From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf1-x132.google.com (mail-lf1-x132.google.com [IPv6:2a00:1450:4864:20::132]) by sourceware.org (Postfix) with ESMTPS id 1BB95384AB55 for ; Tue, 23 Apr 2024 10:47:48 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 1BB95384AB55 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=vrull.eu Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=vrull.eu ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 1BB95384AB55 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=2a00:1450:4864:20::132 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1713869272; cv=none; b=MeRrY1iDqfPb8Qf3DbjHU37yr85wfyEmERUKAJyf6VHUi77V5dDquDja/eoWuEu0FQAoT98tyYcnn6eJVeTRL2N+tS9CtHlcSaFrwU58P9yxAaPZ0OSDSo21ypAIj7SPgkDhi6QWeAhJUyr6XrX3sVh+QCw/UBAkqSHk+odatWs= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1713869272; c=relaxed/simple; bh=N3KZ83JqqYgjoylex+x+oZ/lCkdnSbg/FxkKjeY2n9s=; h=DKIM-Signature:From:To:Subject:Date:Message-Id:MIME-Version; b=iPi+/n9sKem9tx98cnQrUHAlnH4ueVVHQ75ZYhO+gp0TY4GdzEe7cM8lI6Yec2npQFQiu6esNqaSuDewA1o4NhDaXcqPA2L4g9Y2BbXVn9g+YsrGwp5UM6f7D2IAYG8y2eXV0qyjh458ewhCgF+VkFaTdMDg4nXwsq6sHgcXMT4= ARC-Authentication-Results: i=1; server2.sourceware.org Received: by mail-lf1-x132.google.com with SMTP id 2adb3069b0e04-5193363d255so7352195e87.3 for ; Tue, 23 Apr 2024 03:47:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=vrull.eu; s=google; t=1713869266; x=1714474066; darn=gcc.gnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=v1wnXCOoq8w/85dPjgqFjXk1cLmMrudGgjzR6tzmfGM=; b=mBJty2Hl5qojrPwp02YLrspRD1xUGgOwyHSZuR9KxOuMn4yu8AdnQDXwkUuOq+yvoY KZx/GIt736E0/XCdUCXrDS4FYqr6ClsyHfZrLFL6BV+Ev8mkfkGH1HCI3pC9SE4sRUAh PmmE68k4ofIXdo84kSQ0e7Xd6558YdyzMqPpWuNSPBaDA9xa/QQZKqZ9Z7JMcmXQqj7T t4Fdx6KEaemADUOtmRl1W5OQ2m3b0MtMapDzm0IwqTwYDks/3f+ybgLDwv72TRTrPYId 1DMzkJKbFd0Dsvu3cKMSF15LKiFEJ2IedA7yuFxTNXkdbdM+IAlwIlL6fweh7PXMmTwc upJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1713869266; x=1714474066; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=v1wnXCOoq8w/85dPjgqFjXk1cLmMrudGgjzR6tzmfGM=; b=bErKbZMuc2GR5fpBs2Xt8WoI++TaG4tQ0bDNYxc3q6PvCoZkxCFaI5AmMfvR0ewm/C CkXk41SK4ITQlef5V7kFQTW8244eWyo0SrgSxGu5R+GRturKB2K8Q+uc89AVdWYBN2dx Qhl+GSSHA4YrBtV7Lomse2L2eYwrsvPwVM2EfKY0drvS8dqZLyrTFkXwMNsHgRJ0n4ZV 5vHxdjnrAwQf1pw3kXf4JX3Tu5MT/i7TzzLo+xFzWSktPcixYCG0LDfS6p9k6kYwBLey 8ZRdcGvZXUOvT1i6neYTEKM5ZIGTc8RgGgRj1/A6fzKqrDub3nspKWWxmpA0jJ3R5ojs n5IA== X-Gm-Message-State: AOJu0Yxb34Lqefmkrrv4OwQgtAgauglFvcEU2fHfODR7+qTgXdN0XnxO xdzgUnFklW7FXXUqwebg3WAbeqDPVDtwh/iV87zRCdMte8XNbS1PHPqNHNTvvviQBZgpPQyhnRU N0Gk= X-Google-Smtp-Source: AGHT+IE28g13O/QeCQjLXSim6Fe+qkIO45b2PHSDUpRkHWV3V3qn6J51ABi1LGCySqePatYcQV+owQ== X-Received: by 2002:a05:6512:238e:b0:516:c696:9078 with SMTP id c14-20020a056512238e00b00516c6969078mr10392254lfv.50.1713869266006; Tue, 23 Apr 2024 03:47:46 -0700 (PDT) Received: from helsinki-03.engr ([2a01:4f9:6b:2a47::2]) by smtp.gmail.com with ESMTPSA id cf14-20020a056512280e00b00515cb94af43sm1995785lfb.16.2024.04.23.03.47.