From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by sourceware.org (Postfix) with ESMTPS id 9E47E3853D7F for ; Fri, 18 Nov 2022 07:37:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 9E47E3853D7F Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=suse.de Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 27A151F893 for ; Fri, 18 Nov 2022 07:37:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1668757020; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version:content-type:content-type; bh=LOkl1RcRJ2G3SmiB4W0M1+lGIzrYClpO91vfLzSlT6s=; b=s87hKTdQkmETfBImZW0e7huTpgvsXkU51LL6forMfGqlwzTB+x0nQe8obpjuleQtOpW96K PvwTm83JYl+ABoPxzdYGx5ZqDeM+TmO1+2iKvCvIvZhY4d4kmxaLbynfryZQvn1kLU5ixj zqwqmojshzEX+YpOtV8pFv8TcXlQJ90= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1668757020; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version:content-type:content-type; bh=LOkl1RcRJ2G3SmiB4W0M1+lGIzrYClpO91vfLzSlT6s=; b=qKq6mdY8Ccl0FJeJ7mS/0HUQ4B3a6oVABp89kaWqsN9VFbaNI8wladxkNhCw5lHec1kj8L oLFVGAWbixSs/UCg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 151791345B for ; Fri, 18 Nov 2022 07:37:00 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id /R3/Axw2d2NzZgAAMHmgww (envelope-from ) for ; Fri, 18 Nov 2022 07:37:00 +0000 Date: Fri, 18 Nov 2022 08:36:59 +0100 (CET) From: Richard Biener To: gcc-patches@gcc.gnu.org Subject: [PATCH] tree-optimization/107647 - avoid FMA from SLP with -ffp-contract=off MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Message-Id: <20221118073700.151791345B@imap2.suse-dmz.suse.de> X-Spam-Status: No, score=-11.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,KAM_SHORT,SPF_HELO_NONE,SPF_PASS,TXREP 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: Only with -ffp-contract=fast we can synthesize FMA operations like vfmaddsub231ps, so properly guard the transform in SLP pattern detection. Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed. PR tree-optimization/107647 * tree-vect-slp-patterns.cc (addsub_pattern::recognize): Only allow FMA generation with -ffp-contract=fast for FP types. (complex_mul_pattern::matches): Likewise. * gcc.target/i386/pr107647.c: New testcase. --- gcc/testsuite/gcc.target/i386/pr107647.c | 17 +++++++++++++++++ gcc/tree-vect-slp-patterns.cc | 15 +++++++++++---- 2 files changed, 28 insertions(+), 4 deletions(-) create mode 100644 gcc/testsuite/gcc.target/i386/pr107647.c diff --git a/gcc/testsuite/gcc.target/i386/pr107647.c b/gcc/testsuite/gcc.target/i386/pr107647.c new file mode 100644 index 00000000000..45fcb55d698 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr107647.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -ffp-contract=off -mavx2 -mfma" } */ + +void cscal(int n, float da_r, float *x) +{ + for (int i = 0; i < n; i += 4) + { + float temp0 = da_r * x[i] - x[i+1]; + float temp1 = da_r * x[i+2] - x[i+3]; + x[i+1] = da_r * x[i+1] + x[i]; + x[i+3] = da_r * x[i+3] + x[i+2]; + x[i] = temp0; + x[i+2] = temp1; + } +} + +/* { dg-final { scan-assembler-not "fma" } } */ diff --git a/gcc/tree-vect-slp-patterns.cc b/gcc/tree-vect-slp-patterns.cc index dc694b8e531..122d697a809 100644 --- a/gcc/tree-vect-slp-patterns.cc +++ b/gcc/tree-vect-slp-patterns.cc @@ -1035,8 +1035,11 @@ complex_mul_pattern::matches (complex_operation_t op, auto_vec left_op, right_op; slp_tree add0 = NULL; - /* Check if we may be a multiply add. */ + /* Check if we may be a multiply add. It's only valid to form FMAs + with -ffp-contract=fast. */ if (!mul0 + && (flag_fp_contract_mode == FP_CONTRACT_FAST + || !FLOAT_TYPE_P (SLP_TREE_VECTYPE (l0node[0]))) && vect_match_expression_p (l0node[0], PLUS_EXPR)) { auto vals = SLP_TREE_CHILDREN (l0node[0]); @@ -1501,9 +1504,13 @@ addsub_pattern::recognize (slp_tree_to_load_perm_map_t *, } /* Now we have either { -, +, -, + ... } (!l0add_p) or { +, -, +, - ... } - (l0add_p), see whether we have FMA variants. */ - if (!l0add_p - && vect_match_expression_p (SLP_TREE_CHILDREN (l0node)[0], MULT_EXPR)) + (l0add_p), see whether we have FMA variants. We can only form FMAs + if allowed via -ffp-contract=fast. */ + if (flag_fp_contract_mode != FP_CONTRACT_FAST + && FLOAT_TYPE_P (SLP_TREE_VECTYPE (l0node))) + ; + else if (!l0add_p + && vect_match_expression_p (SLP_TREE_CHILDREN (l0node)[0], MULT_EXPR)) { /* (c * d) -+ a */ if (vect_pattern_validate_optab (IFN_VEC_FMADDSUB, node)) -- 2.35.3