABDF72291C; Thu, 16 Nov 2023 06:52:04 +0000 (UTC) Received: from wotan.suse.de (wotan.suse.de [10.160.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 8073A2C18B; Thu, 16 Nov 2023 06:52:04 +0000 (UTC) Date: Thu, 16 Nov 2023 06:52:04 +0000 (UTC) From: Richard Biener To: Juzhe-Zhong cc: gcc-patches@gcc.gnu.org, richard.sandiford@arm.com Subject: Re: [PATCH] VECT: Clear LOOP_VINFO_USING_SELECT_VL_P when loop is not partial vectorized In-Reply-To: <20231116040907.1647406-1-juzhe.zhong@rivai.ai> Message-ID: References: <20231116040907.1647406-1-juzhe.zhong@rivai.ai> User-Agent: Alpine 2.22 (LSU 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Spam-Level: Authentication-Results: smtp-out1.suse.de; none X-Rspamd-Server: rspamd2 X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[] X-Spam-Score: -4.00 X-Rspamd-Queue-Id: ABDF72291C X-Spam-Status: No, score=-10.8 required=5.0 tests=BAYES_00,GIT_PATCH_0,KAM_DMARC_STATUS,KAM_SHORT,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 Thu, 16 Nov 2023, Juzhe-Zhong wrote: > This patch fixes ICE: > https://godbolt.org/z/z8T6o6qov > > : In function 'b': > :2:6: error: missing definition > 2 | void b() { > | ^ > for SSA_NAME: loop_len_8 in statement: > _1 = -loop_len_8; > during GIMPLE pass: vect > :2:6: internal compiler error: verify_ssa failed > 0x7f1b56331082 __libc_start_main > ???:0 > Please submit a full bug report, with preprocessed source (by using -freport-bug). > Please include the complete backtrace with any bug report. > See for instructions. > Compiler returned: 1 > > The root cause is we generate such IR in vectorization: > > _1 = -loop_len_8; > vect_cst__11 = {_1, _1}; > _18 = vect_vec_iv_.6_14 + vect_cst__11; > > loop_len_8 is uninitialized value. > > The IR _18 = vect_vec_iv_.6_14 + vect_cst__11; is generated because of we are adding induction variable with > the result of SELECT_VL instead of VF. > > The code is: > > else if (LOOP_VINFO_USING_SELECT_VL_P (loop_vinfo)) > { > /* When we're using loop_len produced by SELEC_VL, the non-final > iterations are not always processing VF elements. So vectorize > induction variable instead of > > _21 = vect_vec_iv_.6_22 + { VF, ... }; > > We should generate: > > _35 = .SELECT_VL (ivtmp_33, VF); > vect_cst__22 = [vec_duplicate_expr] _35; > _21 = vect_vec_iv_.6_22 + vect_cst__22; */ > gcc_assert (!slp_node); > gimple_seq seq = NULL; > vec_loop_lens *lens = &LOOP_VINFO_LENS (loop_vinfo); > tree len = vect_get_loop_len (loop_vinfo, NULL, lens, 1, vectype, 0, 0); > expr = force_gimple_operand (fold_convert (TREE_TYPE (step_expr), > unshare_expr (len)), > &seq, true, NULL_TREE); > new_name = gimple_build (&seq, MULT_EXPR, TREE_TYPE (step_expr), expr, > step_expr); > gsi_insert_seq_before (&si, seq, GSI_SAME_STMT); > step_iv_si = &si; > } > > LOOP_VINFO_USING_SELECT_VL_P is set before loop vectorization analysis so we don't know whether it is partial > vectorization or not but the induction variable depends on SELECT_VL_P is true. > > So update SELECT_VL_P as false when it is not partial vectorization. OK. > PR middle-end/112554 > > gcc/ChangeLog: > > * tree-vect-loop.cc (vect_determine_partial_vectors_and_peeling): Clear SELECT_VL_P for non-partial vectorization. > > gcc/testsuite/ChangeLog: > > * gcc.target/riscv/rvv/autovec/pr112554.c: New test. > > --- > .../gcc.target/riscv/rvv/autovec/pr112554.c | 12 ++++++++++++ > gcc/tree-vect-loop.cc | 13 +++++++++++++ > 2 files changed, 25 insertions(+) > create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/autovec/pr112554.c > > diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr112554.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr112554.c > new file mode 100644 > index 00000000000..4afa7c2b15c > --- /dev/null > +++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr112554.c > @@ -0,0 +1,12 @@ > +/* { dg-do compile } */ > +/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 --param=riscv-autovec-preference=fixed-vlmax" } */ > + > +int a; > +void b() { > + unsigned long c = 18446744073709551612UL; > +d: > + --c; > + a ^= c; > + if (c) > + goto d; > +} > diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc > index fb8d999ee6b..3f59139cb01 100644 > --- a/gcc/tree-vect-loop.cc > +++ b/gcc/tree-vect-loop.cc > @@ -2657,6 +2657,19 @@ vect_determine_partial_vectors_and_peeling (loop_vec_info loop_vinfo) > = (!LOOP_VINFO_USING_PARTIAL_VECTORS_P (loop_vinfo) > && need_peeling_or_partial_vectors_p); > > + /* We set LOOP_VINFO_USING_SELECT_VL_P as true before loop vectorization > + analysis that we don't know whether the loop is vectorized by partial > + vectors (More details see tree-vect-loop-manip.cc). > + > + However, SELECT_VL vectorizaton style should only applied on partial > + vectorization since SELECT_VL is the GIMPLE IR that calculates the > + number of elements to be process for each iteration. > + > + After loop vectorization analysis, Clear LOOP_VINFO_USING_SELECT_VL_P > + if it is not partial vectorized loop. */ > + if (!LOOP_VINFO_USING_PARTIAL_VECTORS_P (loop_vinfo)) > + LOOP_VINFO_USING_SELECT_VL_P (loop_vinfo) = false; > + > return opt_result::success (); > } > > -- Richard Biener SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)