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Apr 2024 03:47:45 -0700 (PDT) From: Manolis Tsamis To: gcc-patches@gcc.gnu.org Cc: Robin Dapp , Jiangning Liu , Philipp Tomsich , Richard Sandiford , Jakub Jelinek , Manolis Tsamis Subject: [PATCH v4 1/3] [RFC] ifcvt: handle sequences that clobber flags in noce_convert_multiple_sets Date: Tue, 23 Apr 2024 12:47:38 +0200 Message-Id: <20240423104740.4027243-2-manolis.tsamis@vrull.eu> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240423104740.4027243-1-manolis.tsamis@vrull.eu> References: <20240423104740.4027243-1-manolis.tsamis@vrull.eu> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-11.6 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,RCVD_IN_DNSWL_NONE,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: This is an extension of what was done in PR106590. Currently if a sequence generated in noce_convert_multiple_sets clobbers the condition rtx (cc_cmp or rev_cc_cmp) then only seq1 is used afterwards (sequences that emit the comparison itself). Since this applies only from the next iteration it assumes that the sequences generated (in particular seq2) doesn't clobber the condition rtx itself before using it in the if_then_else, which is only true in specific cases (currently only register/subregister moves are allowed). This patch changes this so it also tests if seq2 clobbers cc_cmp/rev_cc_cmp in the current iteration. This makes it possible to include arithmetic operations in noce_convert_multiple_sets. It also makes the code that checks whether the condition is used outside of the if_then_else emitted more robust. gcc/ChangeLog: * ifcvt.cc (check_for_cc_cmp_clobbers): Use modified_in_p instead. (noce_convert_multiple_sets_1): Don't use seq2 if it clobbers cc_cmp. Refactor the code that sets read_comparison. Signed-off-by: Manolis Tsamis --- (no changes since v1) gcc/ifcvt.cc | 106 ++++++++++++++++++++++++++++----------------------- 1 file changed, 59 insertions(+), 47 deletions(-) diff --git a/gcc/ifcvt.cc b/gcc/ifcvt.cc index 58ed42673e5..763a25f816e 100644 --- a/gcc/ifcvt.cc +++ b/gcc/ifcvt.cc @@ -3592,20 +3592,6 @@ noce_convert_multiple_sets (struct noce_if_info *if_info) return true; } -/* Helper function for noce_convert_multiple_sets_1. If store to - DEST can affect P[0] or P[1], clear P[0]. Called via note_stores. */ - -static void -check_for_cc_cmp_clobbers (rtx dest, const_rtx, void *p0) -{ - rtx *p = (rtx *) p0; - if (p[0] == NULL_RTX) - return; - if (reg_overlap_mentioned_p (dest, p[0]) - || (p[1] && reg_overlap_mentioned_p (dest, p[1]))) - p[0] = NULL_RTX; -} - /* This goes through all relevant insns of IF_INFO->then_bb and tries to create conditional moves. In case a simple move sufficis the insn should be listed in NEED_NO_CMOV. The rewired-src cases should be @@ -3731,36 +3717,67 @@ noce_convert_multiple_sets_1 (struct noce_if_info *if_info, creating an additional compare for each. If successful, costing is easier and this sequence is usually preferred. */ if (cc_cmp) - seq2 = try_emit_cmove_seq (if_info, temp, cond, - new_val, old_val, need_cmov, - &cost2, &temp_dest2, cc_cmp, rev_cc_cmp); + { + seq2 = try_emit_cmove_seq (if_info, temp, cond, + new_val, old_val, need_cmov, + &cost2, &temp_dest2, cc_cmp, rev_cc_cmp); + + /* The if_then_else in SEQ2 may be affected when cc_cmp/rev_cc_cmp is + clobbered. We can't safely use the sequence in this case. */ + if (seq2 && (modified_in_p (cc_cmp, seq2) + || (rev_cc_cmp && modified_in_p (rev_cc_cmp, seq2)))) + seq2 = NULL; + } /* The backend might have created a sequence that uses the - condition. Check this. */ + condition as a value. Check this. */ + + /* We cannot handle anything more complex than a reg or constant. */ + if (!REG_P (XEXP (cond, 0)) && !CONSTANT_P (XEXP (cond, 0))) + read_comparison = true; + + if (!REG_P (XEXP (cond, 1)) && !CONSTANT_P (XEXP (cond, 1))) + read_comparison = true; + rtx_insn *walk = seq2; - while (walk) + int if_then_else_count = 0; + while (walk && !read_comparison) { - rtx set = single_set (walk); + rtx exprs_to_check[2]; + unsigned int exprs_count = 0; - if (!set || !SET_SRC (set)) + rtx set = single_set (walk); + if (set && XEXP (set, 1) + && GET_CODE (XEXP (set, 1)) == IF_THEN_ELSE) { - walk = NEXT_INSN (walk); - continue; + /* We assume that this is the cmove created by the backend that + naturally uses the condition. */ + exprs_to_check[exprs_count++] = XEXP (XEXP (set, 1), 1); + exprs_to_check[exprs_count++] = XEXP (XEXP (set, 1), 2); + if_then_else_count++; } + else if (NONDEBUG_INSN_P (walk)) + exprs_to_check[exprs_count++] = PATTERN (walk); - rtx src = SET_SRC (set); + /* Bail if we get more than one if_then_else because the assumption + above may be incorrect. */ + if (if_then_else_count > 1) + { + read_comparison = true; + break; + } - if (XEXP (set, 1) && GET_CODE (XEXP (set, 1)) == IF_THEN_ELSE) - ; /* We assume that this is the cmove created by the backend that - naturally uses the condition. Therefore we ignore it. */ - else + for (unsigned int i = 0; i < exprs_count; i++) { - if (reg_mentioned_p (XEXP (cond, 0), src) - || reg_mentioned_p (XEXP (cond, 1), src)) - { - read_comparison = true; - break; - } + subrtx_iterator::array_type array; + FOR_EACH_SUBRTX (iter, array, exprs_to_check[i], NONCONST) + if (*iter != NULL_RTX + && (reg_overlap_mentioned_p (XEXP (cond, 0), *iter) + || reg_overlap_mentioned_p (XEXP (cond, 1), *iter))) + { + read_comparison = true; + break; + } } walk = NEXT_INSN (walk); @@ -3788,21 +3805,16 @@ noce_convert_multiple_sets_1 (struct noce_if_info *if_info, return false; } - if (cc_cmp) + if (cc_cmp && seq == seq1) { - /* Check if SEQ can clobber registers mentioned in - cc_cmp and/or rev_cc_cmp. If yes, we need to use - only seq1 from that point on. */ - rtx cc_cmp_pair[2] = { cc_cmp, rev_cc_cmp }; - for (walk = seq; walk; walk = NEXT_INSN (walk)) + /* Check if SEQ can clobber registers mentioned in cc_cmp/rev_cc_cmp. + If yes, we need to use only seq1 from that point on. + Only check when we use seq1 since we have already tested seq2. */ + if (modified_in_p (cc_cmp, seq) + || (rev_cc_cmp && modified_in_p (rev_cc_cmp, seq))) { - note_stores (walk, check_for_cc_cmp_clobbers, cc_cmp_pair); - if (cc_cmp_pair[0] == NULL_RTX) - { - cc_cmp = NULL_RTX; - rev_cc_cmp = NULL_RTX; - break; - } + cc_cmp = NULL_RTX; + rev_cc_cmp = NULL_RTX; } } -- 2.34.1